EN IEC 63522-28:2025

Electrical relays - Tests and measurements - Part 28: Thermoelectric electromotive force (e.m.f.)

IEC 63522-28:2025 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 thermoelectric electromotive force (e.m.f.).

Elektrische Relais - Mess- und Prüfverfahren - Teil 28: Thermoelektrische elektromotorische Kraft (EMK)

Relais électriques - Essais et mesurages - Partie 28: Force électromotrice (f.é.m.) thermoélectrique

IEC 63522-28:2025 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 définit une méthode d’essai normalisée pour la force électromotrice (f.é.m.) thermoélectrique.

Električni releji - Preskusi in meritve - 28. del Potencial za termospoje (EMF)

Ta del standarda IEC 63522 se uporablja za preskušanje vseh vrst električnih relejev in vrednotenje njihove zmožnosti delovanja v pričakovanih pogojih med transportom in skladiščenjem ter v vseh vidikih operativne uporabe.
OPOMBA 1: Primeri električnih relejev za potrebe tega dokumenta vključujejo elektromehanske releje, releje reed, kontakte reed, stikala reed, polprevodniške releje, časovne releje in njihove tehnološke kombinacije.
Ta dokument določa standardno preskusno metodo za potencial za termospoje (EMF).
OPOMBA 2: Če so na obeh koncih pritrjene različne kovine in se temperature stikov razlikujejo, bo tok v tokokrogu tekel v eno smer. Lastna napetost, ki povzroča ta tok, se imenuje potencial za termospoje.

General Information

• Status: Published
• Publication Date: 05-Jun-2025
• ICS: 29.120.70 - Relays
• Technical Committee: CLC/SR 94 - All-or-nothing electrical relays
• Drafting Committee: IEC/TC 94 - IEC_TC_94
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 06-Jun-2025
• Due Date: 01-Sep-2023
• Completion Date: 06-Jun-2025
• Ref Project: SIST EN IEC 63522-28:2025 - Electrical relays - Tests and measurement - Part 28: Thermoelectric electromotive force (e.m.f.)

Relations

• Refers: prEN IEC 63522-0:2025 - Electrical relays - Tests and measurements - Part 0: General and guidance
• Effective Date: 03-Feb-2026

Overview

EN IEC 63522-28:2025 is a European Standard developed by CLC and based on IEC 63522-28:2025. It details a standardized test method for evaluating the thermoelectric electromotive force (e.m.f.) in electrical relays. This standard applies to a wide variety of relay types, including electromechanical relays, reed relays, solid-state relays, time relays, and combinations of these technologies. The document is integral for assessing a relay’s performance and reliability under conditions expected during storage, transport, and operational use.

Adherence to this standard ensures consistency and reliability across testing laboratories, providing confidence in the quality and safety of electrical relays within the supply chain.

Key Topics

• Standard Test Method: EN IEC 63522-28:2025 defines a repeatable procedure for measuring thermoelectric e.m.f., focusing on the potential voltage generated by relay contacts due to temperature differences and the use of unlike metals.
• Scope of Application: Applies to all types of electrical relays, including:
  • Electromechanical relays
  • Reed relays
  • Reed contacts and switches
  • Solid-state relays
  • Time relays and technology combinations
• Test Procedure and Conditions:
  • Relays are subjected to temperatures near their maximum permissible limits, with terminals soldered to specific bare copper wires.
  • After thermal equilibrium is achieved, the voltage (e.m.f.) is measured to verify it does not exceed specified limits.
  • Essential test conditions to be specified include the soldering method/materials, ambient temperature, and acceptable e.m.f. limits.
• Reporting Requirements:
  • Test results, methods, ambient conditions, and measured values must be thoroughly documented.
  • If the test is part of another standard’s assessment, results must integrate accordingly; otherwise, a dedicated test report is recommended.

