This European Standard applies to cast aluminium alloy enclosures pressurized with dry air, inert gases, for example sulphur hexafluoride or nitrogen or a mixture of such gases, used in indoor or outdoor installations of high-voltage switchgear and controlgear above 1 kV, where the gas is used principally for its dielectric and/or arc-quenching properties with rated voltages

- above 1 kV and up to and including 52 kV and with gas-filled enclosures with design pressure higher than 300 kPa relative pressure (gauge);

- and with rated voltage above 52 kV.

The enclosures comprise parts of electrical equipment not necessarily limited to the following examples:

- Circuit-breakers

- Switch-disconnectors

- Disconnectors

- Earthing switches

- Current transformers

- Voltage transformers

- Surge arrestors

- Busbars and connections

- etc.

The scope also covers enclosures of pressurized components such as the centre chamber of live tank switchgear, gas-insulated current transformers, etc.