RDX6-40 MCB is suitable for the distribution circuit of AC 50/60Hz, rated voltage up to 400V, rated current up to 63A, rated short-circuit breaking capacity does not exceed 6000A, as the use of circuit's infrequently connecting, breaking and switching, with the functions of over-load, short-circuit protection. Meanwhile, it has strong auxiliary function modules, such as auxiliary contacts, contacts with alarming indication, shunt releasing, under-voltage releasing, and remote release control etc. modules.