es.2.06.0001 - rev a - electrical installation - recommended practises

8/11/2019 ES.2.06.0001 - Rev a - Electrical Installation - Recommended Practises

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QATAR GENERAL PETROLEUM CORPORATION

TECHNICAL DIRECTORATETechnical Services Department

Engineering Standard ES.2.06.0001

Electrical Installation

Recommended Practices

- Revision A -

Status Indicator Date Signature

Prepared ENE/732 AUG 99 Ori ginal signed by ENE/732

Checked ENE/73 AUG 99 Original signed by ENE/73

Approved EE AUG 99 Ori ginal signed by EE

AC7SC0AB0


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TABLE OF CONTENTS

1.0 Introduction

2.0 Custodian

3.0 Purpose

4.0 Application

5.0 Preface to ES.2.06.00015.1 Extracts from the preface to ES.2.03.0001

6.0 Project Documentation6.1 Sources of documents

6.2 Application of documents

6.3 Standards, codes and regulations

7.0 Service and Environmental Conditions7.1 Ambient temperature for design purposes

7.2 Meteorological information for general use

7.3 Special requirements for equipment installed in hazardous areas

7.3.1 Area classification

7.3.2 Selection and installation of equipment

7.4 Contractors responsibility for safety on site

7.5 Test records

7.6 Visual inspection

7.7 Scope of testing at site

7.7.1 Installation contractor

7.7.2 Manufacturer of new equipment7.7.3 Requirements of a particular project

7.8 General requirements for testing cables

8.0 Switchboards and Motor Control Centres8.1 Preliminary checks

8.2 Installation

8.3 Post-installation un-energised testing

8.4 Post-in energised testing

8.5 Commissioning energised testing

8.5.1 Protection relays

8.5.2 Electrical functional testing

8.5.3 High voltage testing

8.6 Testing when cabling is complete

8.6.1 Consumers

8.6.2 Incomer circuit breakers

8.6.3 Bus-section and bus-coupler circuit breakers

9.0 Transformers9.1 Preliminary checks

9.2 Installation


9.4 Post-installation energised testing


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9.5.2 Switching into normal service

10.0 Turbine Driven Generators10.1 Division of discipline responsibilities

10.2 Preliminary checks10.3 Installation


10.4.1 Generators without unit transformers

10.4.2 Generators with unit transformers

10.4.3 Auxiliary equipment




10.6.2 Testing control systems

10.6.2.1 AVR controller

10.6.2.2 Governor controller

10.6.3 Running on open-circuit10.7 Synchronused with other sources

11.0 Engine Driven Generators11.1 Division of discipline responsibilities

11.2 Preliminary checks

11.3 Installation





11.5 Post-installation energised testing11.6 Commissioning energised testing



11.6.3 Running on open-circuit

11.7 Synchronised with other sources

12.0 HV Motors12.1 Division of discipline responsibilities


12.3 Installation


12.5 Post-installation energised testing12.5.1 Shaft coupling



12.6.2 Testing control systems of synchronous motors

12.6.3 Starting time and starting current

13.0 LV Motors13.1 Preliminary checks

13.2 Installation



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13.5.1 Shaft coupling

13.5.2 Running lightly loaded

14.0 Drying Out Generator and Motor Windings

15.0 Packaged and Skid Mounted Equipment15.1 Preliminary checks

15.2 Installation

15.3 Post-installation testing and commissioning

16.0 Cables and the Installation of Cables16.1 Laying of cables in all installations

16.1.1 Qualified cable jointers and supervision

16.1.2 Site modifications to the design

16.1.3 Cable drums and drum schedules

16.1.4 Basic installation practices

16.1.4.1 Cables supported on racks or trays above or below ground16.1.4.2 Cleating and securing cables

16.1.4.3 Cable transits

16.1.4.4 Cables protected at ground level

16.1.4.5 Conduit installations

16.2 Laying of cables in land-based installations

16.2.1 Cables laid directly in the ground

16.2.2 Cables laid in pipes or ducts

16.2.3 Derating cables for environmental conditions

16.3 Laying of cables in platform-based installations

16.3.1 The use of conduit systems

16.4 Glanding and termination of cables16.5 Special considerations for installing 33Kv (and above) cables

16.5.1 Site considerations

16.5.2 Additional requirements for cables laid direct in ground

16.5.3 Additional requirements for cables drawn into ducts

16.5.4 Cables at road-crossings and in areas accessible to vehicles

16.5.5 Cables supported on poles and in buildings

16.5.6 Terminations for 33kV (and above) cables

16.5.6.1 Power cables

16.5.6.2 Terminating and jointing conductors

16.5.6.3 Cable identification

16.5.6.4 Stand off insulators

16.5.6.5 Cable route markers above ground16.5.6.6 Concrete cable tiles

17.0 Batteries, D.C. and A.C. Uninterruptable Power Supply Systems

17.1 Safety

17.2 Terminology

17.3 Vented lead acid batteries

17.4 Vented nickel-cadmium batteries

17.5 Sealed lead acid batteries

17.5.1 Operational restrictions

17.5.2 Battery room temperature


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17.6 Battery rooms and their equipment

17.6.1 Electrical equipment

17.6.2 Maximum charger rating in a battery room

17.6.3 Non-electrical equipment

17.7 Preliminary checks for batteries

17.7.1 Delivery of batteries to site

17.7.2 Unpacking and assembling the cells

17.8 Charger units

17.8.1 Preliminary checks

17.8.2 Installation

17.8.3 Post-installation testing and commissioning

17.9 Inverter units

17.9.1 Preliminary checks

17.9.2 Installation

17.9.3 Post-installation, testing and commissioning

17.10 Distribution Board

18.0 Lighting and Small Power

18.1 Normal Lighting18.2 Emergency lighting

18.3 Escape lighting

18.4 Additional requirements for platform-based installations

18.5 Location of lighting and distribution switchboards and circuit switches

18.5.1 Zone 1 and Zone 2 Hazardous areas

18.5.2 Unclassified areas

18.5.3 Ligthing and distribution isolation and control

18.5.4 Lighting and small power switches in all areas

18.6 Lighting installation considerations

18.7 Types of lighting fittings

18.8 Illumination levels

18.9 Road lighting

18.10 Choice of lamps, luminaires and holders

18.10.1 Lamp holders for tungsten filament lamps

18.10.2 Lamp holders for tubular fluorescent lamps

18.10.3 Lamp holders for high pressure mercury discharge and metal halide lamps

18.10.4 Lamp holders for sodium lamps

18.10.5 Portable luminaires

18.10.6 Low voltage discharge and fluorescent lighting

18.10.7 High voltage discharge lighting and signs

18.11 Small power outlets

18.12 Navigation aids for platform-based installations

18.13 Inspection and testing lighting and socket outlet systems

19.0 Earthing Systems

19.1 Basis of design

19.1.1 Extracts from QES-E-10

19.1.1.1 Faults on electrical equipment and systems

19.1.1.2 Lightning strikes

19.1.1.3 Build-up of static electric charge

19.2 Practical requirements

19.2.1 Earthing and bonding connections

19.2.2 Plant and equipment earthing and bonding

19.2.3 Packaged equipment


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19.2.4 Cable armour termination

19.2.5 Cable dielectric screens

19.2.6 Instrument system earthing for platform-based installations

19.2.6.1 Instrument room power and instrumentation earthing

19.2.6.2 Earthing to provide a reference potential for computing, telecommunications and instrument

equipment.

