PDF Standards IEC 61557-15 Ed. 1.0 b:2014
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 15: Functional safety requirements for insulation monitoring devices in IT systems and equipment for insulation fault location in I
standard by International Electrotechnical Commission, 02/12/2014