Applications

EN IEC 63522-28:2025 is crucial for any manufacturer, testing laboratory, or end user involved with the quality and reliability assessment of electrical relays. Typical applications include:

• Product Qualification and Compliance: Ensuring relays meet industry safety and operational requirements during certification processes.
• Quality Assurance: Supporting ongoing quality control by providing a standardized framework for measuring thermoelectric e.m.f. during manufacturing and final inspection.
• Research and Development: Serving as a reference for R&D teams in the selection of materials or design validation to minimize unwanted e.m.f. effects in high-reliability applications.
• Failure Analysis: Facilitating root cause investigations when unwanted voltages or performance degradation is suspected due to thermoelectric effects.

By specifying clear test methodologies, EN IEC 63522-28:2025 helps organizations consistently assess relay performance and maintain product safety standards, thus supporting reliable operation in a broad range of electrical and electromechanical systems.

Related Standards

Implementing EN IEC 63522-28:2025 often requires consideration of other related standards, such as:

• IEC 63522-0: Electrical relays – Tests and measurements – Part 0: General and guidance (provides foundational test definitions and methods).
• Additional IEC and EN standards relevant to relay design, performance, and safety.
• ICS 29.120.70: Classification covering relays.

For the most up-to-date and harmonized approach to relay testing and electromotive force measurement, it is advisable to consult the latest revisions of these related standards.

Keywords: EN IEC 63522-28:2025, electrical relays, thermoelectric electromotive force, e.m.f., relay testing, CLC standard, relay performance, relay measurement, product compliance, quality standards.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2025
Električni releji - Preskusi in meritve - 28. del Potencial za termospoje (EMF)
Electrical relays - Tests and measurement - Part 28: Thermoelectric electromotive force
(e.m.f.)
Elektrische Relais - Mess- und Prüfverfahren - Teil 28: Thermoelektrische
elektromotorische Kraft (EMK)
Relais électriques - Essais et mesurages - Partie 28: Force électromotrice (f.é.m.)
thermoélectrique
Ta slovenski standard je istoveten z: EN IEC 63522-28:2025
ICS:
29.120.70 Releji Relays
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 63522-28

NORME EUROPÉENNE
EUROPÄISCHE NORM June 2025
ICS 29.120.70
English Version
Electrical relays - Tests and measurement - Part 28:
Thermoelectric electromotive force (e.m.f.)
(IEC 63522-28:2025)
Relais électriques - Essais et mesurages - Partie 28: Force Elektrische Relais - Mess- und Prüfverfahren - Teil 28:
électromotrice (f.é.m.) thermoélectrique Thermoelektrische elektromotorische Kraft (EMK)
(IEC 63522-28:2025) (IEC 63522-28:2025)
This European Standard was approved by CENELEC on 2025-05-28. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 63522-28:2025 E

European foreword
The text of document 94/1127/FDIS, future edition 1 of IEC 63522-28, prepared by TC 94 "Electrical
relays" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2026-06-30
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2028-06-30
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This document is read in conjunction with EN IEC 63522-0:– .
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 63522-28:2025 was approved by CENELEC as a European
Standard without any modification.

Under preparation. Stage at the time of publication: prEN IEC 63522-0:2024.
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
2 3
IEC 63522-0 — Electrical relays - Tests and Measurements EN IEC 63522-0 —
- Part 0: General and Guidance

Under preparation. Stage at the time of publication: IEC CDV 63522-0:2024.
Under preparation. Stage at the time of publication: prEN IEC 63522-0:2024.
IEC 63522-28 ®
Edition 1.0 2025-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical relays – Tests and measurement –

Part 28: Thermoelectric electromotive force (e.m.f.)

Relais électriques – Essais et mesurages –

Partie 28: Force électromotrice (f.é.m.) thermoélectrique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.120.70  ISBN 978-2-8327-0362-5

– 2 – IEC 63522-28:2025 © 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

IEC 63522-28:2025 © IEC 2025 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL RELAYS –
TESTS AND MEASUREMENTS –
Part 28: Thermoelectric electromotive force (e.m.f.)

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 standa
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