19.2.6.3 Intrinsically safe barrier earthing

19.2.6.4 Instrument screen earthing

19.2.7 Pipe flanges

20.0 Overhead Lines

20.1 Soil tests

20.2 Pole and insulator erection

20.2.1 Poles and steelworks

20.2.2 Line sections

20.2.3 Plans, profiles and pole schedules

20.2.4 Pole numbering

20.2.5 Danger plates

20.2.6 Pole earthing20.2.7 Insulators, switches, surge arrestors and fuse isolators

20.2.8 Stays

20.2.9 Anti-climbing guards

20.3 Conductor erection

20.3.1 Planning and schedules

20.3.2 Damage

20.3.3 Running-out blocks

20.3.4 Back staying of poles

20.3.5 Conductor lengths and joints

20.3.6 Conductor hauling devices

20.3.7 Jointing

20.4 Conductor sagging and tensioning

20.4.1 Method

20.4.2 Anchoring and damping

20.4.3 Removal of suspension snatch blocks

20.4.4 Jumper-loops

20.5 Sag and tension charts and templates

20.5.1 Sag and tension erection charts

21.0 Approval to Deviate

22.0 Revision History Log

23.0 Bibliography

APPENDICES

A Abbreviations


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B Technical definitions

C List of standards used for electrical engineering and equipmentC.1 International Electrotechnical Commission (Europe)

C.2 Institute of Petroleum (UK)

C.3 International Standards Organisation (Worldwide)C.4 British Standards Institution (UK)

C.5 American Petroleum Institute (USA)

C.6 CIGRE (France)

C.7 Engineering Equipment and Materials Users Association (UK)

C.8 Electricity Council (UK)

C.9 Verband Deutscher Electrechniker (W.Germany)

C.10 Institute of Electronic and Electrical Engineers Inc. (USA)

C.11 Miscellaneous References from the UK

C.12 QGPC electrical equipment and systems standards (Qatar)

C.13 Periodic Revision of Reference Documents

D Recommended Limits for Test ResultsD.1 Cautionary note

D.2 Insulation resistance tests

D.2.1 Cables

D.2.2 New switchgear and motor control centres

D.2.3 Generators and motors

D.2.4 Liquid filled power transformers

D.3 High voltage tests

D.3.1 New switchboards and motor control centres

D.3.1.1 Reference standards

D.3.1.2 Power frequency tests

D.3.1.3 D.C. testsD.3.2 Power transformers

D.3.3 Generators and motors

D.4 Polarisation index tests for HV generators and power transformers

D.5 Measurement of earth electrode resistance

D.5.1 Resistance of the general mass of earth

D.5.2 Single vertical rod earth resistance

D.5.3 Multiple vertical rod earth resistance

D.5.4 Methods of measurement

D.5.5 Results to be achieved

E. Technical Particulars of 33 kV Overhead Line and Cable

E.1 IntroductionE.2 Schedule-overhead line-general characteristics

E.3 Schedule-overhead line-design conditions

E.4 Schedule - 33kV cables - technical particulars

E.5 Schedule-clearances-internal to line

E.6 Schedule-clearances-external to line

E.7 Schedule-phase conductor-technical particulars

E.7.1 Phase conductor characteristics

E.7.2 Tensioning details

E.8 Schedule-earthwire conductor-technical particulars

E.8.1 Earthwire conductor characteristics


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E.8.2 Tensioning details

F. Temporary Electrical Installations


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ENGINEERING STANDARDS

- ELECTRICAL -

ES.2.06.0001

AMENDMENT RECORD

Rev. No. Date Amendment Section Page

A.1


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1.0 Introduction

This is an engineering standard that gives details about the recommended practices to be used

in new and existing electrical installations.

Note that any changes to this document from its last revision are highlighted by a bold

vertical bar to the left of each area of change. Should there be a need to consult thisdocuments change history log, refer in the first instance to its custodian (EE). References

made throughout this standard are numbered inside square brackets [ ] and may be found in

the Bibliography of Appendix C.

2.0 Custodian

The Custodian of this standard is EE, who is responsible for the accuracy and quality of its

contents and for its future revisions, where these are required to reflect industry trends or

changes to QGPC business practices.

3.0 Purpose

This document shall be used in the engineering and design of land-based plants and platforms

and floating facilities in the sea around Qatar.

4.0 Application

The electrical engineering recommended practices described in this document shall be applied

to the engineering and design of QGPC power systems and their components. These practices

shall be applied to obtain the most suitable technical application and the economicalinstallation, testing and commissioning of the equipment required for these power systems.

5.0 Preface to [ES.2.06.0001]

This document describes the practices required for the installation and commissioning of

systems and equipment at QGPC sites, in accordance with the philosophy of engineering

described in [ES.2.03.0001] and its references. All parties involved in the design and

installation of a plant for QGPC shall use this document to achieve the installation standards

required by QGPC.

This document shall be used in the design and installation of land-based plants, and platforms

located in the sea around Qatar.

To avoid confusion in the use of the terms on-shore and off-shore in general, and in

connection with Halul Island in particular, the following terms will be used instead :-

Land-based installations (LBIs). All plants installed on the mainland of Qatar. All plants

installed on Halul Island.

Platform-based installations (PBIs). All plants installed on elevated platforms or moored

vessels located in the sea or waters around Qatar.


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All installations (AIs). Means that the equipment described applies to both land-based

and platform-based installations.

The primary purpose of this document is to describe the approach needed to be adopted by the

QGPC Engineer and the CONTRACTOR when a new plant, or modifications to an existing

plant, reaches the stage when its equipment is to be installed and made ready for operation. Insome sub-sections cross-references are made to other documents for further reading or for

sources of data. Hence the practices for all future installations should be similar.

The companion document [ES.2.03.0001] is a necessary reference for background

information. These two documents, [ES.2.03.0001 and ES.2.06.0001], address the same

subjects but for different objectives. Consequently, duplication of material has been reduced to

a minimum, and cross-referencing has been adopted so that the reader can obtain a complete

understanding of a particular subject.

The QGPC document [ES-E-040, to be re-numbered] covers commissioning of electrical and

non-electrical equipment. Volume 2 covers the electrical equipment and gives descriptions of

various special tests e.g. injection testing of relays, dielectric and polarization index testing.

This document is divided into sections which concentrate on particular types of equipment,

and in approximately the order in which these main individual items of equipment would be

required to be on the site, e.g. switchgear, transformers, generators. Cables and their systems

follow because they are common to all electrical equipment on a site. Overhead lines are

described as the last main item because they are involved only with land-based plants, and

they are a specialized subject. Overhead lines are normally projects in their own context, and

invariably interface with a major plant at the boundary or battery limits, see [ES.2.03.0001].

For the purposes of this document the following definitions of terms and interpretations shall

apply regardless of any meaning the words may have in other respects.

Shall: The word shall is to be understood as mandatory.

Should: The word should is to be understood as being strongly

recommended.

QGPC : Is the party which initiates the project and ultimately pays for

its design and construction. QGPC will generally specify

technical requirements. QGPC may also include and agent or

consultant to act for QGPC.

CONTRACTOR : Is the party which carries out all aspects or part of the design,

engineering, procurement, construction and commissioning ofthe plant. QGPC may sometimes undertake all or part of the

duties of the CONTRACTOR.

Manufacturer/ Is the party which manufactures or supplies equipment.

Supplier

Document : As used in [ES.2.06.0001], this refers to standards,

recommended practices, guidelines, data sheets, drawings,

schedules etc. issued by QGPC that are required to enable the

engineering and design work to be completed by the

CONTRACTOR.


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Note 5.a: - See Appendix B for definitions of particular technical words

and expressions.

5.1 Extracts from the Preface to [ES.2.03.0001]

This document sets out to establish the QGPC philosophy required for the design and selection

of electrical systems and equipment, in accordance with the latest international standards and

industrial installation practice. All parties involved in the engineering and design of a plant for

QGPC shall use this document to achieve the standards required by QGPC.

The primary purpose of this document is to describe the approach or philosophy needed to be

adopted by the QGPC engineer and the CONTRACTOR when a new plant is being

considered, or when modifications are proposed to an existing plant. In many sub-sections the

reasoning behind a QGPC requirement is outlined or explained, or a reference to further

reading is given. Hence a similar design for all plants should be achieved.

The companion document is [ES.2.06.0001] which concentrates on how equipment is installed

after it has been designed, manufactured and delivered to site. These two documents,[ES.2.06.0001] and [ES.2.03.0001], address the same subjects but for different objectives.

Consequently, duplication of material has been reduced to a minimum, and cross-referencing

has been adopted so that the reader can obtain a complete understanding of a particular

subject.

