cabling an electric shower

[jontyjoan]

I am putting a new 10.5 Kw electric shower in the bathroom. I know I need a 30 amp cable but do I also need a separate earth cable?

 

[PrenticeBoyofDerry]

You don't need 30amp cable, no such thing.
Cable is measured in CSA not amps. This will determine it's current carrying capacity.
10.5Kw shower needs at least 46Amps.

 

[PrenticeBoyofDerry]

Additional info:
You'll need 10mm2 T&E
The circuit will need to be protected be a protective device higer that 45.7A so 50 MCB
This in turn will need to be protected by a 30maRCD.
This will be deemed as notifiable work under part p of building regulations,
this means you will need to apply to building controls to have the work done.
So to fit this shower your aoptions are:
DIY and apply to LABC
Get a non registerd electrician they or you will then still need to apply to LABC
or contact a registered electrician that can self certificate and will notify LABC for you.
Handy Link; http://www.competentperson.co.uk/
I guess this is more complexed than you first thought.

 

[GaryMo]

Additional info:
You'll need 10mm2 T&E

Did you look into a crystal ball to see his intended cable route and installation method?

Anything less than clipped direct (method C) will require a larger cable (table 4D5 for reference).

Problems arise when cables are run underneath and through thermal insualtion in the loft area.
You really need to route cables away, especially when supplying larger loads as cable sizing can end up ridiculously oversized.

 

[PrenticeBoyofDerry]

Additional info:
You'll need 10mm2 T&E

Did you look into a crystal ball to see his intended cable route and installation method?

Anything less than clipped direct (method C) will require a larger cable.

Agree amend to you will need at least 10mm2 if done in T&E.
If cable is routed through thermal insulation, grouped, or the ambient temperature is lower or higher than 30 degrees C. or protected by a BS3036 device cable calculation need to be applied.
Also the length of the cable run could effect the voltage drop.
All these will effect the CSA of your cable.

 

[Spark123]

Also the 10.5kw is usually the 240v rating, the 230v rating is usually less so looks bad in the sales blur.
If the rating is 10.5kw @ 240v then it will pull approx 44A which means a 45A MCB will suffice, however always read the manufacturers instructions.

 

[ban-all-sheds]

I know I need a 30 amp cable

As you can see that is completely wrong.

I'm curious - why did you think that?

 

[seco services]

I know I need a 30 amp cable

As you can see that is completely wrong.

I'm curious - why did you think that?

you got it
they don't think, all they think is they know everything.

 

[Steve]

dont be so nasty to diyers. they come here for help, not to be shot down in flames.

 

[seco services]

then when the installer go's round to do the job
they want to stand in the way telling you how to do your job.

met to many of that kind.

 

[RF Lighting]

Do you have to use those stupid big emoticons?

 

[GaryMo]

then when the installer go's round to do the job
they want to stand in the way telling you how to do your job.

met to many of that kind.

It's probably best for you to leave this forum then considering it's based around DIY'ers.

 

[Steve]

Your signature is very annoying. K-A-R-L

 

[seco services]

then when the installer go's round to do the job
they want to stand in the way telling you how to do your job.

met to many of that kind.

It's probably best for you to leave this forum then considering it's based around DIY'ers.

thats why it's called DIYnot.
sorry i forgot elecys get confused after 3 wires and 3 colours.

 

[GaryMo]

thats why it's called DIYnot.

From the homepage:

"DIY can be both challenging and rewarding - this is where DIYnot.com aims to help. Our expert teams have brought together hundreds of information pages. Why not Do It Yourself?"