ena ts 35-2 issue 6 2014 schedules€¦ · web viewena ts 35-2 issue 6 2014 schedules subject...

PRODUCED BY THE OPERATIONS DIRECTORATE OF ENERGY NETWORKS ASSOCIATION

www.energynetworks.org

Technical Specification 35-2

Issue 6 2014

Schedules

PUBLISHING AND COPYRIGHT INFORMATION

Issue 5 published, June, 2007.

Amendments since publication

Issue Date Amendment

Issue 6

December 2014

Major revision (see ENA TS 35-2 - Full document)

© 2014 Energy Networks Association

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written consent of Energy Networks Association. Specific enquiries concerning this document should be addressed to:

Operations DirectorateEnergy Networks Association6th Floor, Dean Bradley House

52 Horseferry RdLondon

SW1P 2AF

This document has been prepared for use by members of the Energy Networks Association to take account of the conditions which apply to them. Advice should be taken from an appropriately qualified engineer on the suitability of this document for any other purpose.

ENA Technical Specification 35-2 SchedulesIssue 6 2014

Contents

Annex A (normative) Schedule of Requirements for emergency rated system transformers.......................................................................................................................4A.1 Schedule of Requirements (to be completed by purchaser).....................................4

Annex B (normative) Self-Certification Conformance Declaration...........................................7Annex C (normative) Technical Schedules (to be completed by the manufacturer for

emergency rated system transformers)............................................................................20C.1 Manufacturers and places of manufacture, testing and inspection.........................20

Annex D (normative) Additional technical schedules (to be completed by manufacturer)...................................................................................................................22

Tables

Table B.1 — Self-Certification Conformance Declaration.........................................................8


Annex A (normative)

Schedule of Requirements for emergency rated system transformers

A.1 Schedule of Requirements (to be completed by purchaser)

Item Clause Description

1 4.2 Ambient temperature for Emergency Rating °C * 5

2 5.1.1 Rated power at Emergency Rating MVA * 15 / 24 / 30 / 40 / 50

3 5.3 Generator transformer load rejection required * Yes / No

4 5.4.1 HV rated voltage kVLV rated Voltage kV

5 5.4.2 Rated frequency Hz 50

6 6.4 Tapping range * ±8 x 1.25%+4 x 1.43% / -12 x 1.43%±16 x 0.625% / Other (specify)

7 6.4 Category of Tapping Voltage VariationWhere CbVV is selected, provide tap position for changeover between CFVV and VFVV

Tap Number

* CFVV / CbVV

8 6.5 Impedance envelope for 12/24MVAImpedance envelope for 15/30MVA

* 1 (b) / 1 (c)* 1 (d) / 1 (e)

9 6.6 Loss Capitalization Values(i) No-load Loss £/kW(ii) Load Loss at 50% CER £/kW

ORMaximum Guaranteed Losses in accordance with 6.6

(i) No-load Loss W(ii) Load Loss at 50% CER (ONAN operation) W

10 7 Vector group (add phase displacement number) * Dyn__YNyn__Yyn__

11 7 Vector links requiredIf yes, alternative vector group

* Yes / No

12 7 Stabilising windings required on star-star transformers

* Yes / No

13 9.2 Neutral conductor and terminal intended to carry load

* Yes / No

14 9.3 Liquid preservation system

If free breathing, breather type

* Free breathing /Diaphragm conservator* Desiccant / refrigerating

15 9.4 Level of d.c. currents in neutral circuits A



16 11.1.1 For equipment voltage (Um) of 12 kV r.m.sRated lightning impulse voltage (LI) kV peak * 75 / 95

17 11.1.2.1 FRA test required at works and/or on siteIf yes – specify where the test is required

* Yes / No* Works/Site/Both

18 11.1.4 Short-circuit test required * Yes / No

19 14.4.1 Separate cooler bank requiredHeight limitation mmValve & blanking plates required at alternative oil inlet

* Yes / No* 4 880 / 4 270* Yes / No

20 14.4.2 Anti-vibration mountings required (Main TX) * Yes / No

21 14.5 Auxiliary supply voltage * 400 V 3ph / 230 V 1ph

22 14.6 Maximum system short-circuit current kA

23 15.1.5 Provision for sound attenuation enclosure requiredAccess through enclosure roof permitted

