Be Excellent To Each Other

My shower is a 10.3kW shower. When I had it installed, the sparky that did it put in a 32A MCB into my consumer unit (MK Sentry.)

I knew at the time that this wasn't enough, that it needed to be 45A, but I just use the "1" heat mode on my shower and never the "2" mode, as that trips the MCB.

I've had enough of this, I'd like a fully functioning shower.

So, I went to B&Q yesterday and bought a 45A MCB, which looks like this:


Unfortunately, I didn't realise this (as I didn't have the cover off my CU at the time) the MCB for the shower actually looks like this:


I can't find anyone selling that particular type of MCB (LN 6330, 32A, Type 2, 30mA) any more, all I can find are these 45A Type B Curve ones, whatever that means.

Can I use one of those in place of the existing one? The existing one just seems to have the live and neutral wiring going into it, I can't see any wires at the back like the white and blue ones on the photo of the existing one.

Any ideas?

Change the thread title to FAO Joans.

That looks like a combined MCB/RCD. The RCD will trip if there's an earth fault. EG if any water gets into the electrics. Handy for a shower.

Yeah going by the test button on it I'd say it is an RCD as well.

Yeah, it's an RCBO - but I can't work out whether the one that's in there at the moment is compatible with the one I've just bought - I'll take the CU offline and see if I can get the existing RCBO out after I've finished making mah cake.

If the one you've got is just an MCB without the RCD bit, don't use it. The RCD is there for a good reason. If there's room on the fuseboard, you could fit a separate RCD in series with the MCB I think.

I've bought a 50A RCBO.

Tried to take the old one out, and I'm right - there aren't any wires coming out of the back of the existing RCBO, like there are on the new one, so I guess they're not the same and probably aren't compatible.

I'll just get a sparky in I think.

I read the first post and all I could think about was how long it would take before I got mentioned.

If the breaker is undersized for your shower there's a reasonable chance that the cable is too. So, check that.

http://www.tlc-direct.co.uk/Products/CPBR401.html

Yeah, so people have been telling me. I really hope it's not undersized, if it is the sparky that I get in to sort it out is going to have to rip all the wiring out that stretches from the CU through the living room, through the kitchen and into the bathroom.

(Gaz, your new avatar is hypnotic)