ADNOC Classification: Internal
THE CONTENTS OF THIS DOCUMENT ARE PROPRIETARY AND CONFIDENTIAL.
ADNOC GROUP PROJECTS AND ENGINEERING ELECTRICAL ENGINEERING DESIGN GUIDE Guidelines
APPROVED BY:
NAME: Abdulmunim Al Kindy TITLE: Executive Director PT&CS EFFECTIVE DATE:
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ADNOC Classification: Internal
GROUP PROJECTS & ENGINEERING / PT&CS DIRECTORATE
CUSTODIAN ADNOC
Group Projects & Engineering / PT&CS Specification applicable to ADNOC & ADNOC Group Companies
REVISION HISTORY
DATE
REV.
NO
1 June 2020
1
22 Dec 20
27 Sep 21
2
3
PREPARED BY (Designation / Initial) Mohamed El Sadani/ Sr. Elect. Eng. & TA - AGP
Mohamed El Sadani/ Sr. Elect. Eng. & TA - AGP
Mohamed El Sadani/ Sr. Elect. Eng. & TA - AGP
REVIEWED BY (Designation / Initial)
Ashwani Kumar Kataria/ A/MIHE Reuben Yagambaram/ SPM-GPE
Ashwani Kumar Kataria/ A/MIHE Reuben Yagambaram/ SPM-GPE Ali Naser Bagarwan/ HOD Electrical Engineering
ENDORSED BY (Designation / Initial) Abdulla Al Shaiba/ VP-GPE
ENDORSED BY (Designation / Initial) Zaher Salem/ SVP-GPE
Abdulla Al Shaiba/ VP-GPE
Zaher Salem/ SVP-GPE
Najem A.Qambar/ VP Group Engineering - GPE
Ebraheem AlRomaithi / SVP– GPE
Group Projects & Engineering is the owner of this Specification and responsible for its custody, maintenance and periodic update.
In addition, Group Projects & Engineering is responsible for communication and distribution of any changes to this Design Guide and its version control.
This Design Guide will be reviewed and updated in case of any changes affecting the activities described in this Design Guide.
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ADNOC Classification: Internal
INTER-RELATIONSHIPS AND STAKEHOLDERS
a. The following are inter-relationships for implementation of this Design Guide:
i. ADNOC Upstream and ADNOC Downstream Industry, Marketing & Trading Directorate
ii. ADNOC Onshore, ADNOC Offshore, ADNOC Sour Gas, ADNOC Gas Processing. ADNOC LNG,
ADNOC Refining, ADNOC Fertil, Borouge, Al Dhafra Petroleum, Al Yasat
b. The following are stakeholders for the purpose of this Design Guide:
i. ADNOC PT&CS Directorate
c. This Design Guide has been approved by the ADNOC PT&CS is to be implemented by each ADNOC Group COMPANY included above subject to and in accordance with their Delegation of Authority and other governance-related processes in order to ensure compliance.
d. Each ADNOC Group COMPANY must establish / nominate a Technical Authority responsible for
compliance with this Design Guide.
DEFINITIONS
“ADNOC” means Abu Dhabi National Oil Company.
“ADNOC Group” means ADNOC together with each company in which ADNOC, directly or indirectly, controls fifty percent (50 %) or more of the share capital.
“Approving Authority” means the decision-making body or employee with the required authority to approve Policies & Procedures or any changes to it.
“Business Line Directorates” or “BLD” means a directorate of ADNOC which is responsible for one or more Group Companies reporting to, or operating within the same line of business as, such directorate.
“Business Support Directorates and Functions” or “Non- BLD” means all the ADNOC functions and the remaining directorates, which are not ADNOC Business Line Directorates.
“CEO” means chief executive officer.
“Group Company” means any company within the ADNOC Group other than ADNOC.
“Design Guide” means this Electrical Engineering Design Guide
CONTROLLED INTRANET COPY
The intranet copy of this document located in the section under Group Policies on One ADNOC is the only controlled document. Copies or extracts of this document, which have been downloaded from the intranet, are uncontrolled copies and cannot be guaranteed to be the latest version.
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ADNOC Classification: Internal
TABLE OF CONTENTS
GENERAL … 10
INTRODUCTION … 10
PURPOSE … 10
DEFINITIONS AND ABBREVIATIONS … 10
SECTION A - GENERAL … 15
REFERENCE DOCUMENTS … 15
INTERNATIONAL CODES AND STANDARDS … 15
ADNOC SPECIFICATIONS… 18
STANDARD DRAWINGS … 19
OTHER REFERENCES … 19
DOCUMENT PRECEDENCE … 19
SPECIFICATION DEVIATION / CONCESSION CONTROL … 20
DESIGN CONSIDERATIONS … 20
DESIGN BASIS … 20
EQUIPMENT STANDARDISATION … 21
OBSOLESCENCE … 21
CYBER SECURITY … 22
ELECTROMAGNETIC COMPATIBILITY (EMC) … 22
ENVIRONMENTAL / SITE DATA… 22
SELECTION OF ELECTRICAL EQUIPMENT IN HAZARDOUS AREAS [PSR] … 24
ELECTRICAL EQUIPMENT IN COMBUSTIBLE DUST … 25
EQUIPMENT IP RATING … 25
SECTION B – TECHNICAL REQUIREMENTS … 26
POWER SUPPLY AND DISTRIBUTION SYSTEM … 26
MAIN POWER SUPPLY … 26
EMERGENCY POWER SUPPLY … 26
POWER DISTRIBUTION SYSTEM DESIGN … 27
SYSTEM EARTHING … 28
VOLTAGE AND FREQUENCY SELECTION … 28
DEVIATIONS IN SUPPLY VOLTAGE AND FREQUENCY … 30
DEVIATIONS AND VARIATIONS IN SUPPLY WAVE FORM … 31
SYSTEM POWER FACTOR … 31
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SYSTEM OPERATION… 32
SYSTEM STUDIES AND CALCULATIONS … 34
SAFETY AND OPERABILITY (SAFOP) REVIEWS … 35
EQUIPMENT SIZING… 36
CABLE SIZING … 36
EARTHING SYSTEM CALCULATIONS … 39
POWER SYSTEM PROTECTION AND METERING … 40
DISTRIBUTION SYSTEM EQUIPMENT … 47
TRANSFORMERS … 47
HIGH VOLTAGE SWITCHGEAR … 48
LOW VOLTAGE SWITCHGEAR … 49
CAPACITORS … 49
THYRISTOR CONTROL PANELS (TCP) … 50
SUBSTATION BUILDING … 51
PURPOSE … 51
DESIGN OBJECTIVES … 51
SUBSTATION EQUIPMENT … 51
SUBSTATION SIZING AND LAYOUT … 52
TRANSFORMER BAYS … 54
EQUIPMENT ACCESS AND WORKING CLEARANCES … 56
ROOM ACCESS AND ESCAPE ROUTES [PSR] … 57
BUILDING LOCATION … 57
BUILDING DESIGN … 57
SUBSTATION BUILDING HVAC … 59
SUBSTATION LIGHTING AND SMALL POWER … 61
EARTHING AND LIGHTNING PROTECTION … 61
ADDITIONAL REQUIREMENTS FOR PACKAGED SUBSTATION … 61
OVERHEAD LINES … 62
GENERAL … 62
TYPE OF CONSTRUCTION … 62
SUPPORTS … 62
INSULATORS … 63
CONDUCTORS … 63
LIGHTNING ARRESTERS … 64
ACCESSORIES… 64
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EARTHING AND BONDING … 64
CONDUCTOR STRINGING… 65
ROAD CROSSINGS … 65
LINE ROUTE … 65
GROUND CLEARANCE … 66
INSPECTION AND TESTING … 66
ELECTRICAL CONTROL AND MONITORING SYSTEM (ECMS) … 66
ECMS GENERAL … 66
ECMS SCOPE … 66
ECMS FUNCTIONALITY … 67
SYSTEM ARCHITECTURE AND CONFIGURATION … 68
COMMUNICATION … 69
ECMS INTERFACES… 69
ECMS REDUNDANCY … 69
ON-LINE CONDITION MONITORING … 70
UPS SYSTEMS [PSR] … 71
AC AND DC UPS COMMON REQUIREMENTS … 71
AC UPS … 71
DC UPS … 72
BATTERIES … 72
BATTERY MCCB … 72
UPS DISTRIBUTION … 72
MAINTENANCE BYPASS … 73
OPERATOR AND ECMS INTERFACE … 73
MOTORS … 73
GENERAL … 73
MOTOR CONTROL … 74
ADJUSTABLE SPEED DRIVES … 74
ADDITIONAL REQUIREMENTS FOR SYNCHRONOUS MOTORS … 75
MOTOR WATER COOLING … 75
MOTOR CONTROL STATIONS … 76
CABLES AND ACCESSORIES … 76
CABLE REQUIREMENTS … 76
CABLE SHEATH AND CORE COLOURS … 77
CABLE INSTALLATION … 77
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LIGHTING AND SMALL POWER … 80
LIGHTING SYSTEM DESIGN … 80
ILLUMINATION LEVELS … 80
LUMINAIRES … 82
AREA LIGHTING … 82
INSTRUMENTATION LIGHTING … 83
AIRCRAFT LIGHTING … 83
OFFSHORE NAVIGATIONAL AID … 83
LIGHTING CONTROL … 83
LIGHTING INSTALLATION … 84
SOCKET OUTLETS … 84
PORTABLE LAMPS … 84
DISTRIBUTION BOARDS … 84
JUNCTION BOXES … 85
SOLAR POWERED REMOTE STATIONS … 86
CATHODIC PROTECTION TRANSFORMER RECTIFIER UNITS … 86
EARTHING AND LIGHTNING PROTECTION … 86
DESIGN CRITERIA … 86
EARTH GRID DESIGN CRITERIA … 87
EARTH GRID DESIGN … 87
EARTH ELECTRODES… 88
EARTHING CONDUCTOR … 88
BURIED CONDUCTORS … 88
EARTH CONNECTIONS … 89
CABLE ARMOUR EARTHING … 89
MECHANICAL PACKAGE EARTHING … 89
STORAGE TANKS [PSR] … 90
PIPING … 90
PIPELINES AND VALVES … 91
EARTHING WHEN CATHODIC PROTECTION IS APPLIED … 91
EARTHING OF REMOTE PLANT … 91
SUBSTATION EARTHING … 91
JETTIES … 92
INSTRUMENTATION EARTHING … 92
LIGHTNING AND SURGE PROTECTION [PSR] … 93
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ELECTRICAL HEAT TRACING … 93
NON-INDUSTRIAL BUILDINGS … 93
SECTION C – OTHER REQUIREMENTS … 95
DETAILS OF SCOPE SUPPLY … 95
QUALITY CONTROL AND ASSURANCE … 95
SUB-CONTRACTORS, SUB-SUPPLERS … 95
MATERIAL CERTIFICATION … 95
INSPECTION AND TESTING REQUIREMENTS … 95
GENERAL … 95
TESTS REPORTS … 96
TYPE TESTS … 96
SPARE PARTS … 96
PAINTING, PRESERVATION AND SHIPMENT … 96
PAINTING … 96
SHIPMENT … 97
COMMISSIONING … 97
TRAINING … 97
DOCUMENTATION / MANUFACTURER DATA RECORDS … 97
GENERAL … 97
EX EQUIPMENT REGISTER FOR CEE EQUIPMENT … 98
CONTRACTOR DOCUMENTS… 99
GUARANTEES AND WARRANTY … 101
SECTION D – STANDARD DRAWINGS AND DATASHEETS … 102
DATASHEET TEMPLATES … 102
STANDARD DRAWINGS … 102
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LIST OF TABLES
TABLE 1.1 LIST OF ABBREVIATIONS … 11
TABLE 5.1 OUTDOOR AMBIENT AIR TEMPERATURE AND HUMIDITY … 23
TABLE 5.2 INDOOR AMBIENT AIR TEMPERATURE AND HUMIDITY … 23
TABLE 5.3 SELECTION OF EQUIPMENT IN HAZARDOUS AREAS … 25
TABLE 6.1 VOLTAGE LEVELS … 29
TABLE 6.2 MOTOR VOLTAGE SELECTION … 30
TABLE 6.3 CABLE VOLTAGE-DROP VOLTAGE … 39
TABLE 8.1 WORKING CLEARANCES … 56
TABLE 8.2 HVAC DESIGN REQUIREMENTS … 60
TABLE 11.1 ONLINE CONDITION MONITORING … 70
TABLE 12.1 AC AND DC UPS AUTONOMY PERIODS … 71
TABLE 15.1 INDOOR LIGHTING ILLUMINATION LEVELS … 81
TABLE 15.2 OUTDOOR LIGHTING ILLUMINATION LEVELS … 82
LIST OF FIGURES
None
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ADNOC Classification: Internal
GENERAL
Introduction
The scope of this design guide includes the following electrical systems and the associated equipment.
a. Power supply system.
b. Power distribution system.
c. Emergency power generation.
d. Control, monitoring, and protection systems.
e. Power management and load shedding.
f. UPS System.
g. Lighting and small power.
h. Earthing and lightning protection.
i. Electrical heat tracing.
Purpose
This design guide specifies minimum requirements and gives recommendations for the design, engineering and installation of electrical facilities at fixed installations onshore and offshore.
Definitions and Abbreviations
The following defined terms are used throughout this design guide:
‘[PSR]’ indicates a mandatory Process Safety Requirement
“COMPANY” means ADNOC, ADNOC Group or an ADNOC Group Company, and includes any agent or consultant authorised to act for, and on behalf of the COMPANY.
“CONTRACTOR” means the parties that carry out all or part of the design, engineering, procurement, construction, commissioning or management for ADNOC projects. CONTRACTOR includes its approved MANUFACTURER(s), SUPPLIER(s), SUB-SUPPLIER(s) and SUB-CONTRACTOR(s).
“MANUFACTURER” means the Original Equipment Manufacturer (OEM) or MANUFACTURER of one or more of the component(s) which make up a sub-assembly or item of equipment assembled by the main SUPPLIER or his nominated SUB-SUPPLIER.
‘may’ means a permitted option
‘shall’ indicates mandatory requirements
‘should’ means a recommendation
“SUB-CONTRACTOR” means any party engaged by the CONTRACTOR to undertake any assigned work on their behalf. COMPANY maintains the right to review all proposed SUB-CONTRACTORs; this right does not relieve the CONTRACTOR of their obligations under the Contract, nor does it create any contractual relationship between COMPANY and the SUB-CONTRACTOR.
“SUPPLIER” means the party entering into a Contract with COMPANY to provide the materials, equipment, supporting technical documents and/or drawings, guarantees, warranties and/or agreed services in accordance with the requirements of the purchase order and relevant specification(s). The
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ADNOC Classification: Internal
term SUPPLIER includes any legally appointed successors and/or nominated representatives of the SUPPLIER.
“SUB-SUPPLIER” means the sub-contracted SUPPLIER of equipment sub-components software and/or support services relating to the equipment / package, or part thereof, to be provided by the SUPPLIER. COMPANY maintains the right to review all proposed SUB-SUPPLIERS, but this right does not relieve the SUPPLIER of their obligations under the Contract, nor does it create any contractual relationship between COMPANY and any individual SUB-SUPPLIER.
‘auto’ means automatic.
The term emergency generator is used for both emergency and essential services generators.
LATER means ‘The document is not available yet. Each ADNOC COMPANY shall use their own relevant document’.
The abbreviations used throughout this design guide are shown in Table 1.1.
Table 1.1 List of Abbreviations
Abbreviations
AAAC
All Aluminum Alloy Conductor
AC
ACB
Alternating Current
Air Circuit Breaker
ADNOC
Abu Dhabi National Oil Company
ANSI
API
ASD
American National Standards Institute
American Petroleum Institute
Adjustable Speed Drive
ASHRAE
The American Society of Heating, Refrigerating and Air-Conditioning Engineers
ATS
AVR
BCU
Automatic Transfer Scheme
Automatic Voltage Regulator
Bay Control Unit
BEDD
Basic Environmental Design Data
BSI
CAD
CBCT
CCTV
CD
CEE
British Standards Institution
Computer Aided Design
Core Balance Transformer
Close Circuit TV
Compact Disc
Certified Electrical Equipment
CIBSE
Chartered Institution of Building Services Engineers
CPU
CT
Central Processing Unit
Current Transformer
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ADNOC Classification: Internal
Abbreviations
DC
DGA
DGS
DOL
Direct Current
Dissolved Gas Analysis
Design General Specification
Direct On-Line
ECMS
Electrical Control and Monitoring System
EDG
EF
EMC
EMF
EN
EPC
EPL
EPR
ESD
ESP
F&G
Emergency Diesel Driven Generator
Earth Fault
Electromagnetic compatibility
Electromagnetic Field
European Norm
Engineering, Procurement and Construction
Equipment Protection Level
Ethylene Propylene Rubber
Emergency Shutdown
Electric Submersible Pump
Fire and Gas
FEED
Front End Engineering Design
FM
GIS
GPS
GRP
GTG
HTV
HV
HVAC
ICSS
IEC
IED
Fault Monitoring
Gas Insulated Switchgear
Global Positioning System
Glass Reinforced Plastic
Gas Turbine Generator
High Temperature Vulcanised
High Voltage (above 1 kV)
Heating, Ventilation and Air-Conditioning
Integrated Control and Safety System
International Electrotechnical Commission
Intelligent Electronic Device
IEEE
Institute of Electrical and Electronics Engineers
IET
I/O
IP
Institution of Engineering and Technology
Input / Output
Ingress Protection
ISGOTT
International Safety Guide for Oil Tankers and Terminals
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ADNOC Classification: Internal
Abbreviations
ISO
IT
ITP
JB
KNAF
KNAN
kV
kVA
kVAr
International Organisation for Standardisation
Information Technology
Inspection and Test Plan
Junction Box
Synthetic Fluid Natural Air Forced
Synthetic Liquid Natural Air Natural
Kilo Volts
Kilo Volt Amperes (Apparent Power)
Kilo Volt Amperes (Reactive Power)
kVArh
Kilo Volt Amperes (Reactive Power) Hour
kW
kWh
LED
LNG
LV
MCB
MCC
MCCB
MCSA
MOV
MSL
MVA
Kilo Watt
Kilo Watt Hour
Light Emitting Diode
Liquified Natural Gas
Low Voltage (≤ 1000V)
Miniature Circuit Breaker
Motor Control Centre
Moulded Case Circuit Breaker
Motor Current Signature Analysis
Motor Operated Valve or Metal Oxide Varistor
Mean Sea Level
Mega Volt Ampere
NEMA
National Electrical Manufacturers Association
NER
NFPA
OC
OEM
OHL
Neutral Earthing Resistor
National Fire Protection Agency
Overcurrent
Original Equipment Manufacturer
Overhead Line
OLTC
On Load Tap Changer
OPGW
Optical Ground Wire
OWS
PCC
PEC
Operator Workstation
Point of Common Coupling
Parallel Earth Conductor
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Abbreviations
PLC
PMU
PPE
PQM
PRP
PRT
PSR
PVC
Programmable Logic Controller
Power Monitoring Unit
Personnel Protective Equipment
Power Quality Meter
Parallel Redundancy Protocol
Process Risk Tool
Process Safety Related
Poly Vinyl Chloride
RCCB
Residual Current Circuit Breaker
RCU
REF
RMU
ROM
RTD
Remote Control Unit
Restricted Earth Fault
Ring Main Unit
Read-only Memory
Resistance Temperature Detector
SAFOP
Safety and Operability
SCADA
Supervisory Control and Data Acquisition
SF6
SIS
Sulfur Hexafluoride
Safety Instrumented System
SOLAS
Safety of Life at Sea
SPIR
Spare Part Interchangeability Report
TCP
TEV
THD
UAE
UCP
UPS
UV
VDU
Thyristor Control Panel
Transient Earth Voltage
Total Harmonic Distortion
United Arab Emirates
Unit Control Panel
Uninterruptible Power Supply
Ultraviolet
Visual Display Unit
VESDA
Very Early Smoke Detection Alarm System
XLPE
Cross Linked Polyethylene
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ADNOC Classification: Internal
SECTION A - GENERAL
REFERENCE DOCUMENTS
International Codes and Standards
The following codes and standards shall form a part of this design guide. When an edition date is not indicated for a code or standard, the latest edition in force at the time of the contract award shall apply.
AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI)
ANSI C-37.2
Electrical Power System Device Function Numbers, Acronyms, and Contact Designations.
AMERICAN PETROLEUM INSTITUTE (API)
API 650
Welded Tanks for Oil Storage.
BRITISH STANDARDS INSTITUTION (BSI)
BS 6121-1
Mechanical cable glands. Armour glands. Requirements and test methods.
BS 7671
IET wiring regulations.
EUROPEAN STANDARDS
BS EN 12464-1
BS EN 12464-2
BS EN 1838
BS EN 50522
EN 50182
Light and lighting — Lighting of workplaces Part 1: Indoor workplaces.
Light and lighting — Lighting of workplaces Part 2: Outdoor workplaces.
Lighting applications — Emergency lighting.
Earthing of power installations exceeding 1 kV a.c.
Conductors for overhead lines. Round wire concentric lay stranded conductors.
EN 62444
Cable glands for electrical installations.
EU Directive 2013/35/EU
Directive 2013/35/EU - electromagnetic fields.
INTERNATIONAL ELECTROTECHNICAL COMMISSION (IEC)
IEC 60034
IEC 60038
Rotating electrical machines - All parts.
IEC standard voltages.
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INTERNATIONAL ELECTROTECHNICAL COMMISSION (IEC)
IEC 60071
IEC 60076
IEC 60079
IEC 60099
IEC 60332
IEC 60364
IEC 60529
IEC 60617-DB
IEC 60754-1
IEC 60754-2
Insulation coordination.
Power transformers - All part.
Explosive atmospheres - All parts.
Surge arresters - All parts).
Tests on electric and optical fibre cables under fire conditions - All parts.
Low-voltage electrical installations - All parts.
Degrees of protection provided by enclosures (IP Code).
Graphical symbols for diagrams.
Test on gases evolved during combustion of materials from cables - Part 1: Determination of the halogen acid gas content.
Test on gases evolved during combustion of materials from cables - Part 2: Determination of acidity (by pH measurement) and conductivity.
IEC 60794-4-10
Optical fibre cables - Part 4-10: Family specification - Optical ground wires (OPGW) along electrical power lines.
IEC 60831
IEC 60871
IEC 60905
IEC 60909
IEC 60947
IEC 61000
IEC 61034-2
IEC 61039
IEC 61089
IEC 61109
IEC 61363
IEC 61439
IEC 61466-1
Shunt power capacitors of the self-healing type for A.C. systems having a rated voltage up to and including 660 V.
