]KUWAIT OH, COMPANY (K.S.C.)

KOC RECOMMENDED PRACTICE

DESIGN BASIS AND SELECTION OF ELECTRICAL SYSTEMS

DOC.NO. KOC-E-003 PART 1

L

STANDARlDS TEAM.

KUWAIT OIL COMPANY (K.S.C.)

STANDARDS PUBLICATION

KOC RECOMMENDED PRACTICE

FOR

DESIGN BASIS AND SELECTION OF ELECTRICAL SYSTEMS

DOC.NO. KOC-E-003 PART I

STANDARDS TEAM

DOC, NO. KOC-E-003 PART I

KOC RECOMMENDED PRACTICE

FOR

DESIGN BASIS AND SELECTION OF ELECTRICAL SYSTEMS

DOC.WO. KOC-E-003 PART 1

ISSUING AUTHORITY:

STANPARDS TEAM

DOC. NO. KOC-€403 PART 1 '1 Page 3 of 47 k C - - - I REV. 1

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TABLE OF CONTENTS

FOREWORD

SCOPE

TERMINOLOGY 4.1 Definiibns 4.2 Abbreviations

REFERENCE CODES & STANDARDS 5.1 Conflicts 5.2 List of Standards and Codes

ENVIRONMENTAL CONDITIONS

HEALTW, SAFETY AND ENVIRONMENT

CLASYFICATIQN OF HAZARDOUS AREAS

BASIC DESIGN CONSIDERATIONS

ELECTRICAL SYSTEM REQUIREMENTS 10.1 Type of Electrical Loads 10.2 Sources of Power Supply 10.3 Standby Power Supply 10.4 Power Distribution Systems 10.5 System Voltage and Frequency 10.6 Phase Sequence 10.7 Short Circuit Rating (Symmetrical)

ELECTRICAL SUBSTATIONS 11.1 General I . Primary (Bulk Intake) I Area Substations 11.3 Plant Substations I I . Substation Building 11.5 Air-conditioning and Other Safety Systems

in Substations 11 6 Battery Room 11.7 Transformer Bays 1 Generator Building 1 .3 Package Substations

PAGE NO.

5

6

7

7

7 7 7

8 8 8

I I

I I

11

11

13 13 14 95 16 -19 20 20

22 22 22 24 24

26 27 28 29 29

W3W3AL REQUIREMENTS FOR ELECTRICAL EQU!PMEHT 1 2 1 General 12.2 Derating I 2.3 Ingress Protection (IP Rating) 12.4 Equipmentin Hazardous Area 12.5 Hazardous Area Certification

POWER TRANSFORMERS & REACTORS

GENERATOR SETS 1 4 1 General 14.2 Standby Generator Set 'l4, J E rnergency Generator Set

DC POWER SUPPLY UNITS

UPS SYSTEM

HIGH VOLTAGE SWITCHGEAR

RING MAW4 UNIT

LOW VOLTAGE SWITCHGEAR

VARIABLE SPEED DRIVE CONTROLLER

SWITCHGEAR CONTROL PANEL AND ANNUNCIATORS

INTERFACE WITH DCS

MOTORS

MOTOR CONTROL STAT10NS AND MQV FSOLATORS

CABLE

QUALITY ASSURANCE

DOCUMENTATION 27.1 General 27.2 Deliverables

APPENDIX - 1

Ty@cal Electrical Distribution System f~ GC BS I mher Major Operating Facilities

ACKNOWLEDGEMENT

M)C. NO. KOC-ESO3 PART I 1 I Page 5 of 47

FOREWORD

This document "KOC RP for Design Basis and Selection of Electrical Systems" (KOC-E-003, Part 1) is intended to provide minimum requirements for the design basis and selection of electrical system for various KOC Facilities in Kuwait.

This Recommended Practice has been approved by the Standards Team in consultation with the Standards Technical Committee (STC) for use throughout the corporate Engineering and operational functions of Kuwait Oil Company (K.S.C.).

This Recommended Practice sets out to achieve the following objectives:

a ) To unify and update the electrical system requirements for KOC, which has been c:overed in various existing KOC Standards I Code of Practices I Project specification. (for details refer clause No. 1 of this RP - Introduction).

b To provide technical guidance and establish the base document for developing project documents wi th a view t o achieve uniformity, safety, quality, reliability and efficiency in an economical manner.

C) To assist the designers by providing technical information and engineering practices for establishing the basis for detailed design of electrical system.

d) To maintain the KOC requirements of safety and protection to plant, persor.nel and environment established by KOCfs Fire & Safety Regulations, Health, Safety & Environment Management System (HSEMS) and Health and Envirorlment (H&E) Guidelines.

Feedback as well as any comments or suggestions derived from the application of this Recommended Practice at any stage of design, installation or operation are invited and should be directed to:

Team Leader Stmdards Team (Chairman, Stardards Technical Committee) industrial Services Group, K.O.C. P.O.Box-9758, Ahmadi - 61 0 0 8 State o f Kuwait.

Task Force responsible for this Recommenc 1 Practice

The preparation of this Recommended Practice was entrusted by Standards Technical Committee to the Task Force (TF-EEt07) comprising of the following members: -

Mr. A.Unnikrishnan Standards Team Task Force Leader Tel No. 61 633 Mr. Samir Bu-Hamad Opns. Tech. Svcs. (SK) Member Tel No. 22343

Mr. Gobinda Mishra Design Team Member Tel No. 61097 Mr. Andrew Nayak Gen.Projects Team Member Tel No. 61 658 Mr. Abdul Hadi Al-Zabi Maj.Projects Team Member Tel No. 61 583

DOC. NO. KOC-E-OOS PART I Page 6 of 47 REV. I .--- C~--

1.0 INTRODUCTION

I .I The electrical system requirements for KOC have been covered in various existing KOC Standards I Code of Practices I Project specification as follows:

"General Specification for Electrical Engineering" (KOC Std. 381 120)

"KOC Code of Practice for Electrical Systems and Installations Part 1- General Requirements" (COP-E-002, Part 1)

"KOC Code of Practice for Electrical Systems and Installations Part 3- Power System Design" (COP-E-002, Part 3)

"Engineering Group Specification for Electrical design, Installation and Testing " (01 5-PH-1901)

"KOC RP for Power System Protection and Control"(K0C-E-006 Rev l )

1.2 With a v iew to unify the electrical system requirements and to avoid duplica1:ions & likely differences of interpretations between these documents; it is proposed to revise I update and amalgamate the requirements o f these documents into the following KOC RPs, which will in turn supersede the above mentioned KOC documents:

"KOC RP for Design Basis and Selection o f Electrical Systems" (KOC- E-003, Part 1 ) -This document.

"KOC RP for Installation and Testing o f Electrical Equipment" (KOC-E- C03, Part 2 ) .

"KOC RP for Lighting and Small Power Supply System" (KOC-E-017).

"KOC RP for Power System Studies, Protection and Control" (KOC-E- C06 Rev 2).

1.3 The recuirements covered in this document "KOC RP for Design Basis and

Selection of Electrical Systems" (KOC-E-003, Part 1 ) shall supersede similar requirements covered in existing KOC documents mentioned in clause 1.1 of this RP, until those documents are withdrawn.

DOC. NO. KOC-E-003 PART 1 Page 7 of 47 - - REV. 1

This Recommended Practice specifies the requirements for the design basis and selection of electrical systems for various KOC Facilities within Kuwait.

This Recommended Practice also specifies the general requirements for the selection o f electrical equipment.

APPLICATION

The electrical system shall fully comply with all the relevant requirements specified in this Recommended Practice and the reference standards / codes mentioned herein.

Any exceptions or deviations from this Recommended Practice, along with their trerits and justifications, shall be brought to the attention of KOC's Control ing Team for their review, consideration and amendment by Standards Team (if required).

Compliance with this KOC Recommended Practice does not of itself confer immunity from legat or statutory obligations.

For the purposes of this Recommended Practice, the following definitions

apply.

KOC Controlling Team

Any KOC Team authorized t o initiate a request for execution of a project or procurement of materials / equipment for KOC.

Contractor

The person, persons, firm or company contracted by KOC to undertake the execution of the Work defined by the Contract.

Abbreviations:

DC Direct Current

DB Distribution Board

H&E Health & Environment

HRC High Rupturing Capacity

DOC. NO. KOC-E-OO3 PART l I _ L -

Page 8 of 47 R N . 1 ?

