Classification: Internal
NFPS Offshore Compression Complexes Project COMP2
COMPANY Contract No.: LTC/C/NFP/5128/20
CONTRACTOR Project No.: 033734
Document Title
:
ELECTRICAL DESIGN BASIS FOR CP6S AND CP7S COMPLEXES
COMPANY Document No.
: 200-20-EL-DEC-00001
Saipem Document No.
: 033734-B-D-30-SPM-EL-R-10001
Discipline
: ELECTRICAL
Document Type
: DESIGN CRITERIA
Document Category/Class
: 1
Document Classification
: Internal
A
20-Jan-2023
Issued for Review
SS
Salwa Solahuddin
Digitally signed by Salwa Solahuddin Date: 2023.01.20 12:45:13 +08’00’
Nik Sharris 2023.01.20 14:40:43 +08’00’
NA
Digitally signed by Anand Bhatt DN: cn=Anand Bhatt, c=MY, o=Ranhill Worley, email=anand.bhatt@worley.com Reason: I agree to the specified portions of this document Date: 2023.01.20 14:42:03 +08’00’
SRIRAM MURTHY
Digitally signed by SRIRAM MURTHY DN: cn=SRIRAM MURTHY, o=SAIPEM, ou=SAIPEM, email=srirammurthy.valiveti@saipe m.com, c=MY Date: 2023.01.20 11:32:30 +04’00’
AB / SM
REV.
DATE
DESCRIPTION OF REVISION
PREPARED BY
CHECKED BY
APPROVED BY
Saipem S.p.A.
Company No._Rev. 200-20-EL-DEC-00001_A
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NFPS Offshore Compression Complexes Project COMP2 ELECTRICAL DESIGN BASIS FOR CP6S AND CP7S COMPLEXES
REVISION HISTORY
Revision
Date of Revision
Revision Description
A1
A
11-Jan-2023
20-Jan-2023
Issued for Inter-Discipline Check
Issued for Review
HOLDS LIST
Hold No
Hold Description
1
2
Interlock / inter-trip requirement for WHP13S & 14S
General - COMPANY Document Number (under request to CPY)
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TABLE OF CONTENTS
1
2
3
4
5
6
7
INTRODUCTION … 5
1.1 PROJECT OBJECTIVE … 5 1.2 PROJECT SCOPE … 5
DEFINITIONS AND ABBREVIATIONS … 7
2.1 DEFINITIONS … 7 2.2 ABBREVIATIONS … 8
REFERENCE, RULES, CODES AND STANDARDS … 12
3.1 COMPANY DOCUMENTS … 12 3.2 PROJECT DOCUMENTS … 13 3.3 CONTRACTOR DOCUMENTS … 14 INTERNATIONAL CODES AND STANDARDS … 15 3.4
PURPOSE … 18
SCOPE … 18
DESIGN BASIS GENERAL … 18
SITE SERVICE CONDITIONS … 19
7.1 DESIGN LIFE … 19 7.2 ENVIRONMENT … 19 7.3 OFFSHORE AMBIENT CONDITIONS … 19 7.4 DESIGN AMBIENT CONDITIONS … 20
8
BASIC DESIGN REQUIREMENTS … 21
8.1 AREA CLASSIFICATION … 21 8.2 INGRESS PROTECTION … 21 8.3 OPERATIONAL SAFETY AND RELIABILITY … 23 8.4 STANDARDIZATION OF EQUIPMENT AND MATERIALS … 23 8.5 MAINTAINABILITY AND ACCESSIBILITY … 23 8.6 CERTIFICATES, DECLARATIONS AND TEST REPORTS FOR EQUIPMENT … 23 8.7 UNIT AND INFORMATION … 23 8.8 CONDITION MONITORING SYSTEM … 24 8.9 DOCUMENTATION … 24
9
ELECTRICAL SYSTEM DESIGN PARAMETERS … 25
9.1 SYSTEM VOLTAGE AND FREQUENCY … 25 9.2 VOLTAGE AND FREQUENCY VARIATION … 26 9.3 SYSTEM VOLTAGE DROPS … 26 9.4 SYSTEM EARTHING … 27 9.5 SYSTEM POWER FACTORS … 27 9.6 SHORT CIRCUIT RATINGS … 27 9.7 HARMONIC … 27 9.8 ARC FLASH … 27 9.9 ELECTROMAGNETIC COMPATIBILITY (EMC) … 28 9.10 ELECTRICAL LOADS AND POWER SUPPLIES … 28
9.10.1 Classification of loads… 28
9.10.2 Load Assessment and Electrical Equipment Sizing … 29
9.10.3 Gas Turbine Generator Sizing … 30
9.10.4 Emergency Diesel Generators Sizing … 31
9.10.5 Other Electrical Equipment Sizing … 31
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9.11 POWER SYSTEM DESIGN PHILOSOPHY … 31
9.11.1 Power System Design Philosophy … 32 9.12 ILLUMINATION STUDY … 32 9.13 CABLE SIZING … 33 9.14 SAFOP (SAFETY AND OPERABILITY STUDY) … 33 9.15 POWER GENERATION AND DISTRIBUTION … 33
9.15.1 Power Generation … 33
9.15.2 Power Distribution … 34
9.15.3
Interlocking / Inter-tripping System … 34 9.16 ELECTRICAL EQUIPMENT REQUIREMENT … 35
9.16.1 Main Turbine Generator … 35
9.16.2 Emergency Diesel Generator (EDG) … 36
9.16.3 Transformer … 36
9.16.4 MV Switchgear … 37
9.16.5 LV Switchgear / MCC … 38
9.16.6 Power Management System (PMS) … 39
9.16.7 Electrical Integrated Control System … 39
9.16.8 Electric Motors … 40
9.16.9 Uninterruptible Power Supply (UPS) … 41
9.16.10 Battery … 42
9.16.11 Distribution Board (DB) … 43
9.16.12 Cables and Accessories … 43
9.16.13 Lighting System and Small Power … 45
9.16.14 Portable Lighting Units and Lamps … 46
9.16.15 Navigational Aids … 47
9.16.16 Helideck and Aviation Warning Lightings … 47
9.16.17 Multi-Cable Transit (MCT) … 47
9.16.18 Electrical Heat Tracing … 48
9.16.19 Junction Box … 48
9.16.20 Cable Ladder / Tray… 49
9.16.21 Conduits and Accessories … 50
9.16.22 Bus Ducts … 50
9.16.23 Electric Process Heater … 51
9.16.24 Variable Speed Drive System (VSDS) … 51
9.16.25 Protection and Metering … 51
9.16.26 Local Control Station (LCS) … 52
9.16.27 Earthing and Bonding … 52
9.16.28 Lightning Protection… 54
9.16.29 Electrical Room Requirement … 54
9.16.30 Equipment Clearance … 55
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1
INTRODUCTION
The North Field is the world’s largest natural gas field and accounts for nearly all of the state of Qatar’s gas production. The reservoir pressure in the North Field has been declining due to continuous production since the early 1990s. The principal objective of the NFPS Project is to sustain the plateau from existing QG South Operation (RL Dry Gas, RGE Wet gas) and existing QG North Operation (QG1 & QG2) production areas by implementing an integrated and optimum investment program consisting of subsurface development, pressure drop reduction steps and compression. Refer to the figure below for a schematic of the North Field.
Qatargas Operating Company Limited is leading the development of the North Field Production Sustainability (NFPS) Project.
1.1 Project Objective
The objective of this Project includes:
• Achieve standards of global excellence in Safety, Health, Environment, Security and Quality
performance.
• Sustain the Qatargas North Field Production Plateau by installing new Compression Complex facilities CP6S & CP7S in QG south with integration to the existing facilities under Investment #3 program.
• Facility development shall be safe, high quality, reliable, maintainable, accessible, operable,
and efficient throughout their required life.
1.2 Project Scope
The Project Scope includes detailed engineering, procurement, construction, transportation & installation, hook-up and commissioning, tie-in to EXISTING PROPERTY and provide support for start- up activities of the following facilities and provisions for future development. The WORK shall be following the specified regulations, codes, specifications and standards, achieves the specified performance, and is safe and fit‐for‐purpose in all respects.
Offshore
CP6S and CP7S Compression Complexes that are part of QG-S RGE facilities as follows:
• CP6S Compression Complex
• Compression Platform CP6S, Living Quarters LQ6S, Flare FL6S
• Bridges BR6S-2, BR6S-3, BR6S-4, BR6S-5
• Bridge linked Tie-in to RP6S
Production from existing wellheads (WHP6S & WHP10S) and new wellhead (WHP14S) are routed via riser platform RP6S to compression platform CP6S to boost pressure and export to onshore via two export lines through the existing WHP6S pipeline and a new 38” carbon steel looping trunkline from RP6S (installed by EPCOL). CP6S is bridge-linked to RP6S.
• CP7S Compression Complex
• Compression Platform CP7S, Living Quarters LQ7S, Flare FL7S
• Bridges BR7S-2, BR7S-3, BR7S-4, BR7S-5
• Bridge linked Tie-in to RP7S
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NFPS Offshore Compression Complexes Project COMP2 ELECTRICAL DESIGN BASIS FOR CP6S AND CP7S COMPLEXES
CP7S shall receive production from existing wellheads (WHP5S & WHP7S) and new wellhead (WHP13S). There is only one export line for CP7S through the existing export pipeline from WHP7S. CP7S is bridge-linked to RP7S.
RGA Complex Destressing
Migration of the Electrical power source, Telecoms, Instrumentation and Control systems from WHPs and RHPs hosted by RGA to the respective Compression Complexes listed below:
• WHP6S, WHP10S, WHP14S, RP6S and RP10S to CP6S Compression Complex
• WHP5S, WHP7S, WHP13S and RP7S to CP7S Compression Complex
Destressing of Telecoms, Instrumentation and Control system in RGA Complex Control Room, which would include decommissioning and removal of telecom system devices and equipment that would no longer be required post migration and destressing activity.
Onshore
An Onshore Collaborative Center (OCC) will be built under EPC-9, which will enable onshore based engineering teams to conduct full engineering surveillance of all the offshore facilities. The OCC Building will be located in Ras Laffan Industrial City (RLIC) within the Qatar Gas South Plot. MICC & Telecommunication, ELICS related scope will be performed in the OCC building.
Figure 1.2.1: NFPS Compression Project COMP2 Scope
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2 DEFINITIONS AND ABBREVIATIONS
2.1 Definitions
Definition
Description
COMPANY
Qatargas Operating Company Limited.
CONTRACTOR
Saipem S.p.A.
DELIVERABLES
FACILITIES
All products (drawings, equipment, services) which must be submitted by CONTRACTOR to COMPANY at times specified in the contract. All machinery, apparatus, materials, articles, components, systems and items of all kinds to be designed, engineered, procured, manufactured, constructed, supplied, tested and permanently installed by CONTRACTOR at SITE in connection with the NFPS Project as further described in Exhibit 6.
fabricated,
MILESTONE
A reference event splitting a PROJECT activity for progress measurement purpose.
PROJECT
NFPS Offshore Compression Complexes Project COMP2.
SITE
(i) any area where Engineering, Procurement, Fabrication of the FACILITIES related the CPS6S and CP7S Compression Complexes are being carried out and (ii) the area offshore required for installation of the FACILITIES in the State of Qatar.
to
SUBCONTRACT
Contract signed by SUBCONTRACTOR and CONTRACTOR for the performance of a certain portion of the WORK within the Project.
SUBCONTRACTOR
Any organization selected and awarded by CONTRACTOR to supply a certain Project materials or equipment or whom a part of the WORK has been Subcontracted.
WORK
Scope of Work defined in the CONTRACT.
WORK PACKAGE
The lowest manageable and convenient level in each WBS subdivision.
VENDOR
The person, group, or organization responsible for the design, manufacture, the Equipment/Material.
load-out/shipping
testing,
and
of
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2.2 Abbreviations
Code
Definition
AC
ACB
API
ATEX
AWL
BC
CB
CCU
COMP2
CPU
CCTV
CPMS
DB
DC
DCS
DDE
EDG
ELICS
EHT
EMC
EMTP
EPR
EPC
Alternating Current
Air Circuit Breaker
American Petroleum Institute
Atmospheres Explosive
Aviation Warning Light
Battery Charger
Circuit Breaker
Communications Controller Unit
Compression Complex CP6S and CP7S and MICC Installation at Onshore Collaborative Center (OCC)
Central Processing Unit
Closed Circuit Television
Condition and Performance Monitoring System
Distribution Board
Direct Current
Distributed Control System (process control part)
Detailed Design Engineering
Emergency Diesel Generator
Electrical Integrated Control System
Electrical Heat Tracing
Electromagnetic Compatibility
Electromagnetic Transients Program
Ethylene Propylene Rubber
Engineering Procurement Construction
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Emergency Shutdown
Electrical Power System Analysis & Operation software
Engineering Workstation
Fire and Gas
Fire and Gas System
Front End Engineering Design
Glass Reinforced Plastic or Glass Reinforced Polymer
Gas Turbine Compressor
Gas Turbine Generator
Human Machine Interface
High Resistance Grounding
Heating Ventilation and Air Conditioning
Hertz
Integrated Control and Safety Systems
International Electrotechnical Commission
Integrated Motor Control System
Ingress Protection
Interposing Relay Panel
Intrinsically Safe
Local Control Station
Light Emitting Diode
Living Quarters
Load Shedding
Low voltage
ESD
ETAP
EWS
F&G
FGS
FEED
GRP
GTC
GTG
HMI
HRG
HVAC
Hz
ICSS
IEC
IMCS
IP
IRP
IS
LCS
LED
LQ
LS
LV
MCC
Motor Control Centre
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MCT
MV
Multi-Cable Transit
Medium Voltage
NAVAIDS
Navigational Aids System
NFPS
NiCd
NTP
OWS
P&ID
PAGA
PMS
OCC
OLB
PC
PU
QG
QG-N
QG-S
QG-1
QG-2
QR
RFID
RG
RGE
RGA
RL
North Field Production Sustainability
Nickel Cadmium
Network Timed Protocol
Operator Workstation
Piping and Instrumentation Diagrams
Public Address and General Alarm system
Power Management System
Onshore Collaborative Center
Onshore Logistics Base
Personal Computer
Process and Utilities Platform
Qatargas Company Limited
Qatargas North
Qatargas South
Qatargas 1
Qatargas 2
Quick Response
Radio Frequency Identification
RasGas Company Limited
RasGas Expansion
RasGas Alpha
Ras Laffan
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RCCB
Residual Current Circuit Breaker
RF
RP
RTD
Radio Frequency
Riser Platform
Resistance Temperature Detector
SAFOP
Safety and Operability study
UCP
UPS
VRLA
VDU
VSD
WHP
Unit Control Panel
Uninterruptible Power Supply
Valve-regulated lead acid
Visual Display Unit
Variable Speed Drive
Wellhead Platform
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3 REFERENCE, RULES, CODES AND STANDARDS
The following codes, standards and specification are referenced within the document and shall be considered as part of this specification. Conflict among applicable specification and / or codes shall be brought to the attention of the COMPANY for resolution. COMPANY decision shall be final and shall be implemented. The latest editions of codes and specification effective as on date of contract shall be followed.
