1.1 Scope
This standard specifies technical requirements for factory-assembled alternating-current metal-enclosed switchgear and controlgear of rated voltage above 3.6kV and up to and including 40.5kV and of frequency 50Hz for indoor or outdoor installation. The enclosures may include fixed or removable components and may be filled with fluid (liquid or gas) to provide insulation.
Note 1: Although primarily dedicated to three-phase systems, this standard can also be applied to single-phase or two-phase systems.
This standard defines several types of metal-enclosed switchgear and controlgear which differ due to
——the consequences on network service continuity in case of maintenance on the switchgear and controlgear;
——the need and convenience of maintenance of the equipment.
Note 2: Safety of the equipment results from the design, application, adjustment and coordination of products, installations and operations.
For metal-enclosed switchgear and controlgear containing gas-filled compartments, the design pressure is limited to a maximum of 0.3MPa (relative pressure).
Note 3: Gas-filled compartments having a design pressure exceeding 0.3MPa (relative pressure) should be designed and tested in accordance with GB 7674.
Metal-enclosed switchgear and controlgear for special use, for example, in flammable atmospheres, in mines or on board ships, may be subject to additional technical requirements.
Components contained in metal-enclosed switchgear and controlgear are to be designed and tested in accordance with their various relevant standards. This standard supplements the standards for the individual components regarding their installation in switchgear and controlgear assemblies.
This standard does not preclude that other equipment may be included in the same enclosure. In such a case, any possible influence of that equipment on the switchgear and controlgear is to be taken into account.
Note 4: Switchgear and controlgear having an insulation enclosure are covered by IEC 60466.
Note 5: Metal-enclosed switchgear and controlgear for rated voltage above 40.5kV insulated by ambient air may be covered by this standard taking into account the insulation levels of DL/T 593.
