NF C42-198-7*NF EN 61557-7:2007 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
2007NF C42-198-7*NF EN 61557-7:2007 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