scope:

This part of the IEC 60255 series specifies the general requirements for a.c. and d.c. power supplies, for measuring relays and protection equipment for power system protection, including the control, monitoring and process interface equipment used with those systems.
This part is based on:
- IEC 61000-4-11 for a.c. voltage dips, short interruptions and variations;
- IEC 61000-4-17 for voltage ripple;
- IEC 61000-4-29 for d.c. voltage dips, short interruptions and variations.
The objective of the tests is to confirm that the equipment under test will operate correctly when energised and subjected to dips, interruptions and alternating components (ripple).
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.
The object of this standard is to state:
- definitions of terms used;
- test severity levels;
- test equipment;
- test set-up;
- test procedure;
- criteria for acceptance;
- test report.