Consumer units according to S EN IEC 61439-1 and BS EN 61439-3.

A consumer unit is defined in Part 2 of BS 7671 as: ‘A particular type of distribution board intended for operation by ordinary persons, comprising a type-tested co-ordinated assembly for the control and distribution of electrical energy, incorporating manual means of double-pole isolation on the incoming circuit(s) and an assembly of one or more protective devices, signalling and other devices proven during the type-test of the assembly as suitable for such use. This does not preclude the use of consumer units within non-domestic premises.