IEC 63522-5:2025

Electrical relays - Tests and measurements - Part 5: Insulation resistance

IEC 63522-5:2025 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.
This document defines a standard test method for insulation resistance.

Relais électriques - Essais et mesurages - Partie 5: Résistance d'isolement

IEC 63522-5:2025 La présente partie de l'IEC 63522 traite des essais de tous les types de relais électriques et elle évalue leur aptitude à fonctionner dans les conditions prévues de transport, de stockage et dans tous les aspects de leur utilisation opérationnelle. Le présent document a pour objet de définir une méthode d'essai normalisée pour la résistance d'isolement.

General Information

• Status: Published
• Publication Date: 20-May-2025
• ICS: 29.120.70 - Relays
• Technical Committee: TC 94 - Electrical relays
• Drafting Committee: WG 3 - TC 94/WG 3
• Current Stage: PPUB - Publication issued
• Start Date: 21-May-2025
• Completion Date: 23-May-2025

Standards Content (Sample)

IEC 63522-5 ®
Edition 1.0 2025-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical relays – Tests and measurements –
Part 5: Insulation resistance
Relais électriques – Essais et mesurages –
Partie 5: Résistance d'isolement
ICS 29.120.70  ISBN 978-2-8327-0379-3

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– 2 – IEC 63522-5:2025 © IEC 2025
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Test procedure . 6
4.1 General . 6
4.2 Procedure . 6
4.3 Conditions . 6
4.3.1 General . 6
4.3.2 Atmospheric conditions . 7
4.3.3 Test positions . 7
4.3.4 Measurement voltage . 7
4.3.5 Measurement time . 7
5 Evaluation . 7
5.1 General . 7
5.2 Test report . 8
Annex A (informative) Test equipment . 9
A.1 General . 9
A.2 Accuracy . 9
Bibliography . 10

Table 1 – Measurement voltage depending on the rated voltage of the main circuit . 7
Table 2 – Minimum values of insulation resistance . 8

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL RELAYS – TESTS AND MEASUREMENTS –

Part 5: Insulation resistance
FOREWORD
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IEC 63522-5 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
94/1139/FDIS 94/1149/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 63522-5:2025 © 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.
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.
ELECTRICAL RELAYS – TESTS AND MEASUREMENTS –

Part 5: Insulation resistance
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 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 insulation resistance.
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
IEC 63522-9:—, Electrical relays – Tests and measurements – Part 9: Climatic tests
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 63522-0 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
insulation resistance
resistance under specified conditions between two conductive elements separated by insulating
materials
3.2
preconditioning
subjection of a DUT for a specified duration to specific climatic conditions with the object of
removing or partly counteracting the effect of its previous history with respect, principally, to
the temperature and humidity to which it has been exposed
___________
Under preparation. Stage at the time of publication: IEC CDV 63522-0:2024.
Under preparation. Stage at the time of publication: IEC FDIS 63522-9:2024.

– 6 – IEC 63522-5:2025 © IEC 2025
4 Test procedure
4.1 General
Insulation resistance test is to ensure that a sufficient electrical resistance is maintained
between specified circuits of a relay.
To carry out the test, in most cases the use of high voltage is necessary. Care should be taken
to prevent electric shock.
Polarization effects of insulating materials can influence the measurement. It is therefore
necessary to maintain a sufficient time interval between consecutive experiments to ensure
accurate resistance measurement.
NOTE For insulating materials with an insulation resistance of not more than 10 Ω, a period of 1 h after voltage
application can be sufficient.
4.2 Procedure
The DUTs shall be subjected to the following preconditioning, unless other procedures and
values are specified according to the consent between manufacturer and user.
The preconditioning comprises the tests “dry heat” and “damp heat”.
The dry heat test is carried out according to IEC 63522-9:—, 4.2.2 in a heat chamber. The air
temperature is maintained at 55 °C with an accuracy of ±2 K in the area where the DUTs are
mounted. The DUTs are kept in the chamber for 48 h, applying coil voltage and contact load is
not needed.
The damp heat test is carried out according to IEC 63522-9:—, 4.2.6 in a climatic test cabinet
at a relative humidity between 91 % and 95 %. The air temperature shall be maintained at 25 °C
with an accuracy of ±2 K in the area where the DUTs are mounted. The DUTs are kept in the
chamber for 48 h without applying voltage. There shall be no condensation.
The dry heat test shall be started before the damp heat test, the interval between two tests shall
be not more than 2 h.
The insulation resistance shall then be measured with appropriate equipment (referring to
Annex A) within the atmospheric conditions defined in 4.3.1 immediately after the
preconditioning and finished without unnecessary delay. For this measurement the DUT shall
be placed on an insulating underlay. The time to complete the measurement shall be indicated
in the test report.
Preconditioning does not apply when this test is a part of test sequence or evaluation.
4.3 Conditions
4.3.1 General
The test shall be carried out under the conditions defined in 4.3.2 to 4.3.5. Deviations from
these conditions may be specified and are subject to the agreement of manufacturer and user,
details of the deviation shall be indicated in the test report.

