BS 5424-2:1987

This standard BS 5424-2:1987 Low-voltage controlgear is classified in these ICS categories:

• 29.130.20 Low voltage switchgear and controlgear

This standard applies to semiconductor contactors intended for performing electrical operations by changing the state of electric circuits between on state and off state.

This standard is additional to IEC Publication 158-1: Low-voltage Controlgear, Part 1: Contactors (including Supplements A and B) which is applicable, provided it is not amended by this standard.

It applies only to semiconductor contactors, the main circuit of which is intended to be connected to circuits, the rated voltage of which does not exceed 1 000 V a.c. or 1 500 V d.c.

NOTE 1 Semiconductor contactors dealt with in this standard are not intended to provide short-circuit protection of the main circuit, but may contain short-circuit protective devices for semiconductor parts.

NOTE 2 Semiconductor motor-starters will be dealt with in a later publication.

This standard applies also to hybrid-semiconductor contactors, which are also covered by the scope of IEC Publication 158-1 as concerns their electromagnetic part.

Characteristics, conditions of operation and construction and testing requirements for semiconductor contactors for performing electrical operations by changing the state of electric circuits between on and off states.