IEC TS 62993:2017 gives guidance to technical committees which deal with equipment having a rated voltage of more than 1000 VC and up to 2000 VC, or a rated voltage of more than 1500 VDC and up to 3000 VDC. Rated voltages up to 1000 VC and 1500 VDC, as well as higher or lower internal voltages, are covered by IECA 60664-1.
This document applies to equipment for use up to 2000 m above sea level, and provides guidance for use at higher altitudes.
This document gives guidance for clearances, creepage distances and solid insulation for equipment to achieve safety. It includes methods of electric testing.