This Part 215 of IEC 62271 is applicable to phase comparators designed to be plugged into the testing points of a voltage detecting and indicating system (VDIS) according to IEC 62271-213, to give an indication of the result of a phase comparison. The main usage is to provide a clear evidence of the correct phase relationship between two energized parts of a high-voltage network, at the same nominal voltage and frequency before coupling them. This standard or parts of the standard can also be applied to phase comparison function of other devices connected to the VDIS upon agreement of manufacturer and user. This standard does not cover phase comparators to be used directly on bare parts of live electrical installation or at a distance, which are covered by IEC 61481-1:2014 and IEC 61481-2:2014. The products designed and manufactured according to this standard contribute to the safety of the users, provided they are used by skilled or instructed persons, in accordance with safe working procedures and the instructions for use.