2.1 Ty pe of equ ipment
This standard applies to welded composlte enclosures of cast and wrought aluminium and aluminium alloy enclosures pressurized with dry air, inert gases, for example sulphur hexafluoride or nltro-gen or a mixture of such gases, used in indoor or outdoor installations of hlgh-voltage switchgear and controlgear with rated voltages of 72,5 kV and above, where the gas is used principally for its dielectrlc and/or ar c-quenching properties.
The enclosures comprlse parts of electrical equipment not neces-sarily limited to the following examples:
Ci rcult-breakers Switch-disconnectors D1 s connectors Earthing switches Current trtnsformers voltage transformers Surge arrestors Busbars and connections
The scope covers also pressurized components such as the centre-chamber of live tank switchgear and controlgear, gas-insu lated current transformers, etc.