In general, the order of precedence shall be followed:
a) Qatari Governmental and Regulatory Requirements
b) COMPANY Procedures, Policies and Standards
c) Project Specifications
d)
Industry Codes and Standards
e) COMPANY and CONTRACTOR’S lessons learned
If CONTRACTOR / VENDOR deems any deviations from the specifications will result in significant project cost and schedule saving, proposal to such deviations shall be submitted to COMPANY for review and approval. CONTRACTOR / VENDOR shall not proceed with any deviation to the Specifications without prior COMPANY approval.
3.1 Company Documents
S. No
Document Number
Title
EXHIBIT 5
EXHIBIT 6
Contract Agreement
Project Instructions
Scope of Work
ONS-OTS-MNT-03
Spare parts and Material identification, Procurement, Delivery, Receipt and Payment OTS-OED Support Projects Procedure
TCH-000-PRC-005-F01
ICS Security Engineering Switch and Router Hardening Check List (Typical)
TCH-000-PRC-005-F01
INF-ISG-PRC-007
TCH-AIG-PRC-044
ICS Security Engineering Firewall Hardening Check List (Typical)
ICS Security Engineering Workstation Hardening Check List (Typical)
Industrial Control System Security Engineering Specification Procedure
TCH-000-POL-001
Industrial Control system Security Engineering Policy
Qatar National Information Assurance: National Industrial Control System Security Standard
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3.2 Project Documents
S. No
Document Number
Title
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
Electrical Design Basis
Electrical Power Generation Distribution and Control Philosophy
Electrical Protection Philosophy
Load Shedding Philosophy
Electrical Black Start Philosophy
Lighting Design Philosophy
Specification for Electrical Packaged Equipment
Specification for Power Management System (PMS) Specification for Electrical Integrated Control System (ELICS)
Specification for AC UPS
Specification for DC UPS
Specification for Navigational Aids System
for Low Voltage Switchgear, Specification Integrated Motor Control System (IMCS) And Busduct
Specification for Medium Voltage Switchgear
Specification for Power Transformers And NER
Specification for Cable Ladder and Tray
Specification for Electrical Cable
Specification for Low Voltage (LV) And Medium Voltage (MV) Motor Specification for Low Voltage (LV) And Medium Voltage (MV) Variable Speed Drive System
Specification for Low Voltage Distribution Board
Specification for Electrical Heat Tracing
Specification for Electrical Heaters
Key Single Line diagram
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[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
[HOLD2]
Typical Medium Voltage Switchgear Single Line Diagram Typical Low Voltage Switchgear Single Line Diagram
Typical Earthing Block Diagram
ELICS and PMS Architecture Diagram
Project Engineering Design Basis
Process Design Basis
Cyber Security Lifecycle Management Plan
Instrument and Control Systems Design Basis
Telecommunication System Philosophy and Design Basis
Technical Safety Basis of Design
Mechanical Design Basis
Specification for Gas Turbine Generator
Specification for Emergency Diesel Generator
HFE Workplace Design Specification
Equipment Criticality Assessment Workshop Report
Sparing Philosophy
Material Selection Philosophy
SAFOP Close Out Report
Specification for Integrated Control and Safety Systems (ICSS)
3.3 Contractor Documents
S. No
Document Number
Title
Not applicable
Not applicable
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3.4
International Codes and Standards
S. No
Document Number
Title
IEC 60034
IEC 60038
IEC 60072
Rotating electrical machines- All Parts
Standard voltages
Dimensions and Output Series for Rotating Electrical Machines
IEC 60076
Power transformers- All Parts
IEC 60079
IEC 60092-350
IEC 60092-353
IEC 60092-360
Electrical apparatus for explosive gas atmospheres- All Parts
Electrical installations in ships – Part 350: General construction and test methods of power, control and for shipboard and offshore instrumentation cables applications
Electrical installations in ships – Part 353: Power cables for rated voltages 1 kV and 3 kV
Electrical installations in ships – Part 360: Insulating and sheathing materials for shipboard and offshore units, power, control, instrumentation and telecommunication cables
IEC 60146
Semiconductor converters- All Parts
IEC 60183
IEC 60228
IEC 60269-1
IEC 60282-1
IEC 60287
IEC 60309
IEC 60331-21
IEC 60332-3-22
IEC 60364
IEC 60502-1
Guidance for the selection of high-voltage A.C. cable systems
Conductors of Insulated Cables
Low-voltage fuses – Part 1: General requirements
High-voltage fuses – Part 1: Current-limiting fuses
Electric Cables - Calculation of the Current Rating
Plugs, socket-outlets and couplers for industrial purposes
Tests for Electric Cables under Fire Conditions - Circuit Integrity - Part 21: Procedures and Requirements - Cables of Rated Voltage up to and Including 0,6/1,0 kV Tests on electric and optical fibre cables under fire conditions – Part 3-22: Test for vertical flame spread of vertically-mounted bunched wires or cables – Category A
Low-voltage electrical installations – Part 1: Fundamental principles, assessment of general characteristics
Power cables with extruded their accessories for rated voltages from 1 kV (Um = 1,2 kV) up to 30 kV (Um = 36 kV) – Part 1: Cables for rated voltages of 1 kV (Um = 1,2 kV) and 3 kV (Um = 3,6 kV)
insulation and
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IEC 60502-2
IEC 60502-4
IEC 60529
IEC 60598
IEC 60617
IEC 60751
IEC 60754
IEC 60793
IEC 60811
IEC 60896
IEC 60909
IEC 60947-3
IEC 60947-5-1
Power cables with extruded their accessories for rated voltages from 1 kV (Um = 1,2 kV) up to 30 kV (Um = 36 kV) – Part 2: Cables for rated voltages from 6 kV (Um = 7,2 kV) up to 30 kV (Um = 36 kV)
insulation and
their Power cables with extruded accessories for rated voltages from 1 kV (Um = 1,2 kV) up to 30 kV (Um = 36 kV) – Part 4: Test requirements on accessories for cables with rated voltages from 6 kV (Um = 7,2 kV) up to 30 kV (Um = 36 kV)
insulation and
Degrees of Protection Provided by Enclosures
Luminaires – Part 1: General requirements and tests
Graphical symbols for diagrams [DATABASE]
Industrial platinum resistance thermometers and platinum temperature sensors
Test on gases evolved during combustion of materials from cables
Optical Fibres
Electric and optical fibre cables
Stationary lead-acid batteries
Short-circuit currents in three-phase a.c. systems
Low-voltage switchgear and controlgear – Part 3: Switches, disconnectors, switch-disconnectors and fuse- combination units
Low-voltage switchgear and controlgear – Part 5-1: Control circuit devices and switching elements – Electromechanical control circuit devices
IEC 61000
Electromagnetic compatibility (EMC)
IEC 61034
IEC 61204
IEC 61363-1
IEC 61378
IEC 61439
IEC 61537
IEC 61850
Measurement of smoke density of cables burning under defined conditions
Low-Voltage Power Supply Devices, D.C. Output - Performance Characteristics
Electrical Installations of Ships and Mobile and Fixed offshore Units - Part 1: Procedures for Calculating Short- Circuit Currents in Three-Phase a.c
Converter transformers
Low-voltage switchgear and controlgear assemblies
Cable management – Cable tray systems and cable ladder systems
Communication networks and systems for power utility automation
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IEC 61869
Instrument transformers – Part 1: General requirements
IEC 61892
IEC 61914
IEC 62040
IEC 62259
IEC 62271
IEC 62305
IEC 62402
IEC 62477-1
IEC 62477-2
IEEE 519
IEEE/ANSI C37.20.7
Mobile and fixed offshore units – Electrical installations – All Parts
Cable cleats for electrical installations
Uninterruptible power systems (UPS)
Secondary cells and batteries containing alkaline or other prismatic non-acid secondary single cells with partial gas recombination
Nickel-cadmium
electrolytes
High-voltage switchgear and controlgear
Protection against lightning
Obsolescence management
Safety requirements systems and equipment – Part 1: General
for power electronic converter
Safety requirements for power electronic converter systems and equipment – Part 2: Power electronic converters from 1000V AC or 1500V DC up to 36 kV AC or 54kV DC
Recommended Practice and Requirements for Harmonic Control in Electric Power Systems
Testing Switchgear Rated Up to 52 kV for Internal Arcing Faults
- CAA
Civil Aviation Authority
CAP 437
-
GUH
IALA
ICAO
-
NEC
-
NEMA
-
NFPA
SOLAS
Civil Aviation Offshore Helicopter Landing Area – Guidance on Standard
Gulf Helicopter Company
International Association of Light House Authorities
International Civil Aviation Organization
National Electrical Code (NFPA 70)
National Electrical Manufacturers Association
National Fire Protection Association
Safety of Life at Sea
ITU-T G.652
Characteristics of a Single-mode Optical Fibre and Cable
API RP 505
Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Zone 0, Zone 1, and Zone 2.
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4 PURPOSE
The purpose of this document is to define the the design criteria, data and minimum technical requirements for Brownfield and Greenfield Electrical scope in the NFPS COMP2 project.
This document shall serve as basis for design and development of all electrical documents, drawings, calculations and detailed specifications for electrical equipment and systems. This document is applied to offshore and onshore scope.
5 SCOPE
This design basis covering the electrical design requirement for location QG-S RL and RGE compression offshore facilities.
The greenfield development for this PROJECT includes:
• QG-S RGE CP6S Compression Hub (comprises of Compression Platform, Flare Platform and
LQ),
• QG-S RGE CP7S Compression Hub (comprises of Compression Platform, Flare Platform and
LQ),
The brownfield tie-in and modification include, but not limited to:
•
•
•
brownfield tie-ins on QG-S Riser platforms;
brownfield modification at existing QG-S wellhead platforms;
Interface scope at onshore under COMP2 - ELICS at OCC
In general, all specification and standards referenced in this document shall be followed for the greenfield development. For offshore brownfield modification scope, existing facilities design philosophies and specification shall be followed, unless otherwise specified.
6 DESIGN BASIS GENERAL
Facilities will be of a robust and fit for purpose design in accordance with international and COMPANY standards and recognized industry best practices. The facilities shall be designed with the objectives of being safe, reliable, efficient and operable.
For works involving modifications and tie-ins to existing facilities, the design shall comply with the requirements of existing facilities design standards and specifications and design philosophies except as identified in this document to bridge the gap between existing COMPANY specifications and project specifications.
For Electrical Safety Kits, shall refer to “Technical Safety Basis of Design” [43].
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7 SITE SERVICE CONDITIONS
7.1 Design Life
In general, the design life of electrical equipment shall be a minimum of thirty (30) years.
7.2 Environment
All electrical equipment shall be suitable for offshore installation, in a marine environment.
7.3 Offshore Ambient Conditions
The following offshore metrological data shall be used:
• Ambient Temperature
-
Expected maximum daily average
-
Expected maximum daily
-
Expected minimum daily
-
Expected yearly maximum temperature
-
Expected yearly minimum temperature
-
Air cooler design
-
Gas Turbine design
-
Black Bulb Temperature (includes flare and solar radiation)
-
Design temperature for electrical equipment outdoor installed
operating at ambient conditions
• Relative Humidity
-
Minimum
-
Average
-
Maximum
• Atmospheric Pressure
-
Minimum
-
Maximum
• Rainfall
-
Once in 2 years minimum
-
Once in 10 years minimum
-
Once in 50 years minimum
36 °C
41.1 °C
12.7 °C
45.6 °C
8.3 °C
45.6 °C
42 °C
84 °C
49 °C
37 %
71 %
100 %
998 mbar
1020 mbar
12 mm/h
27 mm/h
41 mm/h
Note: Equipment exposed to sunlight shall be designed for black bulb temperature or shall be furnished with a sunshade / canopy where feasible.
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7.4 Design Ambient Conditions
All electrical equipment shall be capable of continuous operation under the service conditions specified in Table 7-1.
Table 7-1 : Design Ambient Conditions
Minimum design ambient temperature
Maximum design ambient temperature for all electrical equipment (outdoor)
Maximum design ambient temperature for all electrical equipment (indoor)
Relative Humidity
Design temperature for Electrical Cable
Offshore +8.3 ºC
+49 ºC
+45 ºC
37 to 100 %
- Aboveground installation
+49 ºC
The indoor main electrical equipment shall be installed in the electrical room. This room shall be air- conditioned but in the unlikely event of HVAC failure, the equipment shall continue to function as long as equipment temperature does not exceed the design temperature and duration to be determined based on HVAC calculation and minimum operation duration required.
For all equipment exposed to direct solar radiation, especially during summer, equipment surface temperature can reach to 84°C due to radiation and equipment design shall take into consideration of this aspect to maintain temperature below this value.
Where outdoor equipment / installation subject to direct solar radiation or flare radiation, the installation shall be provided with sunshade accordingly. All cable trays from Compression Platform to Flare platform shall be covered.
Top most layer of horizontal and vertical cable ladder/ trays, where cable required to protect against direct sun radiation/ UV rays, flare radiations and potential drop object, shall be provided with covers.
All electrical equipment selected for outdoor installation exposed to field ambient conditions shall be suitable for installation and operation in sulphurous corrosive marine conditions with sand and dust storms as encountered on an offshore production platform. Equipment shall be fully tropicalized.