Shunt capacitors for a.c. power systems having a rated voltage above 1000 V (All Parts)
loading guide for dry type power transformers.
Short circuit current calculation in three phase A.C. systems.
Low voltage switchgear and controlgear - All parts.
Electromagnetic Compatibility (EMC) - All parts.
Measurement of smoke density of cables burning under defined conditions.
Classification of insulating liquids.
Round wire concentric lay overhead electrical stranded conductors.
Insulators for overhead lines - Composite suspension and tension insulators for a.c. systems with a nominal voltage greater than 1000 V
- Definitions, test methods and acceptance criteria.
Electrical installations of ships and mobile and fixed offshore units - Part 1: Procedures for calculating short-circuit currents in three-phase a.c.
Low voltage switchgear and controlgear assemblies - All parts.
Composite string insulator units for overhead lines with a nominal voltage greater than 1000 V - Part 1: Standard strength and end fittings.
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INTERNATIONAL ELECTROTECHNICAL COMMISSION (IEC)
IEC 61466-2
IEC TR 61641
IEC 61869
IEC 61936
IEC 62052-11
IEC 62053-21
IEC 62305
IEC 62351
IEC 62402
IEC 62443
IEC 62485-2
IECEx 02
Composite string insulator units for overhead lines with a nominal voltage greater than 1000 V - Part 2: Dimensional and electrical characteristics.
Enclosed LV Switchgear and Controlgear – Guide for testing under conditions of arcing due to internal fault.
Instrument Transformers - All parts.
Power installations exceeding 1 kV a.c. - All parts.
Electricity metering equipment - General requirements, tests and test conditions - Part 11: Metering equipment.
Electricity metering equipment - Particular requirements - Part 21: Static meters for AC active energy (classes 0,5, 1 and 2).
Protection against lightning - all parts.
Power systems management and associated information exchange – Data and communications security.
Obsolescence Management.
Security for industrial automation and control systems - All parts.
Safety requirements for secondary batteries and battery installations - Part 2: Stationary batteries.
IEC System for Certification to Standards relating to Equipment for use in Explosive Atmospheres (IECEx System) IECEx Certified Equipment Scheme covering equipment for use in explosive atmospheres – Rules of Procedure.
IEC TR 60083
Plugs and socket outlets for domestic and similar general use.
IEC TR 62271-303
High voltage switchgear and control gear. Use and handling of Sulphur hexafluoride (SF6) in high voltage switchgear and control gear.
INSTITUTE OF ELECTRICAL and ELECTRONIC ENGINEERS (IEEE)
IEEE 1548
IEEE 80
IEEE C37.101
IEEE C37.102
IEEE C37.99
IEEE 519
IEEE Guide for Performing Arc-Flash Hazard Calculations.
IEEE Guide for Safety in AC Substation Grounding.
IEEE Guide for Generator Ground Protection.
IEEE Guide for AC Generator Protection.
IEEE Guide for Protection of Shunt Capacitor Banks.
IEEE Recommended Practice and Requirements for Harmonic Control in Electric Power Systems.
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INTERNATIONAL SAFETY GUIDE FOR OIL TANKERS AND TERMINALS (ISGOTT)
ISGOTT
International Safety Guide for Oil Tankers and Terminals.
NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)
NFPA 20
NFPA 70
NFPA 101
NFPA 780
Standard for the Installation of Stationary Pumps for Fire. Protection
National Electrical Code.
Life Safety Code
Standard for the Installation of Lightning Protection.
NATIONAL ELECTRICAL MANUFACTURER ASSOCIATION (NEMA)
NEMA MG-1
Motors and Generators.
International Organization for Standardisation (ISO)
ISO 1461
ISO 8528
ISO 12944
Hot dip galvanised coatings on fabricated iron and steel articles - Specifications and test methods.
Reciprocating internal combustion engine driven alternating current generating sets.
Paints and varnishes - Corrosion protection of steel structures by protective paint systems.
MODEL CODE OF SAFE PRACTICE
EI15
Part 15: Area Classification for installations handling flammable fluids.
ADNOC Specifications
Where a document is not available, each ADNOC COMPANY shall use their own relevant document.
AGES-GL-03-001
AGES-PH-03-002
AGES-PH-04-001
AGES-SP-01-003
AGES-SP-01-007
AGES-SP-02-001
AGES-SP-02-002
AGES-SP-02-003
Layout and Separation Distances Guidelines.
Fire and Gas Detection and Fire Protection System Philosophy.
Automation and Instrumentation Design Philosophy.
Structural Design Basis - On Shore Specification.
Drainage System Design and Construction Specification.
Power Transformer Specification.
Synchronous Motor specification.
Air Insulated High Voltage Switchgear and Controlgear Specification.
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ADNOC Classification: Internal
AGES-SP-02-004
AGES-SP-02-005
AGES-SP-02-006
AGES-SP-02-007
AGES-SP-02-008
AGES-SP-04-003
AGES-SP-04-004
AGES-SP-04-006
AGES-SP-05-006
Electrical Adjustable Speed Drive System Specification.
Gas Insulated Switchgear and Controlgear >1 kV – 52 kV Specification.
Low Voltage Switchgear and Controlgear Specification.
Induction Motor Specification.
Electrical Control and Monitoring System (ECMS) Specification.
Fire and Gas System Specification.
Emergency Shutdown (SIS) System Specification.
Instrument and Control Cable Specification.
Rotating Equipment Minimum General Requirements and System Integration Specification.
AGES-SP-07-004
Painting and Coating Specification
DGS-1630-015
DGS-EE-012
DGS-MV-004
Z0-TS-E-04010
Electrical Heat Tracing.
Process Heaters
Synchronous AC generators 1250 kVA and above.
Navigational Aid Systems for Offshore Facility.
Architectural Design Basis.
Prefabrication Metal Buildings.
Environmental Engineering Design Criteria.
Fire Protection System Design Specification.
Building Design Safety.
OT / Cyber security standards.
HVAC Design Basis.
Basic Engineering Design Data (BEDD).
LATER
LATER
LATER
LATER
LATER
LATER
LATER
LATER
Standard Drawings
LATER.
Other References
UAE 2014.
UAE Electricity wiring regulations.
DOCUMENT PRECEDENCE
The specifications and codes referred to in this design guide shall, unless stated otherwise, be the latest approved issue at the time of contract award.
It shall be the CONTRACTOR’s responsibility to be, or to become, knowledgeable of the requirements of the referenced Codes and Standards.
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The CONTRACTOR shall notify the COMPANY of any apparent conflict between this specification, the related data sheets, the Codes and Standards and any other specifications noted herein.
Resolution and / or interpretation precedence shall be obtained from the COMPANY in writing before proceeding with the design / manufacture.
In case of conflict, the order of document precedence shall be:
a. UAE Statutory requirements.
b. ADNOC HSE Standards
c. Equipment datasheets and drawings.
d. Project Specifications and standard drawings.
e. Company Specifications.
f. National / International Standards.
SPECIFICATION DEVIATION / CONCESSION CONTROL
Deviations from this design guide are only acceptable where the CONTRACTOR has listed in his quotation the requirements he cannot, or does not wish to comply with, and the COMPANY has accepted in writing the deviations before the order is placed.
In the absence of a list of deviations, it will be assumed that the CONTRACTOR complies fully with this design guide.
Any technical deviations to the Purchase Order and its attachments including, but not limited to, the Data Sheets, Drawings, and Narrative Specifications shall be sought by the CONTRACTOR only require CONTRACTOR’S and through Concession Request Format. Concession COMPANY’S review / approval, prior to the proposed technical changes being implemented. Technical changes implemented prior to COMPANY approval are subject to rejection.
requests
DESIGN CONSIDERATIONS
Design Basis
The design of the electrical systems shall be based on the following:
a. Safety of personnel and equipment during operation, inspection, and maintenance.
b. Each system and component shall meet the reliability and availability requirements of the project.
c. Simplicity of operation and maintenance.
d. Voltage regulation throughout the power distribution system.
e. Provision and flexibility for future expansion.
f. Lifecycle costs, including equipment downtime and maintenance.
g. The design and engineering of the electrical installation shall satisfy Abu Dhabi national and local
authorities’ statutory requirements.
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Equipment Standardisation
The following equipment standardisation guidelines shall be followed:
a. The equipment shall be standardised to achieve the benefit of the following.
i. Minimise operating and maintenance costs.
ii.
To reduce the need of holding different spares, from different manufacturers.
iii. With standardisation, repair procedures, and equipment and repair training become much less
onerous.
b. Equipment selection process shall evaluate the benefit of standardising equipment ratings.
c. Equipment shall be of similar type and construction and incorporating identical components.
d. Equipment procurement strategy should evaluate the benefit of buying each equipment or a number of equipment of similar type and incorporating similar or identical components/ construction, from the same manufacturer. These shall include but not be limited to the following:
i.
Transformers.
ii. HV Switchgear.
iii. LV Switchgear.
iv. Distribution boards.
v. AC and DC UPS Systems including batteries.
vi. Adjustable Speed Drive Systems.
vii. Emergency Generators.
viii. Power and Convenience outlets.
ix. Luminaires.
x.
Junction boxes.
xi. Motor Control Stations.
xii. Neutral Earthing Resistors.
xiii.
Interposing Relay Panels.
xiv. Protection relays.
xv. ECMS equipment.
Obsolescence
The MANUFACTURER shall submit a statement along with the bid, in accordance with IEC 62402, on any planned or predicted obsolescence of equipment or components over this design life and advise what provisions are made to allow ease of future upgrading of any equipment purchased.
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Cyber Security
Cyber security shall meet the following requirements:
a. A role-based access control shall be incorporated.
b. Cyber security for the products and external interface shall comply with IEC 62443 series of
standards as applicable.
c. Communication protocols shall comply with IEC 62351.
d. SUPPLIER shall provide firewall and malware protection in line with COMPANY corporate cyber
security policy.
Electromagnetic Compatibility (EMC)
5.5.1
EMC
Guidelines for EMC are as follows:
a. The CONTRACTOR shall prepare and implement an EMC management plan, describing the specific EMC requirements during the engineering, procurement, construction and commissioning phase of the project. The EMC plan shall also address any interfacing issues between new and existing facilities.
b. Measures to achieve EMC shall be chosen in accordance with IEC 61000 and other equipment and
system standards as applicable.
c. Further requirements for various equipment and systems are given in each section of this design
guide where applicable.
5.5.2
EMF
Guidelines for protection against EMF are as follows:
a. The design and installation shall ensure that personnel are not exposed to harmful levels of EMF
as defined in the EU Directive 2013/35/EU - electromagnetic fields.
b. Mitigation actions may include:
i.
Restricting access, e.g. transformer pens with lockable gates or room access control.
ii. Monitoring of EMF levels prior to entering areas.
iii. Use of shielding.
iv.
Isolation of equipment for activities that would require working in close proximity to high levels of magnetic field.
Environmental / Site Data
Unless stated otherwise, the site environmental data as below shall apply.
a. Outdoor conditions:
i. Without protective shelter, exposed to direct sunlight and solar gain of up to 1006 W/m². Static
equipment can achieve surface temperatures of up to 85 °C.
ii. Altitude:<1000 m above sea level.
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iii. Wind velocity for design: Refer to AGES-SP-01-003.
iv. Environment corrosivity: Saliferous, sulphurous and dusty environment in conformance with
ISO 12944 parts 2 and 5 classes:
-
C5-I for onshore facilities less than 50 km from the coast.
-
C3-I for onshore facilities greater than 50 km from the coast.
-
C5-M for offshore facilities.
v. Rainfall: Extremely rare, but flash flooding may occur. Measurable rainfall usually occurs in an average of about 10 days per year with a rainfall intensity of 10 mm for 15 minutes. The rainfall is confined to winter and transitional months only.
vi. Soil thermal resistivity: Use 2.5 °C m/W, when data is not available from the site soil thermal
resistivity measurements.
vii. Relative humidity:
-
Maximum: 97 % at 43 °C.
-
Average: 60 % at 54 °C.
Table 5.1 Outdoor ambient air temperature and humidity
Max ambient temp.
(°C)
54
48
40
Hottest monthly Average temp. (°C)
44
38
Annual average temp.
Min temp.
Max relative humidity
(°C)
34
28
(°C)
5
5
13
97 % at 43 °C
97 % at 43 °C
Onshore
Offshore
Soil at 1 m depth
b.
Indoor conditions
Table 5.2 Indoor ambient air temperature and humidity
Max ambient temp.
(°C)
40
45
Hottest monthly Average temp. (°C)
30
35
Annual average temp.
Min temp.
Max relative humidity
(°C)
20
(°C)
5
90 %
NA
NA
90 %
Onshore and offshore with HVAC
Onshore and offshore without HVAC for 8 hours
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c. For OHL following environmental conditions shall apply.
i.
Solar Radiation: 946 W/m².
ii. Rainfall: Refer to AGES-SP-01-007.
d. Average Barometric Pressure: 1.013 bara.
e. Altitude: < 200 m above MSL.
f. Earthquake: Refer to AGES-SP-01-003.
Selection of Electrical Equipment in Hazardous Areas [PSR]
Electrical equipment located in hazardous areas shall meet the following requirements:
a. Electrical discipline will specify suitably certified equipment to be located in hazardous areas based
on the hazardous area zone classification drawings. [PSR]
b. The equipment for each classified zone shall be selected in accordance with IEC 60079 as per the
minimum requirements given in Table 5.3.
c. The equipment in hazardous area shall be IECEx certified.
d. Where it is required to operate or remain energised following ESD, Zone 1 certified equipment shall
be used.
e. All safety critical equipment shall be certified for Zone 1.
f. No electrical equipment shall be installed in Zone 0.
g. Electrical equipment in areas below grade that involve liquid sulphur such as sumps, pits, trenches and areas within the sulphur storage tanks shall be certified for Zone 1, Group IIB for H2S gas with a maximum surface temperature rating of 185°C at 54 °C ambient.
h. Certified Equipment in Non-hazardous Areas:
Equipment installed outdoors in non-hazardous areas within the process plant battery limit shall be certified for installation in Zone 1 or Zone 2 for the following reasons.
i. Minimising different type of equipment.
ii. Commonality of spares.
iii. Catering for the possibility of reclassification of areas.
iv.
Improving safety in case of a large hydrocarbon release by reducing ignition sources.
v. Perimeter and street lighting will not need to be certified unless these are installed within
hazardous area.
i. Zone 1 certified equipment in Zone 2: For the same reasons as described in Section 5.7h, light fixtures, socket outlets, control stations, cable glands, and JBs etc. in Zone 2 or non-hazardous plant areas shall be specified to be suitable for Zone 1 area.
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Table 5.3 Selection of equipment in hazardous areas
Zone
Acceptable Protection Level
Zone 0 IEC EPL Ga
Zone 1 IEC EPL Gb
Zone 2 IEC EPL Gc
Ex ia, Ex ma
Ex ib for intrinsically safe devices Ex db eb for LV motors Ex db eb, Ex pxb for HV motors Ex eb for junction boxes Ex db eb for floodlights, luminaires, control stations, heaters, and sockets Ex db plus Ex eb dual certification for cable glands Ex mb, Ex o, Ex q, for components
Ex db eb, Ex ec for LV motors Ex db eb, Ex pzc or Ex pxb plus Ex ec dual certification for HV motors Ex eb for junction boxes Ex db eb for floodlights, luminaires, control stations, heaters, and sockets Ex db plus Ex eb dual certification for cable glands Ex mc, Ex o, Ex q, for components
Electrical Equipment in Combustible Dust
For electrical equipment in Zone 21 and Zone 22, the following shall apply:
a.
Indoor and outdoor under shade:
Ex tb IIIB, T 146°C, Tamb 54°C, IP65.
b. Outdoor direct sun exposed:
Ex tb IIIB, T 115°C, Tamb 54°C, IP65.
c. Combustible dust certified equipment in non-hazardous areas shall be provided similar to gas
certified area described in Section 5.7.
Equipment IP Rating
a. Unless otherwise specified IP rating of equipment such as HV and LV switchgear, ASDs, control panels, transformer rectifier units, installed indoors in environmentally controlled areas shall be minimum IP 31. Where equipment is likely to be accessed by non-technical personnel the equipment rating should be increased to IP 41.
b. Where equipment is installed indoors but not environmentally controlled, the minimum IP rating
shall be IP 51.
c. For outdoor equipment IP rating for onshore shall be IP 55 and for offshore equipment IP 56.
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SECTION B – TECHNICAL REQUIREMENTS
POWER SUPPLY AND DISTRIBUTION SYSTEM
Main Power Supply
a. Depending on the load demand and the location of the plant, the following power supply options
should be considered.
i. On plot power generation.
ii. Grid power supply.
iii. Combination of on plot power generation and grid power supply.
b. On plot power generation and the available power supply from the grid shall be capable of supplying
110 % of the peak load demand.
c. The total number of generator and grid incomers (N) shall be such as to provide N-1 contingency, where ‘1’ represents the largest generator or grid incomer. Based on power generation availability requirements and economic evaluation, N-2 shall be considered for systems without grid supply.
d. Onsite power generators shall be connected to the grid power supply bus directly or via generator
unit transformers.
e. Synchronous generators shall comply with ADNOC Business Units specification DGS-MV-004
‘Synchronous AC generators 1250 kVA and above’.
Emergency Power Supply
6.2.1
Essential Services
Emergency diesel generators shall be installed to supply power to the following services.
a. Safety critical services: The safety critical services such as ESD, F&G, escape and emergency lighting, general plant alarm system, aviation warning lights, and navigation system shall be supplied from the emergency generators and shall be battery backed.
b. Asset critical and life support services: UPSs, essential lighting, HVAC system, general plant alarm system, instrument air compressor, heat tracing for critical services, fire water system, main power generator and emergency generator auxiliaries, and critical pumps for hydrocarbon drainage sump pump.
6.2.2
Emergency Diesel Generator (EDG)
EDGs shall be designed to provide the following functions and operation.
a. Upon loss of main power EDG shall automatically supply power to essential loads connected to the
essential services switchgear bus.
b. EDG shall be used for black starting of the main power generators, unless dedicated black start
generator is provided.
c. EDG shall restore the power supply back to mains power without any interruption.
d. EDG shall be designed for periodic load testing by paralleling with the mains power.
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e. Stop sequence for EDGs shall be initiated manually.
f. The ECMS shall have the capability to initiate a start and stop of the EDG. The EDG and associated
circuit breaker control shall be from the EDG control panel.
g. EDG shall have a battery primary and an air or hydraulic secondary start system. Each system shall have sufficient stored energy to provide a minimum of six starts equivalent to 180 seconds of cranking time at an ambient temperature of 5 °C.
h. EDG shall be provided with a diesel day tank sized in accordance with regulatory and with the
project specific requirements. The minimum capacity of the diesel day tank shall be:.
i. Onshore: 8 hours.
ii. Offshore: 24 hours.
Power Distribution System Design
a. Power distribution shall be installed as given in the single line diagrams and related documents.
b. Unless otherwise specified, the power distribution system supplying power to the plant loads shall
be of the radial feeder design.
c. Ring main units (RMUs) shall be used for tie-ins at remote locations to the HV power distribution
systems. The ring main unit distribution shall normally be operated as ‘open’ ring.
d. Normally the main switchgear shall have single busbar split into a number of sections by using bus
section circuit breakers.
e. Double busbar arrangements shall be considered for 66 kV switchgear and above for operational flexibility to connect incoming and outgoing circuits in a number of ways that is not practical with a single busbar arrangement. Where specified, 33 kV switchgear with grid supply incomers and / or generator unit transformer incomers shall have double bus arrangements.
f. Transformer incomers to main switchboards shall be 2x100 %. For a specific project 3x50 % incomers can provide a cost-effective solution with adequate redundancy, particularly where it is necessary to limit the short circuit current.
g. Normal duty and standby loads shall be allocated to different buses of the same switchgear.
h. Outgoing circuits shall be connected to busbar sections to minimise power flow across bus section
breakers.
i. The position of incoming circuit breakers along the busbar section shall be selected such that
busbar loading is kept to a minimum.
j. Phases shall be balanced such that the negative phase sequence components of voltage and
current at any point in the system shall not exceed the values specified in IEC 60034-1.
k. Power distribution system shall be designed to continuously carry at least 110 % of the peak load
demand at maximum ambient condition.
l. Site power distribution system designs should be based on the following.
i.
Secondary selective, ‘normally open’ bus section and ‘normally closed’ incomer arrangement.
ii. Normally closed” bus section with dual incomer arrangement.
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iii. Normally the main HV switchgear distributing power to the plant shall be operated with bus section breaker closed and the downstream HV and LV switchgear with bus section breaker open.
iv. Switchgear for voltages 11 kV and above shall be with bus section ‘normally closed’.
m. Overvoltage: System shall be designed to avoid over voltages. Refer to IEC 62305 and chapter 6 of IEEE 141 for guidance on the subject of voltage surges from lightning and switching sources.
System Earthing
Unless otherwise stated the neutral of generators and transformers shall be earthed as described in Sections 6.4.1 and 6.4.2.
6.4.1
Transformer Neutral Earthing
a. Star point of HV windings rated above 33 kV shall be solidly earthed.
b. Star point of HV windings rated up to 33 kV shall be earthed via its own neutral earthing resistor
such that the earth fault current through the associated transformer is limited:
i.
ii.
400 A for 33 kV windings.
100 A for HV windings up to 11 kV.
iii. 10 A for HV motor unit transformers.
iv. For each of the above it shall be ensured that the available earth fault current is greater than three times the capacitive charging current. If necessary, the available earth fault current shall be increased to a value greater than three times the capacitive charging current.
c. Star point of LV windings rated up to 415 V shall be solidly earthed.
d. Star point of LV windings rated 690 V shall be either solidly earthed or earthed via its own neutral
earthing resistor such that the fault current through the associated transformer is limited to 100 A.
6.4.2
Generator Neutral Earthing
a. Neutral earthing of generators connected directly to the switchgear shall be same as for the
transformer neutrals.
b. HV generators with unit transformers shall be earthed via neutral earthing transformers such that the earth fault current is limited approximately 10 to 15 A range. The earth fault current shall be greater than three times the capacitive charging current.
Voltage and Frequency Selection
a. Nominal system voltage shall be selected from IEC 60038 as given in Table 6.1. Highest voltages
corresponding to nominal voltages shall be as given in IEC 60038.
b. Selected voltage shall be based on:
i.
ii.
The most economic voltage for the application.
Lifecycle costs.
c. System frequency shall be 50 Hz for onshore and offshore facilities unless otherwise specified.
d. Economic and lifecycle assessment shall be submitted to the COMPANY for approval.
