scope:

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

(a) 1 kV and up to and including 52kV and with gas-filled compartments with design pressure greater than 3 bar (gauge); and

(b) 72.5 kV and above.