Shower trips MCB.. (edited, it isn`t an RCD) - update....

6mm cable 10years old!
i would be looking at replacing this as soon as you can as you are near the limit of current capacity
get a qualified sparks to renew it with 10mm twin and earth also i would replace the mcb as it will have deteriorated with the constant tripping
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Thanks guys.

Got Triton Tuesday to check the shower and get it up and running, then got an electrician coming to test everything else - he thinks more is afoot than a shower fault.

Will ask him to do the cable and MCB to be on the safe side.

Triton guy came today - said the shower seems all ok.

He looked at the MCB, some resistance to flipping the switch up again, so he says it is most likely that.

Got an electrician coming to have a look tomorrow at 7.30 am !! Initially he said he woudl have thought it was the shower, but now the MCB won`t even re-set (even with isolator and shower off) so i`m thinking it must be that.

new cable, new isolator and new MCB would be great, replace all worn parts and give you capacity for a high-power shower next time without risk of overload.
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yep, i`ve done the isolator myself, going to get the electrician to fix the mcb first, then come back to re-wire with 10mm.

Haven`t had a proper shower for 10 days, so if he can do a quick fix now, then upgrade in 2 weeks when he has more spare time that`s fine by me.
Well, what a pullava.

Electrician came at 7.30 am, bang on time. Did all the tests, told me what he was doing as he went, interesting, but soon forgotten !

Wiring is still very good, no problems there and no need to change it.

Switch i put in is fine, no issues there.

Fuse seemed ok whilst he was here, re-set and shower ran for 1o mins onhot - then tripped.

He concluded that whilst it could be the MCB it was more likely to be the shower.

Triton came out today, a different engineer.

Says the shower is abosultely fine, and is 100% it is the MCB - ran the shower on the mcb next to it, which is only 32amp, and it ran no problem. Fitted it back to the 40amp one, tripped straight away.

First electrician says he has not seen the make of fusebox - protek - and says it doesn`t look good. Not sure he can get an MCB for it.

Luckily, other mate who is an electrician knows someone who sells loads of bits for all sort of makes, he has got a new MCB coming Monday for £8. Hopefully that will do the trick.

Whilst looking at the electrics, first electrician commented that there is no RCD, and the earth wires are 4mm, regs say they ought to be 10mm. Says no immediate need to upgrade, but something to think about.

Anyway, why does an MCB "wear out" ? it has never tripped before this episode, the light one trips whenever a bulb goes but is fine. Is it just one of those things, or does it suggest there must be a cause of the tripping ?
afaict the fast trip part of a MCB works by an electromagnet pulling against a spring, if the spring or it's mouting had in some way failed that could expalin it getting very trip happy.

i'm pretty damn sure that protek are cheap sh1t
Well, finally located a new MCB as it is am older style, not used for 2 years. Electrician has changed it for us, so, fingers crossed, all will be well.

We`ve had Triton check the shower twice, and an electrician do every test he can on the wiring and he says there is nothing wrong with it at all (apart from the CU being a cheapo, and the earth wires not being 10mm...)

So, hopefully a nice warm shower tomorrow !!


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