ISO INTERNATIONAL STANDARD 13577-4 Second edition 2022-07 Industrial furnaces and associated processing equipment Safety - Part 4: Protective systems Fours industriels et équipements associés - Sécurité - Partie 4: Systemes de protection Reference number IS0 13577-4:2022(E) ISO @IS02022 IS0 13577-4:2022(E) COPYRIGHT PROTECTED DOCUMENT IS02022 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may the internet or an intranet, withoutpriorwrittenpermission.Permission can be requested from eitherIso at the addressbelow or Iso's member body in the country of the requester. ISO copyright office CP 401 · Ch. de Blandonnet 8 CH-1214Vernier,Geneva Phone: +41 22 749 01 11 Email: [email protected] Website: www.iso.org PublishedinSwitzerland i @ IS0 2022 - All rights reserved IS0 13577-4:2022(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out through IsO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with IsO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are describedintheIsO/IECDirectives,Part1.Inparticular,thedifferentapprovalcriterianeededforthe different types of Iso documents should be noted. This document was drafted in accordance with the editorial rules of the ISo/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. IsO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the Iso list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation of the voluntary nature of standards, the meaning of IsO specific terms and expressions related to conformity assessment, as well as information about Iso's adherence to www.iso.org/iso/foreword.html. This document was prepared by Technical Committee ISo/TC 244, Industrial furnaces and associated processing equipment, in collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 186, Industrial thermoprocessing - Safety, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement). This second edition cancels and replaces the first edition (IS0 13577-4:2014), which has been technically revised. The main changes are as follows: to provided better clarity methods B and C were combined to create a new method BC, Annex E was rewritten to provide several new examples to better reflect the intent for previously misunderstood elements, Annex B was modified to include clearer language and examples of normative wiring. The original Annex F was merged, created wording to provide a better alignment with IEC 62061, IEC 61511, and IS0 13849-1. A list of all parts in the IS0 13577 series can be found on the ISO website. Anyfeedback orquestions on this documentshould be directedto theuser's national standards body.A complete listing of these bodies can be found at www.iso.org/members.html. iv @ IS0 2022 - All rights reserved IS0 13577-4:2022(E) Introduction This document was developed to specify the requirements of a protective system, which is a safety- related control system (ScS) of industrial furnaces