BS 142-2.3(1991) : 1991

Committees responsible
National foreword
Specification
Section one. General
1 Scope and object
2 Definitions
Section two. Requirements
3 Standard values
4 Accuracy
Section three. Test methods
5 Tests related to operating characteristics and
   accuracy
6 Tests for thermal requirements
Appendices
A Characteristic curves, cold curves
B Characteristic cures, hot curves
C Example for determining accuracy
Tables
1 Reference conditions and test tolerances of
   influencing quantities and factors
2 Previous current values when measuring the effect of
   influencing quantities
3 Standard reference conditions and test tolerances of
   correcting quantities when measuring the effect of
   influencing quantities
4 Standard values of the limits of the nominal ranges
   of influencing quantities and factors
5 Standard values of the limits of the nominal range of
   previous current values
6 Standard values of the limits of the nominal range of
   correcting quantities
Figures
1 Test circuit for determining the minimum operating
   current and the cold characteristic
2 Test circuit for determining the hot characteristics

Describes dependent specified time electrical measuring relays which protect equipment from electrical thermal damage by the measurement of current flowing in the protected equipment. Gives definitions, standard values and accuracy, tests related to operating characteristics and accuracy and thermal requirements, characteristic curves, example for determining accuracy, tables and figures.