In addition the specifications listed in Appendix C, sub-section C.11, describe the essential

technical features that QGPC require from the manufacturers of particular items of equipment

e.g. generators, switchgear, motors, power transformers. These documents develop the basic

principles set out in [ES.2.03.0001] into more detail, and are intended to be the Project

Specifications. In this regard the CONTRACTOR should not need to prepare his version of

[ES.2.03.0001], but he may need to prepare a version of [ES.2.06.0001] for the installation of

a particular project.

6.0 Project Documentation

6.1 Sources of Documents

A project that requires the installation of equipment will provide two basic types of documents

for the erection, testing and commissioning of the equipment. These are :-

a) Detail design documents created by the CONTRACTOR who has been responsible for

the engineering and design of the equipment and associated systems.

b) Equipment documents created by the manufacturer for his particular item of equipment.

In general the documents in b) will be included with the deliverable documents in a). The

CONTRACTOR shall check the suitability and completeness of the b) documents before they

are delivered to site.

The documents in a) will contain installation detail drawings, supporting descriptive material

and procedures particular to the installation.


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Note 6.1a :- This document, [ES.2.06.0001], shall be a major reference document

during the detail design phase of the project, see paragraph one of 5).

The CONTRACTOR should maintain a written record of any significant deviations from the

practices described in this document. The record should include for example, minutes of

meetings, letters, facsimiles, telexes and the like that have been communicated with QGPC.

6.2 Application of Documents

The documents that shall take precedence over any others shall be those created and delivered

by the CONTRACTOR for the particular project, and which should have been reviewed by

QGPC during the detail design phase of the project.

In the absence of suitable documents at site when the installation work is due to commence,

[ES.2.06.0001] shall be referred to for guidance where appropriate. The CONTRACTOR

should then create suitable documents for immediate use and recording purposes to the

satisfaction of QGPC.

6.3 Standards, Codes and Regulations

Many of the principles of this document are based on the [IEC 364] and [IEC 79] publications

or the CENELEC equivalents, e.g. [HD 384] and [EN 50.014] up to and including [EN

50.020]. The entire electrical installation shall be suitable for the environmental influences and

climatic conditions as specified by QGPC, See [Appendix E of ES.2.03.0001]. Furthermore,

the contents of this document and of the standards and publications referred to herein shall be

adhered to, except where amended by specific requirements given by QGPC to a particular

installation and as far as is permitted under the statutory requirements of the State of Qatar.

Electrical equipment and materials shall comply with the relevant specifications and data

sheets or M.E.S.C (Group Materials and Equipment Standards and Code) specifications,

which in turn shall be generally considered as supplementary to IEC equipment standards.

CENELEC or national standards of Qatar may be used in lieu of IEC standards for the design

and engineering of the electrical installation provided they are no less stringent in their total

requirements.

Where BSI standards are quoted, their IEC equivalent documents may also be used.

Appendix C herein gives a list of IEC and other standards that are generally encountered in

electrical system design and equipment manufacturing.

In the event of contradiction between the requirements of QGPC specifications and IEC,

CENELEC, BS, or national standards the former shall prevail, subject to satisfying statutory

obligations. The SI unit system shall be used throughout design work. Electrical symbols shallconform to IEC except where specified by QGPC. Electrical equipment numbering shall

conform to QGPC standards. All documentation shall be prepared, copied and delivered in the

English language.

7.0 Service and Environmental Conditions

See Appendix E of [ES.2.03.0001] for full details.

7.3 Special Requirements for Equipment Installed in Hazardous Areas

7.3.1 Area classification


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All installations should be classified into hazardous and non hazardous areas as fully

described in [ES.2.03.0001, Appendices F and H].

An Area Classification Drawing(s) should be prepared showing these areas, using the

procedure referenced in [ES.2.03.0001, Appendix H, sub-section H.4]. These drawings should

also indicate the gas group and temperature classification of the gases likely to be present in

the area.

Note 7.3.1a:- Area classification should be a joint exercise involving operations,

mechanical, electrical, instrument, safety and loss prevention

disciplines as appropriate.

7.3.2 Selection and installation of equipment

The selection and installation of equipment in hazardous areas should be in accordance with

[ES.2.03.0001, sub-section 7.2, Appendices F and H].

7.4 Contractor Responsibility for Safety on Site

The CONTRACTOR will be responsible for inspection and testing the equipment and cables

that he has installed.

The CONTRACTOR will be responsible for taking all necessary safety precautions, the

supply of all necessary labour and testing equipment, the replacement of all equipment and

sundries, e.g. fuses damaged during testing and the maintenance of the installation until such

time as it is taken over by the QGPC.

Wherever possible no piece of equipment e.g. power switchboard, shall be energised until all

work on it has been completed. Where this is not possible the CONTRACTOR must take all

the precautions necessary to ensure the safety of personnel who continue to work on the

equipment. No equipment shall be energised without prior permission of Electrical

Department of QGPC and the obtaining of any necessary permits. All outgoing circuits shall

be isolated and padlocked in the off position and suitably worded caution boards shall be

prominently displayed.

Wherever possible final inspection and testing should be carried out immediately prior to

commissioning equipment and leaving it in its normal operating condition. Equipment that is

left in a de-energised condition should be subjected to such tests as are deemed to be necessary

by QGPC. This shall be carried out immediately prior to energising to prove that it is in a

satisfactory condition.

The CONTRACTOR is recommended to maintain close liaison with the QGPC inspector so

that inspection and testing may be carried out as the installation and making-off of cable ends

proceeds. This will eliminate the need to re-open terminal boxes and enclosures and disconnect

cables after the installation has been completed. Failure to comply with this will render the

CONTRACTOR carrying out the tests liable for all costs involved in subsequent

disconnection and reconnection required for testing purposes.

Under no circumstances shall a circuit be energised or commissioned prior to its being

inspected and tested.


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Primary injection shall be prefered for all tests where this is normally possible. Where this is

impractical secondary injection may be used, but this must be agreed in writing with QGPC in

advance of the testing being commenced. The CONTRACTOR shall provide all the testing

equipment in either situation.

7.5 Test Records

Accurate records shall be kept of all tests made and their records shall include : -

Details of the equipment or circuit tested.

The test(s) made.

The results of the test(s).

Where appropriate, the commissioning checks made and the results of them.

The signatures of the representatives of the CONTRACTOR and QGPC who witnessedand approved the tests.

All tests shall be recorded on test sheets provided by the CONTRACTOR. Where special tests

are required and no suitable test sheet is available, a suitable test procedure and sheet shall be

produced by the CONTRACTOR and submitted to QGPC for approval prior to beingimplemented.

The test sheets shall be completed by the CONTRACTOR and approved by QGPC. The

CONTRACTOR shall submit the test report to QGPC in quintuplicate within one month of

the tests being carried out.

The QGPC document [ES-E-040, to be re-numbered] contains detailed procedures for special

tests e.g. phase testing of windings, injection testing of protective relays, high voltage testing.

It also contains standard test sheets that can be used if the CONTRACTOR has not prepared

similar sheets.

7.6 Visual Inspection

The installation shall be subjected to a thorough visual inspection to check every part of it

complies with the specifications, standards and drawings; and that a high and acceptable

standard of workmanship has been achieved. In particular:-

Equipment shall be checked for correct identification, rigidity of fixture, freedom from

physical defects, completeness of assembly and installation.

Cables and conductors shall be checked for correct sizing, termination identification,

security of fixtures, defects, termination and freedom from kinks and general damage.

The installation shall be checked for its suitability with respect to the area classification.

Check of internal and external cleanliness and the sealing or greasing of flanges.

Following the completion of commissioning the proper fixing of cover plates shall be

rechecked.

7.7 Scope of Testing at Site

Tests on site shall include, but not limited to, the tests specified hereunder and shown on the

test sheets.

Additional tests shall be carried out as necessary to ensure that every item of equipment and

part of the installation is capable of satisfactorily performing its function.


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No testing shall be undertaken until the appropriate visual inspection has been satisfactorily

completed.

