Is MCB dependent on cable thickness.?

[Shabs]

I have been further looking at my consumer unit installation (had problems previously) and noticed my "cooker" feed has 6mm T+E cable but no electric cooker. Furthermore i have no intention of ever buying an electric cooker. Instead it is being used as a feed for the boiler, washing machine, fridge, and microwave. It has now effectively become a radial socket circuit.

Because the initial wire is 6mm for about 4-5 metres which has a socket attached, then a spur to a further double socket, am i correct in thinking a 40amp MCB is too high for this purpose? Would a 32amp or 16amp be more appropriate or is this not the case due to the cable being 6mm and requiring a 40a mcb regardless of use.

Thanks in advance.

[Christian McArdle]

It should have a 32A MCB (or less, but given its use 32A is more appropriate than a lower value). Ensure it is correctly labelled at the consumer unit.

Christian.

[The Natural Philosopher]

The idea is the MCB goes before the (putatively shorted cable) catches fire.

i.e. Make sure the MCB is the Ann Robisnon of your circuit.

[Sparks]

I thought a radial had to have a 20A breaker?

Sparks...

[Stefek Zaba]

Only if it's wired in 2.5mmsq. Depending on length and where they run,

32A radials are good with 4mmsq or 6mmsq.