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Table 6.1 Voltage Levels
Service
Voltage
Grid supply at 132 kV
132 kV, 220 kV
Grid supply at 33 kV
33 kV
HV generation
3.3 kV, 6.6 kV, 11 kV
Steady State Voltage variation
±5 %
±6 %
±1 %
LV generation
415 V or 690 V
±1 %
HV Distribution
HV Motors (See Table 6.2)
3.3 kV, 6.6 kV, 11 kV, 33 kV
3.3 kV, 6.6 kV, 11 kV
±5 %
±5 %
LV Motors > 0.18 kW (See Table 6.2)
415 V or 690 V
±5 %
Phase/Wire
System Earthing
3/3
3/3
3/3
3/3
3/3
3/3
3/3
Solidly earthed
Resistance earthed
Resistance earthed
415 V solidly earthed 690 V solidly or resistance earthed
Resistance earthed
Resistance earthed
415 V solidly earthed 690 V solidly or resistance earthed
Motors up to 0.18 kW
240 V
415 V, 690 V
±5 %
±5 %
1 Ph+N+E
Solidly earthed
3/4
415 V solidly earthed 690 V solidly or resistance earthed
Three phase distribution boards, cathodic protection transformer rectifier unit
Single phase distribution boards, cathodic protection transformer rectifier units
Power sockets
Welding receptacles
Lighting final circuit, anticondensation heaters
Instrument power supply
Control voltage for switchgears including spring charging motors
Control voltage for contactors
ECMS cabinets, monitors, printers and other peripheral devices
ESP Submersible pump motor and switchgear
240 V
±5 %
1 Ph+N+E
Solidly earthed
415 V
415 V
240 V
240 V
110 V
240 V
240 V
±5 %
±5 %
±5 %
±5 %
±5 %
±5 %
±5 %
3/3
3/3
Solidly earthed
Solidly earthed
1 Ph+N+E
Solidly earthed
1 Ph+N+E
Solidly earthed
DC
Unearthed
1 Ph+N+E
Solidly earthed
1 Ph+N+E
Solidly earthed
3.3 kV
±5 %
Solar power system loads
24 V
Process thyristor control heaters
415 V, 690 V
±10 %
±10 %
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3/3
DC
3/4
Unearthed
Unearthed
415 V solidly earthed 690 V solidly or resistance earthed
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Motor Rating Range (kW)
Table 6.2 Motor Voltage Selection
Available Voltages
240 V
415 V
690 V
3.3 kV
6.6 kV
11 kV
< 0.18
x
≥ 0.18 < 160
≥ 160 < 315
≥ 315 < 1100
≥ 1100 < 3000
≥ 3000
x
Note 1
x
x
x
x
x
x
x
x
x
x
x
Note 1: The use of LV ASD driven or soft started motors is subject to COMPANY approval.
Deviations in Supply Voltage and Frequency
6.6.1
Steady-state Voltage and Frequency Variations
a. Grid supply voltage and frequency variations shall be in accordance with Transco Electricity Code
as below.
i.
Voltage variation for 132 kV shall be within ±5 %.
ii. Voltage variation for 33 kV shall be within ±6 %.
iii. Frequency variation shall be within ±1 %.
b. Voltage and frequency variation at main generation bus during island operation mode shall be as
below.
i.
ii.
Voltage variation shall be within ±1 % as per NEMA MG-1.
Frequency variation shall be within ±2 %.
c. Voltage and frequency variation at diesel generator bus during standby power operation mode shall
be as per Class G3 of ISO 8528 as below.
i.
ii.
Voltage variation shall be within ±1 %.
Frequency variation shall be within ±0.5 %.
d. Voltage and frequency deviations at load during normal steady state operation shall be within Zone
A as described in IEC 60034-1 as below.
i.
ii.
Voltage variation shall be within ±5 %.
Frequency variation shall be within ±2 %.
e. The voltage variations for each voltage level is given in Table 6.1.
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6.6.2
Transient Voltage and Frequency Variations
a. Grid supply voltage and frequency variations shall be in accordance with Transco Electricity Code
as below.
i.
ii.
Voltage variation for 132 kV shall be within ±10 %.
Frequency variation shall be within ±6 %.
b. Voltage and frequency variation at main generation bus during island operation mode shall be as
below.
i.
ii.
Voltage variation shall be within ±2 0 %, recovering to within 1 % in 1.5 s as per NEMA MG-1.
Frequency variation shall be within ±10 % with recovery time of 5 s.
c. Voltage and frequency variation at diesel generator bus during standby power operation mode shall
be as per Class G3 of ISO 8528 as below.
i.
ii.
Voltage variation shall be within ±20 % with recovery time of 4 s.
Frequency variation shall be within ±10 % with recovery time of 3 s.
d. Voltage drop at motor terminals shall not exceed 20 % % during motor starting.
Deviations and Variations in Supply Wave Form
a. System shall be designed such that supply harmonic voltage distortion does not exceed following
IEC and IEEE limits:
i.
IEC 61000-2-4:
-
Class 1 limits (5 % THD) under normal operation.
-
Class 2 limits (8 % THD) under abnormal configuration, e.g. when supplied with a
transformer out of service or via an emergency power supply.
ii.
IEEE 519 limits at each voltage level.
b.
If the facility is supplied from a public utility, THD at the PCC shall not exceed the limits stated by the public utility under most adverse supply conditions.
c. Current and Voltage THD shall be verified by CONTRACTOR by site measurement.
d. Unless a higher value is stated on the data sheets all equipment shall be suitable for operation on
a network supply with harmonic voltage THD up to 8 %.
e. Harmonic voltage distortion limits do not apply to the input terminals of individual items of harmonic generating equipment, e.g. converters, which are supplied via transformers or series reactors.
System Power Factor
a. Power factor at PCC shall be 0.9 as a minimum or maintained within the limits set by the agreement
with the public utility.
b. Where necessary, power factor correction shall be achieved by one or more of the following methods, which are stated in order of preference based on reliability and economic considerations.
i.
Variation of the excitation of synchronous generators.
ii. Variation of the excitation of synchronous motors.
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iii. Static capacitors connected to distribution switchgear via suitably protected switching devices.
c. Power factor correction capacitors shall be located close to the distribution load centres in non-
hazardous area.
d. Capacitor circuits shall have a means to safely discharge stored energy.
e. Unless otherwise specified, the capacitor stages shall be switched automatically.
f. For non-linear loads, capacitors with reactors designed for power factor correction in harmonic
environment shall be employed.
g. Power factor capacitor performance shall be analysed for the following:
i.
ii.
Inrush current when energising the first capacitor bank.
Inrush current when energising the subsequent banks.
iii. Fault on the bus to which the capacitor banks are connected.
iv. Harmonic resonance when non-linear loads such as ASDs are connected to the bus.
v. Circuit breaker performance in interrupting the circuit during fault condition.
System Operation
6.9.1
System Interlocking
Interlocking and intertripping shall be provided for the following:
a. Live circuit cannot be earthed.
b. An earthed circuit cannot be energised.
c. Supplies cannot be paralleled out of synchronism.
d. Short circuit rating of the switchgear is not exceeded.
e. Energisation of transformers from secondary side is prevented, except where power flow in both
directions is allowed.
f. Circuit breaker cannot be closed on a faulty circuit.
g. Key exchange interlocks shall be provided between upstream and downstream circuits to ensure
that:
i.
Circuit is isolated before cable or busbar earthing switch can be closed.
ii. Earthing switch is open before energising the circuit.
h. Where switchboard is operated with bus section breaker ‘normally open’, interlocking between two incomers and the bus section breaker shall be provided such that only two out three breakers can be closed at any one time, with the exception of momentary paralleling during auto transfer.
i. Details of system interlocking and intertripping shall be given in the key single line diagrams and
protection metering diagrams.
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6.9.2
Synchronising
a. Synchronising and check synchronising facilities shall be provided for generator incomers and bus
section breakers.
b. Auto Synchronising: The auto synchronising command is initiated either by the operator or as a part of generator auto start sequence. The auto-synchroniser raises / lowers the voltage and speed of the incoming generator or bus as necessary. When the two supplies are in synchronism, and ‘check sync’ healthy, it sends a close command to the circuit breaker. In case of dead bus, the system will automatically detect the dead bus and close the circuit breaker automatically onto the dead bus.
c. Manual Synchronising: In manual mode, the operator controls the generator / bus voltage and frequency. The operator initiates a circuit breaker close signal when the synchro-scope indicates supplies are in synchronism, or when the busbar is dead.
6.9.3
Auto Transfer Scheme
a. Radially fed switchboards with open bus section breakers shall be provided with secondary
selective transfer scheme.
b. The ATS logic and configuration shall reside in the switchboard’s multifunctional protection relays.
c. Transfer scheme shall have automatic and manual modes of operation, selectable by an
Auto/Manual selector switch.
d. Auto Mode
In automatic operation, the transfer scheme shall:
i.
Detect an undervoltage condition on one side of the bus section.
ii. After a pre-set time delay trips the incomer having the undervoltage condition.
iii. Close the bus section breaker to restore power to the entire bus.
e. Manual Mode
In manual mode the transfer sequence is manually initiated as below:
i.
Restoration: When the faulty incomer is restored, the operator can initiate the transfer sequence which allows momentary paralleling of the incomers and then opens the bus section breaker. To prevent ‘out of synch’ closing, the momentary paralleling will be prevented if the upstream system is not synchronised via a continuous bus.
ii. Maintenance: For maintenance, the operator can select the desired circuit breaker to be tripped manually. The ‘open’ breaker will close and the selected breaker will trip, make-before- break operation.
f. The ATS is provided with interlocking such that under normal operation only two out of three circuit
breakers can be closed except for momentary paralleling in manual mode of operation.
g. Transfer scheme shall be inhibited if:
i.
A fault exists on one bus.
ii. Breakers required to be operated are not racked in the service position.
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6.9.4
Motor Starting
a. Motors shall be started direct-on-line (DOL).
b. Starting methods such as reduced voltage starting, soft starting, and pony motor starting shall be
used where performance of DOL starting is not acceptable.
c. Reduced voltage starting systems for large compression equipment on offshore installations can require unacceptable depressurisation of process plant and flaring, which can affect process availability. Variable frequency soft starting options can enable equipment starting on load.
6.9.5
Load Shedding
The need for a load shedding scheme shall be studied and if required a microprocessor-based load shedding scheme shall be provided. As a backup to this, under frequency load shedding in conjunction with rate of change of frequency relays shall also be provided. The load shedding scheme shall be provided as part of the ECMS. For more details refer to ECMS Section 10.
System Studies and Calculations
6.10.1 Electrical Load Estimate
a. The maximum power demand and the peak power demand shall be estimated for the normal and
essential loads over the operational life of the plant.
b. The power demand estimate shall be based on the following criteria.
i. Maximum Power Demand: 100 % of continuously operating load +30 % of intermittent load or
largest individual Intermittent load if greater.
ii. Peak Power Demand: 100 % of continuously operating load +30 % of intermittent load or largest individual Intermittent load if greater +10 % of the total standby load or largest individual standby load if greater.
c. Where applicable different diversity factor can be applied to the continuous, intermittent, and
standby loads with COMPANY agreement.
6.10.2 System Studies
System studies for the power supply and distribution system shall be carried out and shall include but not be limited to the following. The study shall be carried out using COMPANY approved software package.
a. Load flow studies.
b. Short circuit studies: Short circuit studies shall be carried out in accordance with IEC 60909.
c. Motor starting.
d. Transient stability including frequency response on loss of generation and load shedding.
e. Voltage profile during transformer energisation.
f. Harmonic distortion studies.
g. Power supply availability and reliability studies.
h. Protection studies: For systems with “near to source” power generation IEC 61363 may be used to
determine adequacy of equipment to clear short circuit fault.
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i.
Insulation coordination study.
6.10.3 Arc Flash Studies
a. An electrical arc flash hazard analysis shall be performed to determine the following.
i.
Arc flash incident energy.
ii. Arc flash protection boundaries.
iii. PPE requirements for operation and maintenance tasks.
iv. Arc flash hazard labelling.
v. Optimum protection settings to reduce incident energy levels.
b. Arc flash study shall be carried out for fault at each bus and equipment terminals. The equipment
shall include HV and LV switchgear, distribution boards, ASDs, and UPSs.
c. Arc flash studies shall be carried out for the following conditions.
i.
ii.
For fault clearance time for the protective device on the faulted circuit for both maximum and minimum generation.
For fault clearance time for the protective device upstream of the faulted circuit for both maximum and minimum generation.
d. Arc flash calculations shall be performed by using any of the empirically derived IEEE-1584 models.
e. Electrical design shall evaluate methods to remove risk from arcing incidents, eliminating the need
to operate live equipment to as low as reasonably practicable, e.g. by:
i.
Isolation of equipment.
ii. Eliminating the need for manual racking in or switching of breakers on live equipment from
front of the panels.
iii. Use of early detection protection such as arc UV detection combined with pressure detection.
iv. Use of maintenance mode protection relay settings whilst working near switchgear.
v. Venting arc incident gas exhaust to an outdoor area via ducting.
f. Arc incident energy levels should be reduced to less than 8 cal/cm2.
g.
Incident energy levels that cannot be reduced to 40 cal/cm2 shall be permitted if approved by COMPANY responsible engineer.
h. Design configurations that result in an incident energy levels greater than 40 cal/cm2 shall not be
permitted.
i. The study shall be carried out using COMPANY approved software package.
Safety and Operability (SAFOP) Reviews
a. The SAFOP process is a systematic approach to review the safety and operability of electrical
design from a technical, maintenance and operational viewpoint.
b. SAFOP review will identify design deficiencies and enhancements which will lead to safer and more
efficient operations.
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c. The CONTRACTOR shall agree with the COMPANY the terms of reference. The terms of reference
document shall include the following.
i.
ii.
Procedure and scope of review.
List of participants.
iii. Documents to be reviewed.
iv. Timing of SAFOP review.
Equipment Sizing
HV and LV switchgear, transformers, and the associated cables and bus ducts shall be rated for the following.
a. During FEED: Peak load demand plus 25 % design margin.
b. At completion of the project: Peak load demand +10 % minimum.
c. Sizing shall be such as to permit starting of largest motor with the remaining normal load operating
without exceeding the secondary bus voltage drop limits.
d. The maximum rating of transformers should be limited as below.
i.
ii.
HV winding: Rated current not to exceed 2500 A.
LV winding: Rated current not to exceed 4000 A. This will result in the maximum transformer LV winding ratings 2500 kVA at 415 V and 4000 kVA at 690 V.
e. Motor unit transformers shall be capable of withstanding three successive motor starts and a further
two successive starts after a half-hour cooling-off period.
Cable Sizing
6.13.1 Cable Sizing Factors
The following factors shall be considered in cable sizing:
a. Continuous current rating.
b. Short circuit withstand capacity.
c. Voltage drop limits.
d. Earth loop impedance of TNS systems.
e. Harmonic currents when supplying power to non-linear loads
6.13.2 Cable De-rating Factors
a. De-rating factors shall be applied for the following:
i.
Depth of laying.
ii. Ground / ambient temperature.
iii. Soil thermal resistivity.
iv. Grouping of cables with an assumed load factor of 100 %.
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b. A positive tolerance of 10 % may be allowed on the overall rating factor for the following.
i.
Cable sizes are selected as the next larger standard size.
ii. Not all motors are fully loaded at the same time.
iii. Standby units are installed.
c. Where different overall rating factors apply to different parts of a route, the lowest factor shall be
applied.
d. The cable installation and grouping shall be designed such that the overall de-rating factor shall not
be less than 0.40 for direct buried cables and 0.60 for ‘in air’ cables.
6.13.3 Continuous Current Rating
a. Cables shall be sized for continuous duty considering depth of lay, ambient / soil temperature, soil
thermal resistivity and group derating factors.
b. Continuous current ratings of cables shall be based on IEC 60364-5-52 and cable manufacturer’s
data.
c. Continuous current rating shall be based on a maximum conductor operating temperature of 90°C
for XLPE and EPR insulated cables.
d. Cables ‘in air’ ratings shall be based on maximum ambient temperature and the applicable group
derating factors.
e. Cables ‘in ground’ ratings shall be based on:
i.
A design ambient ‘in ground’ temperature of 40°C.
ii. Soil thermal resistivity, g = 2.5°C m/W, unless more accurate data is available from site soil
thermal resistivity measurements.
iii. A maximum buried depth of 1.0 m.
iv. Applicable group de-rating factors shall be applied.
f. Cables shall be sized such that their continuous current rating exceeds the maximum current
associated with peak load plus 10 % contingency.
g. Transformer primary and secondary cables shall be sized for the transformer kVA name plate rating. Where forced cooling is used the cable shall be sized for the force cooled rating of the transformer.
h. GTG cables to HV Switchboard shall be sized for maximum available power of GTGs, i.e. winter
rating at 5 °C.
i. Cables connected to the load equipment shall be sized for the equipment name plate rating.
6.13.4 Short Circuit Withstand Capacity
a. The short circuit withstand capacity of a cable shall be assessed considering energy ‘let-through’ as limited by the protective features of the circuit switching device. The ‘let-through’ current shall be the maximum rms symmetrical breaking current, derived from system short circuit studies.
b. The 0.2 s, 0.5 s and 1.0 s short circuit ratings for fully loaded cables attaining a short-circuit
temperature of 250 °C shall be derived from cable manufacturer’s data.
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c. For short circuit durations < 0.2 s, the 0.2 s rating for the cable shall be adopted to safeguard against in accordance with cable manufacturer’s
to bursting stresses,
possible damage due recommendations.
d. For short circuit durations t > 0.1 < 5 s the following formula shall be adopted:
Cable minimum cross-sectional area, s = (I√t) / k mm2, where:
I = short circuit current in amps.
t = duration of short circuit in seconds.
k = conductor/cable thermal constant.
k = 143 for XLPE and EPR insulated cables based on 90°C initial and 250°C final conductor temperatures.
6.13.5 Cable Size Selection
a. Cable size shall be selected to meet each of the following criterion.
i.
Full load current of the load
ii. Short circuit withstand capability
iii. Voltage drop limitations including at full load
iv. Voltage drop limitations during motor starting
b. Minimum size of HV cables shall be 50 mm2.
c. Maximum cross section of multi core power cables shall be 185 mm² for motor circuits and 240 mm²
for feeder circuits.
d. Larger cables shall be single core and shall be sized based on the following:
i.
ii.
Above ground cables shall be laid in trefoil formation.
For buried cables optimum size should be determined based trefoil or flat formation.
e. The minimum sizes for low voltage wiring shall be:
i.
ii.
2.5 mm2 for control.
2.5 mm2 for indoor and outdoor lighting and 240 V socket outlets.
iii. 4 mm2 for power circuits.
6.13.6 Voltage Drop Limits
a. Cable voltage drops shall be limited to the values as specified in Table 6.3.
b. Voltages at the terminals of skid mounted auxiliaries on packaged equipment, dc fans or oil pumps,
shall be maintained in accordance with the SUPPLIER recommendations.
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Table 6.3 Cable Voltage-drop Voltage
Feeder Description
Voltage Drop
AC Circuits
Power distribution Feeders
Transformer secondary circuits to main switchboard
EDG to essential switchboard
Motor feeders, running
Motor feeders, starting
Motor operated valves
2 %
1 %
2 %
5 % at motor terminals
15 % at motor terminals
5 % at MOV terminal
Lighting and small power
2 % to distribution panels 3 % for branch circuits
HVAC panel feeders
Package control panels
Process heaters
2 %
5 % generally
1 % to heater control panels 4 % control panel to heaters
AC UPS system control panel feeders
3 %
AC UPS distribution circuits
5 % at rated load at end user
DC Circuits
Battery racks to chargers
Distribution panel feeders
1 %
2 %
DC UPS distribution, circuits
5 % at rated load at end user
Seq. No.
i
ii
iii
iv
v
vi
vii
viii
ix
x
xi
xii
xiii
xiv
xv
Earthing System Calculations
The earthing system calculations and study shall include:
a. Calculation of minimum earthing conductor size required to withstand prospective earth fault current levels for the maximum short times as indicated by fault clearance times derived from the protection studies.
b. Calculations to determine minimum earthing conductor and number and size of electrodes required
to achieve resistance to earth values as specified in Section 16.2.
c. Calculations of step, touch, and mesh potentials in accordance with, and satisfying the levels
specified in, IEEE 80 and BS EN 50522.
d. Calculation of earth loop impedance values on solidly earthed systems.
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Power System Protection and Metering
6.15.1
Introduction and Objective
a. Electrical protection shall be provided to meet the following objectives.
i.
Reduce equipment damage.
ii. Reduce power interruptions.
iii.
Improve power quality.
iv.
Improve Safety for all.
b. This section primarily deals with the electrical protection based on current and voltage quantities. For mechanical protection such as pressure relief devices, oil and winding temperature, oil level, and bearing temperature monitoring etc. refer to the relevant equipment specifications.
c. Numbers in bracket show ANSI protection function designations.
6.15.2 Protection Design Principles
a. Electrical protection shall be designed for the best compromise between equipment damage and
service continuity. The following techniques shall be considered.
i.
Fast isolation of the faulted equipment by providing unit protection and instantaneous protection. Other means such as temperature and light detection methods may become necessary to limit the arc flash exposure time.
ii. Protection co-ordination such that only the faulted equipment is isolated.
iii. Minimise the magnitude of the available short circuit current.
iv. Minimise supply interruption by employing auto-transfer and auto-reclosing schemes
v.
In order to isolate the faulted equipment reliably at least one independent means of back-up protection shall be provided.
vi. The protection system shall be cost effective.
6.15.3 General Requirements:
a. The degree of protection applied to each item of equipment shall depend on its rating and criticality
of service.
b. The protection recommended in this section is to be provided as a minimum. Further protection as necessary for the application and manufacturer’s recommendation for each equipment should be considered.
c. Lockout relays shall be used to block the closing of a breaker under faulty conditions. Lockout relays
shall be separate units.
d. CBCT connected earth fault protection (51G) shall detect less than 5 A primary earth fault current.
e. Line differential protection (87L) shall use the fibre optic cable for the communication between relays
installed at two ends.
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f. Primary and back-up protection:
i. Where no unit protection is provided the normal OC and EF protection will act as primary
protection.
ii. Where no redundant relays as back-up are provided, the upstream device protection will act
as back-up protection.
g. Breaker fail protection
i.