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8 BASIC DESIGN REQUIREMENTS
8.1 Area Classification
Hazardous area classification drawings and document prepared by the Safety Discipline, based on API RP 505 & IEC for Zone type classifications shall be used as the basis for the proper selection of electrical and control equipment and installations. Compliance to API RP 500 is acceptable subject to COMPANY approval. Electrical equipment should, as far as it is reasonably practical and economic, be located in the least hazardous areas and minimize/restrict outdoor installation of electrical equipment that may or could generate spark (i.e., contactor / relay). Control rooms and substations should be situated in non- hazardous areas and pressurized.
Electrical equipment installed in indoor areas (exception of battery room) shall be of standard industrial type. However, shall be suitable for offshore marine environment.
To cater for the possibility of reclassification of areas and for the purpose of spares inter-changeability, all outdoor equipment shall be Zone 2 rated as a minimum even if they are located in non-hazardous area. All electrical equipment located in hazardous area shall be suitable for Zone 2, gas group IIB and temperature class T3 as minimum. Classification of electrical equipment located at outdoor area required to function during emergency condition shall be rated to Zone 1, gas group IIB, temperature class T3. This requirement is not applicable for indoor electrical equipment such as emergency switchgear and distribution boards.
Equipment located in classified areas shall be certified to IEC “Ex” scheme. Equipment having ATEX certification and equipment that complies with NEMA is acceptable subject to COMPANY approval.
All electrical equipment shall be referred to project Area Classification drawings as applicable.
Electrical equipment shall be selected in accordance with the Project Specifications
a) Type of protection appropriate for the zone classification
b) Temperature classification of the equipment (t class) appropriate for the gas, vapour or dust
involved
c) Equipment subgroup appropriate for the gas, vapours or dust involved
d) Equipment construction appropriate for the environmental conditions.
Electrical equipment installed within battery room shall be suitably classified for Zone 1, gas group IIC, temperature class T3 as a minimum.
All electrical bulk, lighting fixtures (including AWL and navigation aids) installed outdoors shall be suitable for minimum Zone 1, gas group IIB, temperature class T3 hazardous area. All lighting fixtures installed inside battery room shall be classified for Zone 1, gas group IIC, temperature class T3 area. All other indoor lighting fixtures shall be industrial type with exception of emergency and escape lighting.
Purged enclosures (Ex p) and pressurized enclosures may be provided only if approved by COMPANY. Purging shall be in accordance with the IEC regulations. Purged enclosures shall be manufactured of stainless steel material (type 316 or better) in accordance with IEC 60529 type, IP 56 (minimum). The pressurizing control system shall be certified for the respective classified area.
8.2
Ingress Protection
The minimum enclosure degrees of ingress protection, in accordance with IEC 60529, taking into account the environmental conditions mentioned above, the following ingress protection shall be considered as a minimum are shown below. With enclosures open, all live parts shall be protected (e.g., shrouded / protective barrier, etc.) and shall provide a minimum degree of ingress protection to IP20.
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Table 8-1 : Ingress Protection
Equipment Type
Dry type transformer / Neutral Earthing Transformer
Ingress Protection IP32
MV Switchgear
LV Switchgear
LV Motor Control Center
Indoor
LV Distribution Board
LV Control Panel AC UPS / DC UPS / BC, ELICS Panel, Thyristor Control Panels, VSD, Package UCPs, Soft Starter
Indoor Junction Box
Transformer / Neutral Earthing Transformer
Electric Motor
Motor Terminal Box / Heater Terminal Box
Motor Local Control Station
Control Panel and Distribution Board
Outdoor
Lighting Fixtures
Socket Outlet / Plug
Junction Box
Subsea Cable Splitter Box
Power Box
Fibre Optic Box
IP42
IP42
IP42
IP42
IP42
IP42
IP42
IP 56
IP 56
IP 56
IP 56
IP 56
IP 66
IP 66
IP 66
IP 66
IP 66
IP 66
The requirements of IP Ratings to protect against temporary or permanent submersion of equipment shall be as below per IEC 60529:
a) Submerged at least IP 68.
b) Where electrical equipment located in especial area (for example sump deck) that can be affected by green water, IP67 protection shall be specified and/or the installation shall be done to minimize / avoid the effect of being submerged by green water. For cable routing in such exposed areas, consideration to be given for covered ladders/trays to protect cables from direct impact due to waves.
Attention shall be paid to the IP classification of equipment and proximity to deluge nozzles etc. If any equipment having an IP rating of IP 56 or less and is located close to a deluge sprinkler nozzle, where deluge water can strike the enclosure with more force than that created by gravity, then additional ingress protection shall be provided in form of external canopy mounted / installed on top of equipment. Such location shall be identified during detailed design phase.
All enclosures installed outdoors shall be provided with drain/breather arrangements. Suitable drain at low point and breather at high point shall be provided on every outdoor power junction box.
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8.3 Operational Safety and Reliability
The design of electrical systems and equipment shall ensure that all operating and maintenance activities can be performed safely and conveniently. Safe conditions shall be ensured under all operating conditions, including those associated with start-up and shutdown of plant and equipment and throughout the intervening shutdown periods.
The selection of electrical equipment shall be governed by fitness for purpose, safety, reliability, maintainability, availability of spares and service, compatibility with specified future technical options, design margins, suitability for environment, economic considerations and past service history.
8.4 Standardization of Equipment and Materials
For ease of maintenance and to limit the spare parts inventory, it is intended that as far as practical, each class of electrical equipment shall be of the same type and supplied by the same Manufacturer wherever it is used in the plant.
Spare parts interchangeability shall be considered when selecting materials and equipment. Standardization of materials and equipment shall be aimed for and compatible with standard design. Electrical equipment which will become obsolete in the near future shall not be installed.
Each vendor shall provide an obsolescence road map for each of the components used within their packaged equipment. Electrical Equipment Obsolescence Dossier shall be in accordance with IEC 62402.
Spare feeders, spare terminals, MCT, spare cable ladder/tray, etc, as requested in this document and other project specification shall be the minimum spares at the end of EXECUTE phase of project and spares shall be for COMPANY handover after EPC.
8.5 Maintainability and Accessibility
Electrical facilities shall be designed, constructed and installed so that components of the facilities are accessible without temporary access platform for maintenance and capable of being repaired and replaced.
Access for maintenance shall ensure that work on equipment can be performed safely without the need to work on or adjacent to live exposures.
8.6 Certificates, Declarations and Test Reports for equipment
For all major equipment, Manufacturer’s test reports shall be obtained from the Manufacturer in accordance with the equipment specifications, i.e., for generators, motors, electric heaters, MV Switchgear, LV Switchgear, VSDS, UPS equipment and distribution transformers.
Further certificates or declarations relating to the application of equipment for use in hazardous areas shall be provided in accordance with the requirements specified in Section 8.1.
8.7 Unit and Information
All quantities and dimensions in the electrical design shall be expressed in System International (SI) units. All information, data, documentation provided by the detail engineering CONTRACTOR shall be in the English language.
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8.8 Condition Monitoring System
Condition monitoring system (e.g., monitoring of partial discharge, temperature, vibration, thermal imaging, etc.) should be applied for equipment such as MV generators, MV motors (depending on COMPANY requirement), 11kV MV switchgear, MV transformers. Equipment suppliers may opt to provide based on the available emerging technologies on their suitability for integration into the equipment and area where can avoid intrusive work that may or will require outages. Provision of glass windows (arc energy rated optic) for infra-red thermography of power compartment doors of the MV feeder panels shall be considered. Systems supplied by others (e.g., subsea cable monitoring system) is limited to ELICS integration under COMP2 scope.
Established technologies shall be applied on an equipment such as MV generator, MV motors, MV transformer, MV switchgear, etc. are usually subjected to high stress and exposed to different levels of constant wear. This wear cannot be monitored with naked eye over a long period, which may lead to failures, unexpected outages and unanticipated financial losses. A monitoring system provided onto the equipment enables remotely online constant monitoring of equipment condition enables in the monitored operating parameters to be recorded at very early stage of fault development. Subsequent expert analysis of the problem, identifying the cause and a repair by the service engineer will make the component suitable for further operation in an incomparably shorter time and at a fraction of the cost of repairing a developed fault.
Condition monitoring system for MV switchgear and MV transformer and subsea composite cable (supplied by others) shall be supplied with an interface with plant ELICS. Condition monitoring system for MV motor and MV generator shall be installed in CPMS cabinet. The main function of monitoring system is to provide predictive maintenance of electrical equipment such as MV generators, MV Motors, MV Switchgear, MV transformer. Monitoring system shall provide an indication of an incipient fault as early indicator of the deterioration of high voltage insulation. The monitoring system shall process the data measured from electrical equipment and recommend actions and trends of incipient faults. The monitoring system evaluation model shall include bushing health condition, cooling system condition, insulation moisture, ageing and life expectancy, core hotspot and overload. The processed data shall remain stored in system and the system access shall be available at plant ELICS.
Detailed requirement on conditioning monitoring system for evaluating actual system response to operator actions, simulation of ‘what if’ scenarios, and anticipation of outcomes using real time and archived data etc. specified in respective equipment specification.
8.9 Documentation
Documentation such as calculation, general arrangement, single line diagram and other documents as detailed in Purchase Requisition shall be part of VENDOR scope to be included in the lump sum for the package.
As part of digitalization, VENDOR to submit the documents including but not limited to equipment data base (EQDB), bill of material (BOM), spare parts list (SPL), special tools, maintenance manual. Installation and operational manual, preservation procedure, etc., Refer to the COMPANY’s standard templates in the document as referred in section 24.2[4].
Further to the above, VENDOR to provide the scanning technology that will help to retrieve the equipment information and details (similar / better to barcode / QR Code / RFID code).
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9 ELECTRICAL SYSTEM DESIGN PARAMETERS
9.1 System Voltage and Frequency
The system voltages shall be selected from IEC 60038 to be compatible with existing installations. Unless otherwise specified, the electrical equipment and systems shall be designed for the operation at the utilization voltages listed as follows. The electrical system frequency shall be 50 Hz as recommended in IEC 60038.
Unless otherwise specified in project particular specification, the voltage levels shall be as follows:
Table 9-1: Utilization Voltage
System Voltage
Application
11 kV, 3Phase, 3 wire
a) Normal Power generation and distribution
b) Power supply for motors > 150 kW (Note a)
c) Normal power distribution
400V, 3Phase, 3 wire + PE
d) Power supply for motor ≤ 150 kW (Note a)
e) Welding socket
400V, 3Phase+N, 3 wire + N + PE
f) Emergency power generation and distribution
400V, 3phase+N, 3 wire + N + PE
230V, 1phase+N, 2 wire + PE
g) Lighting, convenient sockets and utility power
distribution and sub-distribution
230V,1phase+N, 2 wire + PE (from UPS)
h) AC UPS supply for vital loads
110V DC (from UPS)
j) Turbine Generator Control Panel and DC post lube
oil pump
i) Electrical control for switchgear
DC UPS [Note b]
k) Navigational Aids System
Based on Vendor design
Notes:
l) Turbine Compressor Control Panel and DC post
lube oil pump
a) The maximum power demand mentioned in the above table shall be considered as recommended value only and shall not be considered as compulsory limits. The selection of LV or MV motors with ratings higher or lower than those limits may be considered when technically and economically justifiable depending on installation requirements (i.e., distance between switchboard and motor, starting conditions), the availability of suitable material (switchgear, MV fuse) or the load classification (normal, essential or emergency). The selection of LV or MV motors with rating higher or lower than the limits specified in above table shall be approved by COMPANY.
b) Voltages supplied from UPS equipment furnished as part of packaged equipment items, e.g., marine navigational aids, etc., can be in accordance with the Vendor’s standard for the equipment.
c) Brownfield design of existing offshore electrical equipment and system shall be designed for operation at the utilization voltage as per existing facilities design voltage, unless agreed with COMPANY otherwise.
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9.2 Voltage and frequency Variation
All electrical equipment shall be rated for a steady state voltage variation of ± 10% and system frequency variation of ± 5%. Under normal steady state conditions, the system voltage and frequency variations shall be within ± 5% and ± 2% respectively.
During transient voltage depressions or interruptions due to short circuits, motor starts or power supply disturbances/interruptions conditions, the voltages at all points on the switchgear busbar system should be held constant within a tolerance of +20% and -15% of the nominal voltage and the frequency should not deviate from the rated frequency by more than ±10%.
9.3 System Voltage Drops
The maximum allowable voltage drop shall be limited to no more than 5% of its nominal system voltage during steady state conditions. Motor starting conditions shall not cause the voltage at the motor starter and any switchboard bus bar to drop to less than 85% of its nominal system voltage. Additionally, motor starting conditions shall not cause the voltage at the motor terminals and any load terminal to drop to less than 80% of its nominal system voltage unless it can be demonstrated that terminal voltages lower than 80% will not delay the acceleration time to a degree that would be detrimental to the motors insulation system. This shall require COMPANY approval.
For the AC UPS, output voltage shall not deviate from rated voltage by ±1% while output frequency shall be maintained within ±0.5% of nominal rated frequency when operating independently of the bypass.
Total voltage drop from transformer secondary or inverter/converter to the furthest point shall not exceed 5%.
Allowable voltage drop in DC cable shall be based on minimum equipment/load operating voltage whichever possible otherwise based on terminal voltage of 95% of nominal voltage or better.
Voltage spread at lighting fixtures shall not exceed 5% of rated lamp or ballast voltage. Voltage drop in cables shall not exceed the following.
a) All motor feeders – 5% at full load current, including total voltage drop in sub-bus feeder if any
b) Feeders of motors which are to reaccelerate automatically (wherever applicable) – 10% at full-
voltage locked rotor current including total voltage drop in sub-bus feeder if any
c) Lighting feeders – 1%
d) Lighting branch circuits – 2%
e) Overall system voltage drops during automatic reacceleration of motors shall not be allowed to
fall below 80% of bus nominal voltage.
Voltage drop shall not be more than 20% at motor terminals during motor starting.
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9.4 System Earthing
System earthing for individual system shall be as follow:
Table 9-2: System Earthing
Sub-System
Earthing principle
11kV MV system
400V LV system
400/230V lighting and utility power systems
AC UPS system
DC UPS systems
Earthing via Earthing Transformer (IT system with high impedance)
Solidly earthed (TN-S system)
Solidly earthed (TN-S system)
Unearthed (IT system)
Positive (+) & Negative (-) (Floating system)
Transformer and EDG star points are connected directly to platform steel structure beam via dedicated connections.
