FprEN 50708-3-3:2025

SLOVENSKI STANDARD
oSIST prEN 50708-3-3:2023
01-september-2023
Močnostni transformatorji - Dodatne evropske zahteve - 3-3. del: Veliki močnostni
transformator - Pribor
Power transformers - Additional European requirements: Part 3-3 Large power
transformer - Accessories
Transformateurs de puissance - Exigences européennes supplémentaires - Partie 3-3:
Transformateurs de grande puissance - Accessoires
Ta slovenski standard je istoveten z: prEN 50708-3-3:2023
ICS:
29.180 Transformatorji. Dušilke Transformers. Reactors
oSIST prEN 50708-3-3:2023 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 50708-3-3:2023
oSIST prEN 50708-3-3:2023
EUROPEAN STANDARD DRAFT
prEN 50708-3-3
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2023
ICS  -
English Version
Power transformers - Additional European requirements: Part 3-
3 Large power transformer - Accessories
To be completed To be completed
This draft European Standard is submitted to CENELEC members for enquiry.
Deadline for CENELEC: 2023-09-15.

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,
Türkiye 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
© 2023 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Project: 77611 Ref. No. prEN 50708-3-3:2023 E

oSIST prEN 50708-3-3:2023
prEN 50708-3-3:2023 (E)
5 Contents
6 European foreword . 3
7 Introduction . 4
8 1 Scope . 5
9 2 Normative references . 5
10 3 Terms and definitions . 5
11 4 Service conditions . 5
12 5 Main accessories . 6
13 6 Specific requirements for certain accessories . 7
14 6.1 Gas and liquid actuated relay (Buchholz relays) . 7
15 6.2 Specific requirement for wheels . 7
oSIST prEN 50708-3-3:2023
prEN 50708-3-3:2023 (E)
17 European foreword
18 This document (prEN 50708-3-3:2023) has been prepared by CLC/TC 14 “Power transformers”.
19 This document is currently submitted to the Enquiry.
20 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)
oSIST prEN 50708-3-3:2023
prEN 50708-3-3:2023 (E)
21 Introduction
22 This part is a part of EN 50708 series that deals with the accessories for large power transformers.
23 For the purpose of this document, the requirements of the general EN 50708-1-1:2020 apply.
24 This document contains particular requirements for specific transformers or transformer applications, which are
25 based on the requirements of the general EN 50708-1-1:2020.
26 This document should be considered in conjunction with the requirements of the general parts.
27 The particular requirements of the different sub parts of the EN 50708 series supplement, modify or replace
28 certain requirements of the general parts of EN 50708-1 and/or EN 50708-1-X being valid at the time of
29 publication of this document. The absence of references to the exclusion of a part or a clause of a general part
30 means that the corresponding clauses of the general part are applicable (undated reference).
31 Requirements of other -X parts with X greater than 1 being eventually relevant for cases covered by this
32 document also apply. This document could therefore also supplement, modify or replace certain of these
33 requirements valid at the time of publication of this document.
34 The main clause numbering of each part follows the pattern and corresponding references of
35 EN 50708-1-1:2020. The numbers following the particular number of this document are those of the
36 corresponding parts, or clauses of the other parts of the EN 50708 series, valid at the time of publication of this
37 document.
38 In the case where new or amended general parts with modified numbering were published after the sub part
39 was issued, the clause numbers referring to a general part in sub parts might no longer align with the latest
40 edition of the general part. Dated references should be observed.
oSIST prEN 50708-3-3:2023
prEN 50708-3-3:2023 (E)
41 1 Scope
42 This document describes the typical accesso
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