Historical
IEC 61557-8 Ed. 2.0 b Cor.1:2007
"Corrigendum 1 - 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 8: Insulation monitoring devices for IT systems "
International Electrotechnical Commission [iec]