Low-voltage switchgear and controlgear - Part 6-1: Multiple function equipment - Transfer switching equipment

IEC 60947-6-1:2021 applies to transfer switching equipment (TSE), to be used in power systems for ensuring the continuity of the supply and allowing the energy management of the installation, by transferring a load between power supply sources, the rated voltage of which does not exceed 1 000 V AC or 1 500 V DC.
This third edition cancels and replaces the second edition published in 2005, and its Amendment 1:2013. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
– clarification of scope and object;
– clarification of terms and definitions;
– removal of unnecessary definitions;
– modification of characteristics;
– modification of utilization categories definitions;
– introduction of new markings requirements;
– addition of new requirements for clearances and creepage distances;
– addition of new requirements and tests for mechanical and electrical interlocks;
– clarification of transfer sequences;
– modification of requirements for rated short-time withstand currents;
– modification of new requirements for electromagnetic compatibility;
– clarification of performance requirements for CB type TSE, in alignment with requirements stated in IEC 60947-2;
– addition of new test sequence V: Critical load current performance of equipment with DC ratings.

Appareillage à basse tension - Partie 6-1: Matériels à fonctions multiples - Equipement de transfert de source

L'IEC 60947-6-1:2021 s’applique aux équipements de transfert de source (TSE) destinés à des installations qui assurent la continuité de l’alimentation et permettent la gestion de l’énergie de l’installation, en transférant une charge entre des sources d’alimentation dont la tension assignée ne dépasse pas 1 000 V en courant alternatif ou 1 500 V en courant continu.
Cette troisième édition annule et remplace la deuxième édition parue en 2005, et l'Amendement 1:2013. Cette édition constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
– clarification du domaine d’application et de l’objet;
– clarification des termes et définitions;
– retrait des définitions non nécessaires;
– modification des caractéristiques;
– modification des définitions de catégorie d’emploi;
– introduction de nouvelles exigences de marquage;
– ajout de nouvelles exigences relatives aux distances d’isolement et lignes de fuite;
– ajout de nouvelles exigences et de nouveaux essais relatifs aux interverrouillages mécaniques et électriques;
– clarification des séquences de transfert;
– modification des exigences relatives aux courants assignés de courte durée admissibles;
– modification des nouvelles exigences relatives à la compatibilité électromagnétique;
– clarification des exigences relatives aux performances d’un TSE de type CB, en conformité avec les exigences contenues dans l’IEC 60947-2;
– ajout d’une nouvelle séquence d’essais V: fonctionnement au courant critique du matériel ayant des caractéristiques en courant continu.

General Information

Status
Published
Publication Date
15-Mar-2021
Current Stage
PPUB - Publication issued
Completion Date
16-Mar-2021
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IEC 60947-6-1
Edition 3.0 2021-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Low-voltage switchgear and controlgear –
Part 6-1: Multiple function equipment – Transfer switching equipment
Appareillage à basse tension –
Partie 6-1: Matériels à fonctions multiples – Equipement de transfert de source
IEC 60947-6-1:2021-03(en-fr)
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 60947-6-1
Edition 3.0 2021-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Low-voltage switchgear and controlgear –
Part 6-1: Multiple function equipment – Transfer switching equipment
Appareillage à basse tension –
Partie 6-1: Matériels à fonctions multiples – Equipement de transfert de source
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.120.40; 29.130.20 ISBN 978-2-8322-9448-2

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® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – IEC 60947-6-1:2021  IEC 2021
CONTENTS

FOREWORD ........................................................................................................................... 5

INTRODUCTION ..................................................................................................................... 7

1 Scope .............................................................................................................................. 8

2 Normative references ...................................................................................................... 9

3 Terms and definitions ...................................................................................................... 9

3.1 General ................................................................................................................... 9

3.2 Alphabetical index of terms ................................................................................... 10

3.3 Transfer switching devices .................................................................................... 10

3.4 Operation of TSE .................................................................................................. 12

3.5 Main contact positions .......................................................................................... 13

3.6 Symbols and abbreviated terms ............................................................................ 14

4 Classification ................................................................................................................. 14

