Some questions on fitting shower

[roderz]

I'm waiting on getting an electric shower fitted but got a few simple questions,

1. the shower is 9.5 kw jobbie, so I'm assuming it will need 10mm wire ? (it's about a 7mtr run form the cu)

2. the cu is a 12 way mk sentry job with 2 split buzz bars,
at the mo' the one bb has the main 100a sw and 2 mcb's for the lights,
other bb has 80A rcd fitted along with cooker and 2 socket ring mains,
now I assume the shower should be in the bb with the rcd unit via a 50a mcd,
BUT given what's already connected on that bb - my question is will it be ok there - given that the cooker and all house sockets are on the same rcd - is there any possibility it might trip?

Might seem stupid questions but I just want to make sure that the guy does it correctly - and I was wondering if shower should ideally have it's own rcd, or is that just over kill

Thanks in advance.[/u]

 

[securespark]

Might be best off getting a 50A RCBO and putting it on the incomer side.

That way, you've evened out the load and if the shower goes faulty, only the RCBO trips and if the RCD trips, the shower stays on.

 

[PrenticeBoyofDerry]

9.5kW shower will need 41.3A
So you could go with 6.00mm T&E and a 45A RCBO on the side that is not protected by the RCD.
Using an RCBO like this would prevent the rest of the circuits tripping, if the shower should trip.
I assume the route the cable is taking over it's 7 metres it will not be entering and running through thermal insulation? As this will also effect the cable size!
But if it is a new circuit that is being installed, I would go with securespark's recommendation of a 10mm T&E cable. This will then give you scoop for a higher output power of shower, should you wish to have one rated higher than 9.5kW, whether it be now or at a letter date.

 

[ban-all-sheds]

I just want to make sure that the guy does it correctly

So if he does it differently you'll stand there and argue with him because you asked on a DIY advice site?

If you don't feel you can trust your electrician you should find a different one.

 

[roderz]

I just want to make sure that the guy does it correctly

So if he does it differently you'll stand there and argue with him because you asked on a DIY advice site?

LOL, What I really mean is make sure the job is done Safely - and in accordance with the regs etc,
if it's done differently does not nessacerially mean it's wrong or unsafe,

Oh and the cable run is not buried in any walls - all run on ceilings through 3 cupboards.[/i]