BS EN 61557-7:2022+A1:2023

Electrical safety in low voltage distribution systems up to 1 000 V AC and 1 500 V DC. Equipment for testing, measuring or monitoring of protective measures. Phase sequence | Status: Current

1 Scope 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 61010‑1:2010, Annex I and IEC 61010‑1:2010/AMD1:2016, Annex I.