EN 50708-2-4:2022

Power transformers - Additional European requirements - Part 2-4: Medium power transformer - Special tests

This document describes the special tests for Medium Power Transformers ≤ 3150 kVA compliant with the EN 50708 2 series: - for corrugated tank for liquid immersed transformers, - for the method of measurement of losses for one winding in Highest Voltage (HV) and windings in Lowest Voltage (LV) for liquid immersed and dry type transformers.

Leistungstransformatoren – Zusätzliche europäische Anforderungen - Teil 2-4: Mittelleistungstransformatoren – Sonderprüfungen

Transformateurs de puissance - Exigences européennes supplémentaires - Partie 2-4 : Transformateurs de moyenne puissance - Essais spéciaux

Le présent document décrit les essais spéciaux pour les transformateurs de moyenne puissance ≤ 3150 kVA conformes à la série EN 50708 2: - pour la cuve à plis pour les transformateurs immergés dans un liquide ; - pour la méthode de mesure des pertes pour un enroulement en haute tension (HT) et 2 enroulements en basse tension (BT) pour les transformateurs de type sec et les transformateurs immergés dans un liquide.

Močnostni transformatorji - Dodatne evropske zahteve - 2-4. del: Srednji močnostni transformatorji - Posebni preskusi

Ta dokument opisuje poseben preskus za srednje močnostne transformatorje ≤ 3150 kVA v skladu s skupino standardov EN 50708-2:
–   za transformatorje z rezervoarjem iz valovite pločevine, potopljene v tekočino;
–   za metodo merjenja izgub za eno navitje pri najvišji napetosti (HV) in dve navitji pri najnižji napetosti (LV) za transformator, potopljen v tekočino, in suhi transformator.

General Information

• Status: Published
• Publication Date: 08-Sep-2022
• ICS: 29.180 - Transformers. Reactors
• Technical Committee: CLC/TC 14 - Power transformers
• Drafting Committee: CLC/TC 14/WG 21 - Revision of HD 428 and HD 538
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 09-Sep-2022
• Due Date: 29-Jul-2022
• Completion Date: 09-Sep-2022
• Ref Project: SIST EN 50708-2-4:2022 - Power transformers - Additional European requirements - Part 2-4: Medium power transformer - Special tests

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 50708-2-4:2022
01-november-2022
Močnostni transformatorji - Dodatne evropske zahteve - 2-4. del: Srednji
močnostni transformatorji - Posebni preskusi
Power transformers - Additional European requirements - Part 2-4: Medium power
transformer - Special tests

Transformateurs de puissance - Exigences européennes supplémentaires - Partie 2-4 :

Transformateurs de moyenne puissance - Essais spéciaux
Ta slovenski standard je istoveten z: EN 50708-2-4:2022
ICS:
29.180 Transformatorji. Dušilke Transformers. Reactors
SIST EN 50708-2-4:2022 en,fr

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 50708-2-4:2022
---------------------- Page: 2 ----------------------
SIST EN 50708-2-4:2022
EUROPEAN STANDARD EN 50708-2-4
NORME EUROPÉENNE
EUROPÄISCHE NORM September 2022
ICS 29.180
English Version
Power transformers - Additional European requirements - Part 2-
4: Medium power transformer - Special tests

Transformateurs de puissance - Exigences européennes Leistungstransformatoren - Zusätzliche europäische

supplémentaires - Partie 2-4 : Transformateurs de moyenne Anforderungen - Teil 2-4: Mittelleistungstransformatoren -

puissance - Essais spéciaux Sonderprüfungen

This European Standard was approved by CENELEC on 2022-07-25. CENELEC members are bound to comply with the CEN/CENELEC

Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC

Management Centre or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation

under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the

same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,

Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the

Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2022 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Ref. No. EN 50708-2-4:2022 E
---------------------- Page: 3 ----------------------
SIST EN 50708-2-4:2022
EN 50708-2-4:2022 (E)
Contents Page

Contents ............................................................................................................................ 3

European foreword ............................................................................................................ 4

Introduction ....................................................................................................................... 5

1 Scope ......................................................................................................................... 6

2 Normative references .................................................................................................. 6

3 Terms and definitions .................................................................................................. 6

4 Service conditions ....................................................................................................... 6

5 Special test for corrugated tank ................................................................................... 6

5.1 General information ........................................................................................... 6

5.2 Temperature variation ........................................................................................ 6

5.3 Sealing temperature ........................................................................................... 7

5.4 Calculation of the liquid volume variation ........................................................... 7

5.5 Test procedure ................................................................................................... 7

5.5.1 General .................................................................................................. 7

5.5.2 Measurement of pressure range ............................................................. 7

5.5.3 Endurance test ....................................................................................... 8

5.5.4 Leakage test .......................................................................................... 8

5.5.5 Evaluation of the tests ............................................................................ 8

6 Method of measurement of losses on double LV windings ........................................... 8

6.1 Introduction ........................................................................................................ 8

