IEC 63522-13:2024

IEC 63522-13 ®
Edition 1.0 2024-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical relays – Tests and measurements –
Part 13: Corrosive atmospheres due to sulfur impact

Relais électriques – Essais et mesurages –
Partie 13: Atmosphères corrosives – Atmosphères polluées
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IEC 63522-13 ®
Edition 1.0 2024-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical relays – Tests and measurements –

Part 13: Corrosive atmospheres due to sulfur impact

Relais électriques – Essais et mesurages –

Partie 13: Atmosphères corrosives – Atmosphères polluées

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.120.70  ISBN 978-2-8322-4244-5

– 2 – IEC 63522-13:2024 © IEC 2024
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Test procedure . 6
4.1 Purpose . 6
4.2 Procedure . 6
4.3 Conditions . 7
5 Evaluation . 7
5.1 General . 7
5.2 Test report . 8
Bibliography . 9

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL RELAYS –
TESTS AND MEASUREMENTS –
Part 13: Corrosive atmospheres due to sulfur impact

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
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Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
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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 63522-13 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:
FDIS Report on voting
94/1051/FDIS 94/1080/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 63522-13:2024 © IEC 2024
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 the 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 13: Corrosive atmospheres due to sulfur impact

1 Scope
This document is used for testing electromechanical elementary relays (electromechanical
relays, reed relays, reed contacts, reed switches and technology combinations of these) 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 to simulate impacts of sulfuric atmospheres to
relays. The test conditions simulate an artificial situation and allow a performance comparison
for usability of the devices under test (DUT) with regard to known and existing switching
solutions.
The test is a static test without actual operation of the DUT to simulate a worst-case scenario
for corrosion, since corrosion increases over time. The corrosion layer can potentially create
contact sticking, increase resistance or other undesired effects in the relay. Those aspects can
be affected by DUT actuations during the test, which can destroy the corrosion layers or hide
relevant long-term effects.
In addition to polluted atmospheres, the suitability of the DUT for use and/or storage in corrosive
atmospheres can be assessed in a salt-laden atmosphere as described in IEC 63522-44.
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 60068-2-42:2003, Environmental testing – Part 2-42: Tests – Test Kc: Sulfur dioxide test
for contacts and connections
IEC 60068-2-43:2003, Environmental testing – Part 2-43: Tests – Test Kd: Hydrogen sulphide
test for contacts and connections
IEC 63522-0:—, Electrical relays – Tests and measurements – Part 0: Testing – General and
guidance
IEC 63522-1, Electrical relays – Tests and measurements – Part 1: Visual inspection and check
of dimensions
IEC 63522-6, Electrical relays – Tests and measurements – Part 6: Contact-circuit resistance
(or voltage drop)
___________
First edition under preparation. Stage at the time of publication: IEC CDV 63522-0:2024.
First edition under preparation. Stage at the time of publication: IEC CDV 63522-1:2023.