9.5 System Power Factors
Unless otherwise specified, overall system power factor including the reactive power losses in all electrical equipment shall not be lower than 0.8 lagging during normal system operation.
9.6 Short Circuit Ratings
All equipment shall be capable of withstanding the effects of short circuit currents and consequential voltages arising in the event of equipment or circuit faults. Short circuit current shall be performed in accordance with IEC 60909.
The short circuit ratings of equipment and cables, including the short circuit making and breaking capacity of circuit switching devices, shall be based on the peak and maximum fault current on individual circuits respectively.
Switchboards and switchgear at power plant or distribution substations shall have a margin of not less than +10 % between their short-circuit ratings and the worst-case prospective fault level.
9.7 Harmonic
Individual harmonic voltage and current distortions shall be in accordance to IEEE 519. Total harmonic voltage and current distortion at any switchgear or MCC bus shall be no more than limit specified in the IEEE 519. At MV, LV switchgear and including point of common coupling (PCC), proper corrective solutions shall be provided to mitigate harmonic effects resulting from non-linear loads or necessary filtering equipment shall be provided to maintain values below this level.
9.8 Arc Flash
MV switchgear including MV VSDS shall be arc proof design and shall provide type test certificate for Arc test by an approved independent international testing laboratory such as KEMA, ASTA, BASEEFA etc. For MV Switchgear shall be designed to meet arc resistant design requirements as specified in IEC
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62271-200. MV VSDS shall be designed to meet arc resistant design requirements as specified in IEC 62477-2.
The LV switchgear/MCC shall be arc proof and type tested as per IEC 61439 and IEC 61641 and certified for a fault, arc flash compliance and duty rating by an approved independent international testing laboratory such as KEMA, ASTA, BASEEFA etc. Arc resistant testing to IEEE/ANSI C37.20.7 type 2 rating may be acceptable subject to COMPANY approval.
9.9 Electromagnetic Compatibility (EMC)
Electrical equipment shall be designed to meet emission and immunity requirements as specified in IEC 61000 and IEC 60533.
9.10 Electrical Loads and Power Supplies
An electrical load list shall be developed and maintained to identify the electrical loads for each voltage level of normal and essential system to support the electrical equipment sizing. It shall be reviewed and updated regularly throughout the engineering design stage of the project and shall form the basis for provision of the necessary electricity supply and distribution system capacity as well as main equipment sizing i.e. MV Switchboard, LV Switchboard, distribution transformer and UPS. The load list shall also form basis of input to the Electrical power system studies.
The ratings of electrical loads for process equipment shall be as per the P&IDs and mechanical equipment selection data.
For offshore power generation sizing, the load summary shall include sufficient DDE contingency of 10% to account for system design development and manufacturer data. In addition, the final system design shall include a minimum of 10% load capacity for unknown future load growth (COMPANY Spare) with consideration that the known future compression train loads are already included as part of the design loads. The spare percentage for future growth shall be finalized with COMPANY for the consideration of optimum power generation. The DDE contingency can go down to 0% at the end of DDE.
For offshore emergency diesel generator sizing, the load summary shall include sufficient DDE contingency of 10% to account for system design development and manufacturer data. In addition, the final system design shall include a minimum of 20% load capacity for unknown future load growth (COMPANY Spare).
In overall, the power generation and distribution system shall include the capacity to supply the known future loads defined on the project plus here above contingencies.
Adequacy studies and reports shall be prepared for all offshore brownfield modification tie-in scopes.
9.10.1 Classification of loads
a) Normal Loads
Normal loads are defined as the ones which have no effect either on the safety or the safeguard of the installation or equipment in case of normal power generation failure. Normal loads are only fed from the normal (main) distribution systems. On loss of normal electric power supply, power supply to normal loads is not maintained.
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b) Essential Loads
The equipment, loads or systems involves in the safeguard of equipment or installation and in the restarting after plant shutdown such as lube oil pumps, ventilation fans, heat tracing system, diesel transfer pump, main generator auxiliaries, slow roll function (turbine, compressor, etc.), HVAC system, air compressors, electric – hydraulic crane requirement etc.
Under normal operating conditions, all essential loads shall be fed from the normal power generating units and distribution system. On loss of normal power generation, power supply to essential loads shall be fed from the emergency diesel generator.
c) Emergency Loads
The equipment, loads or systems in which failure of equipment causes an unsafe condition of the plant or installation resulting in jeopardy to life and/or major damage such as navigation aid system, PAGA system, FGS, ESD, telecommunication system, emergency lighting, escape lighting, etc.
All emergency loads shall be fed from UPS. Emergency and escape lightings shall be provided with self-contained batteries.
9.10.2 Load Assessment and Electrical Equipment Sizing
a. Continuous Loads
All loads that may be required continuously during normal operation, including lighting.
b.
Intermittent Loads All loads that are operated intermittently during normal operation or does not operate simultaneously.
c. Standby Loads
The loads that are required on following condition: a) during maintenance and those normally not running/in standby mode but required to be started during change over. Standby load shall be started and stabilized during changeover before stopping the running load.
b) during emergencies only, such as fire water pumps or standby air compressor which under lead-
lag configuration.
c) Pump-A is running, Pump- B can be started for simultaneous operation during abnormal
circumstances/pigging / process requirement / change-over /maintenance.
d. Absorbed Load
Calculated mechanical load i.e., the calculated electric power based on pump load. For instrumentation, computers, communication, air conditioning, the required load during full operation of plant. Calculated electric power for lighting based all lighting on during normal operation. For UPS, the electric power required to supply required load plus battery charging current.
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The following formulas are used as follows:
a) Consumed load, kW
= Absorbed Load, kW / Efficiency
b) Load Factor
= Absorbed Load, kW / Motor Nameplate or
Feeder Rating
c) Maximum normal running plant load
= x(%)E + y(%)F
d) Peak Load
= Max. Normal Running load + z(%)G
e) Design load (offshore)
(For power generation sizing where future compression train loads are already included as part of the design loads)
(For all other electrical equipment sizing)
= Max. Normal Running load x 1.10 (10% for
Contingency) & 1.10 (10% for Growth Allowance)
(percentage of future growth is subject to change based on optimized power generation)
= Max. Normal Running load x 1.10 (10% for
Contingency) & 1.20 (20% for Growth Allowance)
E = Total Continuous Load, kW
F = Total Intermittent Load, kW
G = Total Standby Load, kW
x, y & z are diversity factors:
• • •
x = 100% y = 30% z = 0%
9.10.3 Gas Turbine Generator Sizing
The design operating load is based on the calculated maximum operating load at the platform’s expected capacity with the addition of design growth, contingency factors and spinning reserve as defined below.
From Section 9.10 the contingency factor shall be considered as 10%. The contingency can be reduced to 0%, after mechanical equipment purchase orders are awarded and electrical load information is confirmed.
In order to compensate for electrical load changes during the various stages of design, generators shall be sized to maintain a minimum 110% of the calculated load during all phases of the project. This 110% also provides for spinning reserve at the conclusion of the project.
Table below provides the generator sizing and considerations for proper equipment selection at the end of each design stage.
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Table 9-3: Generation Sizing/ selection Considerations
Influencing Factors
Beginning of EPC Phase
End of EPC Phase
Maximum Running Load
A
Contingency
Growth Allowance(1)
Spinning Reserve(2)
Total
A x 10% = B
A x XX%(1) = C
A
A x 0% = B
A x XX%(1) = C
(A+B) x 10% = D
(A+B) x 10% = D
A+B+C+D
A+B+C+D
Notes: (1) (2)
(3)
Growth allowance to be finalized after GTG selection study. Spinning reserve is the reserve capacity of the generator to account for short term load variations, peak loads, motor starting, and simultaneous intermittent load. This 110% also provides for spinning reserve at the conclusion of the project. Applicable for 3+1 i.e. normal operating scenario.
The turbine generator sizing is based on ‘N+1’ configuration where ‘N’ is the number of generator required to supply the load and one generator is in standby. Selection on the ‘N’ number of GTG in operation shall be based on no production lost when one unit of GTG fails (spinning reserve).
Notes:
The spinning reserve of minimum 10% shall be catered for the GTG selection/sizing with the objective of minimizing load shedding or loss of production when one GTG fails.
9.10.4 Emergency Diesel Generators Sizing
Emergency diesel generator shall be sized at design ambient temperature to handle full load on emergency maximum load plus 10% design contingency and 20% growth allowances. (For CP EDG, to limit the EDG rating to 2000 kW, design contingency can be reduced subject to COMPANY approval). Essential switchgear between CP and LQ will be interconnected via MV link.
9.10.5 Other Electrical Equipment Sizing
Transformer, UPS and etc, shall be sized at design ambient temperature based on the present maximum running load, plus 10% design contingency and 20% load capacity for unknown future load growth. Switchboard to be sized based on transformer rating as minimum.
Small distribution boards for lighting and small power shall be sized with 10% spare capacity circuits with breakers and minimum of 10% spare space shall be available for installation of future breakers.
EDG breakers shall have a continuous rating at least equal to 1.05 times the generator maximum continuous kVA rating.
9.11 Power System Design Philosophy
The design of the electrical power distribution system shall be such as to afford the reliability and flexibility in operation consistent with operational requirements.
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The system shall remain stable under all operating conditions. All systems shall be designed for ease of operation and maintenance and simplicity consistent with maximum performance.
The power system shall be designed and sized such that the largest motor, per voltage level, can be successfully started at all levels of load utilisation without detriment to other connected loads.
The power distribution system load and fault levels shall be established such that standard rated, certified and well-proven equipment can be used to simplify procurement.
The generation and distribution systems shall be designed such that electrical faults and loss of generator prime movers are correctly and safely isolated with the minimum disturbance to the healthy system as well as ensuring transient and steady state stability.
Essential and safety equipment supplies shall be backed up to allow maintenance without disturbance to process operation and safety aspects.
9.11.1 Power System Design Philosophy
System studies and protection co-ordination reports shall be provided in support of the detailed design as part of EPC scope. The following power system studies shall be performed using ETAP Power System Analysis Software and EMTP-RV software:
a. Electrical Load Flow Study (ETAP)
b. Electrical Short Circuit Study (ETAP)
c. Electrical Large Motor Starting Study (ETAP)
d. Electrical Transient & Dynamic Stability Study (ETAP)
e. Electrical Protection Relay Co-ordination Study (ETAP)
f. Electrical Arc Flash Study (ETAP)
g. Electrical Harmonic Study (ETAP)
h. Electrical Overvoltage and Insulation Co-ordination Study (EMTP)
i. Electrical Switching Transient and System Capacitive Charging Current Study (EMTP)
The new equipment shall meet the outcome of the system studies. All existing equipment shall be verified to adequate as per the outcome of system studies for brownfield scope.
Overall power system studies for whole complex (i.e. CP, LQ, RPs and WHPs) shall be under COMP2.
9.12 Illumination study
An illumination study shall be carried out and shall include at least the following:
a. Calculation Basis: Illumination levels, parameters, proposed lighting fixture characteristics,
correction factors, etc.
b. Calculation Sheets and Lighting layout for each room / area showing minimum / maximum and
average illumination levels for each square meter.
LED lighting fixtures shall be used to maximum extent possible.
Lighting illumination level shall follow as per Lighting Philosophy [16].
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9.13 Cable Sizing
Cable and conductor sizing shall include the following considerations as minimum and shall be calculated as per IEC 61892-4:
a) System voltage and acceptable voltage drop at the respective load terminal
b) Manufacturer’s applicable short circuit time current curves
c) Rating of cable/conductor in free air, above grade conduits, cable tray
d) Derating factors for multiple conductors in cable ladder / tray
Lighting feeders feeding lighting panels shall have an ampacity of not less than the panel busbar rating ampacity of the lighting panel.
Voltage drop in cables shall not exceed the values as stated in Section 9.3 above.
For VSD system, VSD cable design shall be based on VSD manufacturer recommendation.
9.14 SAFOP (Safety and Operability Study)
A safety and operability workshop shall be conducted during detailed design stages. A third-party specialist subcontractor shall be engaged to conduct the SAFOP workshop. Outcome of the workshop shall be reflected on SAFOP Workshop Report and on SAFOP Action Closeout Report. Recommendations from the FEED SAFOP workshops and closed out report [51] shall be incorporated in the detailed design documents and drawings.
9.15 Power Generation and Distribution
9.15.1 Power Generation
The Power Generation System shall be designed considering the following principles:
-
Be robust and stable
-
Secure emergency power supply and distribution for emergency and essential loads.
-
Provide battery backed supply for critical control and safety equipment.
Unless otherwise specified, N + 1 configuration shall be applied for main turbine generators. Selection of ‘N’ shall be validated by project study with technical and economical consideration. Maintenance requirements, economic size, future load development plan, reliability, maximum load consideration, production loss, load shedding, power generation design efficiency improvement etc. shall be taken into account for generator sizing and selecting number of generating units.
The ‘N’ number of GTG in operation shall be based on no production loss when one unit of GTG fails.
During normal operation, the main power generators shall be capable of meeting the demand of the facilities loads. Each gas turbine generator shall be directly connected to the MV switchgear. Generator Control and Protection Relay panel and Excitation panel shall be installed in the electrical room.
The gas turbine generator is operating at generating voltage connected directly to the MV switchgear via incoming circuit breaker. The generators are sized to supply the maximum load without standby generator. The generated electric power shall then feed into MV switchgear, for main power distribution loads.
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All gas turbine generators shall be designed to be black started by the emergency power systems. Emergency generator shall be diesel engine driven provided as a backup source for the facility essential/emergency and black start electrical loads. Upon loss of normal power supply, the emergency diesel generators shall be automatically started and supply power to the emergency distribution system. Emergency generators shall be designed for parallel operation with the main power generators. The emergency diesel generators shall supply power to the Gas Turbine Generator auxiliaries required for black start of the main power generators. The emergency generator shall be operating at low voltage connected directly to the essential switchgear. All the GTGs are arranged such that it can be black started from the CP EDG one at a time. The LQ EDG shall also provide black start power to the required black start loads on LQ. Additionally, in case of outage of CP EDG during emergency scenario, LQ EDG can be used to supply the CP essential loads related to UPS, HVAC, crane loads and essential lighting via back feed MV transformer. Switching of back feed power supply via MV transformer shall be done automatically by EDG UCP. Also, CP EDG shall operate in parallel with LQ EDG via MV link utilising MV/LV transformer between CP and LQ essential switchgear.
