HD 60364-4-42:2025

Low-voltage electrical installations - Part 4-42: Protection for safety - Protection against thermal effects

Publication date:   Jul 19, 2024

Scope

IEC 60364-4-42:2024 applies to electrical installations with regard to measures for the protection of persons, livestock and property against:

• thermal effects, risk of combustion or degradation of materials, and risk of burns caused by electrical equipment,

• flames in case of a fire hazard being propagated from electrical installations to other fire compartments segregated by barriers which are in the vicinity, and

• the impairment of the safe functioning of electrical equipment, including safety services due to thermal effects.

This group safety publication (GSP) focusing on safety essential requirements is primarily intended to be used as a product safety standard for the installations mentioned in the scope, but is also intended to be used by TCs in the preparation of publications for installations similar to those mentioned in the scope of this GSP, in accordance with the principles laid down in IEC Guide 104 and lSO/lEC Guide 51.

One of the responsibilities of a TC is, wherever applicable, to make use of basic safety publications and/or group safety publications in the preparation of its publications

This fourth edition cancels and replaces the third edition published in 2010 and Amendment 1:2014. This edition constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous edition:

a) the Scope now includes a new paragraph stating that IEC 60364-4-42 has become a group safety publication (GSP) following the Advisory Committee on Safety (ACOS) recommendation for approval of the group safety function "protection against thermal effects for any kind of low-voltage electrical installations" to TC 64; this GSP is primarily intended to be used as a product safety standard for the installations mentioned in the scope, but also to be used by TCs in the preparation of publications for installations similar to those mentioned in the scope of this GSP;

b) new terms and definitions have been added;

c) a new Subclause 421.6 regarding measures for preventing fires originating from the use of an electrical stove or cooker or hob has been added;

d) the previous Subclause 421.7 was expanded and moved to a new Clause 426: Additional protective measures against thermal effect for locations where consequences of fire are severe;

e) requirements for escape routes have been expanded and modified;

f) requirements for final circuits in BE2 locations have been expanded and modified;

g) requirements for locations with irreplaceable goods or with business critical facilities have been expanded and modified;

h) a new Clause 425 for protection against fire due to fault currents has been added;

i) a new Clause 427 for protection against assembly internal arc faults has been added