EN IEC 60947-5-8:2021

Low-voltage switchgear and controlgear - Part 5-8: Control circuit devices and switching elements - Three-position enabling switches

Publication date:   Aug 16, 2021

Scope

<!-- NEW! -->IEC 60947-5-8:2020 is available as <a href="https://webstore.iec.ch/publication/67455">IEC 60947-5-8:2020 RLV</a> which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.</br></br>IEC 60947-5-8:2020 specifies requirements for three-position enabling switches. These switches are used as components of enabling devices to provide signals that,

- when activated, allow machine operation to be initiated by a separate start control, and

- when de-activated,

-- initiate a stop function, and

-- prevent initiation of machine operation.

This second edition cancels and replaces the first edition published in 2006. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:

- due to the increasing range of useful applications of three-position enabling switches, note of scope, operational characteristics and tests are reviewed;

- figures for example of devices incorporating enabling switch are added in Annex A;

- new Annex B for procedure to determine reliability data for the switch used in functional safety applications is added.

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