scope:

This part of IEC 60255 is applicable to measuring relays and protection equipment for power system protection, including the control, monitoring and process interface equipment used with those systems.
This standard specifies the essential requirements for electromagnetic compatibility for measuring relays and protection equipment intended to be used at industrial locations.
Measuring relays and protection equipment used in substations and power plants may require higher immunity test levels.
For equipment not incorporating electronic circuits, for example electromechanical relays, tests according to this standard are not required.
The requirements specified in this standard are applicable to measuring relays and protection equipment in a new condition and all tests specified are type tests only.