HSEMS

H S 2

HVAC

HV

Hz

I P

k A

KOC

kV

LV

MCC

ME / EW

MOV

MVA

SF6

Health, Safety & Environment Management System

Hydrogen Sulphide

Heating, Ventilating and Air-conditioning

High Voltage

Hertz

Ingress Protection

Kilo Ampere

Kuwait Oil Company (K.S.C.)

Kilo Volt

Low Voltage

Motor Control Centre

Ministry of Energy / Electricity & Water

Motor Operated Valve

Mega Volt-ampere

Sulphur Hexafluoride

REFERENCE CODES 8 STANDARDS

Conflicts

In the event of conflict between this Recommended Practice and the latest edition of standards / codes referred herein, or other purchase or contractual requirements, the most stringent requirement shall apply.

List of Standards and Codes

The e ectrical system design and selection of electrical equipment shall conform, except where otherwise specified, wi th the current issues and amendments of the applicable codes and standards, including but not limited to the following:

Intern~tional I National Standards

API 505 Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities

API RP 5 4 0

BS 7430

IEC 60034

IEC 60044

IEC 60076

IEC 60076 Part-1 1

IEC 60255

IEC 60269

IEC 60r-39

IEC 60502 Parts 1, 2, 4

IEC 60529

IEC 60947

IEC 62040

IEC 62271 -200

Recommended Practice for Electrical Installations in Petroleum Processing Plants

Code of Practice for the Protection o f Structures against Lightning

Code of Practice for Earthing

Rotating Electrical Machines

Instrument Transformers

Power Transformers

Power Transformers: Dry-Type Transformers

Electrical Relays

Low-Voltage Fuses

Low-Voltage Switchgear and Controlgear Assemblies

Power Cables with Insulation and their Accessories for Rated Voltage from I kV upto 30kV

Degrees of Protection Provided by Enclosures (IP Code)

Low-Voltage Switchgear and Controlgear

Uninterruptible Power Systems (UPS)

High Voltage Switchgear and Controlgear - Metal Enclosed Switchgear and Controlgear for Rated Voltages above 1 kV and up to and including 52kV

IP-Model Code of Area Classification Code for Installations Handling Flammable Practice Part-1 5 Fluids

ANSI / IEEE Recommended Practice for Power Distribution for IEEE Std.141 Industrial Plants

NFPA 7 0 National Electrical Code

5.2.2 KOC Standards

KOC-C-002 KOC Recommended Practice for Engineering Design Basis of Civil and Structural Work

KOC-E-00 1

KOC-E-002

KOC-€404

KOC-E-005

KOC-E-007

KOC-€408

KOC-E-009

KOC-E-010

KOC-E-011

KOC-E-012

KOC-E-013

KOC-E-015

KOC-E-0 1 8

KOC-E-020

KOC-E-1323

KOC-E-024

KOC-G-002

KOC-G-004

KOC-G-007

KOC-L-002

KOC 381/03

KOC Standard for High Voltage Induction Motors

KOC Standard for High Voltage Switchgear and Controtgear

KOC Recommended Practice for Selection, Installation and Maintenance of Electrical Equipment in Hazardous Areas

KOC Standard for Power Transformers

KOC Standard for Generator Sets

KOC Recommended Practice for the Design, Selection and Installation of Electric Cables, Cable Systems and Wiring

KOC Standard for Low Voltage Switchgear

KOC Standard for Low Voltage Induction Motors

KOC Standard for Uninterruptible Power Supply System

KOC Standard for DC Power Supply Units

KOC Standard for Motor Operated Valve Actuators

KOC Recommended Practice for Electronic Equipment Power Supplies

KOC Recommended Practice for Electric Surface Heating

KOC Recommended Practice for Electrical Installation on Packaged Equipment

KOC Standard for Electrical Power Cables and Wiring

KOC Recommended Practice for Earthing and Bonding

KOC Standard for Hazardous Area Classifications

KOC Standard for Packing, Marking and Documentation

KOC Standard for Basic Design Data

KOC Recommended Practice for the Protection of KOC Services: Clearance Requirements for Buried Pipelines & Piping, Cables, Underground Structures and Buildings

General Specification for Air Conditioning Installations

DOC. NO. KQC-E-003 PART I Page 11 of 47 -- REV. I

Project Specifications

In addition to the KOC Standards and Recommended Practices referenced herein, the Controlling Teams in KOC shall designate other project specifications as requ red including the following:

Cathodic Protection (CP) Design Requirements

Cathodic Protection Transformer Rectifier Units

HVAC Equipment and Installation

Variable Speed Drive Controller

ENVlRONMENTAL CONDITIONS

The environmental conditions in Kuwait are severe and shall be considered carefully while designing Electrical system and selecting electrical equipment. Electrical equipment for outdoor installation shall be suitable for continuous operation a t a desert location under high ambient temperature and humidity. The atmosphere shall be considered to be dusty and corrosive and may contain traces of H2S (hydrogen sulphide).

Refer to "KOC Standard for Basic Design Data" (KOC-G-007), which provides the detailed design information regarding the environmental, site and uti l i ty supply conditions prevailing throughout the KOC Facilities.

HEALTH, SAFETY AND ENVIRONMENT

All relevant safety requirements o f KOC's Fire & Safety regulation, Health, Safety & Environmental Management System (HSEMS) and H&E Guidelines shall be adhered t o while designing the Electrical System.

CLASSIFICATION OF HAZARDOUS AREAS

The cla.ssification of hazardous areas shall be based on the requirements of the KOC Standard for "Hazardous Area Classification" (KOC-G-002) and latest edition of relevant International 1 National Standards / RPs / Code of Practices.

BAS tC DESIGN CQNS1DERATIONS

The power supply system shall be designed to provide safe and economical operation of the facility. The safety aspects shall cover both plant and personr~el. Economic considerations shall cover capital and running costs and an assessment o f the reliability and consequent availability of the system. The cost of improved power systems reliability should be weighed against the progressive potential loss incurred by loss of production.

9.2 The following shall be taken into consideration while designing the electrical system

a) Safety

Safety o f l ife and preservation of property are the most critical factors to be considered while designing the electrical system. This KOC RP ~ n d relevant KOC Standards / Project Specifications shall be followed for the selection o f materials and equipment to ensure a safe system design.

b) Reliability

Reliability of electrical supply is essential for the continuous operation of tne plant. The electrical system shall be designed so that faults can be isolated wi th minimum disturbance to the system as well as providing maximum dependability, consistent with the plant requirements.

C) Simplicity o f Operation

Simplicity of Operation is very important factor in achieving safe and reliable electrical system. The system shall be designed such that operation should be as simple as possible to meet the system requirements.

d) Voltage Regulation

Voltage at the utilization equipment shall be maintained within equipment tolerance limits under all load conditions, in order to enhance the service life of electrical equipment.

e) Flexibility

Flexibility of the electrical system means the adaptability to development, expansion and changes to meet the varied requirements during the life of the plant. Plant voltages, equipment ratings, space for additional equipment, capacity for increased load and spare capacity shall be taken illto consideration while designing the electrical system.

f) Maintenance

-- he electrical system shall be designed to allow easy maintenance

without major interruptions to the plant. While planning the system, accessibility for inspection and repairs of equipment shall be given due consideration.

I

DOC. NO. KOC-E-003 PART I q I1 I REV. 1

g) Equipment Selection

All equipment and materials selected shall be commercially well known, proven for use in similar plant application and designed and manufactured according to the latest International / National standards and technological advancements in the field.

h) Cost

LVhile initial costs are important, safety, reliability, voltage regulation, maintenance and the potential for expansion must also be considered in designing the electrical systems and selecting the best from alternate plans. Cost reductions by using inferior design 1 equipment should never he made at the expenses of performance and safety.

The basic power system configuration shall be selected depending on the type of Facility and load requirements and shall be shown on the overall single-line diagram.

During detailed design, overall electrical single-line diagram and switchgear single-line diagrams showing the distribution system from the incoming supply / generator terminals up to the outgoing circuits of the low-voltage (LV) system with all details of the proposed equipment, fault levels, protection and metering arrangements shall be developed by the designer.

The de-:ailed design shall be based on system studies using reputed software approved by KOC. The studies shall include load flow analysis, short circuit studies, voltage drop studies, stability studies, protective relay coordination and discrimination study, harmonic studies, etc.

ELECTRICAL SYSTEM REQUIREMENTS

T ~ p e of Electrical Loads

General

Electrical loads in KOC operating Facilities shall be categorised into the following:

a) Dynamic load which consists of electric motors driving rotating equipment. (The bulk load on majority of KOC installations comprise of dynamic loads.)

b) Static load consists of non-moving types of electrical equipment such as I ghting, heating, supplies to rectifiers, etc.

