EN IEC 63522-21 EUROPEANSTANDARD NORMEEUROPEENNE EUROPAISCHENORM October 2025 ICS 29.120.70 English Version Electrical relays - Tests and measurements - Part 21:Thermal endurance (IEC63522-21:2025) Relais electriques - Essais et mesurages - Partie 21: Elektrische Relais - Mess- und Prufverfahren - Teil 21 : Endurance thermique (IEC 63522-21:2025) Thermische Bestandigkeit (IEC 63522-21:2025) This European Standard was approved by CENELEC on 2025-09-15. 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 Turkiye and the United Kingdom. CENELEC EuropeanCommitteeforElectrotechnical Standardization Comite Européen de Normalisation Electrotechnique Europaisches Komitee fir 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 63522-21:2025 E ENIEC 63522-21:2025 (E) Europeanforeword The text of document 94/1064/FDIS, future edition 1 of IEC 63522-21, prepared by TC 94 "Electrical relays" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN IEC 63522-21:2025. The following dates are fixed: latest datebywhichthedocument has to be implemented at national (dop) 2026-10-31 level by publication of an identical national standard or by endorsement latest date by which the national standards conflicting with the (dow) 2028-10-31 document have to be withdrawn Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights.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:-1. 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 Thetextof the International Standard IEC63522-21:2025wasapprovedbyCENELECasa European Standard without any modification. In the official version, for Bibliography, the following notes have to be added for the standard indicated: IEC 60038 NOTE ApprovedasEN60038 IEC 60085 NOTE Approvedas EN60085 IEC60947-2:2016 NOTE Approved as EN 60947-2:2017 (not modified) IEC 60947-5-1 NOTE Approved as EN IEC 60947-5-1 IEC 61210 NOTE ApprovedasEN61210 1 Under preparation. Stage at the time of publication: prEN IEC 63522-0:2024 2 ENIEC63522-21:2025 (E) Annex ZA (normative) Normative referencestointernational 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/