EN 61558-2-4:1997

Safety of power transformers, power supply units and similar - Part 2-4: Particular requirements for isolating transformers for general use

This part 2 of EN 61558 applies to stationary or portable, single-phase or polyphase, air-cooled isolating transformers, associated or otherwise. It has the status of a group safety publication in accordance with IEC Guide 104. This part 2 supplements or modifies the corresponding clauses in EN 61558-1,

Sicherheit von Transformatoren, Netzgeräten und dergleichen - Teil 2-4: Besondere Anforderungen an Trenntransformatoren für allgemeine Anwendungen

Sécurité des transformateurs, blocs d'alimentation et analogues - Partie 2-4: Règles particulières pour les transformateurs de séparation des circuits pour usage général

La présente partie 2 de la EN 61558 est applicable aux transformateurs de séparation des circuits, fixes ou mobiles, monophasés ou polyphasés, à refroidissement par air, associés ou non. Elle a le statut de publication groupée de sécurité conformément au guide CEI 104. La présente partie 2 complète ou modifie les articles correspondants de la EN 61558-1

Safety of power transformers, power supply units and similar - Part 2-4: Particular requirements for isolating transformers for general use (IEC 61558-2-4:1997)

General Information

• Status: Withdrawn
• Publication Date: 02-Nov-1997
• Withdrawal Date: 31-Jul-2000
• ICS: 29.180 - Transformers. Reactors
• Technical Committee: CLC/SR 96 - Small power transformers, reactors, power supply units and similar products
• Drafting Committee: IEC/TC 96 - IEC_TC_96
• Parallel Committee: IEC/TC 96 - IEC_TC_96
• Current Stage: 9960 - Withdrawal effective - Withdrawal
• Start Date: 01-Mar-2012
• Completion Date: 01-Mar-2012
• Directive: 2006/95/EC - Directive 2006/95/EC of the European Parliament and of the Council of 12 December 2006 on the harmonisation of the laws of Member States relating to electrical equipment designed for use within certain voltage limits (codified version)
• Directive: 73/23/EEC - Electrical equipment designed for use within certain voltage limits
• Ref Project: SIST EN 61558-2-4:1999 - Safety of power transformers, power supply units and similar -- Part 2-4: Particular requirements for isolating transformers for general use

Relations

• Replaces: EN 60742:1995 - Isolating transformers and safety isolating transformers - Requirements
• Effective Date: 28-Jan-2023
• Replaced By: EN 61558-2-4:2009 - Safety of transformers, reactors, power supply units and similar products for supply voltages up to 1 100 V - Part 2-4: Particular requirements and tests for isolating transformers and power supply units incorporating isolating transformers
• Effective Date: 28-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-1999
Safety of power transformers, power supply units and similar - Part 2-4: Particular
requirements for isolating transformers for general use (IEC 61558-2-4:1997)
Safety of power transformers, power supply units and similar -- Part 2-4: Particular
requirements for isolating transformers for general use
Sicherheit von Transformatoren, Netzgeräten und dergleichen -- Teil 2-4: Besondere
Anforderungen an Trenntransformatoren für allgemeine Anwendungen
Sécurité des transformateurs, blocs d'alimentation et analogues -- Partie 2-4: Règles
particulières pour les transformateurs de séparation des circuits pour usage général
Ta slovenski standard je istoveten z: EN 61558-2-4:1997
ICS:
29.180 Transformatorji. Dušilke Transformers. Reactors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME
CEI
INTERNATIONALE
IEC
61558-2-4
INTERNATIONAL
Première édition
STANDARD
First edition
1997-02
PUBLICATION GROUPÉE DE SÉCURITÉ
GROUP SAFETY PUBLICATION
Sécurité des transformateurs, blocs d'alimentation
et analogues –
Partie 2:
Règles particulières pour les transformateurs
de séparation des circuits pour usage général
Safety of power transformers, power supply units
and similar –
Part 2:
Particular requirements for isolating
transformers for general use
 IEC 1997 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni utilisée No part of this publication may be reproduced or utilized in
sous quelque forme que ce soit et par aucun procédé, électronique any form or by any means, electronic or mechanical, including
ou mécanique, y compris la photocopie et les microfilms, sans photocopying and microfilm, without permission in writing from
l'accord écrit de l'éditeur. the publisher.
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Telefax: [phone] e-mail: [e-mail] IEC web site http: //www.iec.ch
CODE PRIX
Commission Electrotechnique Internationale
PRICE CODE L
International Electrotechnical Commission
Pour prix, voir catalogue en vigueur
For price, see current catalogue

