40A or 50A for a shower

[navgeeza]

hi all, i need some advice about a shower i'm going to be installing, its a 10.5kw triton opal shower. I have a Mem Memera 2000 consumer unit (i dont think the model i have has RCD protection) and i've been looking for a suitable mcb, but it seems like they are only available in a 40A or 50A, which should i purchase? Would a 50A be too much?

I've also reading the manual and here i understand i would require an RCD, would i be better off buying something like this shower (consumer) unit?

thanks in advance

 

[HerefordHywel]

I have an 8.5KW shower this uses 36A and is protcted by a 40amp MCB.

You can work out the current by deviding the voltage (230V in UK) by the wattage - in your case 10,500/230 = 45.7A therefore the 50A MCB should be used.

 

[navgeeza]

thanks for the reply

 

[eddiemoe]

that`s exactly what u need and I=P/V correct too

 

[breezer]

i also trust you are using 10mm cable?

 

[DocD]

Forgive my ignorance, but I was under the impression the UK was on 240v (I am aware that the "official" voltage was change to 230v to match EU standards +/- a set percentage, same as the rest of the EU went from 220v to 230v). Wouldn't this make the rating 43.75 amps - Still a 50 amp fuse in this case - but I am sure in other boarderline situations it could be significant.

Can anyone clarify this?

 

[supersparks]

Forgive my ignorance, but I was under the impression the UK was on 240v (I am aware that the "official" voltage was change to 230v to match EU standards +/- a set percentage, same as the rest of the EU went from 220v to 230v). Wouldn't this make the rating 43.75 amps - Still a 50 amp fuse in this case - but I am sure in other boarderline situations it could be significant.

Can anyone clarify this?

In 1988 an agreement was reached that voltage levels across Europe should be unified at 230V single phase and 400V three-phase with effect from January 1st, 1995. In both cases the tolerance levels have become -6% to +10%, giving a single-phase voltage spread of 216 V to 253 V, with three-phase values between 376V and 440 V.