This part of IEC 61557 specifies the requirements applicable to measuring equipment for testing the phase sequence in three-phase distribution systems. Indication of the phase sequence can be mechanical, visual and/or audible.
This document does not apply to additional measurements for other quantities. It does not apply to monitoring relays.
NOTE Common three-phase distribution systems are depicted in IEC 610101: 2010, Annex I and
IEC 61010-1:2010/AMD1:2016, Annex I.
