DOC. NO. KOC-E-003 PART 1 (1 Page 14 of 47 REV. 1

Critical Loads

These are loads of prime importance to the safety of the installation & operational staff and which require power to permit the safe shutdown of the plant in emergency. They shall have a second independent power source and be generally associated with "no break supplies".

Essential Loads

These are loads whose power loss would affect continuity of operation, resulting in loss of production / export operation, but would not result in an unsafe situation. For all KOC operating Facilities standby generator set(s) shall be provided to cater for these loads unless otherwise specified / approved by KOC.

Non-essential Loads

Non-essential loads are those which do not form an important component of a production or process plant and their disconnection is only of minimal or nuisance value. They usually form a small proportion of the total connected load and may have a single power source unless otherwise specified by KOC.

Sources of Power Supply

Power supply from 'State Grid' - Ministry of Energy / Electricity and Water (ME/EW :

a) The principal source of electric power for KOC is from 'State Grid'. The power from 'State Grid' is transmitted at 300kV / 132kV / 66kV / 33kV / I 1 kV, which is received at the main bulk intake (primary) substation via duplicate or multiple feeders.

b) Single feeder supply from 'State Grid' may be employed only for "Non- Essential" loads for economic reasons or where on-site standby generating equipment is available.

C) The following limitations by ME/EW shall be considered while designing power supply system, fed from 'State Grid' I I kV substations:

I. The maximum power that can be drawn per feeder is limited to 5 MW.

ii. The size of power cable that can be terminated on an outgoing feeder (breaker compartment) - Single run of 3 core 300mm2 (maximum).

DOC. NO. KOC-€403 PART 1 Page 15 of 47 - --

Note: The main power supply availability and other system details shall be obtained from ME/EW for each project that requires bulk power supply, prior to electrical systern design.

10.2.2 On-site Generation with no 'State Grid' Connection:

For a Facility where 'State Grid' supply is not available, on-site generation should be selected as the principal source of power.

'There shall be sufficient generation to meet the "Maximum Demand" .ahen the largest single source of supply is out of service at peak demand times due to maintenance or any other reasons.

'The generator sets shall be suitable for continuous parallel operation and 1 or automatic standby operation.

Two generator sets, each rated for a minimum of 125% of the total Facility load, shall be provided, complete wi th equipment for synchronising, parallel operation and load management, unless otherwise specified / approved by KOC.

In addition to the main supply generators, emergency generator (s) shall be provided to back up the supply to critical loads.

The generator sets shall be capable of starting the largest connected motor in system with all other loads, including the spare capacity taken into account, while still maintaining the voltage drop within the specified limits.

10.3 Standby Power SupvIy

10.3.1 The standby power supply systems include the following:

a) Standby / emergency generator to be started and connected automatically on main supply failure.

b) No break supplies, which includes Batteries and charger system, Un-interruptible power supply (UPS) system, etc. (for critical loads).

10.3.2 Standby power supply required for re-energising electrical plant shall be rated both for the initial closing and the continuous load current. Where there are large numbers of high rated electrical motors to be fed from a generator set, timed sequence motor starting may be employed to suit the process requirements.

10.3.3 Switching back t o normal electrical supply shall be automatic for all standby supply systems, upon the restoration of normal supply.

10.3.4 Manual switching back from standby to normal power supply shall not be attempted until it has been confirmed that the normal power supply has been restored.

Note:

Parallel operation o f Standby / Emergency generators with the 'State Grid' supply is not permitted.

18.4 Power Distribution $ystems

10.4.1 General

The power distribution system for KOC Facilities shall be designed to cater for the maximum demand associated with peak design capacity, at maximum ambient conditions and an additional spare capacity of minimum of 25% to cater for future loads, unless otherwise specified.

The distribution systems shall be designed for the effective and safe control of electrical supplies to plant under all operating conditions.

The distribution system shall be designed to limit fault levels to within the short circuit ratings specified.

Adequate interlocking arrangements and warning signs shall be provided .to prevent fault level limits being exceeded, due to excess parallel "eeders or for any other cause.

'The distribution arrangement shall be selected to have a degree of I-eliability consistent with the type of load being supplied and with the power supply design philosophy which provides for coincidental maintenance and unscheduled outage of the largest component of on-site generating plant or unscheduled outage of the largest feeder component o f the power supply equipment.

Power distribution shall be by means of underground cables or surface cables as approved / specified for particular routes. The use of overhead lines shall be limited to refurbishing of existing installations unless otherwise approved by KOC.

10.4.2 Single Radial System

a) Single radial system should be used to provide power t o non essential electrical loads, where alternative source of power such as standby generating plant is available or those loads for which a lower availability can be accepted by KOC.

REW. I

b) Each component of the single radial circuit shall be capable of supplying the maximum demand associated and a minimum of 25% spare capacity to cater for future addition, unless otherwise specified.

C) Typical application of single radial system includes, but not limited to:

I Minor office buildings I workshops / stores in remote areas.

1 1 . CP System.

10.4.3 Double Radial System

Load centres serving plant necessary for maintaining production, export operations and other major Facilities shall be provided with dual feeders z t each voltage levels. Each feeder shall be sized for the plant's maximum demand load plus a minimum of 25% spare capacity to cater for future additions, unless otherwise specified.

The system shall include the provision of duplicate feeder cables, transformers and incomer circuit breakers so arranged that maintenance can be carried out without interruption to the plant operation.

Each section of the busbar shall be interconnected wi th bus section circuit breaker. The system is normally run with the bus-section breakers c:losed, unless otherwise specified.

Typical application of double radial system includes, but not limited to:

I. Gathering Centers.

i-. Booster Stations.

7 . .

1 . 1 . Other major operating Facilities.

id. Main office complexes in various areas.

Note:

A typical electrical distribution system for GCs 1 BSs / Other major operating Facilities is shown in Appendix -1 for guidance.

1 0.4.4 Triple Radial System

a) Triple radial systems shall be provided where the power requirement is relatively large and cannot be managed with dual radial feeders.

b) Each circuit o f triple radial systems shall be capable of providing at least !50% of the total design load (maximum demand + 25% spare capacity).

DOC. NO. KOC-€403 PART 1 Page 18 of 47 - m- -

d. -- - REV. I

The bus bars shall be split into at least three sections with t w o bus- section breakers. This will allow for the loss of any one of the three circuit feeders, leaving the two healthy circuits still capable of providing the load requirements (maximum demand + 25% spare capacity).

They shall be normally operated with all three ( 3 ) circuits in parallel. In cases where the fault level is very high (normally for 3.3 kV and 440 V systems), they shall be operated with only t w o circuits in parallel to reduce fault levels. The incoming circuit breaker on the third identically rated feeder shall be left open and automatically closed in order to restore rapidly full supplies to the load.

Typical applications of triple radial system includes, but not limited to.

I. Gathering Centers,

I . Booster Stations,

i'i. Other major operating Facilities.

Note: Where the load requirement cannot be met with triple radial system, multiple feeders shall be used. The system shall be designed to allow for the loss of any one of the circuit feeders, leaving the balance healthy circuits still capable of providing the total load (maximum demand + 25% spare capacity).

10.4.5 Ring Fed Systems

Power may be distributed from a primary or central substation to a number of subsidiary load centers by using t w o primary cable feeders connected in a ring emerging from the source busbar and controlled by circuit breakers.

Ring type distribution systems should be used as a cost effective solution for supplying relatively light electrical loads distributed over a large area, with multiple feeding points.

Open type ring system shall be used only to supply non essential loads.

Where the ring is required to be kept closed to improve the reliability, necessary protection and interlocks shall be provided to prevent back feeding.

The whole of the ring circuit shall be fully rated to be capable of supplying at least 1 10% of the maximum demand at all substations.

In order that a faulty section of the primary ring may be disconnected and repaired without power loss during the whole of the repair period, :he ring shall include isolating means at every load substation.

DOC. NO. KOC-€403 PART 1 -

g) Typical application of ring fed system includes, but not limited to:

Ahmadi Housing,

I. Oil / Water Wells.

System Vdtaqe and Frequency

For all voltage levels, the KOC supply system frequency is 50Hz. (Except in joint operations, where the frequency is 6OHz).

Mains voltage is subject to a variation of + 6 % and the frequency is subject to variation of +2.5%.