* Yes / No* Yes / No

24 15.2 Finish colour required

25 15.3.1 Details of HV cable termination (if applicable)Number and size of single core cablesOil-filled disconnecting chamber requiredPosition of cable boxes

* Yes / No* Same side of tank /Manufacturer to decide

26 15.3.3 Plug-in separable connectors * Yes / No

27 15.3.4 HV terminal arrangementNVD capacitor taps requiredNVD capacitance if required pFSurge arresters requiredBrackets for surge arresters requiredCo-ordinating gaps required

* a) / b) / c) / d)* Yes / No* 60 / 90 / 140* Yes / No* Yes / No* Yes / No

28 15.3.5 HV neutral terminal arrangementAccessible isolatable link required

* a) / b) / c) / d)* Yes / No

29 15.3.6 LV terminal arrangementNumber and size of single core cables to be terminatedCable disconnecting links required

* a) / b) / c)

* Yes / No

30 15.3.7 LV neutral terminal arrangementSize of single core cable to be terminatedLV neutral current transformer(s) requiredDetails of LV neutral current transformer(s)Accessible isolatable link required

* a) / b) / c)

* Yes / No

* Yes / No



31 15.3.8 Earthing/auxiliary transformerAdditional flange required for auxiliary transformerRating kVAVector group requiredHV terminations

* Unit / Earthing / No* Yes / No / n/a

* Cable termination / Outdoor bushings

32 15.4.1 Max / min tap position indicator required * Yes / No

33 15.6.1 Type of conservator requiredLow level alarm required * Yes / No

34 15.6.2 Provision required for separate cooler bank at either end of the tank

* Yes / No

35 15.6.5 Winding temperature indicator or sensor

Output required from sensorWinding temperature indicator typeSecond WTI or sensor requiredElectronic WTI d.c. supply voltage Minimum (V)

Maximum (V)Second WTI or temperature sensor required

* Indicator / Sensor / Fibre optic* Yes / No* Dial / Electronic* Yes / No

* Yes / No

36 15.6.6 Current transformer accommodation requiredSecond voltage compounding CT required


37 15.12 Condition monitoring equipment requiredMonitoring system typeRemote indication of WTI’s requiredProvision of top oil indicator requiredProvision for future gas in oil device requiredProvision for future fibre optic winding temperature sensor requiredGas in oil device requiredAdditional remote TPI required

* Yes / No* Current loop / Digital* Yes / No* Yes / No* Yes / No* Yes / No


* Purchaser to delete as appropriate


Annex B (normative)

Self-Certification Conformance Declaration

ENA TS 35-2 Technical Specification for Continuous Emergency Rated (CER) system transformers (66/20.5 kV, 66/11.5 kV and 33/11.5°kV delta/star and star/star connected)

CLAUSE BY CLAUSE CONFORMANCE WITH ENA TS 35-2

Transformers covered by ENA TS 35-2 shall comply with the latest issues of the relevant International and British Standards. ENA TS 35-2 is intended to amplify and/or clarify the requirements of those Standards.

This check sheet identifies the clauses in ENA TS 35-2 and the clauses of IEC 60076-1.

The manufacturer shall declare conformance or otherwise, clause by clause, using the following levels of conformance declaration codes.

Conformance declaration codes* Instructions for completion

NA Clause is not applicable or appropriate to the product

Cs1 the product is fully conforms with the requirements of this clause

Cs2 the product partially conforms with the requirements of this clause

Cs3 the product does not conform with the requirements of this clause

Cs4 the product does not currently conform with the requirements of this clause, but the manufacturer proposes to modify and test the product in order to comply.

Manufacturer:

Product Reference:

Name: Signature: Date:

Check sheet follows…..

