IEC 63522-38:2025

IEC 63522-38 ®
Edition 1.0 2025-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical relays – Testing and measurement –
Part 38: Mechanical interlock
Relais électriques – Essais et mesurages –
Partie 38: Verrouillage mécanique
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IEC 63522-38 ®
Edition 1.0 2025-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical relays – Testing and measurement –

Part 38: Mechanical interlock
Relais électriques – Essais et mesurages –

Partie 38: Verrouillage mécanique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.120.70  ISBN 978-2-8327-0363-2

– 2 – IEC 63522-38:2025 © IEC 2025
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Test procedure . 6
4.1 Purpose . 6
4.2 Procedure . 6
4.3 Conditions to be specified . 6
5 Evaluation . 6
5.1 General . 6
5.2 Test report . 6

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL RELAYS –
TESTS AND MEASUREMENTS –
Part 38: Mechanical interlock
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 this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). 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. 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 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 IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
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6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
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expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
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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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 63522-38 has been prepared by IEC technical committee 94: Electrical relays. It is an
International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
94/1132/FDIS 94/1146/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.

– 4 – IEC 63522-38:2025 © IEC 2025
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts of IEC 63522 series, published under the general title Electrical relays – Tests
and measurements, can be found on the IEC website.
This International Standard is to be used in conjunction with IEC 63522-0:– .
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
___________
Under preparation. Stage at the time of publication: IEC CDV 63522-0:2024.

ELECTRICAL RELAYS –
TESTS AND MEASUREMENTS –
Part 38: Mechanical interlock
1 Scope
This part of IEC 63522 is used for testing all kinds of electrical relays and for evaluating their
ability to perform under expected conditions of transportation, storage and all aspects of
operational use.
NOTE 1 Examples for electrical relays in the sense of this document include electromechanical relays, reed relays,
reed contacts, reed switches, solid state relays, time relays and technology combinations of these.
This document defines a standard test method for mechanical interlock.
This test is applicable to the elementary relays which have the mechanical interlocking
mechanism.
NOTE 2 The electrical interlocking is not applicable to this test.
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.
IEC 63522-0:–, Electrical relays – Tests and measurements – Part 0: General and guidance
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 63255-0 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
opposing contact
other normally open contact of specific normally closed contact and vice versa
3.2
mechanical interlock
interlock which mechanically prevents the operation of the device under test (DUT) if certain
conditions are not met
___________
Under preparation. Stage at the time of publication: IEC CDV 6
...