5 Characteristics .............................................................................................................. 15

5.1 Summary of characteristics ................................................................................... 15

5.2 Type and characteristics of equipment .................................................................. 15

5.3 Rated and limiting values for the main circuit ........................................................ 16

5.3.1 General ......................................................................................................... 16

5.3.2 Rated voltages .............................................................................................. 16

5.3.3 Rated operational current (I ) ........................................................................ 16

5.3.4 Rated frequency ............................................................................................ 16

5.3.5 Rated making and breaking capacities ........................................................... 16

5.3.6 Short-circuit characteristics ........................................................................... 17

5.4 Utilization category ............................................................................................... 17

5.5 Control circuits ...................................................................................................... 18

5.5.1 General ......................................................................................................... 18

5.5.2 Electro-mechanical devices operating the main circuit ................................... 18

5.5.3 ATS controller................................................................................................ 18

5.6 Auxiliary circuits .................................................................................................... 18

6 Product information ....................................................................................................... 18

6.1 Nature of information ............................................................................................ 18

6.2 Marking ................................................................................................................. 18

6.3 Instructions for installation, operation and maintenance, decommissioning

and dismantling..................................................................................................... 20

6.4 Environmental information .................................................................................... 21

7 Normal service, mounting and transport conditions ........................................................ 22

8 Constructional and performance requirements ............................................................... 22

8.1 Constructional requirements ................................................................................. 22

8.1.1 General ......................................................................................................... 22

8.1.2 Materials ....................................................................................................... 22

8.1.3 Indication of the switching position ................................................................ 23

8.1.4 Equipment suitable for isolation ..................................................................... 23

8.1.5 Opening and closing of main contacts ............................................................ 23

8.1.6 Clearances and creepage distances .............................................................. 23

8.1.7 Provision for protective earthing .................................................................... 23

8.1.8 Stored charge energy circuit .......................................................................... 23

---------------------- Page: 4 ----------------------
IEC 60947-6-1:2021  IEC 2021 – 3 –

8.1.9 Stored energy closing .................................................................................... 24

8.1.10 Dedicated enclosures for TSE ....................................................................... 24

8.2 Performance requirements .................................................................................... 24

8.2.1 Operating conditions ...................................................................................... 24

8.2.2 Temperature-rise ........................................................................................... 25

8.2.3 Dielectric properties ....................................................................................... 25

8.2.4 Ability to make, carry, and break under no-load, normal load and

overload conditions ........................................................................................ 25

8.2.5 Ability to make and break under short-circuit conditions ................................. 27

8.2.6 Critical load current performance (DC equipment) ......................................... 29

8.3 Electromagnetic compatibility (EMC) ..................................................................... 29

8.3.1 General ......................................................................................................... 29

8.3.2 Immunity ........................................................................................................ 29

8.3.3 Emission ........................................................................................................ 30

9 Tests ............................................................................................................................. 30

9.1 Kinds of tests ........................................................................................................ 30

9.2 Type tests ............................................................................................................. 30

9.2.1 General test conditions .................................................................................. 30

9.2.2 Test sequences ............................................................................................. 30

9.2.3 Test sequence I – General performance characteristics ................................. 33

9.2.4 Test sequence II – Operational performance capability .................................. 39

9.2.5 Test sequence III – Short-circuit performance capability ................................ 44

9.2.6 Test sequence IV – Conditional short-circuit current ...................................... 47

9.2.7 Test sequence V – critical load current performance of equipment with a

DC rating ....................................................................................................... 48

9.2.8 Test sequence VI – EMC tests ....................................................................... 51

9.3 Routine tests......................................................................................................... 53

9.4 Environmental tests .............................................................................................. 55

Annex A (normative) Assignment of utilization categories based on results of tests ............. 57

Annex B (informative) Items subject to agreement between manufacturer and user ............. 58

Bibliography .......................................................................................................................... 59

Figure 1 – Example of operating sequences for TSE with three positions .............................. 21

Figure 2 – Test circuit for connection to source I and source II supplies ............................... 54

Figure 3 – Test circuit for the verification of making and breaking capacities ........................ 55