Breaker fail protection shall be used where upstream relay must trip faster than the normal back-up co-ordination time delayed operation.
ii. Breaker fail protection shall initiate tripping of breaker which is next upstream to the failed
breaker on source side.
iii. Breaker fail protection shall be included in the protection schemes of the outgoing circuits of
main intake switchboards and main generation switchboards.
h. The protection scheme for cast resin transformers shall include thermal alarm and trip function with
the help of embedded RTD sensors in the low voltage windings.
i. Restricted earth fault protection shall be provided for all HV star windings of the transformers and
LV star windings for ratings 2.5 MVA and above.
j. Differential protection:
i.
ii.
The biased differential protection shall be of the high-speed type.
The relay shall have facility to detect transformer magnetising inrush currents.
iii. Cables and connections between the transformer and the switchgear should be in the
protected zones of the biased differential and restricted earth fault relays.
k. Protection relays: Protection relays shall be micro-processor based, multi-function type,
incorporating a digital display and serial communication facilities.
l. Metering:
i. Metering functions available in multi-functional relays shall be used as far as possible.
ii.
For additional metering requirements, refer to the relevant equipment specification.
iii. Energy metering: Where separate energy meters are provided, they shall meet the following
requirements.
-
Meters shall conform to IEC 62052-11, IEC 62053-21.
-
Meters shall be microprocessor based, programmable with facility for communication with
ECMS via a serial link.
- Unless specified otherwise, CTs for energy metering shall be accuracy class 1 in
accordance with IEC 61869-2.
- Power quality meters (PQM) may be used provided the CT accuracy class stated above
is maintained.
-
Meters shall have an error of no more than 1 minute/month.
-
Meters shall measure voltage, current, kW, kVA, kVAr, kWh, kVArh, power factor, and
frequency.
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m. Protection for lighting and small power feeders shall comply with IET wiring regulations BS 7671
and the UAE Electricity wiring regulations UAE-2014.
6.15.4 Emergency Generators:
a. Protection functions as below shall be provided for the emergency diesel generator.
i.
Voltage restrained OC (51V).
ii. Residual EF (51N/50N).
iii. Neutral CT EF (51G).
iv. Reverse power protection (32) for generators operating in parallel.
v. Undervoltage (27).
vi. Check synch (25) for generators operating in parallel.
6.15.5 Main Generators:
a. Protection functions as below shall be provided for the gas turbine, steam turbine generators and for the generator unit transformers. The generator protection system and trip logic shall broadly be in line with IEEE guidelines IEEE C37.101 and IEEE C37.102.
i. Generator Differential (87G) covering generator windings.
ii. Voltage dependent OC (51V).
iii. Generator stator EF residual overvoltage (59N).
iv. Generator stator EF (51G).
v. Generator rotor EF (64R).
vi. Generator stator EF low frequency injection (64S).
vii. Generator stator EF for high impedance earthed generators, alarm only (59GN/27TH).
viii. Loss of excitation (40G).
ix. Negative sequence (46G).
x. Pole slipping (78).
xi. Generator-transformer overfluxing (24GT).
xii.
Inadvertent energisation (50/27G).
xiii. Undervoltage (27G).
xiv. Under-frequency/Over-frequency (81U/81O).
xv. Generator overvoltage (59G).
xvi. Reverse power (32R).
xvii. Generator circuit breaker fail (50LBB).
xviii. Generator transformer backup impedance (21GT).
xix. Exciter diode failure (58).
xx. Generator transformer differential (87GT) covering generator and unit transformer.
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xxi. Generator transformer HV REF (87N(GT)).
xxii. Generator transformer HV standby earth fault (51G(GT)).
xxiii. Generator transformer OC and EF (51/51N(GT)).
xxiv. Generator transformer directional OC and EF (67/67N(GT)).
xxv. Generator backup impedance (21G).
xxvi. Breaker fail (50BF).
b. Duplicate trip coils shall be provided for the generator circuit breaker and generator transformer
circuit breaker for generators 50 MVA and above.
c. Generators 50 MVA and above shall be protected by:
i.
A minimum of two identical multi-functional relays.
ii. Duplicate trip coils for the generator circuit breaker.
iii. Duplicate coils for the generator transformer circuit breaker.
d.
It is not a requirement to install duplicated current or voltage transformers.
e. Differential protection shall be low impedance (biased) differential type. The use of High Impedance
differential protection scheme is subject to approval by the COMPANY.
6.15.6 Cable Feeder:
a. Protection functions as below shall be provided for cable feeders.
i. OC (51/50).
ii. Residual EF (51N/50N).
iii. CBCT EF (51G).
iv. Cable differential (87L), where necessary.
v.
Load shedding (81U), where required.
6.15.7 Cable Incomer:
a. Protection functions as below shall be provided for cable incomers.
i. OC (51/50) for single, and directional OC (67) for parallel incomers.
ii. Residual EF (51N/50N) for single, and directional OC (67N) for parallel incomers.
iii. EF (51G), for single, and directional EF (67G) for parallel incomers.
iv. Check synch (25) for parallel incomers.
6.15.8 Overhead Line (OHL) Feeder:
a. Protection functions as below shall be provided for OHL feeder.
i. OC (51/50) for single, and directional OC (67) for parallel feeders.
ii. Residual EF (51N/50N) for single, and directional OC (67N) for parallel feeders.
iii. CBCT EF (51G), for single, and directional EF (67G) for parallel feeders.
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iv. Line differential (87), typically for 2 KM to 10 KM lines.
v. Distance (21) for lines greater than 10 KM.
vi. Broken conductor based on I2/I1, normally alarm only.
vii. Auto-reclose relay, where required.
viii. Load shedding (81U), where required.
6.15.9 Overhead Line (OHL) Incomer:
a. Protection functions as below shall be provided for OHL incomers.
i. OC (51/50) for single, and directional OC (67) for parallel incomers.
ii. Residual EF (51N/50N) for single, and directional OC (67N) for parallel incomers.
iii. EF (51G), for single, and directional EF (67G) for parallel incomers.
iv. Line differential (87), typically for 2 KM to 10 KM lines.
v. Check synch (25) for parallel incomers.
6.15.10 HV / LV Transformer Feeder:
a. Protection functions as below shall be provided for transformer incomers.
i. OC (51/50).
ii. Residual EF (51N/50N).
iii. CBCT EF (51G).
b. Fused switch may be used for small transformers up to 500 kVA, and for higher ratings by
COMPANY approval.
c. ASD SUPPLIER should be consulted for the requirement of REF (64).
6.15.11 HV / LV Transformer Incomer:
a. Protection functions as below shall be provided for transformer incomers.
i. OC (51/50) for single, and directional OC (67) for parallel incomers.
ii. Residual EF (51N/50N) for single, and directional OC (67N) for parallel incomers.
iii. EF (51G), for single, and directional EF (67G) for parallel incomers.
iv. REF (64), typically for transformers 2500 kVA and above. The relay shall trip the upstream transformer feeder breaker and the tripling of the feeder breaker will trip the incomer breaker.
v. Check synch (25) for parallel incomers.
b.
In remote isolated locations, it is preferred built-in protection in the ACB/MCCB releases, requiring no external tripping supply.
c. Load break fault make fused switches may be used for small transformers up to 500 kVA, and for
higher ratings by COMPANY approval.
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6.15.12 HV / HV Transformer Feeder:
a. Protection functions as below shall be provided for transformer feeders.
i. OC (51/50) for single, and directional OC (67) for parallel feeders.
ii. Residual EF (51N/50N) for single, and directional OC (67N) for parallel feeders.
iii. CBCT EF (51G) for single, and directional EF (67G) for parallel feeders.
iv. Transformer differential (87T) for transformers 5 MVA and above.
b.
Instead of circuit breakers, fuse contactors can be used for transformers up to 1600 kVA. Protection against fuse failure shall be included.
c. The differential protection for auto transformers shall be high impedance type using nine CT scheme,
3 CTs each in primary, secondary, and star end of the transformer windings.
d. Transformer differential protection is not necessary for ASD feeders.
e. ASD SUPPLIER should be consulted for the requirement of REF (64).
6.15.13 HV / HV Transformer Incomer:
a. Protection functions as below shall be provided for transformer incomers.
i. OC (51/50) for single, and directional OC (67) for parallel incomers.
ii. Residual EF (51N/50N) for single, and directional OC (67N) for parallel incomers.
iii. EF (51G) for single, and directional EF (67G) for parallel incomers.
iv. REF (87N or 64): The relay shall trip the upstream transformer feeder breaker and the tripling
of the feeder breaker will trip the incomer breaker.
v. Check synch (25) for parallel incomers.
b.
In remote isolated locations, it is preferred to have built-in protection in the ACB/MCCB releases, requiring no external tripping supply.
c. Load break fault make switch can be used for small transformers say less than 500 kVA.
6.15.14 Busbar Protection:
a. The OC and EF relays of the incoming or upstream circuits and in the bus section normally provide
the necessary protection of the busbar.
b. Unless otherwise specified bus bar differential protection shall be of low impedance type.
c. A bus zone protection scheme shall be considered as below.
i.
If a busbar fault cannot be cleared within 1 s, or a faster protection method is required for system stability and to limit downstream arc flash energy.
ii. Outdoor HV busbar, switchgear, and associated components shall also be protected by bus
zone protection.
iii. Bus bar differential protection is not normally necessary for voltages less than 69 kV.
iv. For voltages below 69 kV the busbar of gas insulated switchgear constitutes virtually a fault-
free zone and does not require any bus zone protection.
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6.15.15 Motor Feeder:
a. Motor protection relay or IED device consisting of the following functions shall be provided.
i. OC (50/51).
ii. CBCT EF (50G) for motors 30 kW and above.
iii. Neutral voltage EF (59N).
iv. Thermal overload (49).
v. Negative sequence (46).
vi. Locked rotor (51LR).
vii. Stall protection during running (49S) for all HV motors and LV motors where necessary.
viii. Excessive number of starts (66) for all HV motors and LV motors where necessary.
ix.
Incomplete sequence (48).
x. Restart inhibit.
xi. Undervoltage (27).
xii. Load shedding (81U), where required.
xiii. Undercurrent protection (37), where required such as submersible motors.
b.
In addition, the following shall be provided for motor unit transformers and line protection:
i.
ii.
Transformer differential (87T).
Transformer OC and EF (50/50N, 51/51N, 51G).
iii. Transformer/Motor differential (87T/M), where necessary.
iv. HV or LV side line differential (87L), where required.
v. Motor circuit breaker shall be included on motor side of the unit transformer.
vi. The differential protection scheme shall be ‘low impedance (biased)’ type.
c. The following additional protection shall be provided for the synchronous motors:
i.
Loss of excitation (40).
ii. Rotor EF (64R).
iii. Diode failure (58).
iv. Out of step (78).
v. Over voltage (59).
d. Separate motor differential relay (87M) shall be provided for motors 3.5 MW and above.
e. Earth fault protection should be achieved with phase CT if motor differential protection is used.
f. Motor protection for fire safety related motors shall conform to NFPA 20 and NFPA 70 requirements.
g. Where necessary, motor stall protection initiated from motor shaft speed-sensing switch shall be
applied for high inertia motors where run-up time is greater than safe stall time.
h. Undercurrent protection (37) shall be provided for submersible motors where the fluid being pumped
also acts a cooling medium.
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i. For ASD fed motors the protection relay functions shall be available in the ASD controller module.
j. Power factor correction capacitors at motor terminals shall be protected by motor switching device
and motor protection relay.
6.15.16 Capacitor Feeder:
a. Protection of capacitor banks shall comply with IEC 60871 and IEEE C37.99 and the manufacturer
recommendation.
b. Protection functions as below shall be provided for cable feeders.
i. OC (51/50).
ii. Residual EF (51N/50N).
iii. CBCT EF (51G).
iv. Overload (49).
v. Unbalance (46).
vi. Undercurrent protection (37).
vii. Overvoltage (59).
6.15.17 LV Power Feeder
LV power feeders shall be protected by integral protection functions as below of the switching devices ACBs and MCCBs.
a. Short circuit protection.
b. Overload protection.
c. Earth fault protection for 63 A feeders and above using CBCT.
d. Shunt trip coil if specified.
DISTRIBUTION SYSTEM EQUIPMENT
Transformers
a. Power and distribution transformers shall comply with Specification AGES-SP-02-001.
b. Transformer ratings and impedance voltages shall conform to IEC 60076-5 Table 1. Impedance voltages for transformers rated above 25000 kVA shall be determined by considering short circuit limitation requirement and the voltage regulation considerations.
c. Unless otherwise specified, liquid-immersed transformers up to 2000 kVA shall be hermetically sealed type. Transformers rated above 2000 kVA and up to 3150 kVA may be either hermetically sealed or of the conservator type. Unless otherwise specified in the data sheet liquid-immersed transformers above 3150 kVA shall be conservator type.
d. Unless otherwise specified, liquid immersed transformers rated greater than 10 MVA shall be
provided with two stages of forced cooling, for example KNAN / KNAF1 / KNAF2.
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e. Transformers with secondary voltage up to 11 kV shall have Dyn11 vector group unless otherwise approved by COMPANY. Dzn0 vector group shall be used when It is necessary to introduce phase shift to align vectors with Dyn11 transformers.
f. Onshore transformer insulating fluid shall be either:
i. Mineral oil.
ii. Synthetic or natural ester with fire point >300°C in conformance with IEC 61039 if there is a
fire risk to personnel.
g. Offshore transformer insulating oil shall be synthetic or natural ester high fire point fluid.
h. Silicon based high fire point oils shall not be permitted for onshore or offshore facilities.
i. For transformer with full load current rating of 1250 A and above, the low voltage connections may
be either:
i.
Cast resin insulated solid bus ducts.
ii. Single core cables.
j. OLTC shall be provided for the grid supply transformers. In addition, OLTC shall be provided for
transformers where it becomes necessary to satisfy the voltage regulation requirements.
k. OLTC time delays shall be set to exceed the runup time of the largest motor downstream of the transformer to avoid tap changer hunting during starting which in turn could cause unnecessary voltage swings.
High Voltage Switchgear
a. HV switchgear shall comply with the following specifications:
i.
AGES-SP-02-003 for air insulated HV switchgear.
ii. AGES-SP-02-005 for GIS switchgear.
b. HV switchgear shall be type tested metal enclosed ‘factory-built assembly’ with vacuum or SF6
circuit breakers.
c. HV switchgear should normally have 2x100 % rated bus sections.
d. HV switchgear shall have rated short circuit withstand duration of a minimum of 1 s.
e. Unless otherwise specified circuit breaker ratings shall be based on natural cooling, limited to a
maximum of 2500 A.
f. Circuit breakers in the switchgear assembly shall be installed in single tier formation.
g. Motor feeder units at 6.6 kV and 3.3 kV may be installed in double tier formation.
h. At least one motor where applicable and one transformer fully equipped cubicle shall be provided
as spare on each bus section.
i. Space shall be provided to add a further 2 circuit breaker columns, one at each bus section end.
j. Each breaker shall have a key-operated Local/Off/Remote selector switch, key removable only in the remote position, installed in the LV compartment. The following functions shall be included:
i.
Local:
- Breaker, isolator, earthing switch can be operated locally only for distribution feeders.
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- Breaker, isolator, earthing switch can be operated locally in test position only.
ii. Off: breaker, isolator and earthing switch cannot be operated electrically.
iii. Remote: breaker and isolator can only be operated from the ECMS.
k. Breaker/isolator/earthing switch ON/OFF control switches separate from bay control unit shall be
provided.
l.
If applicable automatic transfer systems shall be provided as described in Section 6.9.3.
Low Voltage Switchgear
a. LV switchgear and controlgear shall be provided in accordance with ADNOC specification AGES-
SP-02-006.
b. LV Switchgear assemblies shall be type tested, metal-enclosed withdrawable type. Partitions or barriers shall be provided in the assemblies to obtain Form 4b separation of compartments in accordance with IEC 61439-2.
c. LV Switchgear assemblies shall be air naturally cooled.
d. The switchgear assembly shall be designed, constructed and verification tested for “Internal Arc Containment” in accordance with the requirements of IEC TR 61641. Unless otherwise specified the Arcing Class shall be Class C. Where Arcing Class B and C assemblies are defined, the assembly shall withstand internal arcing for 0.3 s.
e. The coordination between contactor and protective device shall comply with Type “2” as specified in IEC 60947-4-1. MCCBs shall be used as protective device for motor starters and contactor feeders.
f. For three phase circuits where circuit includes separate neutral conductor, four pole circuit breakers
with switched neutral shall be provided.
g. Microprocessor-based multi-functional protection relays shall be used for distribution feeders. Protection relays for motors and static load feeders shall be microprocessor based programmable type motor/feeder manager relay with data communication facilities to ECMS and ICSS.
h. Automatic transfer systems shall be provided as described in Section 6.9.3.
Capacitors
a. LV capacitors shall be of the self-healing type complying with IEC 60831, and can be of either single
phase or three phase unit construction. HV capacitors shall comply with IEC 60871.
b. HV capacitor banks shall be installed outdoors in a suitable containerised metallic enclosure with
necessary door interlocks.
c. Capacitors shall be of the low loss, metal enclosed, hermetically sealed type.
d. All capacitor units shall have individually fused elements; if this is not feasible for certain types of
LV capacitor, internal overpressure disconnectors shall be provided.
e.
Inrush Current: Where necessary, the capacitor inrush current shall be limited by:
i.
Contactors with pre charging resistors.
ii. Serial air coils.
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f. Discharge resistors shall be provided to reduce the voltage to 50 V within 60 s for low voltage and
within 5 minutes for high voltage capacitors.
g. An interlock system shall be provided for all automatically controlled capacitor banks to prevent re-
energisation, when the residual voltage is above 10 % Un.
h. Unless otherwise specified, the capacitor stages shall be switched automatically. Time-delay device shall be used for switching on and off the capacitor stages to prevent unnecessary operation of the controller for momentary signal changes.
Thyristor Control Panels (TCP)
a. Where required by process requirements thyristor control panels shall be provided to supply and control power to the process heaters. Thyristor control panels shall comply with the following ADNOC specifications.
i.
DGS-EE-012 ‘Process Heaters’.
ii. AGES-SP-02-006 ‘Low Voltage Switchgear and Controlgear Specification’.
iii. Where unit
transformer
is provided,
it shall comply with ADNOC specification
AGES-SP-02-001.
b. Power Supply
i.
Incoming power supply shall be from a LV switchgear or from HV switchgear via a unit transformer for process heaters with high power demand.
ii. Power requirements shall include a positive 10 % performance margin when operating at
nominal voltage and frequency.
c. Thyristor Units
i.
Number of stages and sequence of control shall be selected based on the process and turn- down conditions.
ii. Stages shall be controlled either by a step on / off control or a thyristor controller or a
combination of step control and thyristor-controlled stages.
iii. The thyristor stack shall comprise pair of thyristors, in either:
-
Two of the three phases (2 leg control) for delta and floating star configured loads.
In all three of the phases (3 leg control) for four wire star configured loads.
iv. The power of each heater shall be controlled by thyristors fired according to the zero crossover
mode with a controlled output power range down to 3 %.
v. Burst firing control shall not be utilised for large loads fed from relatively weak supply systems
susceptible to electrical disturbances and shall be subject to COMPANY approval.
vi. Phase angle control shall not be utilised.
vii.
If parallel operation of thyristors is necessary for large loads, current balancing shall be applied.
viii. Power semiconductors shall be sized such that the actual current shall be less than 70 % of
the rated continuous current of the device.
d. Thyristor Protection shall include the following:
i. Over-current protection by means of ultra rapid fuses and voltage transient suppressers.
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ii. Over-temperature protection.
iii. Where advised by SUPPLIER, di/dt limiting reactors and dv/dt protection networks shall be
provided.
iv. Over-voltage protection shall be provided to prevent damage to any instruments from faults in
the thyristor trigger circuit.
v. A ramp control unit shall be provided to prevent the heater being switched directly to full load.
SUBSTATION BUILDING
Purpose
The purpose of this section is to outline the basic requirements to enable design, sizing, layout, and construction of the substation building including ECMS and ICSS equipment rooms and the transformer bay area. CONTRACTOR shall develop detailed building specification in accordance with these minimum requirements utilising good, modern engineering practices.
Design Objectives
The building design shall meet the following objectives.
a. Safe operation.
b. Minimise site construction and commissioning.
c. Minimise plot space.
d. Allow access for maintainability of components.
Substation Equipment
The main elements of the electrical and control equipment to be accommodated in the substation building are as follows:
a. High voltage switchgear.
b. Low voltage switchgear.
c. HV and LV ASDs.
d. Transformers: Liquid filled transformers and the associated NERs shall be located outdoors
adjacent to the substation building.
e. Transformer OLTC control panel.
f. AC and DC UPSs and the associated battery banks.
g. Mechanical package UCPs.
h. Thyristor control panels.
i. Distribution boards: Distribution boards shall be generally surface mounted.
j. Capacitor banks.
k. ECMS and ICSS equipment:
i.
I/O marshalling panels.
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ii.
ICSS and ECMS cabinets and equipment.
iii.
ICSS and ECMS operator consoles.
iv.
ICSS and ECMS engineering workstations.
v.
ICSS and ECMS network cabinets.
vi.
Interposing relay interface cabinet.
l. Other Miscellaneous Equipment:
i.
ii.
Data network (IT backbone) cabinets.
Telecommunications equipment and cabinets.
iii. Metering system cabinet.
iv. Emergency generator control panel.
v.
Fire protection and detection panels.
vi. Substation VESDA panel.
vii. VESDA panels.
viii. HVAC equipment.
ix.
Indoor cathodic protection rectifier units.
x. Operator accessories such as desk, chairs, first aid box, safety tools etc.
Substation Sizing and Layout
8.4.1
Substation Rooms and Areas.
The substation building will typically consist of the following rooms and areas.
a. Central control room
b. Control equipment room.
c. ECMS equipment room (if necessary).
d. Electrical equipment room.
e. GIS switchgear room.
f. ASD room (if necessary).
g. Battery room.
h. HVAC room.
i. Transformer bays (outdoor).
8.4.2
Central Control Room
The central control room shall house the ICSS and ECMS engineering workstations. Central control room may or may not be part of the substation building.
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8.4.3
Control Equipment Room
a. Control equipment room shall house ICSS cabinets, marshalling racks and other monitoring, automation and telecoms equipment to be installed, including spare capacity as per AGES-PH-04- 001 Automation and Instrumentation Design Philosophy.
b. There shall be a fully accessible nominal 900 mm deep proprietary computer floor to ICSS
equipment room.
c. Depending on the project layout requirements the ICSS equipment can be housed in a separate
building adjacent to the substation.
8.4.4
ECMS Equipment Room
a. ECMS equipment will house the ECMS cabinets and operator consoles.
b. Where separate ECMS room is not provided, this equipment shall be housed in electrical equipment
room.
