IEC 62155 Ed. 1.0 b:2003

Applicable to ceramic and glass hollow insulators intended for general use in electrical equipment and ceramic hollow insulators intended for use with a permanent gas pressure in switchgear and controlgear. These insulators are intended for indoor and outdoor use in electrical equipment, operating on alternating current with a rated voltage greater than 1 000 V and a frequency not greater than 100 Hz or for use in direct-current equipment with a rated voltage of greater than 1 500 V.