Table 1 – Utilization categories ............................................................................................. 18

Table 2 – Product information ............................................................................................... 19

Table 3 – Verification of making and breaking capacity – Conditions for making and

breaking corresponding to the utilization categories .............................................................. 26

Table 4 – Verification of operational performance – Conditions for making and breaking

corresponding to the utilization categories ............................................................................ 27

Table 5 – Value of the test current for the verification of the ability to operate under

short-circuit conditions .......................................................................................................... 28

Table 6 – Value of the test current for the verification of the ability to operate under

short-circuit conditions (harmonized table) ............................................................................ 29

Table 7 – Acceptance criteria of immunity test ...................................................................... 30

Table 8 – List of type tests (overall scheme of test sequences) ............................................. 31

---------------------- Page: 5 ----------------------
– 4 – IEC 60947-6-1:2021  IEC 2021

Table 9 – List of type tests to which a derived TSE shall be submitted .................................. 32

Table 10 – Number and duration of operating cycles for the making and breaking

capacity test ......................................................................................................................... 41

Table 11 – Number and rate of operating cycles for the electrical and mechanical

operational performance tests for type A utilization categories .............................................. 42

Table 12 – Number and rate of operating cycles for the electrical and mechanical

operational performance tests for type B utilization categories .............................................. 42

Table 13 – Temperature-rise limits for terminals and accessible parts ................................... 43

Table 14 – Number of operating cycles corresponding to the critical load current .................. 50

Table 15 – Test circuit parameters for Table 14 .................................................................... 50

Table 16 – Test sequence V: Critical load current performance of equipment with a DC

rating .................................................................................................................................... 51

---------------------- Page: 6 ----------------------
IEC 60947-6-1:2021  IEC 2021 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –
Part 6-1: Multiple function equipment –
Transfer switching equipment
FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of IEC is to promote

international co-operation on all questions concerning standardization in the electrical and electronic fields. To

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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of

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

International Standard IEC 60947-6-1 has been prepared by sub-committee 121A: Low-

voltage switchgear and controlgear, of IEC technical committee 121: Switchgear and

controlgear and their assemblies for low voltage.

This third edition cancels and replaces the second edition published in 2005, and its

Amendment 1:2013. This edition constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:
– clarification of scope and object;
– clarification of terms and definitions;
– removal of unnecessary definitions;
– modification of characteristics;
---------------------- Page: 7 ----------------------
– 6 – IEC 60947-6-1:2021  IEC 2021
– modification of utilization categories definitions;
– introduction of new markings requirements;
– addition of new requirements for clearances and creepage distances;

– addition of new requirements and tests for mechanical and electrical interlocks;

– clarification of transfer sequences;
– modification of requirements for rated short-time withstand currents;
– modification of new requirements for electromagnetic compatibility;

– clarification of performance requirements for CB type TSE, in alignment with requirements

stated in IEC 60947-2;

– addition of new test sequence V: Critical load current performance of equipment with DC

ratings.
The text of this document is based on the following documents:
FDIS Report on voting
121A/403/FDIS 121A/411/RVD

Full information on the voting for the approval of this document can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

A list of all the parts in the IEC 60947 series, published under the general title Low-voltage

switchgear and controlgear, can be found on the IEC website.

This document shall be read in conjunction with IEC 60947-1:2020, Low voltage switchgear

and controlgear – Part 1: General rules.

The provisions of the general rules are applicable to IEC 60947-1 where specifically called

for. General rules clauses and subclauses thus applicable as well as tables, figures and

appendices are identified by reference to IEC 60947-1:2020, for example, 1.2.3, Table 4, or

Annex A of IEC 60947-1:2020.The committee has decided that the contents of this publication

will remain unchanged until the stability date indicated on the IEC website under

"http://webstore.iec.ch" in the data related to the specific publication. At this date, the

publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The "colour inside" logo on the cover page of this document indicates

considered to be useful for the correct
that it contains colours which are

understanding of its contents. Users should therefore print this document using a

colour printer.
---------------------- Page: 8 ----------------------
IEC 60947-6-1:2021  IEC 2021 – 7 –
INTRODUCTION

The availability of power in low voltage electrical installations is playing an ever increasing

role in modern society. In actual fact, this requirement is a fundamental characteristic for the

creation of economically and functionally efficient installations. A system able to switch a load

from one source to another safely and with minimum disturbance to the load reduces

problems caused by faulty conditions in the normal supply to the minimum.