Part of the practice of installation is the testing of equipment. As far as electrical equipment is

concerned the testing can be broadly divided into the following categories :-

Preliminary checking.

Post-installation un-energised testing.

Post-installation energised testing.

Commissioning energised testing.

Testing when cabling is complete.

The party, or parties, responsible for carrying out the testing depends to some extent on the

nature of the project e.g. completely new plant, extension to an existing plant, replacement of

equipment, old equipment involved, new equipment, major or minor technology involved.

These parties can be divided as follows :-

Installation contractor.

Manufacturer of equipment.

Independent testing contractor.

QGPC maintenance department.

This document mainly concerns the activities of the first two parties, i.e. the installation

contractor, the manufacturer of the installed equipment.

Testing shall include calibration.

Tests that are necessary to retain the manufacturers guarantee will be conducted in

accordance with instructions from the electrical equipment manufacturer. In the absence of

specific manufacturers instruction (MI), electrical site tests will be limited to thosehereinafter specified for the various materials and equipment. An inspection shall generally be

required and it should consist of the combined physical and material defects prior to, during

and after the energizing of an electrical installation.

7.7.1 Installation contractor

The equipment listed below may be regarded as being less sophisticated than those listed in

7.7.2 and consequently it should normally be handled by the Installation Contractor in

cooperation with QGPC.

The following tests should be performed by the Installation Contractor : -

Generators rated below 750kW.

Motors rated below 750kW .

Cables rated 600V and less.

Batteries and chargers.

Lighting and small power systems.

Earthing and bonding systems.

Distribution boards.

Overhead lines.

Power transformers rated below 500kVA .

Hazardous area equipment.


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Trace heating.

Cathodic protection.

Operational and functional testing of all systems prior to energising equipment.

7.7.2 Manufacturer of new equipment

The equipment listed below may be regarded as being more sophisticated than those listed in7.7.1 and consequently it should normally be handled by the manufacturer in cooperation with

the Installation Contractor and QGPC.

The following tests (and calibrations) should be performed by or under the supervision of the

manufacturer or authorized manufacturers representative : -

High voltage generators.

Low voltage generators rated 750kW and above.

Switchboards and motor control centres, including protection relays.

High voltage neutral earthing resistors.

Power transformers rated 500kva and above.

High voltage busducting and busbars.

Cables rated for voltages above 600v.

Supervisory, control, scada, dcs equipment.

Motors rated 750kw and above.

Power management systems.

Variable speed controllers for motors.

Ups equipment rated 100kva and above.

Special purpose equipment.

7.7.3 Requirements of a particular project.

The division of responsibilities listed in (7.7.1) and (7.7.2) should be reviewed for therequirements of a particular project, and should be approved by QGPC before the equipment

is purchased.

7.8 General requirements for testing cables

Cables are common to all installations. It is prefered that no cable should be tested until it has

been fixed in position and particular attention should be paid to cable rigidity at terminal

points. See also 16.1.3 for testing cables that are still on their drums as delivered to site.

LV cables should be individually tested after they have been terminated but, wherever

possible, before they are finally connected.

HV cables shall be tested only when they have been terminated and connected.

If disconnecting links are provided in terminal equipment, they should be removed before the

cable tests are carried out and be replaced immediately following completion of the cable tests.

In the case of HV cables where disconnecting links are not provided in the terminal equipment

prior assurance must be obtained in writing from the supplier to ensure that the full cable test

voltages specified below can be applied to the connected equipment, e.g. motor windings,

switchgear cable spouts and C.T. chambers etc.


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The test voltages which may be applied to existing cables must be arranged by discussion

between all interested parties.

No instrument cable may be tested without the prior approval of the QGPC Instrument

Inspector. To test an instrument cable it may be necessary to disconnect the instrument prior

to carrying out insulation resistance tests on the cable.

Under no circumstances shall any insulation test, bell testing set or other high or low voltage

test be applied to semi-conductor equipment; and all such equipment must be disconnected

prior to carrying out insulation resistance tests on the associated cables.

The CONTRACTOR carrying out the tests will be held responsible for any damaged caused

by the test voltages.

See also 16.1.3.

8.0 Switchboards and Motor Control Centres

8.1 Preliminary Checks

Large switchboards are often delivered in units of three or four cubicles. Check the largest

unit for dimensions and ensure that it can be transported from its storage location to its

permanent location.

Check the permanent location for : -

Dimensions against those of the switchboard manufacturer.

Main cable access ways and channels.

Auxiliary cable access ways and channels.

Fixing points and base frame levelling.

Lifting facilities and access overhead.

Screeding and circuit breaker truck or trolley and access are correct.

Earthing connections are installed.

Supply connections for space heaters.

Check the switchboard nameplate details, tag numbers, cubicle names etc. are correct.

Check the manufacturers instructions (MI) for advice about moving the switchboard into its

permanent location e.g. removal of circuit breakers, temporary fixing of items to prevent

movement and damage within the structure.

8.2 Installation

Installation shall be in accordance with manufacturers instructions (MIs).

Special tools and equipment recommended by the manufacturer shall be supplied, and

maintained in good condition for use when required.


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All bolted connections within the equipment shall be checked for tightness, particularly busbar

connections including correct alignment and connections of interconnecting busbars, to the

torque settings recommended.

Before any cables are connected to the equipment, or insulating compounds added, insulation

checks shall be carried out on all main and control circuits. These shall include high voltage

tests on main connections between phases and earth to ensure that a breakdown of insulation

has not taken place during installation. Follow the manufacturers instructions carefully, and

disconnect all devices, which could be harmed by the test voltages e.g. electronic measuring

circuits.

Bond the switchboard to its earthing facility in the switchroom e.g. cables to switchroom

busbar from the switchboards earth busbar.

Check the bonding details with those described in [ES.2.03.0001].

8.3 Post-Installation Un-Energised Testing

Functionally check all mechanical operations e.g. racking in and out circuit breakers, safetyshutters move into their correct positions, earthing switches, mechanical interlocks of earthing

devices, interlocks for truck positions, open-closing-rewinding mechanism springs.

Test the earth bonding continuity at the various joints using a DUCTOR or similar test

instrument and record the results.

Test the continuity of the main busbars and risers at their main joints. Record the results.

8.4 Post-Installation Energised Testing

Most switchgear will require low voltage supplies for tripping, closing, spring winding,

indication and protection relays. Arrange for suitable permanent or temporary supplies, D.C.

and A.C. of the correct frequency, to be available so that pre-commissioning functional checks

and the setting-up of relays and controls can be carried out.

Apply an insulation resistance (IR) test to the circuit incomers for the above mentioned

auxiliary supplies, with their switching devices in their closed position. Refer to MI for the

lowest IR test voltage to use. Disconnect any electronic devices that may be damaged by an IR

test. Record the results.

Functionally check all electrical operations at each cubicle e.g. open, close, rewind spring,

trip, relays and their tripping circuits (see also 8.5.1), electrical interlocks such as solenoid

bolts in earth switch circuits.

Check all electrical indicating lamps, LEDs, and the like for each cubicle. Voltmeters,

ammeters, wattmeters, power factor meters cannot be tested at this stage. Refer to MI for the

scope of testing that can be carried out.

Record any malfunctions and arrange for their rectification or the replacement of the defective

components.

The above may also be described as pre-commissioning tests.



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8.5.1 Protection relays

Arrange for suitable permanent supplies so that the protection relays can be energised.

Refer to MI for all testing to be carried out for commissioning each cubicle.

At this stage the consumers main and auxiliary cables need not be laid or connected to the

switchboard for the purpose of initially setting up the protection relays. This is a matter of

project planning and urgency, and can be recorded as partial-commissioning.

For each relay to be set-up check the following against the project design documents, the

manufacturers documents and equipment as installed : -

Relay description, type number, feature option code numbers, features required.

Current transformer secondary current.

Current transformer ratio and burden va.

Current transformer accuracy class.

Voltage transformer secondary voltage. Voltage transformer ratio and burden va.

Voltage transformer accuracy class.

Similar details of any interposing current or voltage transformers.

