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

Deals with semiconductor contactors intended for performing electrical operations by changing the state of electric circuits between on state and off state, and is in addition to IEC Publication 158-1: Low-voltage Controlgear, Part 1: Contactors. Concerns only semiconductor contactors, the main circuit of which is designed to be connected to circuits, the voltage of which does not exceed 1000 V a.c. or 1500 V d.c. Hybrid semiconductor contactors are also covered. Sections are included on definitions concerning contactors, semiconductor contactors, states, control and auxiliary circuits, classification, rated values, short-circuit protective devices, nameplates, normal service conditions, mechanical design, enclosures, temperature, dielectric properties, limiting values of operation and tests.