All these operations, commonly known as “transfer switching”, control the installations and

can be done automatically, remotely or manually.
Therefore, an installation with installed “transfer switching” capability:
– ensures the continuity of production processes;
– provides a backup source of power if the main network is out of service;
– reduces the effect caused by network faults on parts of the installation;

– achieves a good compromise between reliability, simplicity and cost-effectiveness;

– provides the facility manager and managing system with a power source able to supply all

or part of the installation.
Key factors motivating customers to use Transfer Switch Equipment (TSE) include:

– the continuous world growth population, the increasing number of electronic devices and

the new demands of electric vehicles;

– the mediated pressure on climate change with a resulting increase in the cost of energy;

– the evolution of the electricity market with a greater number of alternate energy sources;

– the user’s expectations of better grid reliability, better economic performance, and a desire

to manage their energy.

Stakeholders involved in the management of electricity also have new expectations:

– customers want to reduce the cost of their energy and to have a quality energy supply;

– suppliers want to reinforce confidence to their customers;
– producers expect to optimize their investments;

– governments and regulators are willing to create a competitive and sustainable energy

market.

Today, the performance of Transfer Switching Equipment is defined by TSE manufacturers

and also by this document. Consultants, integrators, facility managers and end users rely on

this document for their power availability needs.

Transfer switching are often realised by implementing a transfer function within the electrical

installation, but this critical function can be inappropriately designed. Using a TSE following

the requirements of this document ensures the safety and the performance of the transfer

function which are necessary for reaching the objectives listed above.
---------------------- Page: 9 ----------------------
– 8 – IEC 60947-6-1:2021  IEC 2021
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –
Part 6-1: Multiple function equipment –
Transfer switching equipment
1 Scope

This document applies to transfer switching equipment (TSE), to be used in power systems

for ensuring the continuity of the supply and allowing the energy management of the

installation, by transferring a load between power supply sources, the rated voltage of which

does not exceed 1 000 V AC or 1 500 V DC.
It covers:
– manually operated transfer switching equipment (MTSE);
– remotely operated transfer switching equipment (RTSE);
– automatic transfer switching equipment (ATSE), including the controller.
It does not cover:

1) TSE configurations that are either not manufacturer tested and/or not marked according

to this document as a complete transfer switch;
2) auxiliary contacts (for guidance, see IEC 60947-5-1);

3) transfer switches used in explosive atmospheres (for guidance, see IEC 60079 (all

parts));
4) embedded software design (for guidance, see IEC TR 63201);
5) cybersecurity aspects (for guidance, see IEC TS 63208);

6) TSE rated for direct-on-line starting asynchronous motor of design NE and HE, according

to IEC 60034-12:2016 (for guidance, see AC-3e utilisation category according IEC 60947-

4-1:2018);

7) other types of TSE under consideration including closed transition TSE, overlapping

neutral TSE, multi-source TSE (i.e. TSE with more than two sources of supply), stand-

alone ATS controllers, bypass isolation TSE, TSE with load-shedding functions and bus-

tie TSE.

NOTE TSE used for safety services and for emergency escape lighting systems as described in IEC 60364-5-56

are subject to specific rules and/or legal requirements.
The object of this document is to state:
1) the characteristics of the equipment;
2) the conditions of the equipment with respect to:
a) operation for which the equipment is intended;

b) operation and behaviour in case of specified abnormal conditions, for example, short-

circuit;
c) dielectric properties;

3) the tests intended to confirm that these conditions have been met and the methods for

performing these tests;
4) the product information to be provided by the manufacturer.
---------------------- Page: 10 ----------------------
IEC 60947-6-1:2021  IEC 2021 – 9 –
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 lates
...

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