The KCIC standard distribution voltage levels include:-

High voltage (H.V.):

I . 11 kV, 3 phase, 3 wire, impedance earthed at ME/EW end with 8 ohms resistance.

11. 3.3kV, 3 phase, 3 wire with solidly earthed neutral.

Low voltage (L.V.):

I . 440V, 3 phase, 4 wire with solidly earthed neutral.

11 . 250V, single phase, 2 wire with solidly earthed neutral.

... 111. 1 IOV, single phase, 2 wire, centre point solidly earthed.

Power supply for building services other than in KOC operating areas shall be at 41 5V, 3 phase, 4 wire with solidly earthed neutral, unless otherwise specified.

UPS supply:

1 10 V, + 1 %, 1 phase, 2 wire, 50Hz k0.5Hr neutral, unearthed, unless otherwise specified.

DC power supply:

1 10 VDC + 10% unearthed, or as specified.

Unless otherwise specified in the project document, electrical equipment shall be suitable for the system voltages mentioned in clause 10.5.3 of this RP.

- - - -

DOC. NO. KOC-€403 PART 1 Page 20 of 47 REV. 7 -

10.5.5 Where equipment designed for 415V (3 phase) or 240V (single phase) is offered for 440V (3 phase) or 250V (single phase) supplies respectively, the equipment may be approved on receipt of written submission from suppliers, both detailing any reduced ratings or life expectancy, and confirmation of suitabilii:~ of the equipment for reliable operation at higher voltages. Such equipment shall be restricted to those used for HVAC system, lighting and small power system, or any other special type of equipment approved by KOC.

10.5.6 Equipment voltages of less than 415V, 3 phase or 240V, single phase shall not be used for 440V or 250V supplies.

10.6 Phasesequence

10.6.1 The phase sequence followed in KOC is in the order of Red-Yellow-Blue (R-Y-B) except in some areas where it is Red-Blue-Yellow (R-B-Y), the details of which are given below:

North Kuwait / West Kuwait areas : Red-Yellow-Blue (R-Y-B)

Ahmadi / Burgan / Magwa areas : Red-Blue-Yellow (R-B-Y)

Note: An action plan is being developed for the correction of phase sequence from (R-B-Y) to (R-Y-B) in those areas where non-standard phase sequence is prevailing, in order t o have uniform phase sequence throughout KOC.

10.6.2 All electrical equipment shall have the phases arranged in accordance with applicable international standards (IEC). The switchboards shall be of standard construction with phases arranged Red-Yellow-Blue and connected within equipment in the normal phase sequence with Red-Yellow-Blue laid out from top to bottom and left to right, when viewed from the front.

10.6.3 Electrical equipment modifications and additions shall require particular attention in areas where non-standard (R-B-Y) phase sequence is prevailing. Motor rotation shall be checked and phase alterations to correct the direction of rotation, if required shall be carried out at the motor terminals only. Certain relays, iristrumentation may also be sensitive to phase sequence and should be checked for correct operation.

10.7 Short Circuit Ratinq [Symmetrical]

10.7.1 The short circuit ratings for industrial type electrical equipment shall be selected from the following standard values unless otherwise specified or found as per short circuit studies:

a For I I kV systems 350 MVA (18.3kA) 500 MVA (26.25kA) 600 MVA (31.5kA) 750 MVA (40kA)

b) For 3.3kV systems I 5 0 MVA (26.25kA) 180 MVA (31.5kA) 230 MVA (40 kA)

C) For 440V systems 31 MVA (40 kA) 38 MVA (50 kA) 61 MVA (80 kA)

10.7.2 Lower short circuit ratings may be approved or specified for areas with lower fault levels, but they shall not be less than the following:

a 11kV - 250 MVA (13.1 kA)

c) 440V - 8 MVA (10.5 kA) (For distribution boards)

10.7.3 The shcrt circuit ratings for low voltage "flameproof" electrical equipment shall be minimum 1 0 MVA, unless otherwise specified.

70.7.4 The rated short-time withstand current of switchgear shall be as stated on the single-line diagrams, subject to a design study and verification. The standard ratings are given below:

System Voltage

440 ir 1 415 V (Main switchboard & MCC)

440 V 1 415 V Small power & lighting DBs

Switchgear Short Time

Withstand Current I 26.25 kA for 3 seconds

31.5 kA for 3 seconds

40 kA for 3 seconds

26.25 kA for 3 seconds

31.5 kA for 3 seconds

4 0 kA for 3 seconds

40 kA for 1 second

5 0 kA for 1 second 8 0 kA for 1 second

1 0 kA for 1 second (minimum)

ELECTRICAL SUBSTATIONS

General

Electrical substations include primary (Bulk intake), area and plant substations.

'State Grid' power intakes and generating station if any shall be connected at a common primary (bulk intake) substation, which is used as the main load distribution centre.

Area substation serves the purpose of providing electrical supply to a number of KOC Facilities, which are located in a particular area.

Area substations shalt be fed from the primary substation, unless otherwise specified.

In addition to the primary and area substations, each facility shall have localized plant substation(s) to cater for the loads.

The plant substations shall be fed from primary or area substation.

The design and location of substations and associated switchgear control rooms, battery rooms, transformer bays, generator buildings etc. shall be considered with particular reference to the area classification, equipment function, safety, ease of operation, maintenance access and appearance. Sufficient care shall be taken not to locate these facilities above underground services and the clearance requirements as per "KOC Recommended Practice for the Protection of KOC Services: Clearance Requirements for Buried Pipelines & Piping, Cables, Underground Structures and Buildings (KOC-L- 002) shall be maintained.

The substation building shall not be located in low areas where surface water or liquid hydrocarbon can accumulate. The area surrounding the substation buildings shall be properly graded to divert the f low of surface water.

Primam (Bulk Intake) I Area Substations

Primary / Area substations shall be located in 'non-hazardous' areas preferably outside the plant area. The selected location shall take into account the ability to distribute power to the on-site loads economically.

The pr mary I area substations shall be located centrally to a group of load centres for providing supply to plant / other substations.

DOC. NO. KOC-E-003 PART I , Page 22 of 47

Busbar arrangements shall be selected based on operational flexibility, safety and cost effectiveness. The following shall be taken into account while selecticn of busbar system:

a) Operational flexibility to permit loads and power supplies to be effectively connected under scheduled and unscheduled outages of circuits and busbar sections.

b) Minimal switchgear per bus bar sections and simple control and protection.

C) Unscheduled loss of busbar sections shall not shutdown the system beyond the level designed and provided for.

d) Scheduled maintenance of busbars shall be possible without system shutdowns beyond those designed and provided for.

Unless otherwise specified, double busbar arrangements shall be provided for all "Primary substations", considering their critical nature and to have flexibility in operation.

The area substations shall be provided with single busbar system unless otherwise specified.

The maximum number of busbar sections shall not exceed the number of indiv id~al power sources I incomer feeders.

The owgoing load circuits shall be connected to busbar sections in such a way as to reduce power flow across busbar section switches under normal operating conditions and permit unscheduled and scheduled busbar section outages with the minimum disturbance to the loads being supplied.

The primary / area substations shall accommodate all equipment for the distribution, control and metering of the incoming supply, together with all auxiliary equipment and systems as required, which shall include but not limited to the following:

a) Power Transformers,

b) HV Switchgear,

c) Control I Alarm Annunciator Panels,

d) Data Acquisition System Panel,

e) Battery and Charger Units,

f) Low Voltage Switchboard for Auxiliary Supply, HVAC, Lighting etc.

Plant Substations

Plant substations shall be located in a non hazardous area, as close as possible to the principal load points in the facility.

I t is preferable to have a centralised substation to cater for all the loads in a facility. Where the facility is spread over a large area, more than one substation may be considered t o meet the design / operation requirements.

Plant substations shall be designed to accommodate all equipment for the distribu-tion, control and metering, together with all auxiliary equipment and system:; as required, which shall include but not limited to the following:

a) Power Transformers

b) HV / LV Switchgear

C) Control / Alarm Annunciator Panels

d) Data Acquisition System Panel (as required)

e) Generator Control Panel (as applicable)

f) Battery and Charger Units

g) Low Voltage Switchboard for Auxiliary Supply, W A C , Lighting etc.

Plant substation shall be provided with single bus bar system unless otherwise specified.

Primary, Area and Plant substations shall be of elevated type with cable alley below substation floor, unless otherwise specified by KOC.

The floor level of elevated substations shall be designed so as to achieve a minimurn head clearance of 2100 mm in the cable alley between equipment floor beams / cable trays and finished ground level.