6.2 Limits of this method .......................................................................................... 8

6.3 Resistance measurement ................................................................................... 8

6.4 Measurement of load losses and short circuit impedance ................................... 9

Bibliography ..................................................................................................................... 10

---------------------- Page: 4 ----------------------
SIST EN 50708-2-4:2022
EN 50708-2-4:2022 (E)
European foreword

This document (EN 50708-2-4:2022) has been prepared by CLC/TC 14 “Power transformers”.

The following dates are fixed:
• latest date by which this document has to be (dop) 2023-07-25
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) 2025-07-25
conflicting with this document have to be
withdrawn

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Any feedback and questions on this document should be directed to the users’ national committee. A

complete listing of these bodies can be found on the CENELEC website.
---------------------- Page: 5 ----------------------
SIST EN 50708-2-4:2022
EN 50708-2-4:2022 (E)
Introduction

This document defines the rules for the assessment of energy performance to ensure the product

conformity to the EU Regulation 548/2014 and amendment of 2019.

Regulation leads to have a minimum level of energy performances of power transformers.

NOTE In the document the term Regulation refers to the EU Regulation 548/2014 and amendment of 2019.

For the purpose of this document, the requirements of EN 50708-1-1 apply.

This document contains particular requirements for specific transformers or transformer applications,

which are based on the requirements of EN 50708-1-1.

This document should be considered in conjunction with the requirements of the general parts.

The particular requirements of the different sub parts of EN 50708 supplement, modify or replace

certain requirements of the general parts of EN 50708-1 and/or EN 50708-1-X being valid at the time

of publication of this document. The absence of references to the exclusion of a part or a clause of a

general part means that the corresponding clauses of the general part are applicable (undated

reference).

Requirements of other -X parts with X greater than 1 being eventually relevant for cases covered by

this document also apply. This document could therefore also supplement, modify or replace certain

of these requirements valid at the time of publication of this document.

The main clause numbering of each part follows the pattern and corresponding references of

EN 50708-1-1. The numbers following the particular number of this document are those of the

corresponding parts, or clauses of the other parts of the EN 50708 series, valid at the time of

publication of this document, as indicated in the normative references of this document (dated

reference).In the case where new or amended general parts with modified numbering were published

after the sub part was issued, the clause numbers referring to a general part in sub parts might no

longer align with the latest edition of the general part. Dated references should be observed.

---------------------- Page: 6 ----------------------
SIST EN 50708-2-4:2022
EN 50708-2-4:2022 (E)
1 Scope

This document describes the special tests for Medium Power Transformers ≤ 3150 kVA compliant

with the EN 50708-2 series:
— for corrugated tank for liquid immersed transformers,

— for the method of measurement of losses for one winding in Highest Voltage (HV) and windings

in Lowest Voltage (LV) for liquid immersed and dry type transformers.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments)

applies.
EN 50708 (series), Power transformers — Additional European
...

SLOVENSKI STANDARD
oSIST prEN 50708-2-4:2020
01-oktober-2020
Močnostni transformatorji - Dodatne evropske zahteve - 2-4. del: Srednji
močnostni transformatorj - Posebni preskusi
Power transformers - Additional European requirements - Part 2-4: Medium power
transformer - Special tests

Transformateurs de puissance - Exigences européennes supplémentaires - Partie 2-4 :

Transformateurs de moyenne puissance - Essais spéciaux
Ta slovenski standard je istoveten z: prEN 50708-2-4
ICS:
29.180 Transformatorji. Dušilke Transformers. Reactors
oSIST prEN 50708-2-4:2020 en,fr

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN 50708-2-4:2020
---------------------- Page: 2 ----------------------
oSIST prEN 50708-2-4:2020
EUROPEAN STANDARD DRAFT
prEN 50708-2-4
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2020
ICS
English Version
Power transformers - Additional European requirements - Part 2-
4: Medium power transformer - Special tests
Transformateurs de puissance - Exigences européennes To be completed
supplémentaires - Partie 2-4 : Transformateurs de moyenne
puissance - Essais spéciaux
This draft European Standard is submitted to CENELEC members for enquiry.
Deadline for CENELEC: 2020-10-30.
It has been drawn up by CLC/TC 14.

If this draft becomes a European Standard, CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which

stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CENELEC in three official versions (English, French, German).