8.4.5
Electrical Equipment Room
a. Electrical equipment room shall accommodate LV and HV air insulated switchgear, UPSs, thyristor control panels, distribution boards, electrical control panels, and HV and LV ASDs unless a dedicated room is necessary for large ASD.
b. Space shall be allocated for testing of LV MCC control units, HV/LV circuit breaker trolleys, cabinets
for drawing / documents, notice boards, lockout box for padlocks and keys for isolators etc.
c. Arc flash zones around equipment shall be calculated and marked on the floor of the substation. Notices explaining the level of personal protective equipment required in the area shall be posted at the entrance to the substation.
d. Suitably rated rubber mats shall be provided in front of panels for their entire length.
8.4.6
GIS Switchgear Room:
a. Detection and monitoring of SF6 release in the room shall be provided if required by an
environmental assessment.
b. Warning plates shall be provided outside the building, instructing personnel not to enter without
personal protection when the alarm display is ‘on’.
c. Auxiliary equipment related to the GIS, e.g. protection and control panels, shall be installed in a
separate lockable room.
8.4.7
ASD Room
a. Manufacturers’ installation guidelines must be followed in determining the ASD room layout and
maintenance access.
b. Due consideration shall be given to the following in laying out the area near the drives.
i.
Enclosure door swing and clearance.
ii. Clearance for component removal, maintenance, and repair.
iii. Clearance for lifting equipment, trucks, and ramps to insert or remove power modules.
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8.4.8
Battery Room
a. Batteries of UPS systems shall be installed in a dedicated battery room.
b.
Independent direct access from outside the substation building shall be provided to the battery room.
c. Battery room shall be classified using EI 15 (Model Code of Safe Practice, Part 15: Area
classification for installations handling flammable fluids) [PSR].
d. Ultra-low maintenance type NiCad batteries with design life greater than 20 years shall be used.
e. The batteries shall be vertically mounted on open racks.
f. The electrical equipment in the battery room shall be suitable for the area classification.
g. H2 detectors shall be installed in battery rooms with alarm in accordance with AGES-PH-03-002,
‘Fire and Gas Detection and Fire Protection Philosophy’.
h. Self-contained emergency eyewash station on a wall near battery rack shall be provided in the
battery room.
8.4.9
HVAC Room
HVAC room shall house the HVAC equipment together with HVAC MCC and control panel. Independent direct access from outside shall be provided to the HVAC room.
Transformer Bays
8.5.1
Transformer Layout
a. Liquid filled transformers shall be located outdoors. Transformer separation from other transformers and building walls shall be provided as per Tables 3 and 4 IEC 61936-1. If IEC 61936-1 separation distances cannot be maintained fire walls shall be provided between adjacent transformer equipment and buildings.
b. Each bay shall have wire mesh fencing with lockable gates for the following:
i.
Equipment handling.
ii. Maintenance personnel entry gates, minimum 1000 mm wide.
c. Minimum 1000 mm clearances shall be provided all around the transformer and any neutral earthing
resistor bank. NER’s shall be located adjacent to the associated transformer.
d. Transformers shall be supported on foundations designed in accordance with AGES-SP-01-003
‘Structural Design Basis’.
e. Transformers fitted with liquid immersed OLTC, shall be provided clearance above to allow un-
tanking of the OLTC.
f. A removable roof shall be provided over each transformer to protect it from direct sun and rain.
8.5.2
Transformer Terminal Boxes
a. Transformer terminal boxes shall be oriented:
i.
So that terminal boxes of adjacent transformers do not face each other.
ii. Away from areas where personnel are normally present.
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b. Positioning of transformer shall minimise cable route crossings.
c. Transformer bay layout shall ensure that cooling is not impeded by roof cover or firewalls.
8.5.3
Transformers Liquid Collection System
a. Transformers shall be provided with a liquid collection system.
b. Onshore facility transformer bund shall be sized as follows:
i.
ii.
100 % of the transformer fluid and fire water capacity if dedicated to a single transformer.
150 % of a single transformer fluid and fire water capacity if shared with another transformer.
c. Onshore facility transformer bund shall be provided with:
i.
Facility for pumping out collected liquid/water.
ii. Connection to the storm water drains system through a liquid/water separator, as determined
by the COMPANY in wet climate.
d. Offshore liquid filled transformers shall be provided with a receiving tank underneath the
transformers that is connected to the closed drain system complete with dosing facility.
e. Offshore bund receiving tank:
i. May be common to several transformers.
ii. Shall not be less than 100 % of the volume of liquid of the transformer, or of the largest
transformer in case of a common tank.
f.
g.
If transformer liquid fire point is <300 °C and oil volume is > 1000 litres, automatic fire suppression shall be provided.
In case of several liquid filled transformers installation in adjacent bays, the isolation shall be limited to the single affected transformer and its accessories at the zone.
8.5.4
Dry-Type Transformers
a. Dry-type transformer shall be provided with either:
i.
Integral metallic enclosure.
ii. An earthed, demountable metal barrier or fence of at least 1.8 m high on all sides.
b. The barrier/fence shall have warning signs and a lockable personnel access gate with 1 m clearance from the extremities of the transformer and its cable terminations to allow safe access for visual inspection of the live transformer.
c. Automatically operated total flooding firefighting system shall be provided for indoor transformers.
8.5.5
Transformers in Hazardous Areas [PSR]
a.
If locating outdoor transformers in a hazardous area is not avoidable, transformers:
i. May be located in a Zone 2 area with COMPANY approval.
ii. Shall be IECEx certified or equivalent for minimum Zone 2, IIB, T3.
b. Transformers shall not be located in a Zone 1 area.
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c.
In case certified transformers are not available, pressurised equipment rooms shall be considered conforming to the requirements of IEC 60079-13.
8.5.6
Future Extension:
Substation equipment layout shall be arranged in a manner that allows at least one side extension of the substation building for future expansion.
Equipment Access and Working Clearances
a. Equipment shall be installed to provide the minimum safe working clearance for maintenance, operation, access and removal for repair and replacement. The equipment access and working clearances shall be provided as a minimum as given in Table 8.1. The working clearances shall also comply with the National safety codes and standards, local regulations, IEC 61936-1, IEC 62485-2 and the other applicable IEC standards, and manufacturer’s recommendations.
b. Height of the building shall be minimum 3 m clear from floor to ceiling, and may be increased as required. As a minimum the height of the underside of the building roof or to the lowest obstruction such as light fittings or HVAC ducting shall be such as to permit circuit breaker handling trolleys to be moved into position and lift circuit breakers out for maintenance.
Table 8.1 Working Clearances
Equipment
Working Clearance
In front of 220/132 kV GIS switchgear
Rear side of 220/132 kV GIS switchgear
Between 220 and 132 kV GIS switchgear ends to wall after keeping space for extension
In front of HV switchgear
In front of LV switchgear
Between HV and LV switchgear
Between two rows of LV switchgear
Rear side of HV and LV switchgear (requiring rear cable access)
Rear side of HV and LV switchgear (for front access and front connection only)
Panels for which back access is not required (if installed close to wall)
Between equipment ends and equipment ends and wall (after keeping a provision for extension)
Around transformers
Between transformer and building wall
From highest point of equipment to underside of lowest roof beam
Between back of UPS and wall (if back access required)
Space around battery banks
3000 mm
2500 mm
3000 mm
2500 mm
1500 mm
2500 mm
1500 mm
1000 mm
100 mm
100 mm
1000 mm
1000 mm
750 mm
500 mm
1000 mm
1000 mm
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Room Access and Escape Routes [PSR]
a. An air lock system shall be provided for personnel access to the substation building.
b. Primary access routes shall have a clear width of 1500 mm and height of 2200 mm. Width may be
locally restricted to not less than 1200 mm.
c. Secondary access routes shall have a clear width of 1000 mm and height of 2100 mm. Width may
be locally restricted to not less than 800 mm.
d. HVAC and switchgear rooms shall have equipment and escape doors direct to the external area. Travel distance to exits shall not exceed 25 m. Safety lighting for means of escape shall be with integral battery for 90 minutes operation.
e. The battery room shall not be used as access to another space.
f. Substation building shall have at least two ’opposite end’ accesses. Consideration shall be given to
potential hazards in locating the building access doors.
g. All doors in the substation shall be fitted with panic bar.
Building Location
a. The location of the substation building shall be selected based on guidance and requirements stated in AGES-GL-03-001 ‘Layout and Separation Distances Guidelines’. This requires inherent safety to be considered so that passive and active protection measures may be avoided.
b. Where inherent safety cannot be assured by separation from potential leak sources, there is a requirement to carry out appropriate hazard identification and assessment and so that the required protective measures can be provided,
c. The building shall preferably be located close to electrical load centre.
d. Unless otherwise specified, the building shall be classified as ‘Not Occupied’.
e. Consideration shall be given to the prevailing wind directions for release of toxic gas and/or
explosions.
Building Design
8.9.1
Design and Construction
a. The design of the building shall comply with the design engineering codes, specifications and standards listed in AGES-SP-01-003 ‘Structural Design Basis’. Design shall consider the full operating load as well as temporary loading conditions such as erection, transportation, lifting, etc.
b. Building shall be single storey.
8.9.2
Building Blast Rating [PSR]
a. Substation shall be designed to resist the blast loading (peak side-on overpressure) as per the
process risk tool (PRT) and AGES-SP-01-003.
b. No external windows shall be provided. All external doors shall be outward opening and remain ’Operable’ after a blast event. Effect of underside blast shall be considered in the design of foundations and anchorage.
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8.9.3
Fire protection [PSR]
a. The fire walls for buildings shall comply with the requirements of NFPA 101. The construction and fabrication of building partitions and walls shall be manufactured from non-combustible materials. Doors and ducting etc., which are installed within the firewall, must be of a standard at least equal to that of the wall. All penetrations through the firewalls shall be fitted with fire rated seals to ensure the overall rating of the firewall is not impaired.
b. Fire rated walls shall be A60 minimum.
c. Fire rated walls between the building and the transformer bays shall be rated for four hours.
d. Fire rated doors shall be self-closing and rated for 60 minutes minimum.
e. Ceiling voids shall be segregated every 20 m with a maximum area of 300 mm2.
f. Carbon dioxide extinguishers shall be provided in each room of the substation for smouldering fires
associated with electrical and instrument equipment.
8.9.4
Cable Basement
a. The cable basement shall be open to provide natural through ventilation with a galvanised mesh
screen and access gates located between columns.
b. To allow cable installation, the underside of the substation floor beam shall be minimum 1800 mm
above grade level.
c. Underground cables will enter the substation below ground and then rise vertically through floor
penetrations with cable transits to directly access equipment above.
d. Above ground cables will enter through the cable basement mesh screen at a suitable height.
e. Where necessary, cables shall be installed on horizontal ladder racks within the cable basement.
f. Cable entry to the electrical equipment shall use one of the following methods.
i.
Cable boxes with removable plates shall be provided between the floor beams to facilitate bottom cable entry into the electrical equipment.
ii. Cables shall pass through the substation floor via cable transits and then glanded to the
electrical equipment gland plates.
8.9.5
Fire and Gas Detection
Fire and Gas detection requirements for the substation building shall be in accordance with AGES-PH- 03-002 ‘Fire and Gas Detection and Fire Protection System Philosophy’.
8.9.6
Mechanical Handling
A mechanical handling strategy shall be developed to ensure that all provisions required for the installation, operation, maintenance, repair, removal, and replacement of the equipment are included in the design and layout of the substation building indoor and outdoor areas.
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Substation Building HVAC
8.10.1 HVAC Design
a. HVAC systems shall be incorporated in the building as required to provide air conditioning, ventilation, heating, pressurisation, cooling and humidity control for the safety and comfort of personnel, and for the protection of the equipment.
b. Specific design objectives include:
i. Maintaining environment conditions, temperature and humidity, appropriate to the operating
requirements.
ii. Maintaining pressurisation to prevent dust ingress.
iii. Filtration of dust and chemical contaminants through chemical and carbon activated filters.
iv. The isolation of individual areas and control of ventilation in emergency conditions, through interface with the shutdown logic of the fire and gas detection and alarm safety systems.
v. Reduce onsite work as much as possible, except the final hook-up.
vi. To prevent smoke spreading and keep enclosed escape ways free of smoke in case of fire.
vii. To prevent ingress of potentially explosive/toxic gas-air mixtures into non-hazardous areas,
electrical switch rooms and equipment rooms.
viii. HVAC systems shall have 100 % redundancy.
c. The HVAC system shall consist of a centralised air handling plant supplying fresh and recirculated air to and from the building enclosed areas. The recirculation system shall reduce the heating and cooling loads by returning air from clean rooms back to the supply air handling unit. The supply air system shall also provide nominal pressurisation to the building to prevent ingress of airborne contaminants.
d. Dedicated extract systems shall be installed to discharge unwanted room air from designated areas direct to atmosphere. Upon gas or smoke detection at the HVAC fresh air intake a signal will be sent to the ICSS fire and gas system to initiate shutdown of the complete ventilation system.
e. The HVAC system shall be interfaced with the ICSS to provide status, fault, alarm, and trip alarms. All fire and smoke damper solenoids shall be hard wired back to the ICSS fire and gas system.
8.10.2
Indoor Conditions
Unless otherwise specified in basic engineering design data BEDD document, the HVAC design shall meet the requirements in each area as given in Table 8.2. This is based on industry standards, ASHRAE and CIBSE Guides and shall form the basis for the HVAC System design.
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Table 8.2 HVAC Design Requirements
Area Description
Battery room
Control equipment room
HVAC plant room
Electrical switchgear room
ASD room
Design Dry Bulb Temp. ºC
18 - 22
19 - 25
5 - 30
5 - 30
5 - 30
Relative Humidity %
40 – 60
40 - 60
Not Controlled
40 - 60
40 - 60
Minimum Air Changes per Hour
Maximum Sound Pressure Level dBA
10
N/A
N/A
N/A
N/A
60
60
70
60
75
8.10.3 Outdoor Conditions
The HVAC system shall be designed for the outdoor conditions as stated in Section 5.6 of this design guide.
8.10.4 Blast Considerations [PSR]
Where blast conditions apply all air intakes and exhaust openings shall incorporate suitable arrangements of blast dampers. Equipment which has to be located externally shall be protected by blast resistant barriers.
8.10.5
Toxic Gas Release Protection [PSR]
a. The substation building shall be positively pressurised. Gas detectors in the HVAC air inlet will automatically close the inlet dampers and initiate a local evacuation alarm. All indoor areas of the substation building will be positively pressurised. The design shall ensure inlet closure before toxic gas enters the building if immediate evacuation is not practicable.
b. Air lock shall be provided for external personnel entrances to the building. Gastight self-closing doors shall be used for battery room. Air locks shall not be provided at equipment access doors.
8.10.6 Air Intakes and Discharges
Intakes and discharges shall be separated to prevent cross contamination by recirculation. In-duct smoke and gas detectors shall be provided at all air intakes.
8.10.7 Battery Room Ventilation
a. Air shall be extracted from the battery room of the building via a dedicated extract system.
b. The extract systems shall discharge the air directly to atmosphere. The exhaust fan system shall
be a dual system with 2x100 % fans.
c. Boost charge shall be inhibited in case of failure of both fans.
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8.10.8 Power Supply
a. HVAC systems shall be powered from the main LV switchboard using two 100 % feeders, one from
the main power supply and the other from the standby/essential services power supply.
b. A dedicated HVAC MCC and control panel shall be provided by the HVAC CONTRACTOR.
Substation Lighting and Small Power
a. Lighting and small power shall be provided generally in accordance with Section 15 ‘Lighting and
Small Power’.
b. Lighting shall be provided in cable basement and transformer bay.
c. Two 125 A 415 V, 3 phase 4 wire, 5-pin industrial switch socket outlets complete with plugs shall be provided outside each substation, one at each end, fed from separate bus bars of the switchgear.
Earthing and Lightning Protection
Earthing and Lightning Protection shall be provided generally in accordance with Section 16 ‘Earthing and Lightning Protection’.
Additional Requirements for Packaged Substation
8.13.1 Packaged Substation Size
a.
The size of the substation modules shall be determined by the size of the electrical and instrumentation equipment being accommodated plus an allowance for design development growth.
b. The most optimum sizes shall be determined based on the following.
i.
Practicable envelope sizes and weight limits for transportation by sea and land, installation, and lifting.
ii. Substation “footprint” limitations due to limited space available on plot plan.
iii. Consideration of blast loading.
8.13.2 Shipping and Installation Requirements:
The packaged substation shall be designed to have the required strength and rigidity to resist the forces/loads imposed during transportation and installation. Internal equipment shall be constrained by providing suitable bracing to withstand these forces.
8.13.3 Commissioning
a.
In order to minimise work on site the substation building, and equipment shall be commissioned as far as practicable in the substation fabrication yard. This shall include but not be limited to power up and full combined functional testing of the following equipment and services.
i.
ii.
HVAC system including pressurisation testing.
Lighting and small power.
iii. Fire detection and protection systems.
iv. UPS.
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v.
ICSS.
vi. Telecommunications including CCTV.
vii. ECMS.
viii. Electrical switchgear including distribution boards.
ix. HV and LV ASDs.
b. Where shipping splits are required, the design of the substation shall take account of the dismantling of the substation for transportation to site in such a way as to minimise the reconnect and therefore re- commissioning at site.
OVERHEAD LINES
General
a. The design of overhead lines shall consider Transco and Abu Dhabi local utility practice in
determining the type of construction and the selection of materials.
b. The overhead lines shall be designed by a specialist contractor approved by COMPANY.
c. Depending on the route length, route terrain, system voltage, and current rating, the specialist contractor shall propose most optimum solution taking into consideration the details in this design guide.
d. For standard details refer to ADNOC document LATER.
Type of Construction
a. Circuit construction shall be one of the following:
i.
Double circuit main line with two conductors per phase.
ii. Double circuit feeder line with one conductor per phase.
iii. Single circuit lines of with one conductor per phase.
b. Where possible, overhead lines shall be used to carry communication cables.
Supports
a. The supports shall be lattice steel towers. Wood or concrete poles may be used, if more economical
and meet the design life and approved by the COMPANY.
b. Supports shall be designed to take account of the mechanical forces that will be encountered in
operation and incorporate the specified factors of safety.
c. Factors of safety:
i.
Each standard type of tower shall be designed so that no failure or permanent distortion shall occur in any part of the tower when tested with applied forces equivalent to 2.5 times the maximum working load.
ii. Under broken wire conditions, the factor of safety shall not be less than 1.5.
d. The towers shall preferably be standard pre-designed.
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e. CONTRACTOR shall provide type test certificates. A certificate of a successful loading test shall
also be provided.
f. Towers shall be suitable for the angles of deviation and for the breakage of conductor.
g.
It shall be possible to increase the tower height by using standard extensions.
h. All steel components, including fasteners, shall comply with relevant international or national
standard and be hot-dip galvanised after fabrication in accordance with ISO 1461.
i. Painting: The coating system shall consist of the following as a minimum.
i. One coat of epoxy primer (zinc-rich or red oxide) 40 micron.
ii. One coat of high-build epoxy (polyamide cured) 120 micron.
iii. One coat of re-coatable urethane finish in the required colour 40 micron.
Insulators
a. Unless otherwise approved, insulators shall be silicone rubber composite type.
b. Composite insulators shall be constructed using a central member of solid high-density axially
aligned glass-fibre-reinforced pultruded epoxy resin rod.
c. The sheds shall be moulded from silicon rubber, which is stabilised against the effects of ultraviolet and other solar radiation and against the effects of airborne contaminants described in environmental conditions.
d.
Insulators shall be with a minimum creepage of 40 mm/kV.
e. The composite insulators shall be of sufficient length to provide the required electrical performance
in one single unit.
f. The composite insulator shall comply with IEC 61109, IEC 61466-1 and IEC 61466-2.
Conductors
a. Conductors shall be all aluminium alloy (AAAC) unless otherwise approved by COMPANY.
b. Conductors shall comply with EN 50182 and IEC 61089.
c. Conductor sizing: The required conductor sizes shall be determined considering the following:
i.
ii.
Site environmental conditions.
Thermal short circuit withstand requirement of both phase and earth conductors.
iii. Maximum permissible voltage drop.
iv. Maximum continuous load current.
v. Conductor size to be advised in accordance with IEC 61089.
d. Joints in sections shall be kept to an absolute minimum; no joint shall be closer than 3 m to a point
of support.
e. No tension joints shall be used unless approved by the COMPANY.
f. Where used the composite fibre optic and aluminium clad steel earth wires Optical Ground wire
(OPGW) shall comply with IEC 60794-4-10.
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g. Type tests and routine tests on conductors shall be carried out in accordance with the IEC 61089.
Lightning Arresters
a. Lightning arresters with counters complying with IEC 60099-1 shall be installed at every cable
termination and at every equipment connection point, e.g. transformer tee-off.
b. The current rating of the lightning arresters shall be selected to suit the system short circuit rating.
c. The voltage rating shall be determined as part of the insulation co-ordination, in accordance with
IEC 60071.
d. Lightning arresters shall be of the metal oxide, gapless type enclosed in HTV silicon rubber housing
moulded directly on the ZnO resistors.
e. The lightning arresters shall be designed to facilitate inspection, cleaning, repairs, and correct
operation.
f. The conductor or cable for the lightning arrester and counter shall be insulated for a minimum of 4
kV.
g. Surge arresters shall be contained in an IP 55 weatherproof housing as per IEC 60529.
h. Leakage current meters shall be included as an integral part of the surge counter and shall be
designed for continuous service.
Accessories
a. Vibration dampers shall be used as necessary to minimise the effect of aeolian and other forms of
vibration.
b. Anti-climbing guards shall be installed on poles/towers environment outside the plant boundary
fence.
c. Aircraft warning spheres and warning lights shall be provided as required by the applicable aviation
regulations.
d. Safety signs shall be installed as required by international and national regulations.
e. Phase plates: A set of three phase plates shall be attached about 3 m from ground level and above the anti-climbing guards and be provided at all towers. One set of phase plates are required coloured red, yellow, and blue.
f. Number plates: Number plates shall be provided, one for each tower.
Earthing and bonding
a. All lines shall have one or two overrunning earth conductors, which provide a shielding angle of not
more than 30°.
b. The maximum resistance to earth of the earthed tower shall not exceed 10 ohms.
c. All non-current-carrying metalwork on non-conducting supports shall be bonded together to prevent
pole fires.
d. Earthing of surge arresters: At towers where surge arresters are installed a separate PVC covered, stranded earth conductor with minimum cross-sectional area of 70 mm² shall be connected to the earth terminal of the surge arrester and run to a separate earth electrode of resistance value less than 10 ohms.