Unless otherwise specified or approved by KOC, the construction of non- elevated substations shall be limited for non-industrial use.

The basic design plinth level of non-elevated substations shall be not less than 450 m m from the grade level to avoid water ingress.

All substation buildings shall be designed to provide a clean, dust free and dry location for the installation of switchgear, motor control centres and auxiliary equipment.

The primary and area substation buildings shall have space allocated for office room, pantry, toilets, etc.

The substation building shall have sufficient space to accommodate HV I t V switchgear, control and metering panels, low voltage switchboard for auxiliary supply, HVAC, lighting, battery and battery charger and any other equipment as required, including space for future additions.

There shall be space allocated for the testing of switchgear, storage of testing and maintenance accessories.

Consideration shall also be given to accommodate the panels I equipment required for any other projects planned from the particular substation, in addition to the space requirements for the project under consideration.

Space shall be reserved for four (4) extension panels at each end of all switchboards plus providing at least one metre (1 m) clearance to the nearest wall or other equipment, unless otherwise specified or approved by KOC.

A minimum clearance of one metre (1 m) shall be provided behind all switch- boards for access and maintenance. A minimum clearance of 2.5 m shall be provided in the front of switchboards. This clearance may be reduced to t w o metres (2 m) for non-draw out type LV switchboards.

Room ceiling height o f substations shall be determined based on the requirements o f the largest panel 1 equipment installed wi th due allowance for HVAC ducting, l ight fittings, roof beam depth, use of lifting equipment etc. Ths minimum ceiling height shall not be less than three metres (3 m).

All substation buildings shall be adequately protected against dust, sand, vermin and ingress of water. Double air-sealed doors shall be provided, where specified.

Substation floors shall be of reinforced concrete, levelled wi th smooth screed and floor hardner, designed to support heavy electrical equipment.

Floor areas in front of switchgear and motor control equipment shall be levelled in line vvith the equipment base and shall be trowelled smoothly to facilitate easy withdrawal o f components.

While installation of electrical equipment, it shall be located so as to avoid bridging of floor expansion joints.

Floor openings for cables shall be carefully chosen to suit the switchgearl control panel /other equipment positions.

Approved anti-vermin covers shall be fitted to floors under electrical equipment after all cables have been pulled and made off. Openings for cables shall be sealed with KOC approved sealant.

Floor openings for future cables shall be filled flush with the floor level using a lean concrete mix.

Cable trays / ladder racks shall be provided for incoming and outgoing cables and inter-panel connections.

Underground cables entering and leaving the electrical panels in the elevated substations shall be installed on galvanised cable ladders adequately sized and s ~ p p o r t e d t o accommodate the cables in the cable alley.

The cable ladders and trays in the cable alley shall be laid out in such a manner as to facilitate smooth passage of working personnel from one side to other.

Elevated substations shall have one or more non-slip type external access ramps with a slope not exceeding 1 to 15, leading to equipment rooms.

For elevated substations, each open side of the space beneath the floor shall be provided wi th chain link fencing. Two access gates with pad locking provisions shall be provided on the opposite sides of the fence.

Cable trenches inside the non elevated substations shal removable heavy duty chequered plates.

I be covered wi th

The cable entry / exits points in the cable trenches shall be through sleeves embedded into the walls. These sleeves shall be sealed wi th non-setting, non-flammable and non-toxic liquid tight solvent approved by KOC, to prevent ingress of water / flammable liquid.

For more details on civil construction, fire rating requirements, etc. refer KOC Recommended Practice for Engineering Design Basis for Civil and Structural Works (KOC-C-002).

Air-condition in^ and Other Safety Svstems in Substations

The substation buildings shall be adequately air-conditioned to maintain the room temperature at 25.63 C k 1" C, unless otherwise specified. The HVAC design shall take into consideration the ambient temperature and the heat load added by the electrical equipment.

Unless otherwise specified, the substation building (Primary / Area / Plant) shall be pressurized to avoid ingress of dust.

For small substations in Ahmadi Township / Industrial Areas, remote area substations for oil / water wells etc., where installation of pressurization system is not practical, KOC prior approval shall be taken to exclude pressurization. A n alternate means of protection to prevent the ingress of dust approved by KOC shall be employed.

The air-conditioning shall be provided in accordance with the "KOC General Specification for Air Conditioning Installations" (KOC 381103) and project specification for HVAC Equipment and Installation.

Substations shall be adequately protected with suitable safety and fire protecion systems as approved by KOC, which include but not limited to the following:

a) Automatic smoke & fire detection system, manual break glass station and fire alarm hooter. The fire alarm system shall have provision for connection to the nearest KOC fire stations (auto dialler).

b) Fire protection system approved by KOC "Fire Team".

C) Emergency lighting to cover both internal 1 external areas and exit signs.

d) Telephones with internal and external connection facility.

e} A t least two (2) exits (main and emergency), with doors opening sutwards provided with quick release bars and security locks.

f) External building identification signs, warning notices and break glass ,?mergency entrance key cases,

Battery Room

Batteries shall be installed in a separate room of the substation building provided with anti-slip type, acid resistant tiled floors.

The battery rooms shall be provided with independent ventilation system, which shall be located as close to top of the room to prevent accumulation of battery gases.

Battery chargers shall be installed outside the battery rooms, to avoid corrosion and to permit easy access.

The batteries shall be mounted on open racks and shall be arranged to facilitate the routine inspection 1 maintenance of the batteries.

The battery room shall be provided with wash basin, personal protective equipment such as safety goggle, acid resistant hard gloves, apron etc.

If unavoidable, small battery chargers containing sealed type batteries shall be locatec in related switch rooms with prior approval from KOC.

The b ~ t t e r y room shall be considered as hazardous area in accordance wi th "KOC Standard for Hazardous Area Classification" (KOC-G-002).

Transformer Bavs

The t r~nsformer bays shall be located adjacent to the substation building. In case of process plant, the transformer yard shall be located such that it is not facing the process area.

Transformers, reactors, neutral grounding resistors etc. shall be located in the transfoimer bay.

The foundations for transformers shall be at least 200 m m above the finished grade of the transformer yard, unless otherwise specified.

Transfcrmer shall be installed on a reinforced concrete plinth and be enclosed by approved type chain link fencing with a removable section and lockable personriel gate. Earthing links shall be provided across fencing joints and hinges.

Transformer foundations shall be designed with a surrounding stone filled bund having a void capacity not less than the total transformer oil volume. A separate full depth oil pit shall be built in for pumping out water and any spilled oil.

Bases shall be provided with inverted steel channel sections or other approved means -ror facilitating the positioning and moving of transformers.

Where, more than one (1 1 oil filled transformer has to be installed adjacent to each other, it shall be separated by fire walls.

A canopy of building roof extension or a separate canopy shall be provided for solar protection over transformers and shall be designed not t o obstruct natural ventilation, maintenance or transformer removal.

The transformer bay shall have sufficient space to accommodate alarm/ controll indication panels, cooling fans, automatic tap changing equipment etc. as applicable.

Cables from transformer to substations shall normally be laid underground. Where bus ducts are used, they shall be adequately protected, ventilated and sealed at the substation wall using KOC approved sealant.

All indicating devices on transformers and local panels including silica gel, conservator/tank oil level and any thermometers shall be clearly visible from outside the fence.

Transformer specification nameplates and any other instructions shall also be visible from outside.

Identification numbers and warning signs shall be provided at each Transformer bays.

Each transformer bays shall be provided with 60A T.P&N switch fuse and socket outlet for oil filtration.

Gemrator Buildinq

The generator building shall be sufficiently large to accommodate standby / emergency generator sets as applicable including dummy load bank, generator control panel, starting system, etc. The building shall be of non-elevated type unless otherwise specified.

The Generator building shall be located adjacent to the substation or in a separate building as applicable.

The generator building shall be provided with over-head travelling cranes, rolling shutter with electrical control, one emergency exit door, ventilation systems for generator and building, operating platforms, ladders, cable trenches with covers etc. as required for the safe and proper operation of the generator sets.

The diesel day tank for the diesel generator shall be located outside the generator building at a safe distance in accordance with the requirements of "KOC Standard for Hazardous Area Classifications" (KOC-(2-002).

For further details on generator set and accessories, refer "KOC Standard for Generator Sets" (KOC-E-007).

Packa~e Substations

The package substations shall consist of high & low voltage switchboards and transformer as specified in the project specification that can be readily installed at site. The use of package substations shall be limited for "non-plant" applications.