While switching of back feed power via MV transformers, EDG excitation shall be ramped up gradually to prevent transformers inrush current which will eliminate the need of transformer pre-magnetization facility.
9.15.2 Power Distribution
The Electrical Distribution System shall be designed considering the following principles:
a) Efficiency of power distribution, utilization and equipment selection.
b) Protection of electrical equipment through selective protective devices.
c) Controlled electrical supply to equipment and machinery within the designed operating limits.
d) Prevention of unauthorised access or operation of electrical equipment.
The power distribution system philosophy requires electrical systems to be designed to maximize flexibility, reliability and maintainability.
The ultimate goal during distribution system design is to allow for reliable process operation concurrent with ongoing isolation and maintenance of selected parts of the electrical system.
The generated electric power will then feed into MV switchgear, for main power distribution to the MV loads on the complexes. For LV load consumers, the MV supply is then stepped-down to main LV switchgears/MCCs through MV/LV distribution transformers.
9.15.3 Interlocking / Inter-tripping System
The electrical interlocking and inter-tripping system shall be achieved within the MV and LV switchboards through hardwire breaker auxiliary switches taking into account of the ‘service position/withdrawn’ status and the ‘open/close’ status. The inter-tripping shall be provided between associated switchboard and switchgear to correctly isolate faulty items and to leave the system in a predictable orderly state after the operation of protection devices.
The following actions shall take place:
a) Closing of the downstream breaker shall not be possible if the upstream breaker earth switch is
closed.
b) Operation of the downstream incomer protection shall trip the downstream incomer and inter- trip the corresponding upstream outgoing feeder circuit (except 49 – transformer thermal overload).
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Interlock and inter-trip between upstream and downstream circuit breakers is not envisage for remote WHP5S & 10S transformer feeder. For WHP13S & 14S, interlock / inter-trip requirement to be reviewed and finalized [HOLD1].
The following general principles shall govern the design of the interlocking functions:
a) A generating unit shall be considered as unavailable and prevented from starting when its circuit earthing switch at the incomer circuit breaker assembly is closed. Similarly, manoeuvres of the earthing switch shall not be possible until the unit is at standstill.
b) Closing of a circuit earthing switch shall only be possible if the associated switchgear (circuit breaker(s)/contactor, switch, etc.) are opened and withdrawn. Similarly, closing of circuit breaker shall only be possible if the associated circuit earthing switch is opened and circuit breaker is in “Test” or “Service”.
c) Closing of switchgear (e.g., circuit-breaker, contactor, switch, etc.) shall only be possible if the
associated feeder branch is reported as available (‘fault free’ status).
d) Closing of a circuit breaker shall be performed via a check synchronising relay whenever the electrical system scheme anticipates connection between two live buses. Synchronizing-check relay shall be provided with provision to allow selection of closing of the associated circuit- breaker in any (or all) of the following configuration:
• live line/dead-bus or • dead-line/live-bus or • live line/live-bus or • dead-line/dead-bus configurations.
Operation of network switching shall be done either locally or via the ELICS.
Mechanical interlocking shall be provided as an integral facility of the switchgear, to inhibit in-correct operation of the circuit breakers, e.g., engaging the circuit breaker when closed, prevent an earthing switch being applied to an energised circuit or bus bar. Padlock facilities for maintenance safety shall be provided.
Mechanical key interlocks shall be provided to ensure safety of personnel and equipment when applying earth connections to incomers, busbars and feeder circuits.
Synchronising check relay shall be provided whenever the possible control scheme of MV and LV switchgear may allow for connection between two live buses.
9.16 Electrical Equipment Requirement
9.16.1 Main Turbine Generator
Main turbine generator shall be in accordance with “Specification for Gas Turbine Generator” [45]
The Generator shall be of a single fuel, synchronous, brushless, salient pole rotor type suitable for continuous duty type S1 in accordance with IEC 60034-1. Generator rated more than 10MVA shall comply to IEC 60034-3
Main power generators shall be gas turbine driven provided as normal power source to all facility loads. All main power generators shall be designed to be black started by the emergency power systems. The turbine generator shall be furnished as an enclosed skid mounted gas turbine generator package. The generator & turbine / generator electrical & instrumentation devices, terminal boxes and all associated accessories shall be certified and shall be suitable for operation / installation in hazardous area as specified in GTG data sheet and specification[45] Generator protection relay shall be redundant, microprocessor based and installed in generator control and protection panel. Overall generator
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protection will be divided into two protection relays for redundancy of functions (in case of failure of one of the protection relay).
9.16.2 Emergency Diesel Generator (EDG)
EDG shall be in accordance with “Specification for Emergency Diesel Generator” [46]
The EDG shall be supplied as a complete package with controls, protection and monitoring functions necessary for start-up, running, synchronisation and shutdown. They will only operate in case of power failure of the main power generation. Synchronisation facility shall be provided for all diesel generators.
The EDG is configured to automatically start-up on detection of ‘dead bus’ should power be unavailable from the main power generators.
EDG shall be designed for parallel operation with main power generators to allow a closed transition switchover of power supply. EDG shall be synchronized with normal power supply as well as with another emergency power supply (between CP’s EDG and LQ’s EDG). EDG package shall have design with manual control function for maintenance testing and loading. EDGs at CP and LQ shall be designed for parallel operation via MV link utilising MV/LV transformer at CP and LQ essential switchgear.
The EDG package shall be furnished complete with all controls, governor, automatic voltage regulator and ancillary equipment.
EDG with gradual excitation control shall be provided to energise MV/LV transformer from LV secondary winding.
The emergency generator at each platform shall be rated to supply electrical emergency loads of the respective platform, including HVAC and UPS for ICSS equipment and Telecom.
EDG shall be self-sufficient and shall not require external supplies of water, air, or electric power. The day tank capacity shall be sufficient for not less than 18-hour as per “Specification for Emergency Diesel Generator” [46] continuous operation at full load.
EDG shall be capable of black starting operation.
Start-up of the largest emergency motor connected to an EDG, with the largest possible pre-load of the generator, shall be possible without exceeding a negative voltage tolerance of 20% at the motor terminals or 15% at the main switchboard busbar.
9.16.3 Transformer
Transformer shall be in accordance with “Specification for Power Transformer and Earthing Transformer” [25].
Dry type transformers shall be used for indoor installation. The detail technical requirement of transformer shall be as per project specific data sheet and single line diagram.
Each transformer shall have a minimum of 1m clear space all around. Transformers should be installed so that the cable boxes of the adjacent units do not face each other.
Transformers shall be positioned and oriented in such a way as to minimize cable crossings, especially when multiple single-core cables are required.
If connection are specified by busduct, copper flexible shall be used for the connection of busduct. Where two or more conductors have to be connected per phase, the design shall encompass the necessary provision to ensure a straight connection of conductor by extending the copper bar or by installing an additional copper bar of adequate dimensions and suitable for the continuous rated current and with the ability to withstand the prospective short circuit current.
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Lighting and small power transformers shall be of dry type. Unless otherwise specified, lighting transformers shall have two full capacity 5 percent primary voltage taps below the rated primary voltage.
Transformer shall be supplied with shock/acceleration recorders which shall be used during transportation.
Power transformer shall be designed for bidirectional power flow in order to facilitate paralleling of CP and LQ EDG.
Earthing transformer and VSDS transformer shall refer to project specification for transformer.
9.16.4 MV Switchgear
MV Switchgear shall be in accordance with “Specification for Medium Voltage Switchgear” [24].
The MV switchgear shall be designed and constructed in accordance with the requirements of the latest edition of IEC 62271. MV switchgear shall utilise withdrawable vacuum circuit breaker. While circuit breaker SF6 type shall be subject to COMPANY approval.
For outgoing feeder where fault current required to limit at receiving end or to limit internal arc classification incident energy, MV fuse contactor may be utilised as shown in Key single line diagram and same shall be subject to COMPANY approval.
All incomers, transformer and motor feeders are controlled and protected via incomer Protection Relay, Feeder Protection Relay (FPR) and Motor Protection Relay (MPR) respectively.
Protective relays shall be microprocessor based electronic relays using digital metering techniques and capable of being remotely interrogated. Relays communication protocol shall be IEC 61850 compliant.
Protection relays shall be modular, flush mounted and of the withdrawable type. Protection relay shall be demountable without the need to disconnect secondary wiring. Inductive CT connections shall be automatically shorted if the device is removed.
For incomers and transformer feeders, it shall be possible to monitor and control these feeders from ELICS via shared Ethernet network/hardwires. For motors, it shall be possible to monitor and control these motors from DCS to MV Switchboard through communication link/hardwired. For monitoring signals, MV Motor IEDs shall communicate with IMCS using IEC61850 protocol, further IMCS to DCS communication shall be using Modbus protocol. Shutdown action from ESD shall be through hardwired link. Interposing trip relay for ESD trip shall be SIL3 certified.
The MV switchgear shall be arc proof type and meet all requirement in accordance with latest IEC standards. Arc detection devices shall be installed where required for Internal Arc Classification (IAC). Partitions shall be provided at bus coupler boundaries to prevent an internal arc in one bus section propagating to other bus section. Also phase barrier shall be provided in circuit breaker to prevent internal arc propagation in circuit breaker poles.
Any interposing voltage or signal required for interface with instrumentation and control panels such as the DCS, ESD, FGS, UCPs, etc. the interposing relays shall be provided. The relays shall be located in IRP and of hardwiring connection interfacing.
VTs shall include HRC fuse at primary and miniature circuit breaker at the secondary. VTs primary side fuse blown detection scheme and secondary MCB trip scheme shall be provided to avoid nuisance tripping of circuit breaker.
The auxiliary supply voltage for tripping, control and charging circuit will be input through 2 x 110V DC UPS.
Other DC voltage required such as 24VDC, shall be derived internally within respective Vendor scope through DC/DC converter and DC supply will be fed from DC UPS. Redundancy DC/DC converters shall be provided in each switchgear/MCC.
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9.16.5 LV Switchgear / MCC
LV switchgear/MCC shall be in accordance with “Specification for Low Voltage Switchgear, Integrated Motor Control System (IMCS) and Busduct” [23].
The LV switchgear and motor control centre shall be designed and constructed in accordance with the requirements of the latest edition of IEC 61439.
The switchgear with two transformer incomings and the bus section ACBs shall be interlocked to prevent continuous paralleling of the incoming supplies. Provision shall be made within the interlocking system to allow momentary paralleling for load transfer for maintenance isolation purposes and normal power restoration only. Barrier shall be provided at bus section panel of switchgear to isolate incoming and outgoing busbar at bus tie circuit breaker.
The LV switchgear/MCC shall be fully tested and certified for a fault, arc flash compliance and duty rating by an approved independent international testing laboratory.
The auxiliary supply voltage for tripping, control and charging circuit will be input through 2 x 110V DC UPS.
All incomers are controlled and protected via Feeder Protection Relay (FPR) or Generator Protection Relay (GPR) for EDG. Protection relays shall be modular, flush mounted and of the withdrawable type. Protection relay shall be demountable without the need to disconnect secondary wiring. Inductive CT connections shall be automatically shorted if the device is removed.
The LV Switchgear/MCC controls and protection shall be provided with integrated control, monitoring, protection functions and communication facility serving motor starters (MCU) and feeders (FCU). It shall be possible to monitor and control these motors from DCS to LV switchgear through communication link. Shutdown action from ESD shall be through hardwired link. Interposing trip relay for ESD trip shall be SIL3 certified.
Incoming feeders and major distribution feeders of LV switchgear (withdrawal type) shall utilise withdrawal type air circuit breaker (ACB) while outgoing feeders shall use withdrawal type MCCB feeder. Fuse-switch shall be provided for special application based on package manufacturer’s requirement. The switching of incomer and bus-section ACB in all cases shall be break before make, except during load transfer and normal power restoration. Manual operation of Incomer and bus-tie breaker shall be break before make, except during load transfer utilizing automatic change over control.
Motor feeders shall preferably be direct-on-line (DOL) type using circuit breaker with contactors and motor protection (e.g., overload, undercurrent, etc.). Each motor starter unit shall be of withdrawable type. The motor protection shall be motor protection relay (MPR) with communication link.
If specified in the requisition, an automatic restart facility shall be incorporated in the motor starters for the requested motor.
At any time, parallel incoming power supplies are not allowed except during power supply restoration for switchgear with two incomers and bus-coupler, power supply transfer from emergency to normal supply and emergency generator weekly testing. During this time, it will be parallel supply between main turbine generator and emergency generator supply, accordingly Service-Test position switch shall be provided at EDG UCP.
Any interposing voltage or signal required for interface with instrumentation and control panels such as the PMS, DCS, ESD, UCPs, etc. the interposing relays shall be provided. The relays shall be located in IRP and of hardwiring connection interfacing.
Other DC voltage required, shall be derived internally within respective Vendor scope through DC/DC converter and DC supply will be fed from DC UPS. Redundancy DC/DC converters if required shall be provided in each switchgear/MCC.
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9.16.6 Power Management System (PMS)
PMS shall be in accordance with “Specification for Power Management System” [18].
PMS shall be provided to monitor, and control active and reactive power produced by the generating units to achieve adequate loading/unloading of each generating unit according to its design limits and provide load sharing among generating units running in parallel.
The PMS shall be a PLC based system consists of dual redundant CCU. PMS shall be in a floor- mounted panel provided with a HMI which displays the operational screens and all data and operational pre-sets.
PMS shall have redundant communication link with ELICS which shall perform monitoring and control of electrical distribution and electrical Load shedding.
PMS will be part of GTG UCP supplied by GTG package vendor.
9.16.7 Electrical Integrated Control System
ELICS shall be in accordance with “Specification for Electrical Integrated Control System (ELICS)” [19].
ELICS shall comply to cyber security requirement as per “Cyber Security Lifecycle Management Plan” [40].
The ELICS shall be redundant PLC based systems comprising Central Unit (CU), connecting via Ethernet using IEC 61850 protocol (or other approved communication protocol) to Electrical panels/switchgears/MCC complete with associated software and peripherals for control, monitoring, supervision and diagnostic of the electrical distribution system.