61558-2-4 © IEC:1997 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_________
SAFETY OF POWER TRANSFORMERS, POWER SUPPLY UNITS
AND SIMILAR −
Part 2: Particular requirements for isolating transformers
for general use
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization
for Standardization (ISO) in accordance with conditions determined by agreement between the two
organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61558-2-4 has been prepared by IEC technical committee 96: Small
power transformers, reactors and power supply units and special transformers, reactors and
power supply units: Safety requirements.
It has the status of a group safety publication in accordance with IEC Guide 104: Guide for the
drafting of safety standards, and the role of Committees with safety pilot functions and safety
group functions (1984).
The text of this standard is based on the following documents:
FDIS Report on voting
96/49/FDIS 96/72/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This part 2 is intended to be used in conjunction with IEC 61558-1. It was established on the
basis of the first edition (1997) of that standard.
This part 2 supplements or modifies the corresponding clauses in IEC 61558-1, so as to convert that
publication into the IEC standard: Particular requirements for isolating transformers for general use.

61558-2-4 © IEC:1997 – 5 –
When a particular subclause of part 1 is not mentioned in this part 2, that subclause applies as
far as is reasonable. Where this standard states "addition", "modification" or "replacement", the
relevant text of part 1 is to be adapted accordingly.
This Standard replaces Chapter I of IEC 742.
In this standard, the following print types are used:
– requirements proper: in roman type;
– test specifications: in italic type;
– explanatory matter: in smaller roman type.
In the text of the standard the words in bold are defined in clause 3.
Subclauses which are additional to those in part 1 are numbered starting from 101;
supplementary annexes are entitled AA,BB, etc.

61558-2-4 © IEC:1997 – 7 –
SAFETY OF POWER TRANSFORMERS, POWER SUPPLY UNITS
AND SIMILAR −
Part 2: Particular requirements for isolating transformers
for general use
1 Scope
Replacement:
This part 2 of IEC 61558 applies to stationary or portable, single-phase or polyphase, air-cooled
isolating transformers, associated or otherwise, having a rated supply voltage not exceeding
1000 V a.c. and rated frequency not exceeding 500 Hz, the rated output not exceeding:
– 25 kVA for single-phase transformers;
– 40 kVA for polyphase transformers.
This standard is also applicable to isolating transformers without limitation of the rated
output, however such transformers are considered as special transformers and are subjected
to an agreement between the purchaser and the supplier.
The no-load output voltage or the rated output voltage does not exceed 500 V a.c. or 708 V
ripple-free d.c.
NOTES
1 The no-load output voltage or the rated output voltage may be up to 1000 V a.c. or 1 415 V ripple-free d.c.
to be in accordance with the national wiring rules or for a special purpose.
2 This standard is applicable to those isolating transformers used when the installation rules call for the
separation of circuits for the supply of certain parts of the circuits or of equipment (portable tools, lawn mowers,
etc.).
The no-load output voltage and/or the rated output voltage shall exceed 50 V a.c. and/or
120 V ripple-free d.c.
This standard is also applicable to transformers associated with specific items of equipment,
to the extent decided upon by the relevant IEC technical committees.
This standard is applicable to dry type transformers. The windings may be encapsulated or
non-encapsulated.
NOTES
3 For transformers filled with liquid dielectric or pulverized material, such as sand, additional requirements are
under consideration.
4 In locations where special environmental conditions prevail, particular requirements may be necessary in
accordance with IEC 364-5-51.
2 Normative references
This clause of part 1 is applicable.
3 Definitions
This clause of part 1 is applicable.

61558-2-4 © IEC:1997 – 9 –
4 General requirements
This clause of part 1 is applicable.
5 General notes on tests
This clause of part 1 is applicable.
6 Ratings
This clause of part 1 is applicable except as follows:
Addition:
6.101 The rated output voltage shall not exceed 250 V a.c. for portable single-phase
transformers and 500 V a.c. or 708 V ripple-free d.c. for other transformers.
NOTE – The rated output voltage may be up to 1000 V a.c. or 1415 V ripple-free d.c. to be in accordance with
the national wiring rules or for a special purpose.
Preferred values for the rated output voltage are:
– 120 V and 230 V for portable single-phase transformers;
– 72 V, 120 V, 230 V, 400 V and 440 V for other transformers.
6.102 The rated output shall not exceed 25 kVA for single-phase transformers and 40 kVA
for polyphase transformers.
Preferred values for the rated output are:
– 25 VA, 40 VA, 63 VA, 100 VA, 160 VA, 25
...