IEC Standards IEC 60071-2011 pdf free download – Insulation co-ordination – Part 1: Definitions, principles and rules IEC 60071-2011 pdf free download - Insulation co-ordination – Part 1: Definitions, principles and rules. This part of lEC 60071 applies to three-phase a.c. systems having a highest voltage forequipment above 1 kv. lt specifies the procedure... 02-16 Download Now