4mm protected by 32a mcb

[nicsin02]

Hi guys was testing a board this morning and it had a 4mm radial circuit protected by a 32a mcb, the circuit came from the d/b and ran through metal trunking in the ceiling and then went into conduit and down inside a wall space ( not sore if insulated or not ), and then into dado trunking, regs state 4mm singles ccc is 32a in trunking ON a wall and then drops to around 26/27a (off the top of my head) when it's in conduit inside an insulated wall. Would use guys put this is a fault and recommend smaller mcb?

just another quick question there was a lug damaged on a double socket back box and the socket was obviously hanging loose, I marked this as a C2 fault but there was few other socket faces cracked but not broken and I was stalling wether it would by C2 or C3? Would u guys like all/any damaged sockets/switchgear replaced before a satisfactory report is given.

thanks guys

 

[diditrain]

ESC gives a code 1 for badly damaged accessory`s.
Were there any other circuits within the trunking/conduit, what is the circuit being used for, have you clamped it to see what it is drawing current wise, what is the ambient temperature, are you carrying out an EICR?

 

[kingeri]

Installation methods mentioned will indeed derate 4mm to below 32a. If for EICR then probably a code 3, especially if it's a general use socket circuit, and advise swap to 20/25a breaker. If it is supplying something approaching CCC of cable for long periods, then code 2. Just my view!