IEC 61557-7:2019
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 - Part 7: Phase sequence
Sécurité électrique dans les réseaux de distribution basse tension au plus égale à 1 000 V c.a. et 1 500 V c.c. - Dispositifs de contrôle, de mesure ou de surveillance de mesures de protection - Partie 7: Ordre de phases
| Standard number: | IEC 61557-7:2019 | 
| Released: | 2019-07-26 | 
| Edition: | 3 | 
| ICS: | 17.220.20 | 
| Pages (English/French - Bilingual): | 28 | 
| ISBN (English/French - Bilingual): | 9782832271612 | 
IEC 61557-7:2019
IEC 61557-7:2019 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. IEC 61557-7:2019 cancels and replaces the second edition published in 2007. This edition constitutes a technical revision. This edition includes the following changes with respect to the previous edition:
 a) alignment of the structure with that of the whole IEC 61557 series;
 b) updated requirements in 4.3 in accordance with new editions of IEC 61010-1 and IEC 61010-031;
 c) the information on markings was extended;
 d) the information on the operating instructions was extended;
 e) complement to the information on the testing of leads;
 f) test leads for insulated conductors were introduced;
 g) Annex B was added with information on phase sequence tests and indications.
