MCB CU and Shower...

[crazivan]

Hi all,
I suppose it' s my fault for not looking (also I don't know that much about electrics...) anyway... I got myself a brand new electric shower, went for all the hype at 10.5 kW... Got it all installed and everything...
I realised this was not too peachy when it started tripping the MCB...
I have a 32A mcb...
In an old Proteus CU...
I've been looking for a 50A (or even 45A) MCB to replace the little one, but I can't find any. (The MCBs I've got are called Type 2 ? if that makes any sense...)
Does anyone know of a 45A or 50A mcb that will fit into a Proteus CU?
Apart from that do I have any other option to getting another CU fitted for the shower?
Thanks for any help you may be able to give me!

 

[ban-all-sheds]

..I've been looking for a 50A (or even 45A) MCB to replace the little one, but I can't find any...

That may be just as well... Do you know what cable your shower circuit is wired with?

See FWL's advice page on showers (link is in the reference topic at the top of the page)

 

[crazivan]

Yup, it's 10mm.
p.s. Thanks for the link!

 

[ban-all-sheds]

Sorry to be a pain, but that was a very quick response, and as you did say "I don't know that much about electrics", why are you so sure that it is 10mm?

 

[crazivan]

Sorry to be a pain, but that was a very quick response, and as you did say "I don't know that much about electrics", why are you so sure that it is 10mm?

OK, I'm not sure, but the insulator around the cable is about 20mm * 10 mm. I've seen the terminating cable in the CU and they're rather fatter than all the other circuits I have around the house. I just figured it's not a 6mm and went one up from that.
On top of that the run from the CU to the shower is barely 3m long... I just didn't think the wiring was anything to worry about (but you're right to check!!!)

 

[ban-all-sheds]

Sounds like 10mm....

 

[Juno 60]

I recommend you buy a dedicated shower CU and split the supply to your existing CU and the new one, using a Henley block. Screwfix do a good dedicated shower CU; this comes with a 45 or 50A MCB and RCD.

 

[Big_Spark]

I recommend you buy a dedicated shower CU and split the supply to your existing CU and the new one, using a Henley block. Screwfix do a good dedicated shower CU; this comes with a 45 or 50A MCB and RCD.

To be honest this may be the best course of action. Proteus are shiiite, they couldn't make a decent bit of kit in the MK factory!!

The other way to look at this might be to change your entire consumer unit to a better one. That way you can get the quality and meet your needs at the same time.

 

[crazivan]

I feared as much - to be honest, I think I'm going to have to change the whole unit - I've only got a 63A rated CU anyway, and since I'm going to be all electric for cooker + hob + shower I suspect I may have to upgrade...
Uhhh, unless the shower is on a separate board...
Hmmm... It's probably cheaper just getting another unit just for the shower but, if I do get one, would I need to get the supply fuse upgraded? (I'm not sure what it currently is, but I think it says 60 - 80 on the side.... I'll probably have to ask the electricity company guys...)

Thanks for all the advice btw!

p.s. don't mind my rambling...

 

[plugwash]

fitting a shower cu has another advantage that not many seem to think of

most of them allow fitting a second mcb if you put a 16A in and run a socket off it you can run your power tools with the main switch in the main cu off

 

[Big_Spark]

crazivan, if you think you also need to upgrade your head, get an engineer to do a survey from your supply company. It may be as simple as upgrading the fuse, or you may need a new head.

Either way, if everything is going to be electric I would certainly push for a larger supply. You want at least 100A, possibly a 125A would be better suited if your supplier 1) can give you it without dragging in a new cable 2) is willing to give you one of that rating.