When Cs1 code is entered no remark is necessary

When any other code is entered the reason for non-conformance shall be entered


Table B.1 — Self-Certification Conformance Declaration

Clause / Sub-clause

Requirement Conformance Code IEC 60076-1

Conformance Code ENA TS 35-2

Schedule item Remarks

1 Scope N/A

2 Normative references N/A

3 Definitions N/A N/A

3.1 General N/A N/A

3.2 Terminals and neutral point N/A N/A

3.3 Windings N/A N/A

3.4 Rating N/A N/A

3.5 Tappings N/A N/A

3.6 Losses and no-load current N/A N/A

3.7 Short-circuit impedance and voltage drop

N/A N/A

3.8 Temperature rise N/A N/A

3.9 Insulation N/A N/A

3.10 Connections N/A N/A

3.11 Test classification N/A N/A

3.12 Meteorological data with respect to cooling

N/A N/A

4 Service conditions N/A N/A

4.1 General N/A

4.2 Normal service conditions Value of cooling air temp °C for CER


Clause / Sub-clause




5 Rating and general requirements

5.1 Rating

5.1.1 General Emergency rated powerMVA

5.1.2 Preferred values of rated power Graph of CER vs. ambientGraph of ONAN vs. ambientGraph of CMR vs. ambientMaximum CMR MVA

5.1.3 Minimum power under alternative cooling modes

ONAN rated power MVA

5.1.4 Loading beyond rated power N/A

5.2 Cooling mode N/A

5.3 Load rejection on generator transformers

Is the transformer suitable for generator transformer load rejection?

5.4 Rated voltage and frequency N/A

5.4.1 Rated voltage HV rated voltage kVLV rated Voltage kV

5.4.2 Rated frequency Rated frequency Hz

5.4.3 Operation at higher than rated voltage and/or at other than rated frequency

N/A N/A

5.5 Provision for unusual service conditions N/A N/A

5.6 Highest voltage for equipment Um and dielectric test levels

N/A N/A


Clause / Sub-clause




5.7

5.7.15.7.2

5.7.35.7.4

Additional information required for enquiryTransformer classificationWinding connection and number of phasesSound levelTransport

N/A N/A

5.8 Components and materials N/A N/A

6 Requirements for transformers having a tapped winding

N/A N/A

6.1 Notation of tapping range N/A N/A

6.2 Tapping voltage, current, etc. N/A N/A

6.3 Tapping power N/A

6.4 Specification of tappings Tapping range offered

6.5 Specification of short-circuit impedance Graph of impedance vs. tap position

6.6 Load loss and temperature rise Guaranteed load loss at 50% of CER kW

Peak Efficiency Index (PEI) %

Regulation (EU) No 548/20:Tier 1 compliance?Tier 2 compliance?If not, give reasons


Clause / Sub-clause




7 Connection and phase displacement symbol

Vector groupAlternative vector group where links are providedStabilising winding provided for star-star transformer

8 Rating plates

8.1 General N/A N/A

8.2 Information to be given in all cases N/A

8.3 Additional information to be given N/A N/A

9

9.1

Safety, environmental and other requirementsSafety and environmental requirements

N/A

N/A

N/A

N/A

9.2 Dimensioning of neutral connection Is neutral connection dimensioned for load current?

9.3 Liquid preservation system Description of liquid preservation system

9.4 d.c. currents in neutral circuits

9.5 Centre of gravity marking N/A N/A

10 Tolerances N/A N/A

1111.1

11.1.1

TestsGeneral requirements for routine, type and special testsGeneral

N/AN/A

Rated lightning impulse voltage (LI) kV peak


Clause / Sub-clause




11.1.2 Routine tests Guaranteed sound power level at ONAN dB(A)

11.1.2.1 Routine tests for all transformers Where are FRA tests to be carried out?

11.1.2.2 Additional routine tests for transformers with Um > 72.5 kV

N/A N/A N/A

11.1.3 Type tests Are type test results from an identical unit available?Guaranteed sound power level at CER dB(A)Power taken by the fan and liquid pump motors kWNo-loss loss and current at 90% of rated load kW, A100% of rated load kW, A110% of rated load kW, A