The ELICS construction shall be PLC based design. The CPU and communication module shall be dual redundant. Whereby in the event of failure of one unit, the second unit shall take over control/function in a bumpless manner.
The ELICS shall allow the monitoring, data acquisition and diagnostics of the power distribution system and shall display on the HMI VDU graphical displays indicating the analogue measurements, statuses, trends, alarms, and diagnostics.
The ELICS shall control and monitor the MV and LV electrical distribution and the UPS system, electrical distribution e.g., incomers, breakers and bus-tie breakers and non-process feeders.
The ELICS shall be a gateway between the DCS and switchgear and for the acquisition of status information from MV/LV feeders, UPS, etc. Status information from the UPS, switchgear bus and interconnectors are available to the DCS from the ELICS, if requested by DCS. In general, ELICS shall be the main control of Electrical system switching.
Load Shedding (LS) shall be a sub-system of ELICS whose function is to provide plant operation with the ability to maintain balance between generation and demand to ensure safe and reliable operation of the power system. LS protects the power generation and distribution system against failure or instability caused by a sudden overload or fault following the loss of one normal operating generator or the sudden application of a large load. ELICS shall be designed with facility to disable load shedding function. ELICS shall be designed to include dual action for tripping of loads to improve reliability and avoid load shedding from single component failure. It shall be possible to isolate ELICS for maintenance without causing tripping of loads or generators.
A common alarm shall be provided from ELICS to DCS on load shedding trip initiation. Normalization of load shedding shall be performed at ELICS.
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In order to avoid a blackout during a partial power outage, a load shedding system shall be implemented. LS is designed to meet the requirements to allow the equipment to run under sufficient amount of power generated by GTG, and to commence LS whenever the power generated is insufficient to meet the load demand.
Load Shedding premise shall be based on below listed triggers:
a) Proactive Load Shed on loss of single GTG.
b) Under frequency Load Shedding
c) Low spinning reserve
The backup LS shall be provided via the implementation of under frequency protection in the 11kV feeders IEDs.
For communication with vendor supplied equipment i.e., UPS, conditioning monitoring system etc. communication protocol shall be IEC61850 or MODBUS TCP/IP or equivalent.
ELICS network for onshore and offshore shall interface with digitalization center and accordingly ELICS HMI shall be extended to digitalization center. ELICS shall be provided with required hardware and software for extension of ELICS with digitalization center.
Design of the cyber security for ELICS shall be fully compliance to COMPANY’s Industrial Control Systems Security Engineering Specification Procedure[8], Cyber Security Lifecycle Management Plan[40], Industrial Control System Security Engineering Policy[9] and National Industrial Control System Security Standard[10] throughout the whole project life cycle. Necessary USB malware protection stations to be provided at onshore and offshore locations for the purpose of cyber security which scans and cleans USB devices of malware before it could be used in any workstation, HMI or computers. As a basic requirement specified in Specification for Integrated Control and Safety System (ICSS)[52], the following shall be supplied network level at OCC and compression hub to fulfil cybersecurity requirement:
• Fire walls in between key network levels and interfaces
• Control system security hardening of all the in-scope equipment’s are carried out as COMPANY
hardening templates.
• Data Recovery and Backup Management for Disaster Recovery.
Tool such as Windows Server Update Services (WSUS) shall be provided for patch management. For application patch management, the EPC CONTRACTOR supported tool shall be provided for efficient administration.
9.16.8 Electric Motors
Medium Voltage and Low Voltage Motors shall be in accordance with “Specification for Low Voltage (LV) and Medium Voltage (MV) Motor” [28].
Electric motors shall be designed and constructed in accordance with the latest requirements of IEC 60034 and suitable for operation at MV and LV, 3 phases. Motor shall generally be delivered as part of the pre-engineered package, i.e., mounted on the same skid or base plate as the driven equipment.
For hazardous area installation, motors shall be suitably certified and have appropriate protection method to comply with the temperature rating of Hazardous Area Classification Zone.
All motors located outdoor shall be certified as minimum for Zone 2, gas group IIB, temperature class T3.
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All motors shall be of squirrel cage, totally enclosed fan cooled (TEFC) induction type, continuously operate at rated for duty service S1, and generally suitable for direct-on-line starting where possible.
Motors shall be provided with insulated rated Class F with a Class B temperature rise.
Motors shall be suitable for full voltage starting and capable of withstanding two starts in succession (coasting to rest between starts) from cold conditions, and one start from hot after running at rated conditions. Special applications for motor starting using alternatives such as star/delta starting, use of VSDs or soft starters for process requirements or reducing voltage drop can be considered.
Motor space heaters shall be de-energized whenever the motor controller disconnects (isolated position or completely withdrawn), or the isolating switch is in the OPEN position. As a minimum, motor efficiency shall be IE3 as per IEC 60034-30-1.
Motor anti-condensation heaters shall be automatically energised when the motor is stop. Motor anti- condensation heater shall be controlled and interlocked with the motor starter main contactor auxiliary contact to ensure that when the motor contactor is open, the heater is energized. A prominent warning label shall be provided in the heater terminal box to indicate the circuit may be live when the motor is stationary e.g., “Warning Circuit May be Alive”.
9.16.9 Uninterruptible Power Supply (UPS)
AC UPS and battery shall be in accordance with “Specification for AC UPS” [20].
DC UPS and battery shall be in accordance with “Specification for DC UPS” [21].
Battery back-up systems, either AC UPS or DC UPS shall provide the no break security required for specific services during loss of main and EDG power supply.
The AC UPS shall be designed with redundant configuration with 2 x 50% battery. Each UPS comes with battery charger, battery, inverter, bypass isolation transformer, static switch, maintenance bypass switch, power distribution panel. The redundant UPS sets shall have the provision to parallel the battery sets and each UPS shall also be capable of charging both the battery sets at the same time if required. The two power distribution panels of UPSs shall be connected in parallel by a segregated Tie breaker. No single common failure shall affect both UPSs. UPS system will provide 2 power sources for all control systems (i.e., DCS, ESD, FGS and ELICS) and all telecommunication equipment and other critical services control panels (e.g. HVAC). The power cables from UPS A and B shall be routed as far from each other as practicable.
The DC system shall be ungrounded, and a ground fault detector with an associated notification shall be provided for each load bus. Ground fault detectors shall be sensitive enough to operate for a ground fault occurring on either polarity of the system.
Power supply for GTG package emergency system / LO system shall be from platform DC UPS via common DC distribution board for all GTG Unit.
Alternatively, 1 x 100% AC or DC UPS (including batteries, battery charger and DC distribution board) for each GTG package shall be sized to stop the GTG package safely, with no damage of the machine in case of prolonged power outage and emergency stops. Distribution board for GTG package shall be suitable for Zone 1 to supply power to lube oil pump(s) in case of power outage and platform emergency shutdowns to avoid equipment damage, as necessary.
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9.16.10
Battery
Batteries shall be Valve Regulated Lead Acid (VRLA) type with lead calcium grids, sealed, maintenance-free and shall be approved by COMPANY. Latest VRLA battery technology available at the time of ordering shall be considered.
Alternatively, Ni Cd battery as per IEC 62259 is also acceptable. Partial recombination cell shall have a gas recombination rate not less than 96% under charging mode.
Batteries shall be mounted on racks in air-conditioned battery room. Installation of battery in switchgear room shall comply with IEC 61892-6 Table 1. In general, due to the battery high ampacity hours expected, battery shall be installed in dedicated battery room.
Outdoor skid mounted batteries, such as those serving fire water pumps and diesel-engine generators shall be sealed nickel-cadmium complying with IEC 60623 and shall have charging and monitoring functions for diesel engines.
Battery installation shall be in accordance with “Specification for DC UPS” [21].
The battery circuit breaker, MCCB with lockable in OFF position, shall be provided to facilitate on-load isolation of the battery for battery maintenance purposes. The switching device shall be installed adjacent to the battery and shall be suitably classified for Zone 1, gas group IIC. The battery circuit breaker, MCCB shall have facilities for ESD remote tripping and shall have ‘override’ provision for black start to bypass the ESD tripping. The battery circuit breaker shall be manually close only and shall be Ex’d’ or Ex’de’ type.
A water tap, portable eye-wash, sink and drain shall be installed as per safety requirement, shall refer to “Technical Safety Basis of Design” [43].
For AC-UPS, the batteries shall be rated to energize the relevant loads for not less than:
a) 4 hours for emergency shutdown / ESD and alarm systems
b) 2 hours for distributed control systems (DCS)
c) 4 hours for public address and telecommunication system
d) 4 hours for fire & gas detection systems
e) 4 hours for air navigational aids (helideck)
f) 4 hours for Aviation Warning Lights (AWL)
g) 2 hours for ELICS, HVAC, Package UCP.
For GTG and GTC UPS consumer – autonomy time based on manufacturer’s requirement.
For DC-UPS the batteries shall be rated to energize the relevant loads for not less than:
•
1 hours for switchgear tripping and closing supplies
- number of circuit breakers Open/Close/Open cycles (or cycles agreed by COMPANY) shall be considered in the battery sizing.
For Marine navigational aids:
•
96 hours (from batteries charged by plant power supply via platform Nav-Aids battery charger).
For Emergency and Escape lighting:
•
1.5 hours (from integral batteries)
Purging of battery room and other rooms requirement after normal operation shutdown shall be as per “Technical Safety Basis of Design” [43].
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9.16.11
Distribution Board (DB)
Distribution board shall be in accordance with “Specification for Low Voltage Distribution Board” [30].
Lighting and small power requirements shall be supplied via a network of designated DBs located indoor and strategically in various levels of the platform of load centre.
DBs shall be suitable for the expected environmental conditions and specified area classification.
The fault rating at the point of application and rating of circuit breakers shall be coordinated to provide discrimination between incoming/outgoing breakers with minimum rating being 20kA. Cascading of incomer and sub circuit CBs in order to achieve the design prospective fault level will be considered if needed (e.g. where MCBs are unavailable for the prospective fault level or if the DB size becomes prohibitive).
Outgoing circuits feeding hazardous areas shall have switched neutral. This requires use of 2-pole circuit breakers for 1-phase circuits and 4-pole circuit breakers for 3-phase circuits be class 2 (stranded compact) as requirement for all circuits neutral to be switched.
All outgoing circuit breakers shall be lockable in OFF position for safety isolation purposes during maintenance.
In general, the design of lighting DB shall include normal, essential, emergency, exit lightings for indoor and outdoor. Normal lighting fittings and essential / emergency / exit light fittings, shall be appropriately grouped in separate bus sections with bus – tie circuit breaker in between, in order to enable the switching between the source of power supply automatically, with provision to ON/OFF from local / DCS. Normal bus section to be powered from normal source while essential bus section to be powered from Emergency DG source. During emergency, all lightings shall be powered from essential source. Sizing of EDG shall be accounted for both normal and essential lighting loads. Further, provision of ON/OFF from DCS shall enable to isolate the normal lighting loads if necessary to avoid overloading of EDG.
9.16.12
Cables and Accessories
Cables and Accessories shall be in accordance with “Specification for Electrical Cable” [27].
All cables shall be flame retardant type complying with IEC 60332-3-22, Cat A. Fire resistant cable shall meet the requirements of IEC 60331-21. For all cables, the conductors shall be class 2 for fixed installations and class 5 for flexible installations. Conductor insulation shall be cross linked polyethylene (XLPE) or EPR.
The voltage rating of cable shall be based on the electrical system voltage, the following preferred values shall apply:
•
•
•
•
LV System
3.3 kV System
6.6 kV System
11 kV System
:
:
:
:
0.6/1.0 (1.2) kV
3.6/6 (7.2) kV
6/10 (12) kV
8.7/15 (17.5) kV
For indoor, the use of non-armoured cable shall be considered. The design of these systems shall take into account the specific earthing and bonding requirement for the electrical safety and EMC. For EMC reasons, any non-armoured cabling shall be adequately protected by the mean of cable ladder or cable trunking.
All cables for outdoor installation, cables which are laid partially indoor and partially outdoor shall be armoured cable throughout.
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When cable is required with armour, shall comply to the following:
• Medium voltage cables < 30kV: Double galvanised steel tape for multi core cables. For single core cables, the armour shall be made of tinned copper wire braid, alternatively, Aluminium Tape armour can also be acceptable subject to COMPANY approval. Tape thickness shall be in accordance with IEC 60502-1/ IEC 60502-2 or IEC 60092-350 / IEC 60092-354.
• Offshore LV Cables: Galvanized steel for multi core cables, while Bronze or Aluminium for single
core cables.
Minimum cross-section of LV power cables shall be 2.5mm2, copper and control cable shall be 1.5mm2.
All power cables shall normally be installed as a single unjointed length. All single core AC cables shall be installed and cleated in a trefoil configuration to withstand force during short circuit current passing through them. The cleats shall be suitable for the mechanical forces associated with the associated short circuit level. Cable cleats/trefoil shall be used for securing single core cables to ladder rack at intervals not exceeding 900 mm. These cable cleats shall be in accordance with IEC 61914.
Cable installation shall conform to IEC 61892-6 “Mobile and fixed offshore units – Electrical installations Part 6: Installation” section 6.2.
Cable used for indoor and hazardous area for critical and safety equipment which are fed from UPS system (e.g., communication system, fire & gas detection system, PAGA, navigational aids) and those services which have to be operable under fire condition (e.g., fire line pressuring jockey pump, fire water pump, foam skid and water mist system) shall be of fire-resistant type complying with IEC 60331-21. In general, all cables from UPS including battery cables shall be fire resistant, including safe area installation.
Cable bending radius shall not be less than that recommended by cable manufacturer, where this information is not available it shall be as per IEC 61892-4, section 4.15.
The electric cable construction and the cable glands are to achieve the appropriate seal, such that gas cannot migrate through the cable. Gland selection should consider all aspects including cable type, cold flow, gas hazard, etc.
Cable glands shall be nickel-plated brass, IP66 (for outdoor) and hazardous certified as required. Glands for use in metallic and non-metallic enclosures shall utilize earth tags. The gland plates shall be removable and undrilled. All certified enclosures shall be drilled by Manufacturer or supplied with removable certified gland plates. Drilled holes in certified apparatus shall be fitted with certified stopping plugs. For single core cables, non-magnetic gland plate shall be provided.