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Conductor Stringing
a. With double circuit construction, the circuits shall be on the opposite sides of the support and spaced sufficiently far apart for maintenance to be carried out on one circuit while the adjacent circuit is live.
b. Lines shall be divided into sections by straight-line section supports or deviation supports, to minimise the extent of the damage in case of failure of a support of one or more conductors. This should be done every 10 spans or 2 km line length, whichever is shorter.
Road Crossings
a. Overhead road crossing goal posts shall be erected at both sides of the overhead line, at a distance
of 75 m from the overhead line.
b. Warning signs indicating the maximum vehicle height permitted shall be erected between the goal
posts at both sides of the road.
c. The protective wire between the goal posts shall be installed at the permitted maximum height.
Line Route
a. Line routes shall be accessible and make maximum use of existing roads and tracks for both
construction and maintenance access.
b. Where line routes run parallel to the existing roads and tracks, a minimum clearance of 20 m shall
be maintained between the near edge of the road or track and the centreline of the overhead line.
c. Lines should not be routed in parallel and close proximity with metal pipelines and telephone lines
etc. to avoid harmful induced voltages in parallel services.
d. Unless otherwise specified, following minimum distances shall be kept between 33 kV OHL and
pipelines running in parallel to avoid dangerous induced voltages in the pipelines.
i.
ii.
150 m for route length of ≤2 km.
250 m for route length of >2 km
iii. For earth fault currents of up to 1 kA the route length allowed is 7.5 km.
iv. For earth fault currents of up to 2 kA the route length allowed is 4 km
e. Lines shall not be routed through production or process areas. Lines shall be routed at least 50 m outside the boundary fence or plot limit and shall be terminated at least 20 m from the boundary fence with a cable connection to the plant substation.
f. Lines shall be routed clear of wellheads by at least 50 m so as not to obstruct maintenance access.
g. Minimum clearance around structures shall be as below.
i.
ii.
15 m from any crossing power line structure or conductors.
15 m to the property boundary of any rail corridor.
iii. Lines shall not be routed over buildings.
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Ground Clearance
a. The minimum safety clearances of overhead lines shall be in accordance with EN 50341-1.
b. The minimum ground clearance at any point in a span shall not be less than the minimum value
prescribed in the national or local regulations for the relevant line voltage.
c. The minimum height above the ground shall be 6 m.
d. For road crossings, the minimum ground clearance shall be increased to suit the type of traffic
specified, typically 12 m.
Inspection and Testing:
Type tests, routine tests, load tests, and performance tests shall be carried out as applicable in accordance with the relevant IEC standards.
ELECTRICAL CONTROL AND MONITORING SYSTEM (ECMS)
ECMS General
A dedicated microprocessor based ECMS shall be provided in accordance with ADNOC specification AGES-SP-02-008.
ECMS Scope
a. ECMS scope will consist of:
i.
Control and monitoring of electrical distribution system.
ii. Power management.
iii. Load shedding.
iv. Transformer OLTC control and monitoring.
v.
Fault monitoring.
vi. Power quality monitoring.
b. Depending on the size and complexity of the plant and technology, a number of control and monitoring functions can be implemented more efficiently outside the ECMS scope. The split of functionality between ECMS and other systems shall be agreed at contract award stage. Unless otherwise specified the following functions shall be included in the scope of equipment supplied by others.
i. Generator load sharing functionality can be implemented in the turbine / unit control panel
(UCP).
ii. BCU can be supplied and installed in the switchgear by the switchgear SUPPLIER.
iii. Modern protection relays provided as part of the switchgear will have power monitoring, fault monitoring and transient disturbance recording functionality. The use of available functionality within IEDs and BCUs shall be maximised.
iv. Relays, meters, transducers, and recorders shall all be within the scope of switchgear supply.
v. Ethernet switches to communicate with multiple IEDs shall be included in the switchgear scope of
supply. This results in each switchgear becoming a self-contained automation building block
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with its own Ethernet switches. This building block shall form an integral part of the overall ECMS and the ECMS SUPPLIER shall have the ultimate responsibility of its performance and testing.
vi. Any interface unit required to communicate between ECMS, and other SUPPLIERS’
equipment shall be free issued by ECMS SUPPLIER.
ECMS Functionality
Control and monitoring systems with functionality as below shall be implemented in the ECMS.
10.3.1 Power Management
a. Power management shall be provided for automatic load sharing and monitoring and control of the
main generation and the grid incomers/interconnectors.
b.
The main power management functions shall be as below:
i.
Active power and frequency control.
ii. Reactive power and voltage control.
iii. Active and reactive load sharing.
iv. Optimisation of operational setpoints and modes of control such as droop, isochronous, PQ,
power factor.
v. Synchronisation: ECMS shall include the facility to initiate automatic synchronisation of each generator and manual synchronisation facilities to synchronise power supplies across generator incomer, bus section, and interconnector breakers.
vi.
Initiation of start and stop of main and emergency generators.
vii. Power import and export control.
viii. Monitoring of generation capacity and spinning reserve.
10.3.2
Load Shedding
a. Fast load shedding shall be provided to mitigate the possibility of cascade tripping of GTGs upon loss of supply from one or more GTGs or grid and to reduces the possibility of overloading the running generators.
b. A gradual overload scheme shall be provided to address evolving overload conditions at the
generators.
c. As a backup to the fast load shedding, an underfrequency and rate of change of frequency load
shedding scheme shall also be provided.
d. The level of load shedding is determined by the generators spinning reserve capability, load step,
the amount of load connected, and the system configuration.
e. Motor start inhibit signals shall be given by the ECMS to ICSS and to motor IED to prevent the starting of a motor whose pre-set starting power is greater than the available spinning reserve.
10.3.3 ECMS Control and Monitoring of Electrical Distribution System
The following control and monitoring functions of electrical distribution system shall be included.
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a. Circuit breaker controls:
i.
ii.
Circuit breaker and disconnector switch controls.
Initiate automatic bus transfer sequence.
iii. Reset of electrical trip lockout relays
b. Power monitoring system (PQM) functions shall include:
i.
Detecting and recording voltage sags and surges.
ii. Monitoring of metering parameters.
iii. Capturing current and voltage waveforms.
The functions described above shall be implemented either via a power monitoring unit (PMU) installed on each section of the switchgear bus or by selecting protection relay with such functions.
c. Fault monitoring shall continuously monitor analogue and event data for selected feeders, and upon
detection of a fault and/or disturbance, the FM shall automatically:
i.
Capture and store fault/disturbance data,
ii. Perform data analysis using fault and transient analysis software.
d. Transformer OLTC control and monitoring.
e. Capacitor bank switching control and monitoring.
f. OLTC voltage regulation control and monitoring.
g. Alarms, indications, and measurements.
h. Relay parameter settings.
10.3.4 Data Logging
The ECMS shall detect and record events and alarms, including event detection and logging from metering, protective relays and other external devices, data from online condition monitoring, trends etc.
10.3.5 ECMS Operator Interface
a. The OWS shall be provided with a number of graphics depicting the electrical generation and distribution systems, where the operator can specify the area or size of any part of the single line diagram to be viewed.
b. Main generator MW and MVAr loadings and spinning reserve shall be displayed in tabular form for all generators with additional tables showing the voltages and loads at each of the HV buses.
c. The OWS shall display the status of load shedding, alarms, ATS schemes and start inhibits as part
of the Single Line Diagram.
d. The operator shall be able apply relay settings from the OWS and complete various ECMS updates
and configuration from the engineering workstation.
System Architecture and Configuration
a. The ECMS control philosophy, system configuration and interfaces with other systems and
equipment shall be agreed with the COMPANY.
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b. The ECMS shall be based on a distributed intelligence architecture. The Bay Control Unit (BCU), IED, and protective relays etc. inside the switchgear protection and control cubicles shall be connected to ethernet switch through fibre optic or ethernet cable parallel redundancy protocol (PRP) configuration.
c. Typically, the ECMS architecture shall be structured in the following levels.
i.
Level 1 Local Control - feeder bay control unit (BCU) or protection IED level or other equipment control.
ii.
Level 2 Substation Control and monitoring.
iii. Level 3 Central Control and monitoring.
iv. Level 4 Remote Monitoring.
d. The functionality shall be as close to the feeder level as possible. For example, where possible the fault monitoring, transient disturbance, power monitoring functionalities shall be at bay/feeder level.
Communication
a. The ECMS shall communicate over an ethernet fibre optic backbone between each substation and control building via a fault tolerant dual ring with protocol (e.g. rapid spanning tree) to re-establish the link following a break in the ring.
b.
IEDs shall be networked with data highways within each switchgear line-up.
c. Systems and devices that do not have Ethernet ports shall be integrated into the ECMS using
RS 485 serial links with via data managers or gateways.
ECMS Interfaces
a. The ECMS shall interface with equipment and systems supplied by others such as below:
i.
ICSS.
ii. Generation packages (governors, AVRs etc.).
iii.
Switchgear.
iv. ASD driven equipment.
v. AC/DC UPS.
vi. Capacitor banks.
vii. Transformer OLTC etc.
b. Control of process related loads such as motors and heaters shall be controlled directly from the ICSS. Only the monitoring functions of these feeders shall be communicated to ECMS. Safety critical and control signals from ESD and ICSS to electrical switchgear shall be hard wired through interposing relays.
ECMS Redundancy
All ethernet data highways, ethernet switches, CPU’s, servers and controllers shall be dual redundant with hot-standby arrangement.
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ON-LINE CONDITION MONITORING
Online condition monitoring shall be considered as per the Table 11.1.
Table 11.1 Online Condition Monitoring
Equipment
Fault Type
Dry type transformers
Dry type transformers
HV motors
Insulation degradation
Insulation degradation
Broken rotor bars, eccentricity
HV motors
Insulation degradation
Detection Technique
Winding temperature
Method and Technology
RTD
Partial discharge detection
Transient earth voltage (TEV)+ultrasonic sensors High frequency current transformers
Motor current signature analysis (MCSA)
Partial discharge detection
Intelligent relays
Transient earth voltage (TEV)+ultrasonic sensors High frequency current transformers Capacitive couplers in terminal box
Transient earth voltage (TEV)+ultrasonic sensors High Frequency current transformers
HV switchgear
Insulation degradation
Partial discharge detection
HV switchgear
Insulation degradation
Gas density monitoring
Gas leakage detection for GIS switchgear
HV/LV switchgear
Insulation degradation
Arc flash detection
Intelligent relays + sensors + control unit
HV/LV switchgear
Overheating
HV/LV switchgear
Liquid filled transformers
Liquid filled transformers and OLTC
Liquid filled transformers and OLTC
Liquid filled transformers and OLTC
Breaker Mechanism, burnt liquids, spring charging defects
Insulation degradation
Temperature monitoring
Built-in fibre optic, infra-red, or wireless sensors and monitors
Circuit breaker profiling
Intelligent relays with diagnostics Provision for Kelman profiling
Partial discharge detection
Transient earth voltage (TEV)+ultrasonic sensors High frequency current transformers
Liquid degradation
Dissolved gas analysis (DGA)
Online DGA analyzer
Liquid degradation
Liquid temperature
Liquid degradation
Winding temperature
Digital liquid temperature indicator with remote communication and alarm/trip contacts
Digital winding temperature indicator with remote communication and alarm/trip contacts
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UPS SYSTEMS [PSR]
AC and DC UPS Common Requirements
a. AC and DC UPS systems shall comply with ADNOC specifications for the UPS systems.
b. Each UPS system shall be sized to allow 25 % spare capacity for future growth.
c. Unless otherwise specified AC and DC UPSs with autonomy periods as given in Table 12.1 shall
be provided.
Table 12.1 AC and DC UPS Autonomy Periods
UPS Supplied Equipment/System
Autonomy Period Offshore
Autonomy Period Onshore
ICSS
Pipeline instrumentation
ECMS
SCADA shelter and solar power station
Fire and gas for process plant
Fire and gas for accommodation
Telecom
CCTV
PA system
Switchgear control supply
Non process computer installations
Aircraft warning light
Navigational Aids (offshore)
Helideck and obstruction light offshore
Offshore SOLAS (Safety of Life at Sea) communications equipment;
90 minutes
90 minutes
120 hours
4 hours
24 hours
8 hours
8 hours
8 hours
90 minutes
15 minutes
90 minutes
96 hours
90 minutes
24 hours
30 minutes
18 hours
90 minutes
120 hours
8 hours
24 hours
8 hours
8 hours
8 hours
8 hours
15 minutes
90 minutes
Not Applicable
Not Applicable
Not Applicable
GTG auxiliaries and control supply
GTG supplier to advise
GTG supplier to advise
Post lube oil pump motor
Rotating equipment supplier to advise
Rotating equipment supplier to advise
AC UPS
a. AC UPS shall be dual redundant or dual independent systems complete with the following for
supplying power to critical services as per Table 12.1.
i.
ii.
2x100 % battery chargers.
2x100 % inverters.
iii. 2x50 % batteries.
iv. Static bypass switch.
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v. Maintenance bypass and distribution boards.
b. Where large UPS systems are required, these can be 415 V three phase units.
c. The transient voltage variations shall not exceed ± 5 % of voltage and be restored to within the
steady state limits of ± 1 % within 0.1 s.
d. The frequency shall be maintained within ± 0.5 % of nominal rated frequency.
DC UPS
a. DC UPS shall be dual redundant or dual independent complete with 2x100 % battery chargers,
2x50 % batteries, and distribution boards.
b. Earth fault monitoring unit with a sensitivity of 5 mA.
Batteries
a. Vented NiCad batteries shall be used in all applications for both AC and DC UPS systems.
b. Battery Sizing:
i.
Unless otherwise specified the batteries shall be sized for the load profile and autonomy period as per the Table 12.1. Where the battery is required to be sized for different autonomy periods, timers can be used to switch off loads at the expiry of the autonomy periods of various services.
ii. Switchgear UPS batteries shall be sized based on simultaneous closing of all circuit breakers
followed by simultaneous tripping of all circuit breakers.
Battery MCCB
a. Each battery bank shall be provided with its own MCCB for isolating the batteries. In addition, the two batteries of a dual independent system shall be interconnected via MCCB such that the batteries can be charged from either battery charger. Two out of three interlocking shall be provided between battery isolating MCCBs and the interconnecting MCCB. The MCCB boxes shall be Ex rated.
b. Normal operation of the system will be with interconnecting MCCB open. When one of the charger or batteries are not available, operator can manually open the MCCB of the failed battery/charger and close the interconnecting MCCB to allow charging both batteries from the available charger. The MCCBs shall be located in the battery rooms.
c. The isolating battery MCCBs shall be equipped with black start ESD override key switch.
UPS Distribution
a. Each dual redundant or dual independent UPS shall supply power to its own distribution board. The two distribution boards of the dual redundant/independent system shall be interconnected with interlocking to prevent paralleling of the supplies.
b. Operator can transfer loads from one board to the other by manually switching the interconnecting switches. Where necessary the critical loads shall be supplied from both the distribution boards with auto changeover arrangement at load end for AC loads and parallel supply arrangement with reverse diode for the DC loads.
c. Dual redundant 240 V AC to 24 V DC converters shall be used to supply power to PLC,
communication network devices and protection relays at 24 V DC.
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d. The charger section of all UPSs shall be fed from the essential services side of the LV switchboards and the maintenance bypass of AC UPSs shall be fed from the normal supply side of the LV switchboards.
Maintenance Bypass:
a. Normally both UPSs A and B will be operating independently and supplying power to the load connected to distribution boards A and B. Both UPSs A and B shall be equipped with individual maintenance bypass. A static switch shall be provided to enable uninterrupted and synchronised transfer to bypass and vice versa. For a fault on the UPS the system shall automatically changeover to maintenance bypass. Alternatively, operator can manually initiate the changeover as required.
b. AC UPS Black Start Procedure: Each UPS has black start capability i.e. starting the system from battery only with no other AC or DC power being available. The black start procedure involves charging the DC capacitor before switching on the UPS.
Operator and ECMS Interface:
The control programming and local monitoring of the UPSs will be from the display unit at the front of the UPS panels. Status monitoring from the ECMS is via serial link.
MOTORS
General
a. Motors shall comply with the following specifications:
i.
Induction motors shall comply with ADNOC specification AGES-SP-02-007.
ii. Synchronous motors shall comply with ADNOC specification AGES-SP-02-002.
b. Motors rated <15 MW shall generally be squirrel cage induction. Synchronous motors should be considered for motors rated 15 MW and above. Synchronous motors may be specified for motors rated below 15 MW if justified by a cost benefit analysis approved by COMPANY.
c. CONTRACTOR shall evaluate the life cycle cost for large motors. Life cycle cost results and
conclusions shall be discussed and agreed with the COMPANY.
d. Motor service factor shall be 1.
e. Motors started DOL shall be suitable to start and accelerate the load at 80 % voltage at its terminals.
f. Torsional analysis shall be completed by the driven equipment SUPPLIER. Analysis shall include
synchronous motor twice frequency oscillations during start up.
g. Motors shall be mounted such that they can be easily removed for maintenance without dismantling
the skid, surrounding equipment, or structure.
h. Motor installations shall be such that cable disconnection and reconnection shall not require
temporary platforms. Permanent platforms shall be considered accordingly.
i. Greasing tubes to be provided for motors where the drive end/non-drive end grease nipples cannot be accessed an appropriate grease drain facility shall be available in all greased type of motors.
j. Partial discharge monitoring: HV motors including generators 6 kV and above shall be provided with
winding partial discharge monitoring sensors located within the main terminal box.
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k. Wiring from couplers shall be terminated in a terminal box on the motor frame.
l. One portable analyser shall be supplied loose.
Motor Control
One of the following controls as applicable shall be provided for motors.
13.2.1 UCP and ICSS Control
This applies to process and utility drives that have control logic within the package UCP and ICSS interfaces with the UCP. Logic within UCP starts and stops the motor. UCP shall have the following control and selection functions.
a. Auto start/stop.
b. Manual start/stop.
c. Emergency stop.
d. UCP/ICSS selection.
13.2.2 Operation from ICSS
This applies to process and utility drives that have control logic within the ICSS. Logic within ICSS automatically starts and stops the motor, or the operator can start and stop manually from ICSS.
13.2.3
Field Control
This applies to process and utility drives started and stopped from control stations located close to the motor.
Adjustable Speed Drives
a. ASDs shall comply with ADNOC specification AGES-SP-02-004.
b. ASDs shall be considered for the following.
i.
Centrifugal pumps, including submersible pumps.
ii. Recycle gas compressors and booster compressors.
iii. Fin fan coolers, (two speed motors shall be considered when this can be demonstrated to
provide an efficient method of control of cooling air flow).
iv. Extruders.
c. Some of the benefits that can accrue include:
i. Wide range of throughput at improved efficiency, resulting in energy savings, in comparison
with constant speed drive and throttling control.
ii. Direct drive of driven equipment i.e. dispensing with gearbox.
d. For drive exceeding 15 MW, synchronous motors are preferred due to their proven technology.
e. Remote stopping and tripping of HV ASD’s shall be achieved by one of the following methods:
i.
A direct trip to ASD with short time delayed trip to the feeding circuit breaker if the feeder and drive are in separate items of equipment.
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ii. Via integrated contactor/circuit breaker installed in the converter cabinet.
Additional Requirements for Synchronous Motors
a. Starting current of synchronous motors shall be ≤ 6 time the full load current with no positive
tolerance.
b. A lower value of starting current shall be specified to SUPPLIERs if the voltage drop at HV
switchgear bus or motor terminals would exceed permitted values.
c.
If synchronous motor short circuit contribution results in a fault level at the switchboard that is within 10 % of the switchboard short circuit rating, motor parameters may be adjusted to ensure that margin is retained.
d. Adjustments may be achieved by specifying tolerance limits on the machine transient and sub-
transient reactances as long as they are within SUPPLIERS normal design range.
e. Temperature rise tests for synchronous machines shall be performed using one of the following
methods:
i.
Loading the machine at rated load and voltage.
ii. Superposition method.
iii. Equivalent load method.
f. Test method and Suppliers facility ability to load machine shall be reviewed and approved by
COMPANY responsible engineer prior to placement of purchase order.
g. Temperature rise measurements shall be based on resistance method.
h. Maintenance intervals for synchronous motors shall:
i.
Be aligned with the driven equipment and process plant requirements.
ii. Not exceed intervals recommended by motor supplier.
Motor Water Cooling
a. Heat exchangers for ‘essential’ motors shall be provided with a minimum of 2x50 % heat
exchangers.
b.
In the event a single heat exchanger fails it shall be possible to run the motor at rated capacity within class F temperature rise for up to 8 hours.
c. Tube material shall be selected for compatibility with cooling medium as follows:
i.
Titanium tubes shall be used with sea water cooling.
ii. Copper-nickel for clean and treated cooling water.
d. Double tubes arrangements shall be used for ‘essential’ motors.
e. Coolers that are mounted off the machine may be provided if approved by COMPANY.
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Motor Control Stations
a. A motor control station close to the motor shall be provided close to each motor.
b. Control stations shall be heavy duty push button with lock off stop. Other
functions as below shall be provided where required by the operational control philosophy.
i.
Start.
ii. Hand / off / auto selector switch with locking in ‘off’ position.
iii. Ammeters.
c. Control station enclosure shall be of high impact, flame retardant, ultraviolet resistance glass
reinforced polyester. Ingress Protection IP 66.
d. Control stations shall have metric threaded entries for cable glands.
e. Each motor operated valve (MOV) shall be provided with a local isolation switch near the MOV to isolate both power and control connections. The switch shall have pad locking facility in “off’ position.
CABLES AND ACCESSORIES
Cable Requirements:
a. Cables shall be in accordance with relevant IEC standards and shall comply with ADNOC
specification ‘Electrical power, control and earthing cables.
b. Power and control cables shall be of annealed stranded copper conductors, XLPE insulated, steel wire armoured, and overall PVC sheathed. EPR cables can be used for offshore installation where greater flexibility is required. Earthing cables shall be PVC sheathed, coloured yellow/green.
c. Armour for single core cables shall be of aluminium.
d. HV cables shall have conductor and insulation screen.
e. Lead sheath cables or equivalent eco-friendly sheathing shall be used subject to COMPANY
approval for underground cables in hydrocarbon contaminated soil.
f. Fire resistant cables:
i. Where fire resistant cables are specified, they shall comply with IEC 60331 and shall be zero
halogen low smoke type.
ii. Where fire-resistant properties are required for the above ground section of an underground cable, a proprietary fire proofing can be applied provided the above ground cable length does not exceed 10 % of the total length, with COMPANY approval.
g. Flame retardant cables
i.
ii.
Flame retardant cables shall be installed in normally manned and indoor areas.