11.1.4 Special tests Guaranteed and expected change of impedance after short-circuit testSpecial tests included in offer

11.2 Measurement of winding resistance N/A

11.3 Measurement of winding ratio and phase displacement

N/A

11.4 Measurement of short-circuit impedance and load-loss

N/A


Clause / Sub-clause




11.5 Measurement of no-load loss and current

Guaranteed no-load loss kW

11.6 Measurement of zero-phase sequence impedance (ZPSI)

Guaranteed ZPSI Ω/ph

11.7 Tests on OLTC N/A N/A

11.8 Leak testing with pressure for liquid immersed transformers

N/A

11.9 Vacuum deflection test N/A

11.10 Pressure deflection test for liquid immersed transformers

N/A N/A

11.11 Vacuum tightness on site for liquid immersed transformers

N/A N/A

11.12 Check of core and frame insulation N/A N/A

11.13 Temperature Rise at Emergency Rating N/A N/A

11.14 Determination of Sound Levels N/A N/A

11.15 Frequency Response Analysis N/A Is frequency response analysis is included in offer?

11.16 Measurement of the harmonics N/A 3rd harmonic component %

11.17 Insulation resistance measurements N/A N/A

11.18 Site tests N/A N/A

12 EMC N/A N/A

13 High frequency switching transients N/A N/A


Clause / Sub-clause




1414.1

Transformer detailsNo. of phases and frequency

N/A N/A

14.2 Cooling medium N/A Cooling medium offered

14.3 Cooling N/A Cooling type at CER

14.414.4.1

Limiting dimensionsSeparate cooler bank arrangement

N/A Does the transformer meet requirements of 14.4.1?

14.4.2 Anti-vibration mountings N/A Percentage isolation value and description of AV mountings

14.5 Auxiliary supply voltage N/A Supply voltage for tap-changer and cooler

14.6 Duty under fault conditions N/A Short-circuit capability demonstrated? (supply details & test certificates)

15 Construction details N/A N/A

15.1 Tanks and covers N/A N/A


Clause / Sub-clause




15.1.1 Tanks N/A Total oil required (including cooling system). litresFilling medium for transportOverall height when arranged for transport on trailer mmOverall weight when arranged for transport on trailer tonnesTotal weight as installed in service including cooler plant, all fittings and oil. tonnesType of haulage facilities offered

15.1.2 Covers N/A Is offer for bolted or welded cover?

15.1.3 Gaskets N/A Description of gasket material and thickness

15.1.4 Earthing connections N/A N/A

15.1.5 Sound attenuation enclosures N/A Is sound attenuation enclosure offered?

15.2 Surface finish N/A Finish colour offered

15.3 Terminals N/A Are separate disconnecting chambers provided?Position of HV and LV terminals


Clause / Sub-clause




15.3.1 Cable boxes N/A Position of cable boxesOil-filled disconnecting chamber included?

15.3.2 Outdoor bushings N/A N/A

15.3.3 Plug-in separable connectors N/A Type of cone offered

15.3.4 HV terminals N/A Type of terminals offeredNVD capacitor taps offered?Surge arresters included?Brackets for surge arresters included?Co-ordinating gaps included?

15.3.5 HV neutral terminal N/A Type of terminal offeredAccessible isolatable link offered?

15.3.6 LV termination N/A Type of termination offeredCable disconnecting links included?

15.3.7 LV neutral termination N/A Type of termination offeredLV neutral current transformer(s) included?Accessible isolatable link included?


Clause / Sub-clause




15.3.8 Earthing/auxiliary transformer N/A Earthing/auxiliary transformer type?Is flange and valve included?RatingHV terminationsOther details, if not standard

15.4 On-load tap-changer N/A N/A

15.4.1 Operating mechanism N/A Description of motor protectionIs a max/min tap position indicator included?

15.4.2 Segregation of compartments N/A N/A

15.4.3 Method of operation N/A N/A

15.5 Clearance to exposed conductors N/A N/A

15.6 Fittings N/A N/A

15.6.1 Conservator N/A Is low oil level alarm included?


Clause / Sub-clause




15.6.2 Cooling plant N/A Cooling loss kWNumber of pumpsContinuous rating of pump motor shaft kWStarting current of pump motor ANumber of fansContinuous rating of fan motor shaft kWStarting current of fan motor AFan diameter mmSpeed of fans rpmProvision for separate cooler bank at either end of the tank?

15.6.3 Gas-and-oil actuated relay N/A N/A

15.6.4 Pressure relief device N/A N/A

15.6.5 Winding temperature indicators N/A Description of provision of winding temperature indicationIs a second WTI included?

