NBN EN 50069 : 1994

Applies to welded composite enclosures of cast and wrought aluminium and aluminium alloy enclosures pressurized with dry air, inert gases, e.g. sulfur hexafluoride or nitrogen, and used in indoor or outdoor installations of high voltage switchgear and controlgear with rated voltages of 72,5 kV and above, where the gas is used for its dielectric and/or arc quenching properties. Enclosures comprise parts of electrical equipment such as circuit breakers, switch disconnectors, disconnectors, earthing switches, current and voltage transformers, surge arrestors and bushbar and connections. Includes pressurized components such as centre chamber of live tank switchgear and controlgear, gas insulated current transformers, etc.