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Can i run an induction hob on 6mm cable
I have an existing cooker/hob that is wired on the same fusebox using a 6mm cable, the fuse box has a 32A in it for this circuit. The wiring goes up into the ceiling from one side of the room to the other about 5m away. Walls are dot and dab.
I have a double oven rated at 4.3Kw and a Gas hob. I want to install an Induction hob that is rated at 7Kw. Can I install both on the same curcuit? I know it adds up to over 11Kw but I would never use everything on at the same time. Can 6mm handle this?
If not, what are my options, easiest way to install 10mm if needed?
(Sorry for my lack of technical detail)
Regulation 311.1 of BS7671 deals with the topic of diversity and with regard to cooking appliances the general rule that is allowed for is:
The first 10 A of the rated current plus 30 % of the remainder of the rated current in excess of 10 A plus 5 A if a socket-outlet is incorporated in the cooker control unit.
Therefore 7000 + 4300 = 11300 watts / 230v = 49amps
Taking off the first 10 amps leaves 39 amps.30% of this is approx 12 amps, and adding another 5amps for a socket if there is one fitted would mean that the average current liklely to be drawn on the circuit is around 29 amps. Therefore a 6mm cable feeding both cooking appliances would be permitted provided it is protected by a 32amp or 40amp MCB
10mm could be installed and would allow more current to be drawn, but as you say its rare to use all four rings and both ovens, grill etc all at once.
As the other reply has already highlighted if your planning on doing the alteration yourself you will need to get part P building regulation consent from your local authority first and pay their fee. Failure to pre-notify your intent to carry out DIY electrical work can result in up to a £5000 fine.
Similarly as the existing kitchen circuit will be being altered it will need to comply with BS7671:2008 and an RCD fitted if there is not one already fitted on this circuit.
Answered 19th Dec 2012
an oven up to 15kw can be run on a 6mm cable 32amp mcb. It is in the on site guide
Answered 22nd Dec 2012
Well done Roberts Electrical.
You got that spot on.
The simple answer is. YES. ---------- as on the regs
It's will be nice for Electricians ref any answers - pls stop making up as you go along. Read your Regs
Answered 5th Jan 2013
the oven hob combined would require a 50A supply run on a 10mm cable. another option would be to put your hob(7KW) on your existing supply (6mm) as that is suitable and run a new supply in 2.5mm for the oven(4.3KW) covered by a 20A breaker. you will need to take into account RCD protections required and instalation cert and registration so you will probably need an electrician unless you get your local council to check all stages of your works and pay the required fees. Its usually cheaper and easier to get a spark in to do this for you but make sure he/she is affiliated with one of the required associations as it will not be legal if he/she is not and you will not get your required compliance certificate. NOTE: The compliance certificate is not the instalation/minor works certificate issued by the electrician, this is issued by the governing body on behalf of your local borough council.
Hope this helps-Kevin
Answered 19th Dec 2012