The various equipment in the packaged substation shall be fully assembled and rigidly mounted on a skid and shall be suitable for outdoor use.

The equipment used in the package substation shall be designed and built in accordance with the relevant KOC Standards / project specifications.

Particular attention shall be given to electrical and mechanical safety. The package substation shall be provided with warning signs, equipment rating labels a7d operating instructions.

The package substation shall be installed on prepared foundations specifically designed for the skid assembly based on manufacturer's instructions and drawincs.

GENERAL REQWREMENTS FOR ELECTRICAL EQUIPMENT

General

All Electrical Equipment shall be new and in all respects suitable for continuous operation in the service conditions stated in KOC Standard for Basic Design Data (KOC-(3-007).

The following shall be considered while selection / design of equipment:

a) Reliability of service.

b) Ease of maintenance and availability of spare parts.

C) Protection of personnel and equipment during operation and maintenance.

d) Ease of operation.

e) Provision for addition of future loads.

Reliability o f all equipment to perform continuously in the service conditions specified is essential. Equipment typical of that being supplied shall have been type tested and in operational use without problems, elsewhere under similar environmental conditions as specified in KOC Standard for Basic Design Data (KOC-G-007) for a minimum period of t w o (2) years from the date of type test. Prototype or unproven equipment not having a well-established record shall not be considered.

Equipment located inside buildings shall be rated for continuous operation throughout the range of specified ambient temperatures, without regard for the air conditioning. All electrical equipment shall continue operation without failure under the temperature from -3'C to 50°C.

Equipment located outdoors shall be provided with sunshades, where required, to reduce solar gain.

The equipment used in hazardous areas shall meet the requirements specified in clauses 1 2.4 &I 2.5 of this RP.

lndustrial type electrical equipment shall be used in all safe areas of industrial plant.

Non-industrial type electrical equipment shall normally be used for office, buildings and housing where the equipment is required to blend in aesthetically with the surroundings, industrial equipment may alternatively be used wherever specified or approved by KOC.

-.

DOC. NO. KOC-EO03 PART 1 Page 31 of 47 REV. 1 I

Electricd equipment, components and accessories shall be standardised wherever possible to enhance replacement / maintenance and to reduce spare holding

Outdated electrical equipment and those requiring spares, which are not expected t o be continuously available for the following 10 years, shall not be used, except for any installations intended to be short-lived subject to prior approval from KOC.

Electrical equipment shall comply with the applicable KOC Standards / Recommended Practices 1 Project Specification and this KOC Recommended Practice.

Prior approval from KOC shall be obtained before installation of electrical equipment.

The submittals for approval shall include drawings, technical data, installation & testing details, operation and maintenance manuals, spare parts details, warranties etc.

The ratings of all the electrical equipment shall be their continuous ratings, after suitably derated for the service conditions and ambient temperature specified. The ambient temperature t o be considered shall not be less than 50°C.

A m in i r~um derating factor of 0.8 shall be applied by the manufacturer to all current carrying equipment other than cables and flexible cords, unless otherwise specified by KOC. The manufacturer shall submit a certification to this effect for KOC review and approval.

Additional derating may be specified for a particular environmental and / or heavy duty applications.

Derating factors for cables and flexible cords shalt be taken from the latest edition of the IEE Regulations for Electrical Installations / manufacturers catalogues.

The nameplate rating of HRC fuses shall be derated 1 % for each 1°C above 35°C temperature in the surrounding.

The nameplate of electrical equipment shall reflect their continuous rating (derated value).

Derating factors shall be retained in air-conditioned areas, to ensure capacity rating in the event of air-conditioning system (HVAC) failure.

lnlqress Protection CIP Rating)

The ingress protection for electrical equipment shall be as specified in the respective KOC Standard 1 Project Specification to suit the particular applica-tion. The minimum degree of protection of electrical equipment shall be based on the following considerations:

a) The electrical equipment installed outdoor shall have an ingress protection o f IP 55 in accordance wi th IEC 60529.

b) -he electrical equipment installed in a shelter exposed to open environment shall have an ingress protection o f IP 5 4 in accordance wi th IEC 60529.

C) Electrical equipment installed within an enclosed buildin constructed to prevent the entry of dust and water shal ingress protection o f IP 4 2 in accordance wi th IEC 60529.

g suitably I have an

Equipment in Hazardous Area

All eq~l ipment to be installed in a hazardous area shall conform to the relevant parts o f KOC Recommended Practice for Selection, Installation and Maintenance of Electrical Equipment in Hazardous Areas (KOC-E-004) and KOC Standard / Project specification for the respective electrical equiprrent.

While selection o f electrical equipment for installation in hazardous areas, the following shall be taken into consideration:

a The zone classification of plant area.

I he apparatus enclosure group. b) --

c The apparatus temperature classification.

All materials and Installation methods shall meet the requirements of defined hazard classification. However, to assist in standardisation and spares holding, equipment shall be specified to meet the requirement for the worst general classification identified for a particular Facility.

The guidelines given below shall be followed while selecting the following electrical accessories for Hazardous areas:

Marshalling boxes, cable glands, junction boxes, switches, remote control stations and welding outlets installed in both Zone 1 and Zone 2 hazardous areas shall be certified "EExd ".

DOC. NO. KOC-E-003 PART I -

Hazardous Area,.Certification

The equipment to be installed in a hazardous area shall be certified for use in thos5 areas by a testing authority of an international recognition. The list of test'ng and certifying agencies acceptable to KOC are given in KOC-E- 0 0 4 Part-2.

The copies of relevant certification documents shall be submitted for KOC review and approval.

POWER TRANSFORMERS & REACTORS

Power transformers shall be suitable for outdoor use in service conditions as specified in clause 6.0 of this RP.

The pcwer transformers should be sized to take care of all running loads (determined from the name plate ratings) including motors, lighting and all other electrical equipment keeping an additional margin of minimum 25% for future projects.

Consideration shall be given to the motor starting voltage drop while selecting the transformer rating. The transformer should be sized so that the voltage drop at the farthest motor terminal does not exceed 15%, when starting the largest motor ivith all other loads connected to that transformer in operation.

For double radial systems, each transformer shall be sized to carry at least 125% sf the maximum demand and for triple radial systems, each transformer shall be sized to carry at least 50% of the total design load (maximum demand + 25%) spare capacity).

The impedance voltages of transformers shall be selected to ensure that the short circuit levels and motor starting voltage drops are within limits. The impedaice values shall be consistent with the minimum values specified in IEC 60076 Part 5 , unless specified otherwise for particular application.

The maximum transformer rating for independent operations shall be as follows unless specified otherwise for a particular application:

a) Transformers with a 440V secondary rating shall be limited to 3 MVA.

b) Transformers with a 3.3kV secondary rating shall be limited to 7.5 MVA.

Note: Hating of transformers, operating in parallel shall be further limited based on the fault level.

Unless otherwise specified, the secondary voltage of a step down transformer shall be as follows:

,\ominal Voltage

a) 3.3kV

No Load Voltaqe

3.45kV

b ) 440 Volts 457 Volts

Earthing transformers shall be generally of similar construction to distribution transformers and shall be adequately rated for specified maximum prospective fault ledels and durations.

Series current limiting reactors shall generally be constructed similar to transformers and may be oil or air-cooled. The reactors shall be adequately rated f ~ r both normal duty and maximum prospective system fault level for at least tkree (3) seconds unless otherwise specified.

For more details on Power transformers, refer "KOC Standard for Power Transformers" (KOC-E-005).

GENERATOR SETS

The generator set shall be designed for continuous unattended operation under the site condition specified.

The generator shall be suitable for automatic start without any external power requirement (black start), unless otherwise specified.

The generator sets shall be capable of starting the largest connected motor in the system with all other loads, including the spare capacity running, while still maintaining the voltage drop within the specified limits.

Generator sets shall be available for immediate start up on receipt of an automatically or manually initiated control signal.

Generator sets shatl be provided with a control panel for the proper and safe operation of the generator.

The generator control panel shall be equipped with all accessories for control, metering, indication, alarm and shut down requirements.

A sepxate transfer / interlock / synchronising panel shall be provided for the automatic transfer of load and parallel operations as required.

A dummy load resistance back with a minimum rating of 40% of the generator rating 1:ogether with associated switchgear shall be provided, for generator sets unless otherwise specified.

Page 35 of 47 REV. I

For more details on Generator Sets, refer "KOC Standard for Generator Sets" (KOC-E-007).

