7/.036 Cable

uksparks · Sep 28, 2015

Hi,

Just a question, I know what I would do but wondering what others do.

7/.036 is the old imperial version of 4mm supposedly, do you put it on a 20A MCB or a 32A MCB ??

We are referring to a radial, not a ring.

Personally I put it on a 20A MCB, as looking at the old regs book, not that I have one, but one I found, it can only take 27A if I am correct.

I did a consumer unit change today, had an 8.5kW shower connect on a 7/.036 with 30A Fuse, never been a problem, but I have just disconnected it and put a warning on it etc, we had the conversation of rewiring it which could be done in about 2 hours with minimal effort and the customer didn't want it.

The customer has called me and said he has reconnected it, can't help some people, I did connect it and see how much it was pulling and it was 35.9A.

Hellmooth · Sep 30, 2015

lol whoops just noticed it was me who started the MOT thing, dunno why I thought you had said that Midwest haha!

Midwest · Oct 1, 2015

Let you off

Hellmooth · Oct 1, 2015

A service is a better example anyway lol! Thanks Midwest that's a good start to the day

sparksburnout · Oct 1, 2015

You are changing the CU, not taking responsibility for the entire installation. Did the shower cable pass the IR test, you have said it has no indications of thermal damage and has been in for 10 years. The existing cable on a 32A MCB should easily hold up for the short time a shower is running, as has been demonstrated by the lack of previous problems? If you have pointed out the situation to the customer and he won't pay to have HIS cable replaced then just document it and stop worrying.

Midwest · Oct 1, 2015

sparksburnout said:
You are changing the CU, not taking responsibility for the entire installation. Did the shower cable pass the IR test, you have said it has no indications of thermal damage and has been in for 10 years. The existing cable on a 32A MCB should easily hold up for the short time a shower is running, as has been demonstrated by the lack of previous problems? If you have pointed out the situation to the customer and he won't pay to have HIS cable replaced then just document it and stop worrying.

Totally agree with your last sentence.