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Electrical

Can an existing RCD circuit be extended & is it too big for a cooker?

Anonymous user 23/02/2024 - 3.22 PM

Hi, I have a house that is a nightmare for routing cable. I have an RCD circuit that used to run to an electric shower, it has a 40 amp breaker & is installed with 10mm cable. The cable runs through the loft to a large switch on the wall outside the bathroom. We no longer use the shower so would it be possible to move the switch into the loft, then from there, run in more cable down to a new cooker in the kitchen? Second question is, the cooker is 5.1kw so I understand it is just too big for a 20 amp breaker & would normally be fitted with a 32 amp breaker using 6mm cable. Is it a problem to use the existing 40 amp breaker with the existing 10mm cable? ***EDIT Thanks Endeavour Electrics & VK Services for your answers. Due to the difficulty of routing the cable, can we keep the existing 10mm cable, change the RCD to a 32 amp one, & run the extra new cable from either a junction box or the switch in the loft? ***

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3 Answers

Endeavour electrics

Rating: 5 out of 5

Poole

Hi, yes it is possible to re-route the existing 10mm cable and would imagine you would not be effected by VOLT DROP this would need to be checked by an electrician. The existing switch would be redundant and there are various ways of connecting the new additional 10mm feed as you can maintain it even though it would not be the greatest display of accessibility. Bit of overkill on 40A breaker and would be better with 32A, around £3-5 any merchants. Bit of shuffling inside consumer unit to follow "discrimination" few test, also electrician and finish off with certificate for the introduction of new circuit. Hope this helps Good calculation it's actually 22A

Answered14 March 2019

VK SERVICES (ESSEX) LTD

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Grays

No, this is not a problem. The 40a MCB is capable of protecting the 10mm cable. If you move the switch to the loft, continue the cable run in 6mm to save costs and drop the MCB size down to 32a. So in summary, Move the existing 10mm to the loft, join a 6mm to it and extend to the cooker position (local isolation required) and drop the MCB size down to 32a. Regards

Answered15 March 2019

Anonymous user

The calculation is approximately 14 A for 5.1 kw cooker. If you are changing conductor size to 6mm in circuit put a note on the board to let anyone in future know it’s there

Answered15 March 2019