Shower CU?

[Greenie9657]

Hi all

I was just browsing TLC and screwfix as I'm bored and as wondering is there any advantage on fitting a dedicated shower CU? When I eventually get round to it, I'm wanting a power shower for an en-suite and was gonna use 10mm2 t+e from a 50A MCB, RCD protected in the main CU. But would it be better to run a non RCD protected cable to a dedicated shower CU nearer to the en-suite? Then onwards from there?

I came across a shower CU by searching for a 100amp double pole isolator as when I have the electrics done I'm going to have to get the meter tails extended to about 5M. I knew the shower CUs existed just never thought of the advantages.

Many thanks

 

[Aragorn84]

I think they're typically installed when the rest of the installation doesnt meet the requirements of the current regulations, and folk are being somewhat cheap.

IE no RCD's or old fusebox with rewireables etc etc.

Instead of the large cost of replacing the whole board, and potential remedial work that might then bring up, you can with less hassle simply split the meter tails and add a new CU for the shower alone, leaving all the original wiring as it was.


RE your other point about long meter tails, i believe that you'd actually need a switchfuse, rather than simply an isolator, if the tails are over 3M.

 

[Geps]

I'm pretty sure they tend to be used on old (say fused) systems where you only want to upgrade a single circuit without having to put in a complete new CU.

You can do either but it's the extra cost for an enclosure, another place that requires access for inspection and test, and the extra measures when running a non RCD protected cable would make me question what you'd gain from doing so.

 

[Greenie9657]

Thanks for both the replies.

I did think it would be pointless if you already had a 50a MCB RCD protected at the CU.

Aragorn I ment the switch fuse. Been looking at a couple on TLC. One of the units I've seen is :
CG FS100 100A SP&N Fused Switch c/w 63A 80A & 100A fuses

Looks pleasing to eye as well rather that some of the bulking ones that are about.

 

[Taylortwocities]

Been looking at a couple on TLC. One of the units I've seen is :
CG FS100 100A SP&N Fused Switch c/w 63A 80A & 100A fuses

Looks pleasing to eye as well rather that some of the bulking ones that are about.

Thanks Greenie. I had not seen that one before. Looks good for a project that's coming up soon.

 

[Aragorn84]

These are even tidier and more pleasing to the eye:

http://www.amazon.co.uk/800KMF-100A-Mains-Fused-Switch/dp/B0091PZ2CG

Not ideal for SWA though.

 

[Taylortwocities]

Indeed, cr@p for SWA.

 

[Greenie9657]

These are even tidier and more pleasing to the eye:

http://www.amazon.co.uk/800KMF-100A-Mains-Fused-Switch/dp/B0091PZ2CG

Not ideal for SWA though.

Would it still be as good quality even though it's half the price? I don't mind paying the extra as it's going to be my own house. And if it doesn't look right..... Well, we all know what wife's are like!

 

[Aragorn84]

Indeed, cr@p for SWA.

If you want something similar, but would like decent branded non-crap parts, RS do 22x58 fuse holders in decent brands which you can put into your metalclad enclosure of choice.

I've just bought a pair of 14x51 holders (max 50A), which were about £8 each:

http://uk.rs-online.com/web/p/rail-mount-fuse-holders/0482897/

They do the larger 22x58 versions too for not much more.

 

[Aragorn84]

Would it still be as good quality even though it's half the price? I don't mind paying the extra as it's going to be my own house. And if it doesn't look right..... Well, we all know what wife's are like!

I'd say the MEM 800KMF is likely better quality than the cheap-tat thats supplied with the other board you linked to.

Though i notice now that the one i linked may not be a MEM part, i'm not sure if the clones are of decent quality or not.

 

[mfarrow]

I've only ever used genuine 800KMFs but they don't come with the 'entry gland' (plastic cover) for the top to attain IP4X protection, you have to buy them separately. The fakes come with 1 only.

So unless you have DI singles they're a pain without adaptable boxes, but still cheaper than the TLC offering, which is also available from other manufacturers of more reputable heritage.

 

[Greenie9657]

Hi mfarrow.

Isn't the 800KmF only single pole?

 

[Aragorn84]

http://www.neweysonline.co.uk/neweys/pdf/MEM_SP_&_N_Switchfuses_800KMF_Technical.pdf

That indicates they are double pole.

 

[ekmdgrf]

Get one that is at least IPx4.

 

[Taylortwocities]

Get one that is at least IPx4.

Err why?
I don't think its going in the shower