Electric Shower

[kimrobinson]

I have installed an electric shower 9.5 kw using 10mm2 cable on a run of approx 12 metres and 40amp MCB. When I turn on the isolating switch eveything seems ok but as soon as I turn the shower on the RCD trips. I have added an additional earth cable from the shower to the consumer unit (Seaboard told me to that on a previous installation at different house) and also cross bonded to the water pipes in the bathroom.

 

[Scoby_Beasley]

9.5kw uses 39.58 amps, thats close, electricity does "surge" slightly when appliances first turned on, perhaps a 45amp mcb better?

 

[kimrobinson]

9.5kw uses 39.58 amps, thats close, electricity does "surge" slightly when appliances first turned on, perhaps a 45amp mcb better?

Made a mistake in my original note. Should have read 8.5kw. Does same apply. It's the RCD that is tripping not the MCB.

 

[Scoby_Beasley]

Have you put the mcb next to your rcd ? Highest amps should go next to the incoming power and work your way down (lights (5a) furthest away).
8.5kw takes less than 36a so is ok with your 40a

 

[breezer]

if it is the rcd that is tripping it means a fault has developed with your shower (i presume it only trips when the shower is used?)

 

[kimrobinson]

Have you put the mcb next to your rcd ? Highest amps should go next to the incoming power and work your way down (lights (5a) furthest away).
8.5kw takes less than 36a so is ok with your 40a

Thanks for the info. Worked first time

 

[Scoby_Beasley]

Glad to have helped