WG 7 - TC 36/WG 7

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.

Applies to composite hollow insulators consisting of a load bearing insulating tube made of resin impregnated fibres, a housing (outside the insulating tube) made of elastomeric material (for example silicone or ethylene-propylene) and metal fixing devices at the ends of the insulating tube. Composite hollow insulators as defined in this report are intended to be used under conditions involving internal pressure or free of pressure. They are intended for use in outdoor or indoor 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 greater than 1 500 V.

Applies to hollow insulators made of ceramic material, with their fixing devices, intended for use with a permanent gas pressure greater than 50 kPa gauge having an internal volume equal to or greater than 1 l (1 000 cm3). They are intended for use in electrical equipment operating on alternating current with a rated voltage greater than 1000 V and a frequency not greater than 100 Hz or for use in direct current equipment with a rated voltage greater than 1 500 V.