BS 142-4.2(1984) : 1984

Foreword
Committees responsible
Specification
Subsection one. General
1 Scope
2 Definitions
Subsection two. Performance
3 Characteristic values
4 Limits of the operative range of the auxiliary
    energizing quantities
5 Operation and accuracy
6 Thermal requirements
7 Rated burden
8 Mechanical classification
9 Construction
10 Contact performance
11 Marking and data
Subsection three. Tests
12 General
13 Tests related to accuracy and operating
    characteristics
14 Insulation tests
15 Thermal tests
16 Mechanical tests
17 High-frequency disturbance test
Appendix
A Recommended methods of presenting relay
    characteristics and performance
Tables
1 Reference conditions and test tolerances of
    influencing quantities and factors
2 Limits of the nominal ranges of influencing
    quantities and factors
Figures
1 Operating characteristic of a power relay
2 Operating characteristic of a power relay at a given
    angle
3 Operating characteristic of a directional (angle
    measuring) relay
4 Operating characteristic of a directional relay with
    varying values of the reference input energizing
    quantity
5 Operating time for a dependent time power relay
6 Operating time for an independent time power relay
7 Operating time for a specified time power relay
8 Operating time for a specified time directional
    relay
9 Resetting time for a specified time directional
    relay
10 Example of test circuit for checking operating
    characteristics and associated accuracies

Describes the performance requirements of directional and power relays with two input energizing quantities whose values are declared by the manufacturer. Excludes impedance relays and deals specifically with relays measuring phase angle and measuring power. Applies only to relays in a new condition.