A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to

the CEN-CENELEC Management Centre has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,

Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the

Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to

provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and

shall not be referred to as a European Standard.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Project: 70486 Ref. No. prEN 50708-2-4 E
---------------------- Page: 3 ----------------------
oSIST prEN 50708-2-4:2020
prEN 50708-2-4:2020 (E)
1 Contents

2 European foreword ......................................................................................................... 3

3 Introduction .................................................................................................................... 4

4 1 Scope ...................................................................................................................... 5

5 2 Normative references ............................................................................................... 5

6 3 Terms and definitions ............................................................................................... 5

7 4 Service conditions .................................................................................................... 5

8 5 Special test for corrugated tank ................................................................................ 5

9 5.1 General information ........................................................................................ 5

10 5.2 Temperature variation ..................................................................................... 6

11 5.3 Sealing temperature ........................................................................................ 6

12 5.4 Calculation of the volume variation .................................................................. 6

13 5.5 Test procedure ................................................................................................ 6

14 5.5.1 General ............................................................................................... 6

15 5.5.2 Measurement of pressure range .......................................................... 6

16 5.5.3 Endurance test .................................................................................... 7

17 5.5.4 Leakage test ....................................................................................... 7

18 5.5.5 Evaluation of the tests ......................................................................... 7

19 6 Method of measurement of losses on double LV windings ........................................ 7

20 6.1 Introduction ..................................................................................................... 7

21 6.2 Limits of this method ....................................................................................... 7

22 6.3 Resistance measurement ................................................................................ 8

23 6.4 Measurement of load losses and short circuit impedance ................................ 8

---------------------- Page: 4 ----------------------
oSIST prEN 50708-2-4:2020
prEN 50708-2-4:2020 (E)
25 European foreword

26 This document (prEN 50708-2-4:2020) has been prepared by CLC/TC 14 “Power transformers”.

27 This document is currently submitted to the Enquiry.
28 The following dates are proposed:
• latest date by which the existence of this (doa) dor + 6 months
document has to be announced at national
level
• latest date by which this document has to be (dop) dor + 12 months
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) dor + 36 months
conflicting with this document have to be (to be confirmed or
withdrawn
modified when voting)
---------------------- Page: 5 ----------------------
oSIST prEN 50708-2-4:2020
prEN 50708-2-4:2020 (E)
30 Introduction

31 This document defines the rules for the assessment of energy performance to ensure the product

32 conformity to the Commission Regulation (EU) No 548/2014 of 21 May 2014 and its amendment No

33 2019/1783 of 1 October 2019.

34 Regulation leads to have a minimum level of energy performances of power transformers.

35 NOTE In this document, the term Regulation refers to the Commission Regulation (EU) No 548/2014 of 21

36 May 2014 and its amendment No 2019/1783 of 1 October 2019.

37 For the purpose of this document, the requirements of the general EN 50708-1-1:2020 apply.

38 This document contains particular requirements for specific transformers or transformer applications,

39 which are based on the requirements of the general EN 50708-1-1:2020.

40 This document should considered in conjunction with the requirements of the general parts.

41 The particular requirements of the different sub parts of EN 50708 supplement, modify or replace

42 certain requirements of the general parts of EN 50708-1 and/or EN 50708-1-X being valid at the time

43 of publication of this document. The absence of references to the exclusion of a part or a clause of a

44 general part means that the corresponding clauses of the general part are applicable (undated

45 reference).

46 Requirements of other -X parts with X greater than 1 being eventually relevant for cases covered by

47 this document also apply. This document could therefore also supplement, modify or replace certain

48 of these requirements valid at the time of publication of this document.

49 The main clause numbering of each part follows the pattern and corresponding references of

50 EN 50708-1-1:2020. The numbers following the particular number of this document are those of the

51 corresponding parts, or clauses of the other parts of the EN 50708 series, valid at the time of

52 publication of this document.

53 In the case where new or amended general parts with modified numbering were published after the

54 sub part was issued, the clause numbers referring to a general part in sub parts might no longer align

55 with the latest edition of the general part. Dated references should be observed.

---------------------- Page: 6 ----------------------
oSIST prEN 50708-2-4:2020
prEN 50708-2-4:2020 (E)
56 1 Scope

57 This document describes the special test for Medium Power Transformers ≤ 3150kVA compliant with

58 the EN 50708-2 series:
59 — for corrugated tank liquid immersed transformers;

60 — for the method of measurement of losses for one winding in Highest Voltage (HV) and 2 windings

61 in Lowest Voltage (LV) for liquid immersed and dry type transformer.
62 2 Normative references

63 The following documents are referred to in the text in such a way that some or all o

...