Standby Generator Set

Where a local standby generating plant is selected to provide power to KOC Facilities, it shall be either diesel engine or gas turbine driven generator set(s) each with its own dedicated fuel supply.

The standby generator set shall be continuously rated to supply all the essential operating loads of a facility, sufficient to maintain the normal operation of the plant in the event of 'State Grid' power shutdown. The generator shall be sized for not less than 125% of the maximum demand calculated.

The standby generator set shall automatically start and connect to the electrical system when all incoming power supplies fail, in accordance with the automatic transfer scheme.

Ernerqencv Generator Set

Emergency generator shall be provided for loads critical for personnel / plant safety or shutdown of the Facility.

The emergency generator set shall be continuously rated for the maximum demand calculated plus a minimum of 25% for future addition.

The s ~ p p l y from the emergency generator shall be distributed by a switchboard designsted as an "emergency switchboard", which shall be normally fed from the m ~ i n power supply system.

In the event of loss of main power supply voltage, the emergency generator shall automatically start and connect to the emergency switchboard, in accordance with the automatic transfer scheme.

Unless otherwise specified, the emergency switchboard shall be an independent switchboard (Ref.Appendix-I for details).

Provision for automatic restart of loads connected to the emergency switchboard shall be provided on all circuits.

The typical loads in an operating plant to be backed up by an emergency generator shall include, but not limited to the following:

a) Instrument power supply,

b) UPS systems.

C) DC power supply units.

d) Fire detection / alarm / protection systems.

e) Emergency lighting.

f) CCTV 1 Security systems.

g) Communication systems.

h) Control building WAC.

i Any other power supply required for the safety and security of personnel/Facility.

14.3.8 The ernergency generator back up supply requirements for office and other buildings shall be project specific based on the type of the building and its purpose of use. The typical loads to be considered for emergency generator back up shall include, but not limited to the following (as applicable):

Emergency lighting.

UPS systems.

DC power supply units.

Fire detection I alarm / protection systems.

CCTV / Security systems.

Communication systems.

Building Management System.

Data Processing / Management System.

HVAC system (as required).

Elevators.

Any other power supply required for the personnel1Facility .

safety and security of

15.0 DC POWER SUPPLY UNITS

DC power supply units for control and indication of switchgear, powering rotating plant auxiliaries etc. shall be in accordance with the requirements of "KOC Standard for DC power Supply Units" (KOC-E-012).

96.0 UPS SYSTEM

The uninterruptible power supply system for the DCS, ESD, fire and gas systems and other requirements shall be in accordance with the "KOC Standard for Un nterruptible Power Supply System" (KOC-E-011).

DOC. NO. K O C - ~ - 0 0 3 3 1 Page 37 of 47 - - -

HIGH VOLTAGE SWsTCHGEAR

High vcltage switchgear shall be of sheet steel construction, free standing type with withdrawable circuit breakers / motor starters housed in a separate full height vertical panel accommodating control, monitoring, protection and indicating equipment.

The HL' circuit breakers shall be of vacuum or SF6 type as specified in the project document / data sheet.

All HV switchboards shall be extendable on both sides.

Selecticn of outgoing circuit breaker rating range shall be limited as far as practiceble and all breakers with common ratings shall be fully interchangeable.

HV switchboards shall have 25% equipped spare compartments for future use with a minimum of one (1) compartment of each feeder type / rating in each bus sections.

HV switchboards shall be provided with a control panel to be installed in a separate location in the substation.

For further details on High Voltage Switchgear refer "KOC Standard for High Voltage Switchgear and Controlgear" (KOC-E-002).

RING MAIN UNIT

Ring main units shall be suitable for outdoor installation, where relatively light loads are distributed by cables over a large area.

Ring main units shall be extendable type, unless otherwise specified.

The ring main unit shall comprise of oil / SF, / Vacuum type load making switches, as specified, with provision for cable earthing.

Outgoing feeders of RMUs shall be provided with fuses / protective system as specified.

Any fuse failing / fault in one phase shall trip all three (3) phases and necessary interlocking systems shall be provided to ensure total safety.

Switchi l~g mechanisms of ring main units shall be independent manual, spring- assisted type, with visible ON / OFF / Earthed indication.

Ring main units shall be provided with capacitive type Neon lamps for indication of energised supplies and manual reset type earth fault indicators.

LOW VOLTAGE SWITCHGEAR

The low voltage switchgear shall be designed suitable for installations in indoor locations, unless otherwise specified.

Low voltage switchgear shall be of single-front design. Switchgear of double front design should be allowed only in unavoidable cases, due to space limitations, which requires prior approval from KOC.

Pressu-ising connections and fittings shall be provided for enclosures where specified for dust laden areas.

Centra ised direct-on-line, contactor type motor starting, with an individual starter for each motor, shall be provided at motor control centres, unless otherwise specified.

Reduced voltage starting methods such as Star-Delta / soft starters may be employed only if specifically called for to meet a particular application.

All new low voltage switchgears should have a minimum of 50% fully equipped spare compartments for each category o f outgoing feeder circuits with a minimum of one unit of each type / rating.

For details of Low Voltage Switchgear refer "KOC Standard for Low Voltage Switchgear" (KOC-E-009).

VARIABLE SPEED DRIVE CONTROLLER

Variable speed drive controllers shall comply wi th the Project Specification for "Variable Speed Drive Controller". The units shall be installed in an air- conditioned substation located adjacent to the driven equipment.

SWITCHGEAR CONTROL PANEL AND ANNUNCIATORS

Control panels for HV switchgear shall be of robust design and shall be fitted with protection I control / indicating / metering equipment as required and any auxiliary electrical equipment which cannot be conveniently located in the switchgear panel.

"Duplex type" control panel with all protection I control / indicating / metering requirements shall be provided for all "bulk intake substations" and "Area substations" (where double busbar system is employed).

Contrc,l panels for HV switchgear in plant / other substations shall be fitted with control 1 indication equipment as a minimum.

Contrc'l panels shall be of floor mounting type with front and back removable hinged door access.

For de1:ails of switchgear control panel refer to "KOC Standard for High Voltage Switchgear and Controlgear" (KOC-E-002).

Power system status shall be displayed using "Mimic Board" complete with all circuit indication. Discrepancy semaphore indicators shall also be provided.

All visual indications, meter scales, digital displays and identification labels shall be c lex ly legible from normal operator control positions.

Alarm annunciators shall be provided at each primary area 1 plant substations to indicate particular faults in the electrical system. Each annunciator shall have a cancel, reset and test push-button and relaying contacts for common alarm, to the DCS.

The common alarm 1 annunicator panel provided at substations shall monitor all equipment in the substation, which shall include but not limited to the following:

a 'Transformers.

b) 1 1 kV 1 3.3kV 1 440 Volts Switchgear.

C) 3esel Engine and Generator.

d) Substation battery I charger.

1NTERFAC.E WITH DCS

Electrical equipment shall have provision for DCS interface for control I signalling 1 monitoring etc. as required in accordance with the project documents.

The DCS interface shall be provided in the form of volt free contacts wired out to the terminals for indication of the running 1 stopped 1 tripped status of the equipment, as a minimum.

The DCS interface shall also be provided for the monitoring of analogue signals of elec-trical equipment as applicable.

Motors shall be squirrel cage induction type suitable for continuous operation, unless otherwise specified for special applications.

Motors shall be suitable for direct-on-line starting when coupled to their designed loads.

motor^ shall be protected from direct sunlight by suitable shelters.

For details on high voltage / low voltage motors, refer to "KOC Standard for High Voltage Induction Motors" (KOC-E-001) and "KOC Standard for Low Voltage lnduction Motors" (KOC-E-010) respectively.

MOTOR CQMTROL STATIONS AND MOV ISOLATORS

All motor control push button stations shall have a minimum degree of protection of IP55 and shall be suitable for the hazardous area classification of the area of installation.

The motor control stations located adjacent to the motors shall include the followi i g :

a) Start pushbutton, green, shrouded type.

b) Stop pushbutton, red mushroom-head, stay-put type, pad lockable in the stopped position.

C) Local / off / remote selector switch as required by project specification / P&I D.

d) Ammeter for all motor drives with rating 15 kW and above.

e) Indicating lamps as required by project specification.

I I kV / 3.3kV motor control:

a) Closing and tripping manually from a local control station (near motor) a i t h provision for automatic control from DCS / ESD systems as 3pplicable to meet the process requirements.

b) Test closing and tripping from the switchgear panel front and from the :ontrol panel (within the substation).

