BS EN 61557-8:2007

This standard BS EN 61557-8:2007 Electrical safety in low voltage distribution systems up to 1000 V a.c. and 1500 V d.c. Equipment for testing, measuring or monitoring of protective measures is classified in these ICS categories:

• 29.080.01 Electrical insulation in general
• 29.240.01 Power transmission and distribution networks in general
• 17.220.20 Measurement of electrical and magnetic quantities

This part of IEC 61557 specifies the requirements for insulation monitoring devices (IMD) which permanently monitor the insulation resistance to earth of unearthed IT a.c. systems, for IT a.c. systems with galvanically connected d.c. circuits having nominal voltages up to 1 000 V a.c., as well as of unearthed IT d.c. systems with voltages up to 1 500 V d.c. independent from the method of measuring. This second edition cancels and replaces the first edition published in 1997. This edition constitutes a technical revision. The following changes were made with respect to the previous edition: a) definitions complemented; b) revision of some requirements; c) addition of information on operating instructions; d) sections "type tests" and "routine tests" complemented; e) modification of Table 1; f) addition of Annexes A and B. The contents of the corrigendum of May 2007 have been included in this copy.