Similar details of any transducers used on the circuit,

e.g. winding temperatures of generators, motor, transformers.

Auxiliary supplies.

A Protection Relay Schedule and the switchgear data sheets should show the above details.

Carry out secondary current injection tests, with voltage circuits also energised as appropriate

for the tests. Refer to the test equipment MI for details of how to select, inject and interpret thereadings. Set up each relay in accordance with the relay MI and check the relay response

against at least 5 current values well spread over the characteristic of the relay, assuming a

time dependent form. For definite time and instantaneous relays set up the desired values and

check their actual threshold responses using the injection equipment.

Record all results and malfunctions. Arrange for malfunctions to be corrected or replaced.

Where the project documentation calls for primary injection current testing then this shall be

carried out in preference to secondary injection testing.

8.5.2 Electrical functional testing

If the functional testing in (8.4) has been carried out over one month before the tests in (8.5)

are to be carried out then a representative number of cubicles of each type e.g. generator,

feeder, motor, shall be re-tested.


Where high voltage A.C. or D.C. testing of the busbars, risers and switching device

components is required the details of test voltages and durations shall be obtained from the MI


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in the first instance, or if not available from the documents of (6.1.a) . These tests shall be

kept to a minimum to avoid unnecessary stressing of the system insulation.

The safety precautions given in (8.6.2) shall be used.

8.6 Testing when Cabling is Complete

8.6.1 Consumers

The word consumer herein refers to the load connected at the far end of a cable, e.g. a motor,

a distribution board, another switchboard, a UPS.

At this stage it is assumed that the consumer has been installed and its pre-commissioning test

have been completed. Similarly the main and auxiliary cables are assumed to be laid,

terminated and tested.

The cable shall be tested at this stage for : -

Earth loop resistance. Earth continuity of its armouring.

Earth continuity of its insulation screens where appropriate.

See Appendix D for typical values of the resistances that should be obtained. Refer to the

cable MI or data for particular requirements. Refer to the consumer MI for particular

requirements.

Carry out the following checks before energising the consumer : -

Visit the consumer and visually check that any moving parts are free to move, terminal

boxes are covered, earthing bonds are in place.

Warning and safety signs are fixed and clearly visible.

Safety barriers are in place.

Couplings of rotating machines are coupled or uncoupled in accordance with the specificrequirements of the project or the manufacturer. This is necessary to check the direction

of rotation.

Couplings are covered with a proper metallic guard.

Locate a competent person at the site of the consumer to observe all activities during the

test.

Carry out an insulation resistance test of the consumer and its cable(s) from the

switchgear cubicle outgoing terminals, to verify that no faults are present prior to

energising the cable(s).

Energise the consumer for the first time by manually (not by automatic control) closing its

circuit breaker or contactor. Refer to the consumers MI for details of this part of the testing

procedure, e.g. duration of first energisation, what needs to be checked and measured, how

much load can be applied, with or without the coupling coupled.

Check the instruments and read-outs at the switchboard e.g. current per phase, relay response

if any.

Record all relevant details.


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8.6.2 Incomer circuit breakers

At this stage it is assumed that the source of supply has been commissioned and its main

cables energised up to the incoming terminals of the switchboard. The incoming circuit

breaker shall have been racked out, or if this is not possible pad-locked in its OFF position.

Carry out the following before energising the busbars of the switchboard : -

Withdraw or lock OFF all outgoing circuit breakers and contactors.

Place warning and safety signs on the incoming cubicle and other clearly seen areasnearby e.g. entrance to the switchroom.

Place a safety barrier around the access area to the cubicle.

Allow only authorised persons to be present.

Carry out an insulation resistance test of the busbars, to verify that no faults are presentprior to energising them.

Energise the busbars for the first time by closing the incoming circuit breaker manually at the

switchboard. Refer to the switchboards MI for details of this part of the testing procedure e.g.

duration of first energisation, what needs to be checked and measured.

Check the instruments and read-outs at the switchboard e.g. current per phase which should be

negligibly small, busbar line voltages, relay response if any.


8.6.3 Bus-section and Bus-coupler circuit breakers

These circuit breakers and their adjacent busbars can be energised as part of the programme

for the incomer circuit breakers.

When one section of the busbars is being energised for the first time the bus-section or bus-

coupler adjacent to it can be kept un-locked but switched OFF.

After the procedure of (8.6.2) is completed the bus-section or bus-coupler circuit breaker can

be closed to energise the adjacent busbar.

Check the voltages measured for both sections of busbars, i.e. either side of the circuit

breaker.



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9.0 Transformers


Check the dimensions of the largest part of the transformer and ensure that it can be

transported from its storage location to its permanent location. Check whether or not it has

wheels or needs rollers to move it.

Check the permanent location for : -

Dimensions against those of the transformer.

Main cable access ways and channels.

Auxiliary cable access ways and channels.

Busducting access ways, connections and method of support.

Fixing points and base frame levelling.

Access overhead.

Bunding arrangements, if appropriate.

Earthing connections are provided for the base frame and terminal boxes.

Fire water systems have been installed, if appropriate.

Erect a safety fence.

Check the nameplate details, connection notation, winding arrangements and phasing, tag

numbers, ratings etc. are correct.

Check that all auxiliary devices are provided e.g. pressure relief valve, Buchholz surge device,

conservator tank, temperature detectors, tap-changer, forced air fans, fan control system,

breathers, earthing arrangements.

Check that there are connections to enable an external transformer oil filtering/vacuum unit to

be used.

Check that the gland plate is non-magnetic metal if single core cables are to be used.

Check the MI for advice regarding moving the transformer into its permanent location e.g.

with or without insulting oil, with or without the radiators.

Check that a sufficient quantity of new topping-up transformer oil of the correct type is

available.

9.2 Installation

Transformers used on QGPC sites will frequently be of the liquid filled type, either as

hermetically sealed or as conservator units. Dry types with epoxy resin encapsulated windings

are suitable for special locations where the liquid could be a disadvantage.

Auto-transformers for power applications shall not be used, unless approved in writing by

QGPC during the detail design phase of the project.

A bund shall be provided for all liquid filled transformers located in both land-based and

platform-based installations. The bund shall have a base and walls that are leak proof, and

shall have been duly inspected for being leak proof. The bund volume shall equal the liquid

volume plus a 25% safety margin. The bund shall be provided with a simple but effect means


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of draining the liquid to temporarily connected equipment designed for the purpose e.g. pump

connection, pipe with a locked-off valve, pipe with a suitable plug.

For bunding of transformers, see also [ES.2.03.0001, section 11].

For transformers located indoors there shall be a system of fire and smoke detection. Before

the transformer is energised the fire and smoke system shall be tested.

For transformers located outdoors they shall be surrounded by a purpose designed fence. The

fence shall be bonded to the station earth and the earthing arrangements tested before the

transformer is energised. For fencing design see [ES.2.03.0001 sub-section 7.1]. The fence

shall be at least 2 metres high, and provided with an access door and pad-locking facilities.

The transformer base frame shall be bonded to the station earthing system from two steel

bosses welded at diametrically opposite corners. All main and auxiliary terminal boxes

attached to the transformer shall be bonded to the base frame or directly to the station earthing

system. All other attachments which are bolted to the main structure of the transformer shall

be bonded to the main structure or base frame if there is insufficient bolting to provide a

reliable path for earth currents. [ES.2.03.0001] gives guidance on the design of earthing andbonding.

Liquid filled transformers of the sealed type will be delivered filled with liquid and no topping

up or dielectric testing should be necessary, but refer to the MI follow as appropriate e.g.

sampling the liquid. However, transporting the transformer to its permanent position should be

carried out with extra care due to the large volume of liquid it contains, and damage that this

may cause if the transformer receives sudden mechanical impacts or shocks, eg bumped down

by a crane.

Liquid filled transformers of the conservator type will probably be delivered empty of liquid,

unless they are small units. Upon arrival at site they should be filled with liquid as soon as

possible. They shall be stored at all times away from direct sun-light whilst they are empty.