15.6.6 Current transformers N/A Current transformer accommodation fitted?Second voltage compounding CT fitted?

15.6.7 Other fittings N/A N/A

15.6.8 Valves N/A N/A


Clause / Sub-clause




15.7 Marshalling/control box N/A Means of condensation protectionDescription of security

15.8 Interconnecting cables N/A N/A

15.9 Magnetic circuit N/A N/A

15.10 Core and winding assemblies N/A N/A

15.11 Padlocks N/A N/A

15.12 Condition monitoring equipment N/A Condition monitoring equipment specified? (If so provide details)

15.13 LV switchgear and controlgear N/A N/A

16 Documentation N/A Proposed maintenance schedule

16.1 Drawings N/A Electronic drawing format

16.2 Assembly, operation and maintenance instructions

Electronic format for instruction manual


Annex C (normative)

Technical Schedules (to be completed by the manufacturer for emergency rated system transformers)

C.1 Manufacturers and places of manufacture, testing and inspection

Item Manufacturer’s Drawing Number and/or Type Designation

Manufacturer Place of Manufacture

Place of Testing and Inspection

Transformers complete

On-load tap-changer equipment

Transformer core

HV Bushings

LV Bushings

Neutral bushings

Winding conductor

Solid insulation kits

Transformer tank

Radiators

Pipe work expansion devices

Oil

Oil valves

Oil pumps

Oil pump motors

Fans

Fan motors

Dehydrating breather

Conservator diaphragm system


Item Manufacturer’s Drawing Number and/or Type Designation

Manufacturer Place of Manufacture

Place of Testing and Inspection

Gas and oil actuated relay(s)Main tankTap-changer

Pressure relief device

Outdoor marshalling/control box

Temperature indicating devices

Material for anti-vibration mounting

Any deviation from this Schedule shall be notified in writing as soon as possible for the purchaser’s approval.


Annex D (normative)

Additional technical schedules (to be completed by manufacturer)

Item Description Details

Magnetic circuit

1 Core construction (a) Taped/banded/bolted limbs (b) Taped/banded/bolted yokes (c) Taping/banding material (as applicable)

2 Insulation of:- (a) Core bolts (b) Core bolt washers (c) Side plates (d) Core laminations

Windings

3 Types and arrangement of:- (a) HV Windings (b) LV Windings (c) Tapping windings (as applicable) (d) Winding arrangement, i.e. Core /.../...../...../

4 Conductor insulation (a) HV Windings (b) LV Windings (c) Tapping windings (as applicable)

5 Oil circulation e.g. Natural/Partially directed/Directed:- (a) To windings

(i) HV windings(ii) LV windings(iii) Tapping windings (as applicable)

(b) Through windings(i) HV windings(ii) LV windings(iii) Tapping windings (as applicable)

6 Short-circuit capabilityPotential axial thrust for worst fault condition in each winding:(i) HV windings tonnes(ii) LV windings tonnes(iii) Tapping windings (as applicable) tonnes

Coil clamping short-circuit withstand capability:



(i) HV windings tonnes (ii) LV windings tonnes (iii) Tapping windings (as applicable) tonnes

7 Current density in windings (as nominal tapping position and emergency rating): (a) HV windings A/mm2

(b) LV windings A/mm2

(c) Tapping windings A/mm2

Performance characteristics

8 No-load loss at nominal tap (excluding cooling plant loss) kW

9 Cooling plant loss kW

10 Load losses: (a) ONAN rating, 75 °C nominal tapping kW (b) CER at 115 °C extreme negative tapping kW

Tank and cooler

11 Thickness of tank: (a) Sides mm (b) Base mm (c) Cover mm

12 Thickness of radiator plates mm

13 Total oil required:(a) Tank litres(b) Cooling system litres

14 Volume of oil to be removed:To effect in-situ change of HV bushing litres

15 Total volume of conservator(s) litres

16 Total volume of conservator(s) betweenhighest and lowest visible levels litres

17 Continuous rating of oil pump motor shaft kW

18 Starting current of oil pump motor amps

19 Total number of fans

20 Nominal diameter of fans mm

21 Speed of fans rev/min

22 Continuous rating of each fan motor shaft kW

23 Starting current of each fan motor amps

General

24 Filling medium for transport



25 Weights: (a) As prepared for transport tonnes (b) As installed in service including cooler plant, all

fittings and oil tonnes (c) Cooler complete with oil conservator, etc. tonnes (d) Silica gel breather charge kg


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