4.3.2 Atmospheric conditions
The atmospheric conditions for test procedure and the verification of test equipment shall be as
follows:
• temperature 15 °C to 35 °C
• air pressure 86 kPa to 106 kPa
• relative humidity 25 % to 75 %
The actual atmospheric conditions during the test shall be recorded.
4.3.3 Test positions
Terminals to which the measurement voltage shall be applied, selected from the following:
• terminals of each contact circuit; break contacts shall be opened for this test,
• all terminals requiring the same test voltage connected together and any exposed
conductive part not intended to be electrically connected, the latter being simulated by a foil
wrapped around relays having an insulating enclosure,
• terminals of separate coil windings (bifilar or not),
• all coil terminals requiring the same test voltage connected together and all contact circuit
terminals connected together,
• terminals of separate contact circuits.
4.3.4 Measurement voltage
The measurement voltage shall be according to Table 1.
Table 1 – Measurement voltage depending on the rated voltage of the main circuit
Rated voltage (AC RMS or DC) Measurement voltage
V VDC
≤ 1 000 500
1 001 to 2 500 1 000
2 501 to 5 000 2 500
5 001 to 12 000 5 000
> 12 000 12 000
NOTE Voltages higher than 1 500 VDC or 1 000 VAC are for covering the contact
load voltages in IEC 61810-4:2020, 5.8.

4.3.5 Measurement time
The measurement of insulation resistance shall be made 1 min after applying the voltage, faster
measurement is permitted provided the instrument reading is steady.
NOTE Theoretically the insulation resistance is monotone increasing until the steady state is achieved, from this
perspective a shorter measurement time (for example 5 s) is appropriate for a pass or fail test in production line.
5 Evaluation
5.1 General
The insulation resistance measured shall be not less than the minimum value given in Table 2
or specified by the manufacturer or relevant product standard.

– 8 – IEC 63522-5:2025 © IEC 2025
Table 2 – Minimum values of insulation resistance
Insulation under test Insulation resistance
MΩ
Functional insulation 2
Basic insulation 2
Supplementary insulation 5
Reinforced insulation 7
SOURCE: Table 9 of IEC 61810-1:2008.

5.2 Test report
If this part of the IEC 63522 series is executed as a part of a test record of another standard,
then the results shall be reported as required in the other standard.
Otherwise, it is recommended to issue a dedicated test report according to this document.
The test report shall contain all the information necessary to reproduce the test. In particular,
the following shall be recorded:
a) Identification and description of DUT;
b) Number of DUTs;
c) Preconditioning;
d) Atmospheric conditions during the test;
e) Test positions of DUT;
f) Measurement voltage;
g) Measurement time;
h) Measuring equipment, the accuracy and calibration information;
i) Values and observations;
j) The required minimum value of insulation resistance;
k) Date of test.
Annex A
(informative)
Test equipment
A.1 General
Insulation resistance measurements shall be made on an apparatus suitable for the
characteristics of the component to be measured, such as a megohm bridge, megohm-meter,
insulation resistance test set, or other suitable apparatus.
A.2 Accuracy
The measuring device is recommended to determine the unknown resistance with an overal
...