BS EN IEC 60947-3:2021

This part of IEC 60947 applies to switches, disconnectors, switch-disconnectors and fuse-combination units and their dedicated accessories to be used in distribution circuits and motor circuits of which the rated voltage does not exceed 1 000 V AC or 1 500 V DC. NOTE 1 Accessories are interconnecting units, extended terminals, internal coils, auxiliary contacts, motor operator, etc. offered as options with the basic unit. This document does not apply to equipment coming within the scope of IEC 60947-2, IEC 60947-4- 1 and IEC 60947-5-1. Particular requirements for switches, disconnectors, switch-disconnectors and fuse-combination units for use in photovoltaic (PV) DC applications are given in Annex D. Specific requirements for LV switchgear intended for the connections of aluminium conductors are given in Annex E. Guidance on measurement of power loss is provided in Annex F. This document does not include the additional requirements necessary for electrical apparatus for explosive gas atmospheres. NOTE 2 Depending on its design, a switch (or disconnector) can be referred to as \'a rotary switch (disconnector)\', \'cam-operated switch (disconnector)\', \'knife-switch (disconnector)\', etc. NOTE 3 In this document, the word \'switch\' also applies to the apparatus referred to in French as \'commutateurs\', intended to modify the connections between several circuits and inter alia to substitute a part of a circuit for another. NOTE 4 In general, throughout this document, switches, disconnectors, switch-disconnectors and fuse-combination units will be referred to as \'equipment\'. The object of this document is to state: the characteristics of the equipment; the conditions that apply to the equipment with reference to: operation and behaviour in normal service; operation and behaviour in case of specified abnormal conditions, e.g. short-circuit; dielectric properties; the tests for confirming that these conditions have been met and the methods that are adopted for these tests; the information relevant to the marking of the equipment or made available by the manufacturer, e.g. in the catalogue. Specific items requiring agreement between the user and the manufacturer are identified in Annex B. Specific items requiring agreement between the user and the manufacturer are identified in Annex B.