Flame retardant cables shall conform to IEC 60332 with a minimum light transmission value of 60 % as per IEC 61034-2 and halogen gas emission of 0.5 % as per IEC 60754-1 and IEC 60754-2.
h. At least 20 % spare cores shall be provided in control cables subject to a minimum of one core in
each cable.
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Cable Sheath and Core Colours:
a. Cable core colours for power cables shall be as per ‘The Electricity Wiring Regulation’
UAE 2014-Part 2
b. The colour of outer PVC sheath for the cables shall be as follows:
i.
ii.
33 kV
11 kV
iii. 3.3 kV
Orange RAL2004.
Red RAL2002.
Yellow RAL1016.
iv. LV Power
Black RAL9005.
v. Control Cables
Black RAL9005.
c. Control cable up to 4 cores shall be colour coded red, yellow, blue, and black. Control cables above
4 cores shall be numbered.
Cable Installation
14.3.1 General
For cable installation details refer to ADNOC standard drawings.
14.3.2 Underground Cable Installation
a. Unless otherwise specified field cables shall be directly buried.
b. Cable cleats shall be certified for the applicable peak short circuit current. Cleats used for single
core cable shall be non-magnetic.
c. Cable joints shall not be used except with COMPANY approval where length and size of cable
exceeds maximum manufacturing capability.
d. A list of all joints complete with the GPS coordinates, drawings, make and part number of the joint
shall be provided.
e.
In paved areas, concrete shall be coloured red over electric cable trenches, and green over instrument cable trenches.
f. HV cables in trenches shall be laid in single layer.
g. LV cables in trenches can be laid in two-layer formation.
h. Spacing between cable centres shall be as follows:
i.
Between HV cables:
ii. Between HV and LV cables:
iii. Between LV cables:
300 mm.
300 mm.
150 mm.
iv. Between LV power cables and instrument cables:
600 mm.
v. Between HV power cables and instrument cables:
1000 mm.
i. Cable markers shall be installed along the cable route as per the standard drawings. For underground cables in unpaved areas, cable route markers shall be provided at every 25 m, at change of direction, and at both ends for road and pipeline crossing.
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j. Direct buried cables shall not be routed through areas proposed for future expansion.
k. Due consideration shall be given to routing of power cables with respect to low energy instrument and control cables to avoid interference. A minimum separation of 1500 mm shall be allowed between long parallel power and low energy instrument and control cables. Additional separation of 4000 mm is required from high voltage cables. A vertical separation of 150 mm shall be provided for cables crossing at 90°.
l. Control cables shall be laid alongside their respective power cables.
m. Cables crossing roads shall be installed in concrete encased PVC pipes. At least 20 % spare pipes subject to a minimum of two shall be installed for future requirements. Bell mouths shall be installed and sealed at both ends.
14.3.3 Above Ground Cable Installation
a. Cable tray and ladder racks supported from structures shall be used for above ground cables.
b. Cable ladders shall be laid in horizontal formation supported at a distance of not more than 3 m,
unless otherwise agreed.
c. Cable trays shall be typically supported every 1.5 m to 2 m. Number of cables in the trays shall be
limited to two layers.
d. Mechanical and electrical continuity of all cable trays and ladders shall be maintained.
e. Minimum 25 % space shall be provided in each cable tray and ladder rack for future use.
f. Cable trays / ladders / covers shall be heavy duty, hot dip galvanised, or stainless steel SS 316L, where specified. Cable tray/ladder covers shall be provided where cables are likely to be exposed to direct sunlight or mechanical damage. The cover arrangement shall allow free ventilation. Rungs for the cable ladders shall be welded to the side rails. Thickness of steel used for fabrication of cable tray / ladder / covers shall be 2 mm minimum.
g. Cable ladder racks if laid in multi-tier shall have sufficient maintenance access throughout the cable
length.
h. GRP material shall be applied to marine installations where high corrosion is a determinant factor.
Material original colour shall be retained in this application.
i. All cable ties shall be of stainless-steel insert and PVC coating.
j. Where specified by ‘process safety discipline’, fire protection coating shall be applied to cable
installation to enhance the temperature withstand to 1000°C for one hour.
k. A minimum spacing of 300 mm shall be maintained between cables and high temperature surfaces.
l. Spacing between cable centres shall be as follows:
i.
Between LV power cables and instrument cables:
600 mm
ii. Between HV power cables and instrument cables:
1000 mm
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14.3.4 Single-core Cables
a. Single-core cables of a three-phase circuit shall be laid in trefoil formation, except in the case of
short cable runs.
b. Single-core cables laid in trefoil formation, shall be braced by preformed non-magnetic cable cleats.
14.3.5 Cable Identification and Marking
a. A cable numbering system shall be developed by the CONTRACTOR in consultation with
COMPANY. For existing plants, their existing numbering system shall be followed.
b. Cable numbers shall be marked on the cables along the route and at termination ends. For underground cables the spacing between cable numbers along the route shall not exceed 5 m and for above ground cabling 25 m. Cables shall also be numbered where they branch off from main route.
c. Underground cable markers shall be of stainless-steel sheet with cable number printed by letter / cipher punches. For above ground cabling, plastic markers resistant to the atmospheric conditions shall be specified. All cable markers shall be tied to the cable using PVC coated stainless steel cable ties.
14.3.6 Cable Glands
a. Cable glands shall be designed and manufactured in conformance to IEC 60079 series of standards,
EN 62444, and BS 6121-1.
b. Cables glands shall be double compression type and ISO metric threaded type.
c. Cable glands shall be manufactured from marine grade brass and shall be nickel plated for the
following services.
i.
ii.
For offshore use.
For onshore fertiliser plant.
iii. For aluminium wired armour cable.
d. All cable glands shall have an earth tag.
e. Cable glands in hazardous area:
i.
Shall be dual certified Ex ’d’ and Ex ’e’.
ii. Shall be certified to the IECEx 02 scheme in conformance to IEC 60079.
f. For standardisation purposes, and to reduce the risk of errors, the same “Ex” glands shall be
adopted for all plant areas.
g. Cable glands installed outside the plant areas and in a non-hazardous area shall comply with EN
h. Non-metallic cable glands may be used with non-metallic termination boxes to terminate braided or
non-armoured cable.
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LIGHTING AND SMALL POWER
Lighting System Design
The lighting system shall consist of the following.
15.1.1 Normal Lighting:
a. Normal lighting is supplied from main power supply.
b. The lighting design and illumination levels shall be in accordance with BS EN 12464-1 and 2.
15.1.2 Essential Lighting:
Essential lighting is same as normal lighting except that it powered from emergency generator.
15.1.3 Emergency and Escape Lighting: [PSR]
a. Emergency lighting is supplied from emergency generator with integral battery backup for 1 hour
full illumination and another 30 minutes for reduced illumination.
b. The emergency and escape lighting shall be provided as defined in BS EN 1838.
c. The number of emergency luminaires in relation to the total number of luminaires shall be
determined as follows:
i.
Utility area 20 %.
ii. Process area 10 %.
iii. Administrative area 5 %.
iv. Control room and auxiliary rooms 50 %.
v. Substations, field auxiliary rooms, compressor and generator buildings 30 %.
d. The escape lighting fixtures shall have integral batteries rated to maintain the lighting level of
minimum 1 lux for at least 1 hour.
Illumination Levels
Illumination levels required for ADNOC typical installations are extracted from the tables in Section 5 of BS EN 12464-1 and 2 and are presented in Table 15.1 and Table 15.2.
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Table 15.1 Indoor Lighting Illumination Levels
BS EN 12464-1 Table Ref
Type of area / task / activity
Maintained illuminance Ēm (Lux)
Specific Requirements (EN Standard)
5.1.2
5.1.3
5.1.4
5.2.1
5.2.3
5.2.4
5.2.6
5.3.1
Stairs
Elevators, lifts
Loading ramps/bays
Canteens, pantries
Rooms for physical exercise
Cloakrooms, washrooms, bathrooms,
Rooms for medical attention
Plant rooms, switch gear rooms
5.4.1
Store and stockrooms
5.5.3
5.5.4
5.10.4
5,20.2
5,20.3
5,20.4
Control stations
Storage rack face
Precision measuring rooms, laboratories
Boiler house
Machine halls
Side rooms, e.g. pump rooms, condenser rooms, etc.; switchboards (inside buildings)
100
100
150
200
300
200
500
200
150
150
200
500
100
200
200
5,20.5
Control rooms
500
5.26.2
5.26.4
5.26.5
5.26.6
5.29.2
Office Writing, typing, reading, data processing
CAD workstations
Conference and meeting rooms
Reception desk
Kitchen
5.33.2
Libraries, reading rooms
500
500
500
200
500
500
Requires enhanced contrast on the steps.
Canteen: 100 Lux
Gym
Toilets and locker rooms
First aid room
Switch rooms, including relay and auxiliary rooms
Warehouse bulk storage: 50 Lux Outdoor storage areas: 5 Lux
Vertical illuminance, portable lighting may be used.
Laboratories and analyser rooms
Local on workbenches and machine tools: 400 Lux
Plant rooms, battery room
Rear of panels: 150 Lux Auxiliary rooms: 300 Lux Outside, near entrances: 150 Lux Instrument room and telecom room: 500 Lux
Gate house, reception area
Catering areas (food preparation and serving)
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Table 15.2 Outdoor Lighting Illumination Levels
BS EN 12464-2 Table Ref
5.1.1
Type of area/task/activity
Walkways exclusively for pedestrians
Maintained illuminance Ēm (Lux)
5
5.1.2
Traffic areas for slowly moving vehicles (max. 10 km/h), e.g. bicycles, trucks and excavators
10
5.8.2
Ladders, stairs, walkways
100 (25)
5.8.3
5.9.1
5.10.1
5.10.2
Offshore boat landing areas / transport areas
Light traffic, e.g. parking areas of shops, terraced and apartment houses; cycle parks
Remote-operated processing installations
Processing installations with limited manual intervention
5.11.4
General servicing work and reading of instruments
100
5
50
150
100
Specific Requirements (EN Standard)
Non-operational areas with limited attendance, e.g. tank farms without equipment requiring regular operator intervention: 0.5 Lux Fence lighting: 0.5 Lux Road lighting: 5 Lux
Plant and jetty approaches and road intersections Road lighting
walkways, platforms, stairways, ladders, module roofs (offshore)
Car parks: 1 Lux
Safety colours shall be recognisable. General plant area
Operating areas requiring regular operator intervention such as pumps, compressors, generators, drivers, valves, manifolds, loading arms, etc.
Where possible level gauges and instruments to have integral lighting or be lit from single light.
Luminaires
a. LED light shall be used and in case of non-availability for specific application or range, energy
saving type should be used.
b.
Industrial decorative type LED luminaires shall be used for illumination in substations, control rooms, offices, etc.
c.
Indoor luminaires shall be IP 51 and outdoor IP 66.
Area Lighting
a. Use of LED flood lights shall be maximised as far as possible for illumination of open general areas.
b. Flood lights shall be generally used for open area lighting. Flood lighting fixtures shall be mounted at sufficient elevation and directed so as to provide uniform illumination. Plant structures shall be used where possible for mounting such flood lights.
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c. Tank farm lighting shall generally be by flood lighting. However, flood lighting poles and towers shall
be located outside the tank dykes.
d. Street and perimeter fence lighting.
i.
The perimeter fence lighting shall be fed from emergency power supply.
ii. Perimeter fence lighting shall be provided for the plant fencing with LED lamps on 6m high
poles.
iii. Each lighting pole shall include a fuse box as well as a four-pole terminating box for looping
the feeder cable.
Instrumentation Lighting
a. Luminaires for general illumination shall be located as close as possible to instruments, gauges etc.
as to avoid special lighting for these devices.
b. Where possible, instruments and gauges etc. shall be selected with integral lighting.
Aircraft Lighting
a. Aircraft warning lights shall be installed in accordance with local aviation regulations.
b. The warning light fixtures shall each consist of a double lamp unit with automatic changeover to the
stand-by lamp upon failure of the operating lamp.
c. The lamp used for aircraft warning lights shall be of long-life type.
d. A facility shall be provided for lowering the luminaires for re-lamping.
Offshore Navigational Aid
For offshore navigational aid lighting refer to ADNOC specification Z0-TS-E-04010.
Lighting Control
a. All outdoor plant lighting, street lighting, fence lighting and flood lighting shall be controllable by
photo electric cells.
b. All outdoor plant emergency lighting shall be controlled by photo electric cells fed from the same
emergency supply.
c. Normal lighting in industrial and non-industrial buildings shall be controlled by infra-red occupancy
detectors.
d.
It shall be possible to manually switch on the lighting by over-riding the infra-red detectors and timers.
e. Lighting specifically installed for gauge glass illumination shall be controlled by a locally mounted
switch.
f. Lighting installation in control rooms shall be designed for switching off independently ceiling light groups to suit operator needs. Dimmers shall be provided to control the illumination level. The reflectors on the luminaires shall be such as to provide glare free light with high degree of visual comfort on VDU screens.
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Lighting Installation
All luminaires in plant areas shall be solidly fixed and not suspended by means of chains or conduits etc. They shall be mounted such that routine maintenance can be carried out safely and without the use of temporary scaffolding.
Socket Outlets
The following small power socket outlet systems shall be provided:
a. Safety socket outlet shall be 110 V, 15 A, double pole switched, 3-pin with spring flap cover and shall be supplied via double wound transformers with solidly earthed centre tapped secondary windings.
b. Convenience socket outlets located outdoors shall be switched 240 V, SP&N + E, 16 A, with spring flap cover. The outlets shall be located throughout the plant such that portable tools, hand lamps and test equipment can be supplied via a 25 m extension cable.
c. Convenience socket outlets located indoors in substation and control rooms shall be switched 240 V, SP&N + E, 16 A. Minimum 2 double convenience socket outlets shall be provided in each room in the buildings.
d. Convenience outlets for desk top computers and associated printers shall be 240 V, SP&N + E, 13
A, supplied from AC UPS system.
e. Welding socket outlets shall be supplied directly from the LV Switchboard. Welding outlets shall be 415 V, TP+N, 63 A, 4-pin switched outlets interlocked to prevent plug removal from a loaded circuit.
f. Welding socket outlets shall be installed at strategic locations throughout the plant such that equipment can be reached by a 50 m extension cable. The welding socket outlet circuits should not serve any other equipment and should not have more than three outlets connected per circuit.
g. All outdoor socket outlets shall be provided complete with canopies.
h. Convenience outlets for non-industrial buildings shall be 240 V, SP&N + E, 13 A, 3-pin. The outlets shall be spaced not more than 3 m apart along the wall with a minimum of 2 sockets per room.
i. Socket outlet circuits shall be protected by residual earth leakage circuit breaker (RCCB). The RCCB operating current shall be 30 mA for circuits of less than 125 A and 300 mA for circuits equal to or greater than 125 A.
Portable Lamps
Hand-held portable lamps for maintenance shall be provided rated for 24 V AC. These shall be connected to portable 240 V.AC / 24 V. AC double wound transformers which are fed from 240 V plant socket outlets which have earth leakage protection set at 30 mA. Primary side of these transformers shall be provided with 30 m long flexible cable and a plug for connection to socket outlet.
Distribution Boards
a. Lighting and small power systems including heat tracing and MOVs shall be supplied from
415 V / 240 V, TP&N, 4 wire, distribution boards located within the plant.
b.
Incoming power supply for the distribution boards shall be by using four pole MCCB for three phase and two pole MCCB for single phase boards.
c. The distribution boards shall consist of outgoing circuits as below.
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i.
ii.
Four pole MCBs for three phase feeders supplying power to a sub distribution board.
Three pole RCCB supplying power directly to three phase load.
iii. Three pole MCCB supplying power to MOVs.
iv. Two pole RCCB for single phase L-N feeders and for L-L 415 V feeders.
d. Each RCCB shall be equipped with the following.
i.
30 mA earth leakage protection.
ii. Auxiliary contacts for ‘tripped’ and status indication.
iii. Padlocking facility.
e. No more than three socket outlets shall be wired to one circuit.
f. Unless otherwise specified, distribution boards shall be provided with bolt-on circuit breakers.
g. The circuit breakers shall be lockable in de-energised position by means of permanently mounted
padlocking facilities.
h. One group alarm for each distribution board shall be sent to ECMS to indicate outgoing MCBs
tripped status.
i. Where necessary and in order to minimise site installation a separate dedicated distribution board
should be provided in each area for lighting, small power, and heat tracing.
j. Distribution boards shall be supplied with copper busbars.
k. The neutral bus length shall accommodate connection of every branch circuit requiring a neutral conductor. Neutrals of each separately derived system shall be earthed at only one point in the system. The neutral conductor size shall be equal to the phase conductors.
l. Branch circuits loading shall not exceed 80 % of rating of branch circuit protective device rating.
m. Each distribution board shall incorporate 20 % equipped spare ways to allow for future growth.
n.
Indoor distribution boards generally shall be wall mounted.
o. Outdoor distribution boards shall be housed in a weatherproof fibre glass enclosure.
p. Distribution boards shall be suitably located in relation to the loads served to minimise the cabling
and site installation work.
q. Distribution boards installed outdoors shall be located in non-hazardous areas as far as practicably
possible.
r. A sunshade shall be provided on all outdoor lighting and small power panels.
Junction Boxes
a. Junction boxes used for lighting and small power circuits shall be of high impact, flame retardant,
ultraviolet resistant glass reinforced polyester.
b. Junction boxes shall be suitable for Zone 1, gas group II, temp class T6.
c. Junction boxes shall be with degree of protection IP 66.
d. Junction boxes shall use closed cell neoprene gasket with detachable lid and stainless-steel captive
fixing screws.
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Solar Powered Remote Stations:
For solar power supply to SCADA and telecom equipment located in remote locations refer to ADNOC document AGES-PH-04-001 ‘Automation and Instrumentation Philosophy’.
Cathodic Protection Transformer Rectifier Units
a. Transformer rectifier units shall be provided to step down, isolate, and rectify to supply controlled
DC output to cathodic protection system.
b. Rectifier units shall be capable of supplying full load DC output at maximum ambient temperature
applicable.
c. Rectifiers shall be silicon-controlled rectifiers or similar full wave bridges with tap switches to allow
full range adjustment of the DC output voltage.
d. The DC output rating shall be obtainable with a nominal supply voltage and frequency as specified
in Table 6.1, without damage to the transformer, rectifier, or other components.
e. A fast acting electronic current limiting feature shall prevent short-circuit and overload damage to
any part of the circuit. Semiconductors shall be protected with fast acting fuses.
f. The rectifier enclosure material shall be SUPPLIER standard. Ventilation openings shall be
provided with screens and filters.
g. Maximum audible noise level shall not exceed 85 dBA @ 1m.
h. The following order of preference is recommended for locating the transformer rectifier units.
i.
Indoors.
ii. Outdoors in non-hazardous locations.
iii. Outdoors in hazardous locations. Transformer rectifiers shall be certified for use in hazardous
areas, as required.
i. With doors open the degree of protection shall be minimum IP 20.
j. Following alarms and metering shall be provided.
DC ammeter and DC voltmeter, three 4-20 mA transducers for DC amperes, DC volts, and potential to earth. A voltage free contact for common alarm shall be provided. These signals shall be monitored in ECMS system.
k.
If specified, AC and DC lightning surge protection with high energy metal oxide varistor (MOV) arrestors, and secondary surge suppression with disk-style MOVs shall be provided.
EARTHING AND LIGHTNING PROTECTION
Design Criteria
a. An integrated earthing system shall be provided to minimise danger to life and damage to equipment
arising from:
i.
ii.
Step and touch voltages.
Lightning.
iii. Accumulation of static charge.
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iv. EMC interference.
b. Protective earthing, bonding and lightning system earthing shall be provided in accordance with
IEC 60364-5 and IEEE 80 guidelines.
c. The earthing system shall be configured as a single common earth grid in the form of an earth ring with branch interconnections to the enclosures of electrical equipment, plant structures, buildings and vessels.
Earth Grid Design Criteria
a. The size of earthing grid conductor and the number and size of earth electrodes shall be such as
to limit the resistance to earth as follows:
i.
ii.
The resistance of all electrodes connected to the main earth grid shall not exceed 1 ohm.
The resistance of all electrodes connected to the main earth grid shall keep the touch and step voltages within safe limits.
iii. The combined resistance to the general mass of earth of the electrodes provided for lightning
protection shall not exceed 10 ohms when isolated from the plant earth grid.
iv. The individual earth electrode resistance shall not exceed 25 Ohms.
Earth Grid Design
a. The earthing system shall be designed on the ring principle with interconnecting conductors as necessary. This ring shall be connected to the earth well or electrodes. Earthing grids of various substations and plant units within the plant shall be interconnected.
b. Soil resistivity measurements shall be made as part of the geotechnical survey.
c. Based on the soil resistivity, an earth electrode design shall be carried out to optimise the location and number of electrodes to meet the resistance to earth requirements. Calculations of touch and step voltages for both electrical fault and lightning strike conditions shall be carried out using the actual soil resistivity and surface materials. Distances between rods shall be greater than their depth. A minimum separation of the order of 3 m shall be considered. At least one more than the required minimum number of electrodes shall be installed.
d. Whenever possible, earth electrode shall be installed deep enough to reach water table or
permanent moisture level, and deep enough to reach stable ground conditions.
e. Bentonite or similar material may be used to improve contact efficiency in difficult ground conditions.
f. For the earthing of electrical systems, equipment and structures, each installation shall have one
common earth grid connected to at least two groups of earth electrodes.
g. Connection between earth electrode and earth cable shall be arranged in a pit with cover to allow
maintenance and testing.
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ADNOC Classification: Internal
Earth Electrodes
a. Earth electrodes shall consist of a number of rod sections complete with driving ends.
b. Materials for earth rods shall be selected to meet requirements of soil resistivity and corrosion
resistance based on site experience.
c. Unless otherwise stated earth rods shall be selected from the following types.
i.
ii.
50 mm diameter 3.5 m long hot dip galvanised steel pipes minimum thickness 3 mm.
19 mm diameter copper bonded steel rods with copper cladding minimum thickness of 250 microns.
d. Where it is not possible to drive earth rods, drilled earth wells complete with electrode and back fill
shall be provided.
e. Refer to IEC 62305 for recommended materials for the manufacture of lightning protection
components.