The handling and transfer of the oil shall be in strict accordance with the MI and QGPC safety

practices.

The liquid shall be carefully checked before the transformer is filled that it is the correct liquid

for the purpose. Several samples from the storage vessels shall be taken and tested in a

laboratory for content of water and impurities, and tested for dielectric strength.

The dielectric and impurities checks shall be performed : -

When the liquid first arrives on site. Two weeks prior to being filled into the transformer.

One day prior to being filled into the transformer.

If the transformer arrives on site filled with liquid then the above shall apply but be related to

the day of energisation.

The minimum voltage stress for the dielectric tests on insulating oils and liquids, without

breakdown, shall be 30000 Volts D.C. (for silicone liquid) with a 40 mil gap as per [ASTM-

D-1816, BS 148 or IEC 296]. The associated procedure shall be as described in Note 9.2.a

unless the transformer MI states otherwise.


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The liquid shall be filled into the transformer from a heated, vacuum, filter and pump unit;

specially designed for the purpose. The heat and vacuum will degas the liquid during the

filling process. The filler unit MI shall be used for the filling procedure.

Once the transformer is filled the liquid shall be allowed to settle and breath before the

transformer is energised.

If the transformer is not energised within a period recommended in the MI then sampling and

testing shall be repeated just prior to energisation.

Bushings shall be vented and checked for leaks.

Completely assembled, factory-sealed-tank transformers shipped with an insulating liquid

successfully passing the dielectric strength tests without filtering, may be put into service after

inspection if the cold coil insulation resistance between windings and between windings and

ground tests above the minimum values shown in the table below. In the event that the

insulation resistance value falls below the minimum acceptable value, given in the Table

D.2.4.A of Appendix D, the transformer coils must be dried.

Coils for factory sealed-tank-transformers shipped with an insulating liquid failing the

dielectric strength (before filtering) and coils for tank type transformers shipped separately

without insulating liquid must undergo an out-of-liquid short-time megger test for insulation

resistance to ground and to other windings at a temperature between 60-70 C. The out-of-

liquid insulation resistance must measure above one megohm per thousand volts of rated line

voltage. Coils with insulation resistance values failing this requirement must be dried.

In the event that drying is necessary the transformer coils will be heated to a temperature of

60-70C for a period of 24 hours by circulating current through the windings from a variable

temporary supply. This may be accomplished by short circuiting either windings (HV or LV)

and impressing between one and one-half percent of nameplate voltage, (at normal frequency)

across the other. Current should be limited to one-fifth of the rated normal full load current by

a rheostat in series with exciting winding, or by using a suitable auto-transformer. As the

maximum coil temperature is approached, the circulation current should be gradually reduced

until a steady temperature condition is reached within the 60-70C range.

The transformer tank and all fittings shall be inspected and tested for adequate sealing to

prevent leakage of insulating liquid, entrance of moisture and loss of inert gas protection

before the transformer is energized. During a leakage test the transformer tank shall not be

subjected to a pressure greater than the amount specified on the nameplate. If there is no

nameplate pressure specified, a test pressure of 5 psi will be used. A vacuum shall be pulled

on the tank and the dew point of the gas measured. A hot gas recirculation shall continue untilmanufacturers recommended values are reached. The liquid dielectric will be slowly pumped

into the sealed transformer until the correct liquid level is reached. Additional nitrogen shall be

added to the tank until the pressure reads 5 psi. Joints, connections, and gaskets will be

checked with chalk dust to detect leaks. Any appreciable leakage will cause a pressure drop

within a few hours.

A dielectric adsorption test shall be made winding-to-winding and winding-to-ground. A sixty-

second test shall be made, unless the transformer is larger than 1500 kVA or if the windings

are rated above 15kV in which case a ten-minute test shall be run. The polarization index shall

be computed as the ratio of the sixty-second to the thirty-second reading, or the ten-minute to


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the one-minute reading, as appropriate. Test voltages shall be in accordance with Appendix D.

The absorption test polarization index should be above 1.5 or 2.5 respectively, unless an

extremely high value is obtained at the end of the shorter time limit that when doubled will not

yield a meaningful value with the available test equipment.

Pressure gauge readings for sealed tank transformers shall be taken for two different

temperatures, differing over as wide a range as possible. Manufacturers design pressure

requirements shall be checked.

Note 9.2.a: - New liquid dielectrics shall be tested for dielectric strength with a

standard testing device consisting of a test cup, instrument, control and

high voltage power supply. The test cup internals shall support two

spherically capped electrodes, separated by a 40 MIL gap minimum.

Sixteen ounces of liquid will be required for the test. After the electrode

spacing has been checked with a standard round gauge, having a

diameter of 0.04 inch., the electrodes will be locked in position. After a

suitable rinsing procedure, the test cup will be immediately filled with

the liquid sample to be tested. The liquid should be at a temperature

between 20-30

C. During the test the uniform rate of applied voltageincrease should be about 2,000 volts per second. One breakdown

should be made on each of 5 fillings, of the test cup. Any individual test

which deviates the average by more than 25% will be test recorded and

replaced by an additional test. The average of the first five tests within

the allowable deviation will be taken as the dielectric strength of the

liquid. PCB liquid shall not be used in any type of transformers.

The power cable terminations may be one of the following types, but standardised for the

project : -

Elastimold, also called Euromold or Bi-mold, plug and socket types. These shall be

certified for the rated voltage and short-circuit duty at the terminal box.

Heat shrink types manufactured by Raychem.

Busducting may be used for the higher current winding of the transformer, but it shall be fully

fault rated for at least one second when a bolted three phase fault is applied across its

terminals. It shall be rated at the highest ambient temperature and when exposed to direct sun

light at the hottest period of the year. Busducting shall be designed and provided with

expansion connections at both ends to allow for its casing to expand with ambient temperature

and the conductors to expand with the heat produced by their current. See [ES.2.14.0019] for

the specification of busducting systems.


Functionally check the mechanical operation of the off-load tap changer, if fitted, and the oil

drainage and filling devices. Check that any venting devices are not blocked.

Test the earth bonding continuity at the various joints using a DUCTOR or similar test

instrument and record the results.

The cables or busducting used on the lower voltage windings will normally have large cross-

sectional areas and often several in parallel per phase. Check that all conductor connections to


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the transformer phase connections are tightly bolted. Refer to the MI for details of torque

settings.

At this stage the higher voltage winding need not be terminated to its supply cables.

Test the continuity of the terminations. Record the results.

The above may also be described as pre-commissioning tests.


Arrange suitable temporary A.C. supplies for test equipment, and the fans if fitted.

The following checks and tests shall be carried out with the use of the low voltage supply.

Check the data for correct phase rotation and polarity.

If provided, check and test current transformers for turns ratio (using primary current

injection), polarity and winding connections.

Perform ratio tests on all tap positions. Turns ratio test results should not deviate more than

one-half of one percent (0.5%) from calculated ratio.

When making primary-to-ground measurements, e.g. insulation resistance, high voltage A.C.

or D.C., all secondary terminals and tanks must be connected to ground. Likewise, the

primary terminals and case must be connected to ground when making secondary-to-ground

measurements. Primary and secondary terminals and case shall be connected to ground when

making neutral-to-ground measurements. Any deviation from this procedure shall be reported.

Perform polarity and phase relation tests on rated voltage connection.

If provided, check operation of cooling fan relay, circuit and fan rotation.

Inspect high and low voltage bushings and lightning arrestors for cracks, chips, etc. Remove

all dust, dirt, or foreign matter and polish the porcelain.

Tap changers shall be manually operated and set at their proper setting in accordance with the

load flow or voltage profile studies.

9.5 Commissioning Energised Testing

Arrange for suitable permanent high voltage and auxiliary voltage supplies to be available sothat the windings may be energised in their normal state for a prolonged duration, i.e. longer

than for only the testing period.

Refer to MI for all testing to be carried out for commissioning the transformer as a complete

unit.

At this stage the primary cables and secondary cables, or busducting, shall have been tested

and terminated and shall be ready for permanent service.