All cables and glands shall comply to IEC 60079-14 and IEC 60079-10-1.
For special cable i.e. battery cable shall have barrier type cable gland.
Cables installed on cable ladders shall be secured by “Tie Wraps” of suitable size. “Tie Wraps” shall be black ultraviolet resistant type. All cables shall be neatly and securely cleated or tied to the cable ladder by means of nylon coated stainless steel, bevelled edged cable straps for vertical runs, and ultraviolet- resistant nylon cable ties for horizontal runs. Cable in a vertical cable tray shall be attached at intervals not exceeding 600 mm or at every rung. Cable in a horizontal cable tray shall be attached at intervals not exceeding 900 mm.
Cables should be segregated and suitably identified in the applicable cable category,
a) Power (MV and LV)
b) Power and control cables
c) Fire and gas (detection and protection)
d) Telecommunications (CCTV and security systems)
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e) Telecommunications (RF cabling)
The above-mentioned categories shall be further sub-divided into normal and intrinsically safe (IS) circuits. MV cables shall be segregated from the LV cables.
MV multicore cables may be laid in one layer touching, and LV multicore cables in up to a maximum of two layers touching, with the applicable group rating factor applied and a maximum of 25 % spare rack capacity. Multiple cable having smaller cross section area, shall be bunch and cable bunches may be laid in up to maximum of two layers touching.
Individual cables emerging from floors, decks or gratings shall be protected against mechanical damage by means of kick plate installation. Single core cables emerging from floors, decks or gratings shall be protected by kick plate. These pipes of kick plates shall extend at least 100 mm above ground or floor level.
Cable identification and labelling shall comply to “Specification for Electrical Cable” [27].
9.16.13
Lighting System and Small Power
The lighting system shall be designed and constructed in accordance “Lighting Design Philosophy” [16].
Lighting shall be installed in all areas of the facilities to ensure that there is an adequate level of illumination for operators / maintenance personnel to safely access all areas. Luminaires shall be installed to facilitate easy maintenance and re-lamping. Refer to “HFE Workplace Design Specification” [47].
Suitable illumination shall be provided at facilities to facilitate normal operation and maintenance activities and at the same time ensure safety of the operating personnel. Lighting shall be LED type.
General lighting on the new facilities shall be categorised into the following:
a) Normal lighting
b) Essential lighting (minimum 30% of normal lighting)
c) Emergency and Escape lighting
Essential lighting luminaries shall be installed at strategic locations including control rooms, switchgear room, instrument electrical room, living quarters and areas where required for essential services. Power supply to essential lighting shall be backed-up by emergency diesel generator.
Part of the essential lighting shall be emergency lighting and escape lighting. The emergency and escape lighting to be located such as to illuminate the escape routes, ladders and walkways to allow safe movement of personnel to the muster points, lifeboats, including safety equipment etc.
Emergency and escape lighting shall be provided with self-contained batteries with autonomy of 90 minutes. The self-contained units shall be equipped with test provision and have an automatic switching device to light the unit when the normal lighting supply fails. Emergency and escape lighting shall operate continuously, and light sensor shall not be used for switching emergency and escape lighting circuit. Emergency and escape lighting shall be equipped with local battery monitoring system which shall include local indication for charging/operation, fault, automatic functional test, etc.
Lighting for outdoor operating areas that are not continuously attended shall be controlled via photocell and auto-on/off selector switch.
All lighting fixtures installed outdoors shall be suitable for minimum Zone 1, gas group IIB, temperature class T3 hazardous area. All lighting fixtures installed inside battery room shall be classified for Zone 1, IIC, T3 area. All other indoor lighting fixtures shall be industrial type.
Lighting feeders feeding lighting panels shall have an ampacity not less than the ampacity of the lighting panel.
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Lighting poles shall be completely and properly sealed at both ends and holes; they shall be painted with anti-corrosion paint. Mounting of the lighting fixtures should be done externally without any hole on the pole to prevent corrosion. Lighting pole shall be collapsible type.
The location and mounting of luminaries shall take account of efficient illumination, accessibility of luminaries and convenience of servicing. Luminaries shall not be mounted above machinery having exposed moving parts. Adjacent light fittings shall, as far as practicable, be on separate circuits. Lighting circuits shall also be arranged to prevent stroboscopic effects, so minimum two (2) circuits of lighting shall be provided at each area. Emergency lighting with self-contained batteries Ex type to be installed above but not limited to Essential Switchgear, MV switchgear, EDG UCP panel, GTG Synchronization UCP panels.
Sufficient power and convenient socket outlets shall be provided to enable maintenance to be carried out. For CP, bridges, outdoor and LQ utility deck, as a general guideline, one socket outlet per every 20m radius outdoor, one welding socket outlet per 50m radius outdoor. Socket outlet circuits shall be protected with earth leakage protection in the distribution board or MCC and shall have facility for FGS remote tripping in the event of confirmed fire/gas detection.
Convenience sockets and plugs for use in indoor area shall be suitable for 230V, 50 Hz, 1phase, 3- wire, rated 13A suitable for flush mounting on wall with polycarbonate housing, BS 1363 switched type. Outdoor Welding sockets and plugs shall be suitable for installation in outdoor hazardous area Zone 1, IIB, T3, rated 63A, 400V, 50Hz, 4-Wire (3Ph+PE). Outdoor convenience socket outlet shall be suitable for installation in outdoor hazardous area minimum for Zone 1, gas group IIB, temperature class T3 rated 16A, 230V, 50Hz, 1phase. 3 phase socket outlets shall be self-lockable from power i.e.: no power supply to the outlet pins unless plug is inserted, as a safety precaution. Power outlets installed in hazardous areas shall be fitted with padlocking facilities.
In other areas, outdoor, process etc., the socket outlets shall be located approximately 1.5m above deck level measured to centre of socket outlet.
Sockets outlets earth pin shall be connected to earth via dedicated earth wire. Circuits connected to convenience socket outlets shall be provided with RCCB at distribution board.
Plugs shall not be interchangeable with sockets of a different voltage or current rating, nor shall it be possible to insert an industrial type of plug into a Zone 1 classified outlet.
9.16.14
Portable Lighting Units and Lamps
Rechargeable portable hand lamps minimum two numbers will be provided for all areas where operating personnel may be present at all times the followings:
a)
b)
c)
Central Control room
Switchgear rooms
Local Equipment Room
The portable hand lamps will be installed on each exit door. The portable lamps and hand lamps shall be explosion proof battery powered lamp of 3 hours autonomy time and suitable for operation in a Zone 1, gas group IIB, temperature class T3 atmosphere.
Fire and emergency response crew changing room and Helicopter Rescue Equipment minimum number of portable explosion proof battery powered lamp requirement shall be as per “Technical Safety Basis of Design” [43].
Each portable hand lamps shall comprise a fixed wall mounted battery charger. The unit shall be kept on float when not in use and fed from emergency lighting distribution board.
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9.16.15
Navigational Aids
Navigational Aids System shall be designed and constructed in accordance with the requirements of “Specification for Navigational Aids System” [22].
Navigational aids for the offshore platforms shall be provided for new offshore structures, complying with International Association of Lighthouse Authorities (IALA) recommendations.
All equipment and all its accessories shall be suitable for areas classification of Zone 1 gas group IIB and temperature Class T3.
The navigational aids shall be purchased as integral packages complete with all wiring between those equipment which are mounted on a common frame. Provision shall be made to accept interconnecting cables which will be provided by others. The Navigational aids system (i.e., lanterns) shall be synchronized with the existing bridge connected facilities navigational aid system.
The standby power supply system shall be dedicated to navigational aids consumers and should be assembled as part of the Navigational Aids Central Control Panel (NCCP).
The only exception shall be the DC power supply for navigational aids, which shall never be tripped even under gas conditions. Battery backup time shall be at least 96 hours as per section 9.16.10. DC panel shall be Ex type.
9.16.16
Helideck and Aviation Warning Lightings
Helideck and Aviation Warning lighting shall be provided in accordance with the latest ICAO CAP 437 regulations. Red obstruction lights shall be installed on crane according to CAP 437 Chapter 4 – Obstacle-Marking and lighting.
Helideck shall be lighted up the perimeter of the landing area along with helideck. Helideck lighting shall be designed such that glaring to the pilot and hazard to helicopter landing is avoided. Power supply to the helideck lighting shall be from the AC UPS power supply via Helideck Lighting control panel installed outdoor.
Any deviations from regulatory agreements shall be agreed with Gulf Helicopter Company (GHC) by CONTRACTOR.
All helideck lighting and junction boxes shall be certified for Zone 1, gas group IIB and temperature Class T3, hazardous area classification. Lighting fixture is preferably of LED type.
9.16.17
Multi-Cable Transit (MCT)
The propagation of fire from one space to the other shall be prevented by the proper sealing of openings around cables with fireproof material.
All cable entry penetrating through a firewall wall into a pressurized room, between rooms, blast wall, substation floor or walls shall be suitably sealed. Where such cable entry holes are required to be gas tight and/or fire resistant, multi-cable transits blocks shall be installed or silicone foam, weak-mix concrete (in floors only) or a chemical compound with subliming heat resistant and fire-retardant properties may be used. Multi-cable transit fire rating shall maintain integrity with the firewall or blast wall rating. Each multi-cable transit shall be provided with 20% spare. In addition, another 20% of MCT frame (EMC type) complete with blocks shall be provided.
In general, all bulkheads and deck penetrations shall be fitted with minimum 1-hour (A60) rated multi- cable transits. This arrangement shall particularly apply to:
a)
fire walls
b) walls between hazardous and non-hazardous areas
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c)
through walls, roofs and floors to the open air
MCT frames shall be Mild steel suitable for offshore application. For single core cables, where each phase is not covered by individual frame, the MCT frame shall be made stainless steel (non- magnetic material). MCT sizes and frame configurations (including whether non-flange type for welded installation or flange type for bolt-on installation). MCTs shall be certified for use in hazardous area if cabin is installed in hazardous area.
MCT shall be complete with all accessories to make a complete MCT system, e.g., stainless-steel stay plates, insert modules, packing unit (wedge), etc. Lubricant shall also be included for installation of insert modules. Insert modules shall come in two-halves and shall be selected for the cable outside diameter.
Where indicated in the MTO, fire rated and/or blast resistant type MCT systems shall be provided to maintain integrity with the firewall or blast wall rating.
9.16.18
Electrical Heat Tracing
The Electrical Heat Tracing (EHT) shall be designed, constructed & tested in accordance with “Specification for Electrical Heat Tracing” [31].
Electrical Heat Tracing (EHT) shall be used to maintain the minimum temperature of fluid contents in process equipment and piping subject to freezing, congealing, separation, excessive increase in viscosity, or forming water by condensation. In some cases, EHT may be required to be provided where product heat-up is required or if over-temperature can degrade a product. The electrical heat tracing shall be designed based on self-regulating/self-limiting heater or constant wattage type system consists of a solid metal sheath containing one or two conductors separated by mineral insulation (MI cable). For specific applications, however, where the self-limiting characteristic of the heating cable is unsuitable regarding response or temperature limitations, temperature control device control shall be used.
The design life of the EHT system (cables, ancillary materials and control system) shall be minimum 30 years from the date of installation.
Each heat tracing circuits shall be equipped with 30 mA RCCB with trip indication. Common alarm shall be given to a central alarm system for each sub distribution board. Sub distribution boards shall be provided for local power distribution to the heat tracing system in each functional area. The distribution boards shall not be located in hazardous areas or in exposed environments.
The heat tracing system shall be of manufacturer’s standard design and shall be as compact as practicable to minimize space requirement while at the same time provide adequate space within the components to facilitate maintenance. The heat tracing system shall comply with IEC 60079-30 for hazardous area installation.
9.16.19
Junction Box
These shall be 316 stainless steel material except lighting junction box. Lighting junction box made by high impact resistant, flame retardant glass-reinforced black polyester with internal earth continuity plate will be accepted.
Intermediate junction boxes or cable splices are not permitted on power cabling unless approved in writing. In general, this is only permitted to connect regular power cable to motor cable e.g., submersible motor. All package skid interface junction boxes shall be at the skid edge external to any acoustic enclosure.
FRP/GRP JB shall comply for Hazardous Area and Fire/Safety Requirements installation. All hardware and fixing clamps shall be stainless steel, grade 316L and marine environment rated.
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Junction boxes for lighting and small power circuits within the living quarters/accommodation areas shall be of the standard industrial as a minimum. All outdoor junction boxes shall be certified for the applicable hazardous area classification.
Junction boxes (except junction boxes for power distribution) shall include a minimum of 20% spare terminals to allow later modification without invalidating the certification.
All outdoor junction boxes cable entry shall be from bottom except for lighting junction boxes where side and/or bottom entries are acceptable. Suitable drain at low point and breather at high point shall be provided on every outdoor power junction box.
9.16.20
Cable Ladder / Tray
Cable ladder / tray shall be in accordance with “Specification for Cable Ladder and Tray” [26].
Hot dip galvanized (HDG) or Glass Reinforced Polyester (GRP) cable ladder/tray shall be used for indoor installation and Glass/Fiber Reinforced Polyester (GRP/FRP) cable ladder/trays shall be used for outdoor installation. All nuts, bolts, washers, etc. shall be of stainless steel, grade 316L.
However, the use of painted SS 316L cable ladder / tray for outdoor installation is acceptable subject to COMPANY approval.
The cable ladder/tray support could be made of carbon steel for indoor and outdoor installation.
Care shall be taken to avoid corrosion due to coupling of different metals, i.e., tray support and tray. For outdoor areas, insulators (e.g., neoprene rubber insulating pads) shall be used between carbon steel and stainless steel (or any other dissimilar metals) to prevent galvanic corrosion.
All main cable ladders, trays fixing materials used shall have a minimum of 25% spare rack, trays or ladders capacity.
The cable ladder/tray laying pattern shall be as follows:
a) For uniformity, both vertical and horizontal arrangements of cable ladders/trays shall have a fixed order e.g., MV cabling on top, LV in the middle and instrumentation at the bottom or MV cabling on the left, LV in the middle and instrumentation on the right.
b) Cables shall be supported by cable trays or cable ladders all the way up to their terminations.
c) Cable ladders installed horizontally shall have sufficient space to facilitate cable pulling and cleating/ strapping. It shall be minimum 300mm free space between top of one ladder edge to bottom of next ladder edge, and from top ladder edge to roof. Crossing at right angles is acceptable without further segregation.
