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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> Induction hob on oven circuit? https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1435251084 Message started by Flashbang on Jun 25^th, 2015, 5:51pm

Title: Induction hob on oven circuit?
Post by Flashbang on Jun 25^th, 2015, 5:51pm

Hi all,
Mrs FB had taken a liking to a new induction hob! http://www.currys.co.uk/gbuk/built-in-appliances/built-in-cooking/hobs/electric-hobs/hotpoint-cix744ce-electric-induction-hob-black-10131816-pdt.html?gclid=CNaUlLTuq8YCFcfnwgod2zoJWQ&srcid=198&cmpid=ppc~gg~%28LTC%29+0103+Hobs~10131816+-+CIX744CE+Hotpoint~Exact&mctag=gg_goog_7904&s_kwcid=AL!3391!3!71587108284!p!!g!!hotpoint%20cix744ce&ef_id=VYhUXQAABV6OO-Wf:20150625221108:s#longDesc or http://ao.com/product/VIB744CE-Indesit-Induction-Hob-Black-33864.aspx
The problem as I see it (I may be looking at this wrong though!) is they are both rated at 7.2Kw. I know Diversity plays its part in circuit design which AFAIK is 10Amp at full then allow 30% of balance, is that correct?
We currently have a gas hob plus a built in Whirlpool electric oven. No longer sold but here...http://www.reevoo.com/p/whirlpool-akz161. Rating plate states... 4.3Kw Model AKZ161/03/IX.
The oven is protected by a 45Amp isolator 'Cooker' switch with no socket and a 32Amp RCD in the consumer unit which is located in a top cupboard and about 1.5Mtrs from the oven. The 'cooker' switch is roughly an equal distance from oven housing and hob location (about 400mm each way).
So, can I wire the hob to the oven outlet plate in 6mm T&E and run both hob and oven from the existing circuit? My assumption is may be! but then I may be wrong? Or do I have to provide a totally separate hob circuit RCD and isolating switch? The latter is not possible due to the inability to get the cable concealed behind a tiled wall.

Thanks

Title: Re: Induction hob on oven circuit?
Post by Flashbang on Jun 29^th, 2015, 1:39pm

Well, 3days and 38 views and so far not a reply!

So my thinking is - please correct me if wrong...

Domestic Cooker diversity is first 10Amp then 30% of remaining balance...

Oven 4.3Kw + Hob 7.2Kw = 11.5Kw total.
11500 watts = 47.916 Amp (11500/240 = 47.916666) so for ease round up to 47.92A Note if supply is classed as being 230v then Amp = 50.0A

1st 10A plus 30% of balance is :-
30 x 37.92/100 = 11.376A Or 30 x 40 / 100 =12.0

So 10A + 11.38 (rounded up) = 21.38A Or for 230v... 10A + 12A = 22A

So my 6.0mm2 cable and 32A RCD should be fine?

Anyone not agree or feel I should factor in something else?

Title: Re: Induction hob on oven circuit?
Post by Lectrician on Jun 29^th, 2015, 1:57pm

You're looking at 50amp total for the two.

With diversity applied, it would allow you connect it to a 30amp circuit with ease. However, the diversity guide is fairly old, and kitchen habits have changed.

Assuming the cable is 6mm, the largest breaker you can use is 32amp. If the cable was clipped direct, and not buried in a wall/above a ceiling, you could rate it at 45amp.

It is up to you to try. Most bog standard cookers are rated around the 10-11kw rating. You should be fine.