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Note 9.5.a: - Their tests shall have included, earth loop resistance, earth continuity

of cable armouring, earth continuity of cable insulation screens where

appropriate.

Note 9.5.b: - See Appendix A for typical values of the resistances that should be

obtained. Refer to cable MI or data for particular cable requirements.


Where high voltage A.C. or D.C. testing of the windings is required the details of the test

voltages and durations shall be obtained from the transformer MI, in the first instance, or if

not available from the documents of (6.1.a) ). These tests shall be kept to a minimum to avoid

unnecessary stressing of the transformer and cable insulation.

The safety precautions given on (8.6.2) should be used at the switchboards and labels,

barriers, pad-locking etc. used at the transformer enclosure. Allow only authorised persons to

be present.

Record all test and inspection results.

9.5.2 Switching into normal service

Close the primary circuit feeder circuit breaker at the upstream switchboard to energise the

transformer and its main power cables.

Check that the secondary circuit is energised in all phase conductors. This can be achieved by

observing the voltmeters at the downstream switchboard, or by using insulated probes or test-

sticks at the circuit breaker cubicle. If test-sticks are used then special safety precautions

shall be used, and the test-sticks MI applied.

10.0 Turbine Driven Generators

Turbine driven generators are usually HV machines of a rating greater than 750kW . In most

cases QGPC high voltage generators will be driven by gas-turbines. Steam turbines may

occasionally be used.

In general the generator will be supplied as part of the gas-turbine manufacturer's contract

purchase order. Some of the generator auxiliary functions will be interfaced with those of the

gas-turbine auxiliary functions.

Before any checking or testing is carried out the CONTRACTOR shall carefully study all themanufacturers documents, especially those relating to pre-commissioning and testing.

The CONTRACTOR shall plan the work to be done and in so doing liaise closely with the

gas-turbine manufacturer, the generator manufacturer, and the site representative of the

principal. QGPC shall approve the plan and scope of work.

The following descriptions shall be regarded as the minimum work to be carried out by the

CONTRACTOR.

The generator may arrive on site in one of two forms : -


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Function Electrical Instrument Mechanical

Shaft alignment 2 1

Frame fixings 2 1

Bearings 2 1

Lubrication system 2, 3 1

Water cooling system 2, 3 1

Purging air system 2, 3 1

Cooling air system 2, 3 1

Fire and gas systems 1

Fuel system 3 1

Inlet and exhaust systems 1

On skid cabling, electrical 1

On skid cabling, instruments 1

Skid edge terminal boxes 1 2

Motor terminal boxes 1, 3

Generator main terminal boxes 1

Skid earthing and bonding 1

Generator earthing and bonding 1Generator protection transducers 1

Generator instrument transducers 2 1

Shaft vibration monitoring 1 2

Bearing temperature monitoring 1 2

Excitation and AVR controls 1

Governor control panel 2 1

Winding temperature monitoring 1 2

1 = main discipline responsible for the function

2 = discipline with an interest in the function

3 = motors and their cables.


The storage and transfer of the skid mounted generator should be the responsibility of the

mechanical discipline. All dimensional checking should have been carried out at the factory

testing and inspection of the generator when it was separate from the turbine, or later when it

was coupled to the turbine.

Check all the name plate details of the generator for, voltage, current, frequency, winding

connections, tag numbers, ratings etc, against the project documents.

Check the name plate details of the auxiliary motors for, voltage, current, rated power, powerfactor, efficiency, frequency etc against the project documents. Check that standby auxiliaries

have been installed e.g. standby lube oil pump, and whether they need a D.C. supply.

Remove all inspection covers on the generator main frame and inspect the internals. Replace

the covers if no defects are found.

Remove all terminal box covers on the generator, the auxiliary motors and the skid-edge

terminal boxes. Store them in a clean place, and ensure the gaskets are not damaged.

10.3 Installation


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Before the generator is energised by its exciter and the shaft run at speed, the fire, gas and

smoke systems shall be tested.

The generator frame shall be bonded to its base frame at two points which are spaced

diagonally across the corners. The points on the base frame shall be large welded bosses, each

capable of accepting a 12 mm dia bolt for the bonding cable.

All auxiliary motors, power terminal boxes and other electrical items which are bolted to the

base frame or extensions to it shall be bonded to the same structure using green/yellow

insulated stranded cable. [ES.2.03.0001] give guidance on the design of earthing and bonding.

The skid frame should normally be fixed to its foundation as follows : -

For land-based installations by bolts grouted into the concrete foundations.

For platform-based installations by welding to the main decking beams.

In either case the skid frame shall be provided with two large welded bosses, each capable of

accepting a 12mm dia bolt for the bonding cable. The bosses shall be at diagonally opposite

corners of the skid frame. The bonding cables shall bond these bosses to the main stationearthing system. For an LBI this shall be the cable connected ring network and earthing

electrodes. For a PBI this shall be a specially located earthing busbar, mounted on insulators

and provided with link connectors for testing the earthing resistance. For both cases see

[ES.2.03.0001] for details, earthing designs and sizing of components.

All on-skid cables shall be run on trays and shall be in accordance with the temperatures and

environment within the skid e.g. high ambient temperature, adjacent to hot surfaces, fire

retardance, fire resistance, see [ES.2.03.0001]. Check the fixing of these cables to their trays,

and their tag numbering.


Test the earth continuity at the joints of the main bonding connections and record the results.

Generators having large ratings will require several cable cores connected to each phase

terminal in the main terminal box. Alternatively, busducting shall be used. The generator may

be provided with two main terminal boxes, one for the phase terminals and the second for the

star point end of the phase terminals and the neutral connection terminal. The second box will

usually contain current transformers for protection relays and AVR control signals. The first

box may contain current transformers if a unit transformer accompanies the generator.


Most QGPC generators will not need unit transformers because they will feed their

switchboards directly at the same voltage.

Because the generated current is usually relatively high the cable or busduct connection will

be bulky and difficult to disconnect for testing. In some cases disconnecting links may have

been provided in the terminal boxes to facilitate testing.

The cables or busducting shall be installed and appropriately tested before being connected to

the generator or its circuit breaker. This shall have been planned in advance by the

CONTRACTOR.


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Assuming therefore that the main connections should not be disconnected they should then be

checked for tightness and electrical continuity. Record the results, and refer to the generator

MI for a comparison of results.


When a unit transformer is required the rating of the generator will be high and consequently

the stator current will be unusually high. The result will be a complicated and bulky

termination system both at the generator and at the transformer primary winding. It will be

undesirable to disturb these connections.

The cables or busducting shall therefore have been fully tested before being connected to the

generator and transformer terminals.

This shall be carefully planned in advance by the CONTRACTOR.

Check all connections for tightness and electrical continuity. Record the results, and refer to

the generator and transformer MIs for a comparison of results.


Check in test records that all the necessary cables have been laid, terminated and tested.

All pre-commissioning testing of auxiliary equipment shall be carried out in the manner

described in the document under the appropriate sub-section e.g. motors.

Check that the current transformers are installed and have been connected, but not short

circuited with links or temporary wires.

Check that the NER, if required, and the external star point to earth circuit has been installed

and fully tested.

10.5 Post-Installation Energised Testing

Arrange A.C. supplies so that test equipment can be used.

Check that all auxiliary motors and control systems can be operated in normal service fromtheir permanent switchgear.

Check the phase sequence connections of the generator complete with its stator cables and unit

transformer, and that these correspond with those at the associated main circuit breaker and

switchboard busbar system.

Check that the notation is correct i.e. L1, L2, L3. Table 10.5.A may be used in the absence of

other design information.


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Table 10.5.A

Phase sequence notation

QGPC preference L1 L2 L3

UK origin Red Yellow Blue

European origin U V W

R S T

USA origin A B C

1 2 3

Use low voltage test equipment to test for the following functions: -

Polarity of current transformers.

Ratio of primary and secondary currents in cts. Continuity of power connections.

Earth loop impedance, if not covered previously under cable or auxiliary equipment tests.

Indication from measuring circuits at all locations e.g. UCP, CCR, switchboard.

