BS 5424-2:1987

Foreword
Committees responsible
1 General
1.1 Scope
1.2 Object
2 Definitions
2.1 Definitions concerning contactors and semiconductor
     contactors
2.2 Definitions concerning states, control and
     auxiliary circuits of a semiconductor contactor
3 Classification
4 Characteristics of semiconductor contactors
4.1 Summary of characteristics
4.2 Type of semiconductor contactor
4.3 Rated values
4.4 Control circuits
4.5 Auxiliary circuits
4.6 Co-ordination with short-circuit protective devices
5 Nameplates
6 Standard conditions for operation in service
6.1 Normal service conditions
7 Standard conditions for construction
7.1 Mechanical design
7.2 Enclosures
7.3 Temperature rise
7.4 Dielectric properties
7.5 Limiting values of operation
8 Tests
8.1 Verification of the characteristics of
     semiconductor contactors
8.2 Type tests
8.3 Routine tests
8.4 Special tests
Appendices
A Information to be given by the user when conditions
     for operation in service differ from the standard
B Clearances and creepage distances for low-voltage
     contactors (under consideration)
C Protection of a contactor by a short-circuit
     protective device (under consideration)
D Conventional test circuit for the verification of
     rated making and breaking capacities of contactors
E Method of presenting a load diagram
F Test equipment and circuits for showering arc test

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.

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.