Individual cables may be fixed directly to the main structures, walls, ceilings or columns by means of proper fixing and supporting materials (e.g., steel flat bar). However, no more than 2 cables shall be installed along a common route.
Cable ladders and trays covers shall be provided for all cable trays installed within 2.4m above floor ground. Cable ladders and trays covers shall be provided for all top and vertical Cable Trays and all cable trays/ladders located in flare area (including bridge from CP to FL platform)
SS316L cable trays or ladders shall be bonded to the platform steel structure or to the metallic equipment enclosures, junction boxes or structures where the cables end.
Ladder cover shall be provided where drop object occurrence is a possibility apart from direct solar radiation or flare radiation.
Circuit separation for different circuits and classes of services shall conform to the following specific requirements.
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a) Conductors rated 600V and less with the same insulation level may be installed in the same
raceway provided that interference between circuits is eliminated.
b) Separation between instrumentation and other type circuits shall comply with Table 9-4 below.
c) Telephone and signal circuits shall be routed in separate trays or physically separated by barriers. Separation between communications wiring and power circuits shall comply with Table 9-4.
d) Substation control circuits associated with a single power source may be routed in a common raceway or cable. Station control circuits associated with primary-selective, secondary- selective, or spot-network substations that have alternate power sources shall be separated according to their related power source. GTG differential relay circuits to be kept separate from other GTG differential circuits.
e) Spacing between instrumentation circuits and power circuits in cable tray, shall be maintained
to prevent noise on instrument circuits. Refer to Table 9-4 for minimum separation.
Table 9-4: Minimum Separation Between Power and Signal Wiring
Power Wiring System Voltage (V)
Separation*
230
400
6600 and higher
300mm
450mm
900mm
12in
18in
36in
- Between power tray edge and signal tray edge
Tray and ladder installation should not obstruct other regular activities like maintenance, inspection, etc. All cable ladder/tray installation shall be accessible for maintenance and future installation. Kick plate shall be fitted around penetrations in floor where cables/tubing are exposed to mechanical damages. Protection shield shall be installed where cables can be exposed to physical damages, minimum 500mm above the floor.
Glass/Fiber Reinforced Polyester (GRP/FRP) cable ladder/trays shall comply with a glow wire temperature of 850 deg.C by Glow-wire flammability test as per IEC 60695-2-11.
9.16.21
Conduits and Accessories
Conduit shall be rigid metal, heavy wall with threaded joints. Aluminium conduit for offshore use shall be copper-free. Hot dip galvanized conduit at outside is not allowed due to corrosion issue.
All flexible conduits shall be supplied with groundable termination fittings and external green insulated bonding jumpers. Conduits shall be supported at such intervals as required to prevent objectionable sag, but in no case shall intervals exceed 3 m. Conduit shall not be supported directly on equipment. Conduit shall not be supported from piping.
9.16.22
Bus Ducts
The bus duct shall be designed and constructed in accordance with “Specification for Low Voltage Switchgear, IMCS and Busduct” [23].
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9.16.23
Electric Process Heater
Electric Process heater and its thyristor control panel shall be designed and constructed in accordance with “Specification for Electrical Heaters” [32].
The electrical process heaters are suitable for three phase LV system and shall be capable of operation within the nominal voltage and frequency variation.
A heater control panels shall control the entire unit. Heater control panel shall be designed such that safe access to the control wiring and system is possible without isolation of the main power to the system including protection from live exposure and arc flash hazards.
9.16.24
Variable Speed Drive System (VSDS)
The VSD shall be designed, constructed & tested in accordance with “Specification for LV and MV Variable Speed Drive System” [29].
The MV VSDS comprises the electrical motor, the converter with its control and protection equipment, the supply transformer and harmonic filters (if required due harmonic contents exceeded). The LV VSDS comprises the electrical motor and the converter with its control and protection equipment.
The order for VSDS shall be placed through the Manufacturer of the driven equipment. The Manufacturer of the driven equipment has the responsibility for the correct operation to specification of the combination of VSDS and driven equipment.
The Manufacturer of the VSDS shall be responsible for the performance of the VSDS as described in specification and for compliance with requirement of the driven equipment as given to him by the driven equipment Manufacturer at the time of order.
VSD shall be provided with serial communication link with ELICS and DCS. Alternatively, if the dual communication port not available in VSD, then required signals shall be hardwired to ELICS.
9.16.25
Protection and Metering
The electrical protection shall be in accordance with “Electrical Protection Philosophy” [13].
The electrical system shall be equipped with automatic protection which shall provide safeguards in the event of electrical equipment failures or system mal operation.
All protective relays shall be microprocessor based electronic relays using digital metering techniques and capable of being remotely interrogated. Relays communication protocol for protection relay at MV switchgear and LV switchgear shall be IEC 61850 compliant.
In any event this shall be within a time corresponding to the short circuit current withstand capability of equipment, system stability limits and the maximum fault clearance times. All protection related to generator engine protection will be provided by generator engine supplier which form part of unit control panels.
Electrical protection shall be provided, coordinated with existing equipment / system setting and type for the incoming and outgoing feeders in accordance with “Electrical Protection Philosophy” [13] and “Typical MV/LV Switchgear Single line diagram” [34].
All protection relays shall be programmable and multifunctional based on latest technology. They shall be able to communicate with other panel / control systems with IEC 61850 protocol.
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9.16.26
Local Control Station (LCS)
In general, all motors shall be equipped with the following LCS.
For electrically operated motor starters, the control circuit shall include a local control station that is in sight of and near the motor on the side opposite the power cable entry as far as possible. In case layout does not permit the LCS shall be installed away from the motor terminal box.
The Local Control Station shall be in accordance with “Specification for Electrical Packaged Equipment” [17].
9.16.27
Earthing and Bonding
Earthing and bonding system shall comply with the requirements of IEC 61892-6, IEC 60092-350 and IEC 60079-14.
The steel deck and structure of an offshore installation is an inherently very low impedance structure capable of conducting earth fault currents as well as high frequency disturbing currents from lightning strikes without giving rise to sparks, dangerous touch voltages or transients that are destructive for electronic equipment. Good electrical continuity is achieved by welding, so that earth bonding cables need not be used between pieces of non-electrical equipment and between equipment and the steel deck. If facility/package is built in modules, the modules need to be bonded together if they are not welded.
In general, all exposed metal of electrical items, equipment and installation other than current carrying parts will be double bonded and earthed, that is, earthed via a separate earthing conductor connected from equipment frame externally to the platform steel structure.
Earthing conductors are required to bond the main components of the generation and distribution systems (namely generators, transformers, switchboards, motors, UPS units, battery stands/racks etc.) to the structure steel work.
Earth conductors connected to individual switchgear and controlgear assemblies shall be sized so that their total cross-sectional area is capable of carrying the rated short circuit capacity of the installation until it will be cleared by protection system. The metallic enclosure of electrical equipment and all non- current carrying metal parts shall be connected to the structure steel work.
Bonding to prevent building up of static as per the requirements of IEC60079-32-1 i.e., in order to prevent dangerous build-up of static charges resulting from the flow of fluid in conductive piping, the resistance per unit length of pipe, fitting, etc. shall not exceed 1 mega-ohm per meter, liquids flowing through insulating pipes can generate high charge levels and voltage at the pipes walls. The resistance to earth from any point in the piping system shall not exceed 1 mega-ohm. If applicable Plastic and GRP pipes shall be earthed at regular intervals as required to vendor recommendations or be conductive type.
All non-electrical metallic equipment and installation not welded to structural steel framework including skid mounted packages, vessel, steel structures etc. shall be provided with (diagonally opposite where possible) earthing bosses welded to the equipment skid. Earthing conductors will then be connected to the equipment earthing from main steel structure beam.
Where driven equipment, vessels, tanks, instruments etc. comprising part of a package is directly welded to the Package, no additional earth connection is required.
Two numbers of diagonally opposite earthing conductors are required to bond the main components of the generation and distribution systems (namely MV and LV generators, transformers, switchboards, motors and UPS units) to the platform steel work/main structure beam.
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The metallic enclosures of electrical equipment shall be bonded to the platform steel structure, which acts as an earth grid. The metallic enclosures of non-electrical equipment, e.g., vessels, shall also be bonded to the platform steel structure by means of earth boss. At least two earthing bosses diagonally opposite, suitable for the connection of earthing cable shall be provided for the purpose of connecting the package unit to the main earth system. The bosses shall be of a SS316 material.
Bonding or earthing circuit protective conductors shall be single core earthing cable, stranded copper, Class 2, in accordance with IEC 60228. Insulation shall be green and yellow.
For earth wire that run together with current carrying conductor in as cable, the earth cable size shall not be less than the size required by Table 2 of IEC 61892-2 as tabulated below.
Table 9-5: Size of earth continuity conductors
Cross-section Q of associated current carrying conductor mm2
Minimum cross section of earth conductor
Q ≤ 16 mm2
Q > 16 mm2
Q
50% of the current-carrying conductor, but not less than 16 mm2
The minimum size of equipotential earthing conductor shall be in accordance with below table.
Table 9-6: Equipotential Bonding Cable size
Intended use
Conductor Size
Main loop
Loop interconnection
Power transformer enclosure
Building and Pipe Rack Steel
Bus enclosure
Building earth bus
Control panel
70 mm2
70 mm2
70 mm2
35 mm2
70 mm2
70 mm2
35 mm2
Switchgear and MCC Earthing bus
As per fault current (Refer to Typical Earthing block Diagram [36])
Other Equipment such as support stands, lighting & small power junction box, cable gland, lighting enclosure, motor control station and other metallic equipment.
Metallic Cable Ladder and Tray
Equipment Skid
Pump and Motor
Tank, Columns and Tall Structure
2.5 mm2
16 mm2
70 mm2
35 mm2
70 mm2
The steel structure of the platform shall form the main earthing system with the steel jacket legs acting as electrodes. All metallic equipment shall be earthed.
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NFPS Offshore Compression Complexes Project COMP2 ELECTRICAL DESIGN BASIS FOR CP6S AND CP7S COMPLEXES
Earth bars shall be located in front of equipment to allow easy access for usage, inspection and maintenance. All earthing bars and terminals shall be visible and possible to be checked also after termination of cables.
All metallic cable ladders and trays shall be electrically continuous and earthed by a separate conductor or earth cable insulated.
9.16.28
Lightning Protection
Lightning protection shall be in accordance with IEC 62305. Any structure within a zone of protection may be considered to be adequately shielded against lightning so that further protection is not required.
Offshore platform topside shall be of fully structural steel construction welded to the jacket and the jacket naturally connected to earth (sea). Hence lightning protection study to be performed to identify the requirement of lightning protection system for the fixed offshore platforms. As additional safety measure, the tall structures on the platform top deck and sensitive instrument systems shall be provided with the following lightning protection:
a)
Tall structures (e.g., flare tower and crane) on platform shall be protected against lightning by effectively earthing them to the nearest platform primary steel work, thus providing a direct low impedance path for the lightning discharge to earth.
b) Where the metal frame or steel structure is not welded to platform deck or steelworks, and
therefore is not continuous to earth, adequate bonding shall be provided.
Pedestal Cranes: separate lightning protection shall not be required. The Crane Pedestal shall be securely bonded to the platform steel structure. Crane cabin top shall have air terminals.
9.16.29
Electrical Room Requirement
Electrical room shall be located outside hazardous areas and close to service loads. Access to the electrical room shall be designed in full compliance with safety requirements.
The electrical room shall have suitable dimensions to ensure safety for operation and maintenance. Access for maintenance, inspection and removal of the electrical equipment in the electrical room shall be facilitated. At least one door shall be sized for the largest equipment entry.
The electrical equipment (door open) shall not obstruct any walkway, escape way or stairway and shall not obstruct operation of other equipment.
High-voltage warning signs shall be prominently displayed on the appropriate individual sections of electrical equipment within the buildings. This shall include, but is not limited to, voltage level warning stickers.
Electrical room shall be furnished with safety equipment cabinet as detailed in HFE Philosophy [47].
All floors within the building containing electrical distribution equipment shall be supplied with “wall to wall” nonconductive electrical floor matting.
The electrical floor matting shall be heavy duty insulating mats manufactured from elastomeric compound with a non-slip surface. Insulating mats shall be appropriate for switchgear voltage. During construction matting shall be rolled up and painted floor shall be protected against traffic.
Service lines e.g., fuel, water and air lines, shall not be routed over the MCC/Switchgear.
Access control shall be provided to electrical room as per “Telecommunication System Philosophy and Design Basis” [42].
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NFPS Offshore Compression Complexes Project COMP2 ELECTRICAL DESIGN BASIS FOR CP6S AND CP7S COMPLEXES
Two (2) purge fans for each Electrical Room (i.e., Switchgear / UPS / Battery room) shall be provided for purging prior to starting the HVAC system after prolong shutdown, fire/smoke incident or black start. Control panel including Blower fan starter shall be designed to receive power supply from temporary diesel generator during emergency operation and from essential switchgear for testing purpose. Socket outlet shall be provided outside electrical room for the purpose of connection of temporary diesel generator to control panel. Control panel shall be provided with selector switch for power supply selection and on/off facility. Blower fan Control panel and socket outlet shall be located outside the electrical room and equipment shall be certified to IEC “Ex” scheme. CP Ex control panel will be fed from LQ LV Switchgear and LQ Ex control panel will be from CP LV Switchgear for the normal test purposes. Circuit breaker shall have padlock facility in open position.
9.16.30
Equipment Clearance
Unless otherwise recommended by the equipment VENDOR, minimum equipment clearance are as follows:
Table 9-7: Equipment Clearance
Item
Required Minimum Clearance
In front of MV Switchgear
In front of LV Switchgear
Min. 2500mm
Min. 1250mm
Rear side of MV Switchgear
Min. 1000mm
Rear side of LV Switchgear
Min. 100mm
Between MV and LV gear
Min. 2500mm
Between LV and LV gear
Min. 750mm
Sides of LV/MV gear
Above Switchgear
Min. 1000mm
Min. 1000mm
Electrical equipment shall be installed so that there is sufficient space to facilitate maintenance requirements.
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Project: Q-21699 - Saipem COMP2 Folder: Electrical