Earthing Conductor:
a. Cross section of earthing conductors shall be standardised to 185 mm2, 70 mm2, 35 mm2 and 16
mm2.
b. Earthing conductors shall be insulated when routed above ground. Earthing conductor shall be of stranded annealed copper conductor with 450/750 V or 600/1000 V grade green / yellow PVC insulation for electrical earth, and green PVC insulation for instrument earth.
c. Earthing conductors installed underground shall be bare conductors unless otherwise required to
be insulated due to cathodic protection considerations.
d. Earthing conductors shall be sized to carry the prospective fault current for the duration of the fault
without damaging conductor or associated insulation.
e. The cross-sectional area of protective conductors shall comply with the minimum requirements determined by methods given in clause 543.1 of IEC 60364-5-54. or as given in the ADNOC earthing philosophy diagram.
f. Sole reliance on cable armouring and/or metallic sheathing shall only be made if it is adequately
fault rated as a protective conductor.
Buried Conductors:
a. Conductors shall be laid at a depth of 450 mm minimum below grade level. Where possible, earthing
conductors shall be run in cable trenches.
b. The connection between the cable and the earth-rods shall be with copper ferrules by hydraulic crimping. Copper joints below ground shall be made using exothermic welding technique or compression joints.
c. Joints in protective conductors shall be avoided.
d. To protect against lightning-induced currents, it may become necessary to install a separate earthing conductor, known as PEC, along cables in trenches. PECs shall be bonded to the above ground cable ladder racks and supports. The number of PECs shall be determined as part of an EMC assessment, considering the number of cables, the transfer impedance of the cables, the expected lightning current, trench width, and the allowable transient voltage.
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ADNOC Classification: Internal
Earth Connections
The connections to the earthing network shall be as follows:
a. Earth bar and enclosure of major equipment such as switchgear, TCPs, ASDs, transformer frames, HV Motors, pipe racks, vessels, storage tanks and columns shall be earthed at minimum two points.
b. LV Motors shall be provided with one earthing connection.
c. One core in the power supply cable shall be an earth continuity conductor for equipment with non- metallic enclosures such as distribution boards, junction boxes, local control stations, welding and convenience socket outlets.
d. Gates and fence shall be earthed at a maximum interval of 75 m.
e. Cable tray/ladder connections to plant earthing system shall be provided at maximum 30 m intervals. If cable trays/ladders are provided with specially designed coupling plates which provide earth continuity, bonding jumpers are not required at expansion joints.
f. Enclosures in permanent direct metallic contact, e.g. via pump bedplates, vessels, piping,
structures, etc. with earthed plant steelwork require no further connection to the earthing system.
g. Enclosures not in direct metallic contact with earthed plant steelwork or pipework shall be bonded to the earthing system or to the adjacent earthed steelwork by means of a copper conductor.
h. Plant steel work shall be connected to the earth network at a minimum of two points. An earth lug or boss shall be welded to main columns at regular intervals and at specific heights above ground level.
i. All connections to earthing bars and equipment shall be carried out using compression connectors.
j. Earthing connection to equipment/structures shall be made with bolted connections. Foundation
bolts shall not be used for earthing.
Cable Armour Earthing
a. Cable armour, lead sheath, and shields of multicore cables shall be solidly bonded at both ends.
b. Cable armour, lead sheaths and shields of single cables shall normally be solidly bonded at both ends. With both end bonding singe core cables may need derating due to circulating currents.
c. Where approved by the COMPANY only field end of the cable armour can be earthed with sheath
voltage limiters at switchgear end as necessary.
Mechanical Package Earthing
16.9.1 Package Earth Loop:
Two earthing bosses shall be welded at diagonally opposite corners of mechanical package skid. A loop of earth cable shall be run between these two bosses and all skid mounted equipment shall be earthed by connecting them to this earth loop.
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ADNOC Classification: Internal
16.9.2 Machine Sets with Non-electric Drive
a. When driving and driven machines are in direct metallic contact with an earthed steel structure, no
additional earthing is required.
b. When driving and driven machines are bolted to a common metallic bedplate on a concrete or other poorly conducting foundation, one connection shall be taken from bedplate to earthing system.
c. When driving and driven machines are on separate bedplates mounted on separate plinths, bedplates shall be bonded together and minimum one connection taken to general earthing system.
16.9.3 Motors
a. Metallic enclosures and motor termination boxes shall be bonded to motor enclosure or to earthing system to which motor is connected. This may be achieved through the mounting bolts and earthed steelwork.
b. Driven equipment casings shall be provided with 2 diagonally located standard earthing bosses, suitable for direct connection to site earth grid in addition to those provided as standard i.e. 4 in total.
16.9.4 Vessels
a. Vessels shall be bonded to the earthing system or to the nearest earthed steelwork at two points. If
the vessel is welded to earthed steelwork, no additional bonding is required.
b. When vessel mounting is insulated from steelwork, two earthing connections shall be taken from
the vessel to common earthing system.
c.
If a vessel has insulation and an outer metal cladding or wire reinforcement, the metal cladding or reinforcement shall be electrically continuous and bonded to the vessel.
d. Cable armour entering the vessel shall be bonded to vessel shell at the point of entry.
Storage Tanks [PSR]
a. Lightning protection for storage tanks shall be provided as per API 650, NFPA 780, and IEC
62305-3
b. Earthing lugs shall be welded to the tank shell at maximum intervals of 30 m. Earthing Boss shall be as per Figure 5.23 API 650. All tanks shall be furnished with a minimum of four equally spaced earthing lugs.
c. Earthing lugs on tanks shall be connected to earth busbars located inside modules.
d. Tank internals, e.g. mixers, gauge floats and sling arms, shall be bonded to tank shell at one or more locations depending on size of internal object. Bonding can preferably be achieved by direct bolting.
e.
If high winds prevail shunt strips may be replaced with cables bolted in position. Shunts shall be fitted above the sealing arrangement.
Piping
It is not necessary to bond across flanges of piping joints, or earth pipes separately, as adequate earthing is provided via vessels and other equipment to which pipes are connected.
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ADNOC Classification: Internal
Pipelines and Valves
a. Long pipelines crossing open ground shall be earthed at or near plant boundary.
b. Spindles of ball valves shall be bonded to their pipeline if:
i.
ii.
The ball valve is controlling a two-phase mixture.
The valve is not fitted with a special earthing washer.
iii. The valve is immediately downstream of fine filtration facilities.
c. Static charge is increased in a two-phase mixture due to the increased surface area of the individual
phases.
d. Static charge is increased downstream of fine filters due to extensive charge separation.
e. An exception to valve earthing described above shall be made if liquefied petroleum gas is handled, such as tanker loading bays. Particular attention shall be paid to earthing across flexible connections.
f. Where pipe flanges are fitted with insulating inserts, the flange shall be fitted with an earth strap
unless other design considerations, such as cathodic protection, prevent it.
Earthing when Cathodic Protection is Applied
a. Cathodic-protected sections of pipeline shall be isolated from unprotected sections and from any earthing systems. Presence of electrically operated valves may make complete isolation impractical.
b.
Isolation can be achieved when electrically operated valves or other devices are installed by inserting insulating bushings between cable gland and device. Device shall be bonded to pipeline. It shall be established that a return earth path via the pipeline is sufficient to ensure correct operation of protective devices on supply to equipment.
c.
If required, impressed current cathodic-protected buried pipelines may be earthed by polarisation cells or alternatively by use of earthing rod materials of a suitable galvanic potential.
d. When plant is cathodic-protected, either by sacrificial anodes or by an impressed current system, the design of earthing systems shall be agreed with SUPPLIERs and designers of cathodic protection system.
Earthing of Remote Plant
When the equipment is remote from plant and connection to the common earthing system is impractical, two connections shall be taken from the equipment to separate earth electrodes and the resistance to earth of each electrode shall be less than 10 ohms.
Substation Earthing
a. Earth electrodes shall be installed in the vicinity of the substation to form a substation area earthing
ring which shall be interconnected to the main earthing grid.
b. Each electrical substation shall have two main copper earth bars. Earth bars inside the substation
shall be made of tinned hard drawn copper.
c. The minimum size of earth bars shall be 50x6 mm and will be located at opposite corners of the substation. The earth bars shall be interconnected to each other by an earthing cable and connected to the substation area earthing ring by at least two independent fully rated connections.
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ADNOC Classification: Internal
d. Switchgear earth bars shall be connected to the substation earth bars via two separate connections.
e. All transformer frames shall be connected to the substation earth bars via two separate connections.
Jetties
a. Earthing and bonding of jetties shall be executed in accordance with IEC 60079-14 and ISGOTT.
b. The application of these rules results in electrical isolation between ship and jetty installations,
regardless of whether or not the jetties are cathodic protected.
c. Pipe and/or hose connections between the ship and the jetty shall be provided with insulating flanges or joints, whose minimum insulation resistance after installation shall be 1000 ohms, measured at 1 kV. The maximum insulation resistance shall be 1 megaohms to prevent static build- up.
d. Gangways shall be insulated from the ship by means of insulated rollers.
e. Slings shall be fabricated from non-conductive material, e.g. nylon.
f. To earth the vessel to the jetty, a ship to jetty bonding cable and a jetty mounted Ex db isolating
switch shall be provided for each berth.
g. The jetty cathodic protection system, if any, shall consider the leakage current to the onshore
earthing system.
h. Berthing dolphins, fenders and the jetty itself, if metallic, shall be insulated from the ship’s hull, e.g.
by wooden facings.
Instrumentation Earthing
a. Separate earthing system shall be provided for earthing of instrumentation systems. Unless otherwise specified dual redundant earth bars for each of the earthing system as below shall be provided in the substation and switch room.
i.
ii.
Intrinsically safe instrument earth bar.
Instrument earth bar.
iii. Safety electrical system earth bar.
b. The instruments earth bars are used for earthing instrument power supply isolation transformers,
signal cable screens and various electronic systems associated with instrumentation.
c. For instrument earthing no closed loop shall be formed until it is finally connected to the earth grid.
d. The instrument earth bars shall be connected to the electrical earth bar by two interconnecting
cables, whilst maintaining the star arrangement.
e. Measures shall be taken to achieve Electromagnetic Compatibility (EMC) in accordance with IEC
61000, IEC 62305 and IEC 60364-4-44.
f. Special consideration shall be given while routing cables which carry small power signals through
electromagnetically polluted areas.
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ADNOC Classification: Internal
Lightning and Surge Protection [PSR]
a. Lightning protection installation shall comply with IEC 62305-3.
b.
It is not necessary to carry out risk assessment for each site. Based on ADNOC experience lightning protection shall be installed as below.
i.
Tall steel structures such as towers or structure columns, provided they are electrically continuous, shall be considered inherently protected against lightning by their connection to the earthing system. Bonding across joints may be used to ensure electrical continuity if necessary.
ii.
For structures and buildings, lightning protection shall be provided by roof-mounted aerial lightning conductors connected directly to earth by copper tape.
iii. Floating roof storage tanks shall be fitted with retractable bypass conductors. See Section
16.10.
iv. Surge protective devices shall be installed to protect sensitive electronic equipment.
ELECTRICAL HEAT TRACING
a. Electrical heat tracing shall be provided as required and in accordance with ADNOC specification
for heat tracing DGS-1630-015.
b. Heat tracing shall be provided for process heating to maintain fluid temperature between required
limits.
c. Separate heat tracing systems shall be powered from normal or essential power sources as
necessary.
d. Heat tracing circuits shall be energised at 240 V, AC SP&N 50 Hz via 415 V / 240 V distribution
panels.
e. Heat tracing circuits can be supplied from lighting and small power distribution boards where
necessary.
f. The following heater types may be used, in order of preference as below. The heaters shall be
procured from a COMPANY approved SUPPLIER.
i.
Self-regulating/self-limiting heaters.
ii. Constant wattage parallel heaters.
iii. Skin effect heat tracing for welded pipes.
NON-INDUSTRIAL BUILDINGS
a. Non-industrial buildings comprise all buildings outside the process areas, e.g. workshops warehouses, canteens, administration buildings, fire stations, training centres, gatehouses, chemical stores, etc.
b. The design and installation of the power, lighting and earthing systems shall comply with the
following.
i.
IEC 60364.
ii. UAE 2014: UAE electricity wiring regulations.
iii. The lighting design and illumination levels shall be in accordance with BS EN 12464-1 and 2.
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ADNOC Classification: Internal
iv. The emergency lighting shall comply with the requirements of BS EN 1838.
v.
Lighting and small power, lightning protection, earthing, bonding and cabling shall be generally complying with the requirements as given in the relevant sections of this design guide.
c. All wiring shall be in concealed conduits.
d. Emergency lighting shall be installed in the building switch room.
e. Escape lighting shall be installed along all the emergency exit routes from the building. Escape
lighting shall be provided using luminaries with integral 30-minute battery backup.
f. Twin outlets of the domestic pattern standard rated for 13 A, 3-pin shall be used. Where Industrial duty convenience outlets and power outlets are required, e.g. in workshops, they shall be same as specified in this design guide for substation buildings.
g. Power supplies to lifts shall be derived directly from the main switchboard.
h. Power supplies to central air conditioning units shall be arranged as radial feeders from the main switchboard, and those to fan coil units from a sub distribution board of the air conditioning system.
i. Through wall air conditioners shall be supplied as radial feeds from the distribution board.
j. Energy meter shall be installed in accordance with local regulations.
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ADNOC Classification: Internal
SECTION C – OTHER REQUIREMENTS
DETAILS OF SCOPE SUPPLY
The scope of supply of shall include:
a. Detailed design.
b. Supply of materials.
c. Factory and site inspection and testing.
d. Documentation including certification.
e.
Installation, commissioning and start-up assistance; where specified in the requisition.
f. Spare parts for 2 years operation.
Refer to the project requisition document for detailed requirements.
QUALITY CONTROL AND ASSURANCE
Equipment shall only be purchased from SUPPLIER approved by ADNOC Category Management. This approval indicates that the SUPPLIER has an approved quality management system and a proven track record in supply of this type of equipment.
SUB-CONTRACTORS, SUB-SUPPLERS
Not applicable.
MATERIAL CERTIFICATION
Not applicable.
INSPECTION AND TESTING REQUIREMENTS
General
a. Before leaving the SUPPLIER’S works, each item of equipment shall be inspected and tested in
accordance with the relevant standards as listed in Section A of this design guide.
b. The SUPPLIER shall provide an Inspection and Testing Plan (ITP) at least 8 weeks’ notice prior to
the testing date.
c. The ITP shall be submitted for review and acceptance by the COMPANY and include Witness and
Hold points in the programme for SUPPLIER, CONTRACTOR, and the COMPANY.
d. The COMPANY/CONTRACTOR or his nominee shall inspect the equipment and witness the
required tests indicated in the Requisition at the time the equipment is offered for final inspection.
e. A detailed test procedure of factory tests shall be submitted at least 3 months in advance of any testing, detailing the proposed inspection, testing and witness testing programme throughout the design and build of the equipment.
f. Test certificates for each item of equipment shall be submitted prior to delivery for COMPANY
acceptance.
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ADNOC Classification: Internal
Tests Reports
a. Test reports in accordance with the relevant IEC standards including the following shall be
submitted to COMPANY.
i.
ii.
The design values.
The tolerance values.
iii. The real values as measured, including, if any, the intermediate values causing provisional
refusal.
b. SUPPLIER shall compile the records of all inspections and tests including routine tests and special
tests in one document and shall submit as part of technical documentation.
Type Tests:
a. SUPPLIER shall submit the type test certificates for each item of equipment for tests as required in
the applicable IEC standards.
b. Type test certificates shall be submitted with the bid.
c. Test certificates shall be from an internationally recognised, independent testing authority, and shall
be subject to COMPANY acceptance.
SPARE PARTS
a. The SUPPLIER shall propose:
i.
A list of commissioning spare parts.
ii. A list of 2 years operation spare parts.
iii. A list of special tools required for erection, commissioning and maintenance.
b. Special tools required for erection, commissioning and maintenance shall be shipped together with
the Switchgear.
c. Each spare part shall be separately packed and clearly identified for storage management.
PAINTING, PRESERVATION AND SHIPMENT
Painting
a. Surface preparation and painting shall be in accordance with the COMPANY standard.
b. Alternatively, SUPPLIER may propose the standard for enhanced protection against corrosion in outdoor climates. The paint system applied shall provide adequate protection against the adverse effects of the climatic conditions specified. Full details of SUPPLIER’s painting specification shall be provided with the proposal for COMPANY approval.
c. The equipment shall be fully tropicalised.
d. Colour shade shall be in accordance with the COMPANY standard, AGES-SP-07-004 ‘Painting and
Coating Specification’.
e. Hot dip galvanised or stainless steel equipment shall not be painted.
f. Equipment made of GRP, e.g. junction boxes, light fittings etc. shall maintain its natural colour.
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Shipment
SUPPLIER’s standard packing shall be acceptable unless otherwise stated in the COMPANY’s preservation and export packing procedure and on data sheet. Installation of impact recorders on individual packing boxes and containers shall be included.
COMMISSIONING
The requirements of commissioning shall be included in the requisition document.
TRAINING
The requirements of commissioning shall be included in the requisition document.
DOCUMENTATION / MANUFACTURER DATA RECORDS
General
a. SUPPLIER shall submit the type and number of drawings and documentation for CONTRACTOR’S
authorisation or information as listed in the Material Requisitions and Purchase Orders.
b. Schedule of documents and data submittal shall be as agreed in the purchase order.
c. Comments made by CONTRACTOR on drawing submittal shall not relieve the SUPPLIER of any responsibility in meeting the requirements of the specifications. Such comments shall not be construed as permission to deviate from requirements of the Purchase Order unless specific and mutual agreement is confirmed in writing.
d. Each drawing shall be provided with a block in the bottom right-hand corner incorporating the
following information:
i. Official trade name of the SUPPLIER.
ii. SUPPLIER’s drawing number.
iii. Drawing title giving the description of contents whereby the drawing can be identified.
iv. A symbol or letter indicating the latest issue or revision.
v. Purchase order number and item tag numbers.
e. Revisions:
i.
Document and drawing revisions shall be identified with symbols adjacent to the alterations.
ii. A brief description of each revision shall be given in tabular form.
iii.
If applicable, the authority and date of the revision shall be listed. The term “Latest Revision” shall not be used.
f. All documents shall show the relevant order number, item tag numbers and SUPPLIER’s references and
shall be distributed as specified in the purchase order documents.
g. Graphic symbols for electrical diagrams shall be according to IEC 60617-DB. Device code numbers
shall be as per ANSI C-37.2.
h. All documents and drawings shall be in English.
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i.
Installation, operating and maintenance manuals shall be arranged as follows:
i.
The front cover, spine and inside page shall state the purchase order number and SUPPLIER’s reference number.
ii.
The inside front page shall carry an index listing the contents of each section of the manual.
iii.
Individual sections shall be completed and shall refer to the equipment actually supplied.
iv. Published data shall also be included, including published data for bought-in items.
v.
Full detail for installation setting up shall be included.
vi. Recommended test data shall be stated, covering initial and also regular testing shall be given.
For example, high voltage AC or DC test values.
vii.
Items requiring regular inspection, checking, testing and maintenance shall be listed, and the time scale clearly indicated.
viii.
Important items shall be cross referenced to other part of the manual as necessary.
ix. Fault finding chapter shall be included.
x. As built panel and interconnection wiring diagrams.
xi. CD ROM for programming protection relays.
xii. Parts and equipment lists.
EX Equipment Register for CEE Equipment
a.
In compliance with Standard IEC 60079-17 to inspect and maintain CEE Equipment (Certified Electrical Equipment), the EPC CONTRACTOR shall develop and provide an Ex Equipment Register for all the CEE Equipment installed in the plant. The Ex equipment register shall be developed in suitable format for import into the computerised maintenance management system, with minimum requirements as stated below.
i.
ii.
Serial No.
Location.
iii. Zone Information (Zone, Gas Group, Temperature Class).
iv. Equipment Tag No.
v. Make.
vi. Model.
vii. Duty Class (continuous, intermittent, standby).
viii. Voltage.
ix. Feeder Rating Amps.
x. Max Amps for Exe Equipment.
xi. Enclosure Protection.
xii. Ex Class.
xiii. Gas Group.
xiv. Temperature Class.
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xv. Certifying Authority.
xvi. Certificate (Number, Validity Date).
xvii. Supplied From (Switchgear tag number, feeder number, substation number).
xviii. Type of Inspection (Initial). Initial detailed inspection shall be conducted before the equipment
is brought into service as per 4.3.1 of IEC 60079-17.
xix. Date of Inspection.
b. A separate Ex Register shall be developed for each but not limited to the following CEE Equipment:
i.
ii.
High Voltage Motors.
Low Voltage Motors.
iii. RCU and Push Buttons.
iv. Luminaires.
v.
Lighting and Small Power Junction Box.
vi. Socket Outlets.
vii. Distribution Boards.
viii. MOVs.
ix.
Instrument Junction Boxes.
x.
Instrument Local Control Panels.
Contractor Documents
CONTRACTOR shall submit the following documents as a minimum.
a. Drawings and document schedule.
b. Specifications and material requisitions:
i.
Power system operating philosophy.
ii. Project specifications.
iii. Equipment specifications.
iv.
Installation specification.
v. Equipment data sheets.
vi. Material requisitions.
vii. Equipment and cable numbering system.
c. Single line and circuit diagrams:
i.
Key single line diagrams / system phasing diagrams.
ii. Single line diagrams for each switchboard with protection and metering and load schedule.
iii. Emergency power distribution single line diagram.
iv. Single line diagrams for AC and DC UPS.
v. Protection and metering diagram.
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vi. Control schematic diagrams.
vii.
Interconnection diagrams.
viii. Lighting and small power circuit diagrams.
d. Layout drawings:
i.
Substation layout drawings.
ii. Cable routing layouts.
iii. Earthing layouts.
iv. Cable trench/tray details and sections.
v.
Lighting layouts.
vi. Power layouts.
vii.
Installation standards for power, lighting, earthing, cable ladder racks and trays.
viii. Trace heating system layouts and schematics.
e. Schedules:
i.
Electrical load schedule.
ii. Switchgear feeder schedule.
iii. Distribution board schedule.
iv. Relay setting schedule.
v. Cable schedules.
f. Studies and calculation reports:
i.
Electrical load summary and power demand calculations.
ii. System studies and calculation as per the system study and calculation sections of this design
guide.
iii. Protection discrimination curves and relay settings.
iv. SAFOP terms of reference and SAFOP findings report.
v.
Illumination level calculations.
vi. Generator / transformer / ups sizing calculations.
vii. Earthing design calculations.
viii. Cable sizing calculations.
g. Miscellaneous:
i.
Field test procedures for electrical equipment and test record forms.
ii. Design manuals.
iii. Operation manuals.
iv. Spare parts list and SPIR.
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GUARANTEES AND WARRANTY
The requirements of guarantees and warranty shall be included in the requisition document.
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SECTION D – STANDARD DRAWINGS AND DATASHEETS
DATASHEET TEMPLATES
Not applicable.
STANDARD DRAWINGS
LATER
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