Historical
IEC/TR 62271-310 Ed. 1.0 b:2004
High-voltage switchgear and controlgear - Part 310: Electrical endurance testing for circuit-breakers of rated voltage 72,5 kV and above"
Applicable to class E2 circuit-breakers rated 72,5 kV and above, intended for use on overhead lines.
International Electrotechnical Commission [iec]