Electrical safety in low voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c. – Equipment for testing, measuring or monitoring of protective measures – Part 7: Phase sequence

Published by	Publication Date	Number of Pages
IEC	07/26/2019	28

Category: IEC

Description

IEC 61557-7 Ed. 3.0 b – Electrical safety in low voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c. – Equipment for testing, measuring or monitoring of protective measures – Part 7: Phase sequence

IEC 61557-7 specifies the requirements for measuring equipment applied to testing the phase sequence in three-phase distribution systems. Indication of the phase sequence may be mechanical, visual and/or audible. This part of IEC 61557 does not apply to ancillary measuring equipment for other quantities, for example voltage testers comprising an additional phase sequence indicator. It does not apply to monitoring relays.