Calibrate if necessary to ensure all readings are the same.

Loop test instrumentation and measurement circuits, if not covered by tests by non-

electrical disciplines.

Insulation resistance of embedded temperature detectors in stator windings and bearings.

Run auxiliary motors and their systems for a long time, particularly the lubricating oil, jacking

or barring gear, cooling water systems; so that leaks and malfunctions can be corrected and

the cleaning and filtering can be completed. Replace filters prior to final commissioning.Record any malfunctions.

10.6 Commissioning Energised Testing

Arrange supplies to be available so that the windings may be energised in their normal state

for a prolonged duration, i.e. longer than the testing period.

Refer to MI for all testing to be carried out for commissioning the generator as a complete unit

with its turbine and control systems.

Check that all cables and auxiliary systems have been tested and put in to normal service.

Check that all high voltage cable armouring and insulation screens have been earthed at their

correct locations, and have been tested for earth loop resistance. Refer to cable MI or data for

particular requirements.



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Where high voltage A.C. or D.C. testing of the generator stator windings, stator circuits, unit

transformer windings is required the details of the test voltages and durations shall be obtained

from their respective MI. Since several manufacturers are involved with different types of

equipment connected together, care shall be exercised to ensure that the selected test voltage

magnitude is the lowest for the common circuit. The factory acceptance routine test records

shall also be reviewed for comparison of test voltages and test results.

Check the various MIs for the methods and procedures to be used.

The safety precautions given in (8.6.2) should be used at the main switchboard, and labels,

barriers, pad-locking etc. also used at the generator and unit transformer. Allow only

authorised persons to be present. Do not close the main circuit breaker at this stage. Record

all test and inspection results.


The two main control systems of the generator will be the voltage control by the AVR and the

speed control by the governor.

10.6.2.1 AVR controller

The AVR shall be tested and commissioned by the manufacturer or his designated

representative, using methods and procedures specific to the AVR.

The QGPC shall ensure that the following functions are tested and demonstrated to his

satisfaction : -

The full range, or span, of the AVR set-point shall be demonstrated by indicating the

stator terminal voltage on open circuit, preferably by using the panel voltmeter at the

main circuit breaker cubicle.

That the reactive power droop and gain settings give stable responses for a step change inthe AVR set-point. Adjust if necessary. Record all AVR settings and results using a pen

or photographic recorder.

Check that the AVR current compounding circuit is switched into circuit and functions

correctly.

Set the AVR to function on droop control at between 4% and 5%, not on isochronous

control.

Check that the auto-manual change-over functions operate smoothly, and that no large

changes in the terminal voltage occurs.

10.6.2.2 Governor controller

The governor shall be tested and commissioned by the manufacturer or his designated

representative, using methods and procedures specific to the governor.

QGPC shall ensure that the following functions are tested and demonstrated to satisfaction: -

The full range, or span, of the governor set-point shall be demonstrated by indicating thestator terminal frequency when the main circuit breaker is open. This shall be preferably


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be by using the panel frequency meters at the main switchboard or GCP, or by a shaft

speed tachometer permanently fixed in the TCP.

That the active power droop and gain settings give stable responses for a step change inthe governor set-point. Adjust if necessary. Record all governor settings and results using

a pen or photographic recorder.

Finally set the governor to function on droop control at 4%, not on isochronous control.

10.6.3 Running on open-circuit

After the tests of (10.6.2) have been completed run the turbo-generator on no-load open-

circuit for as long as possible or as recommended by the MI, noting that gas-turbines do not

normally run in this mode. This will ensure that all the electrical circuits are stable, free of

malfunctions and have been subjected to their rated voltages without faults nor breakdown in

insulation.

10.7 Synchronised with the Other Sources

After the generator has run successfully on open circuit it shall be shut-down and prepared for

synchronising to the supply i.e., the runningbusbars.

Before this can take place the power system shall be arranged to have a substantial load, so

that the new generator can be controlled in such a manner as to deliver power into the system

immediately after it has been synchronised. Hence, one or more existing or runninggeneratorshall already be loaded to load factors in the order of at least 40% each. This should ensure

that the new or incominggenerator will take up a reasonable level of load without reducing

the load on the runninggenerators to too low a level (which could lead to poor operation e.g.hunting, reverse power relay operation, low forward power relay operation).

The same reasoning can be applied if the running system is supplied by a grid source e.g.MEW 132kV network.

The contractor shall liaise with QGPC to carefully plan this procedure.

When the synchronisation procedure is ready to be carried out, the generator shall be started

and run up under control of its automatic sequence controllers, but not under auto-

synchronising control.

The first synchronisation process shall be MANUALLY controlled. For this the voltage and

frequency shall be adjusted by the manual operator. When the synchronizing instruments

indicate a suitable moment to synchronise, the operator shall close the circuit breaker and

almost immediately raise the governor set-point and the AVR set-point by a small amount.

These adjustments should ensure that the generator delivers active power and reactive power

at a good power factor (0.7 to 0.9 p.u. lagging) and that the reverse power relay or low

forward power relay operation does not respond and trip the generator.

At this stage the generator can be controlled to take up more load, refer to the MI for a

recommendation for loading levels during commissioning.

If the MI does not restrict the initial level of loading, then the automatic load sharing

capabilities of the governor and AVR should be demonstrated. In this situation the generator

set-points can be adjusted so that the generator takes its equal portion of the load compared


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with the other generators. One of the other generators can then be manually adjusted to take

more and less than its initial equal share. When these adjustments are made the othergenerators (including the new generator) are not adjusted. Readings of voltage, frequency,

active power, reactive power and current are taken for each generator when the old

generator is adjusted.

If the new generator has had its control systems properly set up, then its changes in active andreactive powers for a common change in busbar frequency and voltage should be the same,

ideally, or at least very similar. If all the readings are taken simultaneously and with pre-

calibrated instruments then it should be possible to calculate the actual droop of each

generator and turbine that run in synchronism.

After these tests have been completed the new generator shall be un-loaded, its circuit breaker

opened and then allowed to run idle. The auto-synchronisation shall then be tested. In order to

achieve this it may be necessary to shut down the turbo-generator, because the auto-

synchronisation may be part of the sequential start and run-up process.

The turbo-generator shall then be run up in its auto-synchronising mode, which should not

require manual intervention. Whilst this process takes place the testing personnel shallcarefully observe the UCP and CCR indications, in particular when the voltage and speed are

almost correct for synchronisation, and just after the circuit breaker closes. Upon closure the

generator controls should increase the load on the generator, and if provided switch in the

automatic load sharing control loop so that all the running generators become equally loaded

with active and reactive power.

Load the generator to approximately 10% to 15% of rating, and carry out a load rejection

test by tripping the main circuit breaker. Check that the generator responds correctly and

smoothly, and settles at almost rated voltage and speed.

11.0 Engine Driven Generators

Engine driven generators are usually, but not always, LV machines of a rating equal or less

than 750kW . In most cases QGPC low voltage generators will be driven by diesel engines,

and will run in an island mode i.e. not in parallel with others or the grid.

In general, the generator will be supplied as part of the engine manufacturers contract

purchase order. Some of the generator auxiliary functions will be interfaced with those of the

engine auxiliary functions.

Before any checking or testing is carried out the CONTRACTOR shall carefully study all the

manufacturers documents, especially those relating to pre-commissioning and testing.

The CONTRACTOR shall plan the work to be done and in so doing liaise closely with the

engine manufacturer, the generator manufacturer, and the site representative of QGPC. QGPC

shall approve the plan and scope of work.

The generator should arrive on site as an integral part of a skid mounted package.


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11.1 Division of Discipline Responsibilities

The CONTRACTOR shall clearly separate the responsibilities of the electrical, instrument

and mechanical personnel involved. As a guide the basic tasks are separated as shown in

Table 10.1.A for turbo-generators, a similar approach is applicable.


See (10.2).

11.3 Installation

See (10.3).

Note 11.3.a: - The diameter of the earthing boss bolts shall be at least 12 mm.

11.4 Post-Installation un-Energised Testing

See (10.4).