440 V motor control:

a Closing and tripping from local control station (near motor) with provision for automatic control from DCS 1 ESD systems as applicable t o meet the process requirements.

b) Test closing and tripping from the front of LT switchgear panel.

A local power and control supply isolator shall be provided for motor operated valves (MOVs), unless otherwise specified.

For more details on motors operated valve actuators, refer to "KOC Standard for Motor Operated Valve Actuators" (KOC-E-013).

DOC. NO. KOC-E403 PART 1

CABLE

Cables shall comply with the "KOC Standard for Electrical Power Cables and Wiring" (KOC-E-023).

Cables shall be sized to meet both the voltage drop criteria and the short circuit condition (for HT Cables only) for a time determined from the maximum protective relay setting plus operating time and the circuit breaker operating time.

The cable voltage drops and minimum conductor sizes are as specified in "KOC Recommended Practice for the Design, Selection and Installation of Electric Cables, Cable Systems and Wiring" (KOC-E-008).

All Control cables should have a minimum of 20% spare cores over the original design requirements.

QLMLlrt' ASSURANCE

The Designer 1 Contractor shall operate a quality system preferably based on IS0 9030 series o f standards to ensure that the requirements of this RP are achieved. The Designer I Contractor shall demonstrate compliance by providing a copy o f the accredited certificate or i ts quality manual. Verificetion of the Designer / Contractor quality system is normally part o f the pre-qualification procedure and is, therefore not detailed in the core text of this RP.

DOCUMENTATION

General

All corrsspondence, instructions, drawings, data sheets, design calculations or any other written information shall be in the English language. In the case of dual language, one language shall be English.

All dimensions, units of measurement, physical constants, etc. shall be in SI units, uqless otherwise specified.

All design calculations should clearly mention the applicable codes and standards referenced.

In addition to the hard copies, all documents (texts, specifications, data sheets, drawings, etc.) shall be provided with electronic files in the approved software (MS Word, Excel, AutoCAD, etc.). Design calculations shall be submitted in the approved and widely used software, agreed by KOC.

- -.

DOC. NO. KOC-E403 1 PART I , I REV. 1 b - - - 7

27.2.1 The Dssigner / Contractor shall submit the necessary documents for KOC review / approval, which shall include, but not limited to the following:

a) Power system study report consists of:

, Load flow analysis.

, i . Short circuit study.

ii. Motor starting study

-v. Protective relay coordination study.

v . Transient stability study (as applicable).

i . Harmonic analysis study

t~ii. Any other studies as specified in the project specification or required to establish design basis.

b) IElectrical calculation consists of:

I.

II.

... 1 1 1 .

iv.

'1.

'ji,

t i .

viii.

ix.

X .

xi.

Calculation for short circuit current.

Calculation for cable sizing.

Calculation for transformer sizing.

Electrical load calculation for standby generator sizing.

Electrical load calculation for emergency generator sizing.

Calculation for earthing system.

Calculation for lighting system.

Calculation for UPS sizing.

Calculation for battery charger sizing.

Calculation for battery sizing.

Any other calculations as specified in the project specification or required to establish design basis.

The Designer I Contractor shall submit the necessary drawings for KOC review and approval, which shall include, but not limited to the following:

a) Single line diagrams showing power sources, transformer, switchgear, metering and relay details, feeder with load details etc.

b) Electrical equipment layout and arrangement drawings.

c) Hazardous Area Classification Drawings.

d) Schematic diagrams, including power system protection, control, indication and alarm, small power, lighting, any input to a data processor, and connections to and between electrical equipment.

e) Cable schedules detailing cable identification, type, size, number of cores, estimated length and gland requirements.

f 1 Cable interconnection drawings indicating cable identifications and routes.

g) Cable route layout drawings.

The Lesigner 1 Contractor shall submit documents / drawings for all electrical equipment provided by the equipment manufacturers for KOC review / approval while submitting the offer, which shall include, but not limited to the following:

a) Seneral arrangement drawings showing main dimensions, weights, arrangement of components and the minimum space requirement for installation of the equipment.

b) Foundation plan showing location and details of foundation bolts including static and dynamic loadings as applicable.

C) Electrical schematic and wiring diagrams.

d) Supply record for identical equipment.

e) Hazardous area certification document as applicable.

f) Type Test Certificates of similar equipment as applicable.

g) Completed Data Sheets as applicable.

DOC. NO. KOC-Em3 PART I I Page 44 of 47 REV. 1 .!,m

27.2.4 The documents / drawings related to electrical equipment t o be submitted for KOC1s review / approval, record and use shall include, but not limited to the foliowing:

Detailed drawings for all equipment and accessories showing dimensions, weights, arrangements o f components, cable termination, 3iping connection and all other details as applicable.

Floor plan wi th foundation / fixing details.

3etailed electrical schematic, wiring and interconnection diagrams.

3ata Sheets filled wi th all details.

~a ta logues , Installation, testing & commissioning, operation & maintenance instructions for all equipment and accessories.

'arts l ist wi th all technical details, Maker's Name, Type, Serial \lumber, etc.

'aint Specification.

nspection and Test Plan.

nspection / Test reports.

-ist o f Manufacturer's recommended Spare Parts for t w o (2) years ,lorma1 operation.

'acking details.

27.2.5 Electrical equipment drawing supplied by the Manufacturer shall have the following information as a minimum:

a) 3rawing title.

b) Manufacturer's name and address.

C) \lame of the project.

d) Manufacturer's order or contract number.

e) Purchaser's order number.

f ) Manufacturer's drawing number and revision number wi th dates.

27.2.6 Packing, Marking and Shipping Documentation shall comply wi th "KOC Standerd for Packing, Marking and Documentation" (KOC-G-004).

28.0 APPENDIX-I Typical Electrical Distribution Svstem for GC I BS I

Other Major Operating Facilities

DOC. NO. KOC-E-003 PART 1 -

Page 46 of 47 - I!

ACKNOWLEDGEMENT

This KOC Recommended Practice has been approved by the Standards Technical Committee (STC} consisting of the following:-

Mr. Abdul Redha Al-Haddad Mr. Mohd. Emam Mr. S. Kumar Mr. Henry S. Hi'l Mr. A. Unnikrishnan Mr. Khalaf Hamada Mr. N. Ramanathan Mr. Ali Hassan Al-Faila kawi Mr. Abdul Razzaq Al-Shammari Mr. Daniel Pino Mr. Khalid Al-Ahmad Mr. Abdul Aziz Akbar Mr. Moataz Khalaf

(Standards Team) Chairman (Insp.& Corr. Team-S) Deputy Chairman (Standards Team) SecretaryIMember (Opns. Tech. Svcs.Team-S) Member (Standards Team) Member (Design Team) Member (Export Facilities Team) Member (HSE Systems Team) Member (Insp. & Corr. Team-N&W) Member (Utilities Team) Member (Gen. Proj.Team) Member {Proj. Mgmt.Team-N) Member (Information Systems Team) Member

The draft of this Standard has been circulated to the KOC User Teams for their review and responses were received from the following:-

OPNS. GROUP [WEST) AHMADI SERVICES GROUP

Team Leader Maintenance Team Leader Proj. Design Team Leader Opns. Tech. Svcs. Team Leader Utilities Team Leader Proj. Engg, & Facilities-DZ

ENGINEERING GROUP INDUSTRIAL SERVICES GROUP

Team Leader Design Team Leader Insp. & Corr. (S&E

OPNS. GROUP (SOUTH) OPNS. GROUP (EAST)

Team Leader Prod. Opns. Team Leader Opns. Tech. Svcs. Team Leader O ~ n s . Tech. Svcs. Team Leader Gas Operations

MAJOR PROJECTS GROUP

Team Leader Proj. Support

HSE GROUP

Team Leader HSE Systems

DRILLING SERVICES GROUP

Team Leader Drilling

DOC. NO. KOC-E-003 PART 1 I/ Page 47 of 47 - This "KOC RP for Design Basis and Selection of Electrical Systems" (KOC-E-003, Part 1, Rev. 1) l a s been prepared by the Task Force (TF-EEt07) comprising of the following membsrs:

Mr. A.Unnikrishran Standards Team Task Force Leader Tel No. 61 633 Mr. Samir Bu-Hamad Opns. Tech. Svcs. (SK) Member Tel No. 22343 Mr. Gobinda Mis9ra Design Team Member Tel No. 61 0 9 7 Mr. Andrew Nayak Gen. Projects Team Member Tel No. 61658 Mr. Abdul Hadi kl-Zabi Maj.Projects Team Member Tel No. 61 583