– 6 – IEC 63522-13:2024 © IEC 2024
IEC 63522-7, Electrical relays – Tests and measurements – Part 7: Functional tests
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 63522-0 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
4 Test procedure
4.1 Purpose
The purpose of the test procedure is to assess the resistance of a DUT to atmospheres polluted
with sulfur dioxide or hydrogen sulfide. The primary purpose is to evaluate the effects of a
polluted atmosphere within a short time after the test to gain repeatable data, because storage
conditions after the test may alter the test results.
4.2 Procedure
The tests stated in this document shall be carried out with appropriate test conditions and
severities, as well as suitable measurements conditions.
The DUT shall be in a new and clean condition, mounted as in service or mounted as specified
by the manufacturer. The test shall be performed under applicable reference conditions given
in IEC 63522-0:— , 4.4.
The test shall be carried out in accordance with the sulfur dioxide test according to test Kc of
IEC 60068-2-42 and/or with the hydrogen sulfide test according to test Kd of IEC 60068-2-43.
A different pollution severity or pollution content of the atmosphere in parts per million (ppm)
may be defined.
There shall be no preconditioning, unless otherwise specified by the manufacturer.
The initial value of the contact circuit resistance of all DUT contacts shall be measured.
Then the DUT is placed in the test chamber without any electrical contact load and energization
supply and is kept in the polluted atmosphere for a period as specified in 4.3 f). After DUT
removal from the polluted atmosphere and a recovery period of not more than 2 h under
conditions specified by the manufacturer, preferably the applicable reference conditions as
given in IEC 63522-0:—, 4.4, the functional performance of each DUT shall be evaluated and
the contact circuit resistance of all of its contacts shall be measured.
Depending on the underlying corrosion mechanism, in some cases, the contact resistance can
increase further during storage in air after the test. Thus, the relevant contact resistance can
consistently be measured only within 2 h after removal from the polluted atmosphere. For a
detailed observation of the corrosion mechanism, a regular recording of the contact resistance
during the test is recommended (electrical connections have to be fed outside of the test
chamber). In addition, the contact resistance may be checked again also after several days
after the test.
___________
First edition under preparation. Stage at the time of publication: IEC CDV 63522-0:2024.

4.3 Conditions
The conditions to be specified are the following:
a) test with sulfur dioxide or hydrogen sulfide, or both (if both tests are carried out, then sulfur
dioxide shall be tested for first, followed by hydrogen sulfide);
b) composition and conditions of testing atmosphere, in accordance with
IEC 60068-2-42:2003, Clause 4 (25 ± 5 ppm sulfur dioxide) and IEC 60068-2-43:2003,
Clause 4 (10 ppm to 15 ppm hydrogen sulfide), respectively, if not specified otherwise by a
detailed application specification;
c) DUT contact state open or closed, or both. If both states are specified to be used for the
test, it shall be done on separate DUTs. Each set of DUT with contacts either open or closed
shall be considered as an independent test on a new set of DUTs;
d) preconditioning, only if required;
e) initial value(s) of contact circuit resistance as specified in IEC 63522-6 (irrespective of test
condition 4.3 c));
f) duration of the test (recommended values: 4, 10, 21 days);
g) functional testing parameters as specified in IEC 63522-7;
h) energization of the DUT coil shall be at rated operate value unless otherwise stated by the
manufacturer;
i) recovery conditions as specified by the manufacturer, preferably the applicable reference
conditions as given in IEC 63522-0:—, 4.4.
NOTE Tests with hydrogen sulfide are primarily intended for tests of DUTs with contacts with silver or silver alloy
surfaces, but also copper materials in general. Tests with sulfur dioxide are mainly intended for any other contact
surface alloys. Both tests can be carried out in sequence as defined, in order to have the most aggressive atmosphere
simulation. A mixed flow gas test according to IEC 60068-2-60 is not appropriate, as concentrations are too weak
and test duration would be too long for relevant results.
5 Evaluation
5.1 General
The evaluation results shall only refer to the situation after full completion of the tests Kc, Kd
or Kc followed by Kd. If both tests are run sequentially, an interim evaluation after Kc may be
carried out as per the bulleted list below.
Final evaluation shall be done and documented as follows:
• the contact resistance is measured in accordance with IEC 63522-6. The contact circuit
resistance value(s) shall not exceed twice the specified initial value(s), or shall not exceed
a value either specified by the manufacturer or agreed by the parties, representing a
permissible heat rise. For that, IEC 60068-2-42:2003, 6.3 and/or IEC 60068-2-43:2003, 6.3
shall be adhered to;
• functional test as specified in IEC 63522-7. The DUT shall respond to each functional test
step with its intended contact state for each defined voltage step;
• visual inspection as specified in IEC 63522-1 for RT II, RT II and RT III relays, only. There
shall be no evidence of corrosion, peeling and chipping, or of mechanical deterioration that
could impair operation. The visual inspection is not required for RT IV and RT V relays, as
they are sealed;
• any other measurements, if required.
...