scope:

This standard gives supplementary requirements for such enclosed distribution boards (DBU) which are stationary, type tested assemblies (TTA) for indoor use , containing protective devices and intended for use either in domestic (household) application or in other places where unskilled persons have access for their use . Control and/or signalling devices may also be included. They are for use on a.c., with a nominal voltage to earth not exceeding 300 V. The outgoing circuits contain short-circuit protective devices, each having a rated current not exceeding 125 A with a total incoming load current not exceeding 250 A. Unskilled persons normally have access to these assemblies, e.g. for switching operations and for replacing fuse-links. Requirements for assemblies for outdoor use are under consideration.