Induction hob requirements & expected cost

[EggMella]

I've just purchased an induction hob which I want installed in my kitchen along with the existing double oven.

Double Oven is Candy FDP 231/X rated at 4 kW (Max. absorbed power)
Induction Hob is Hotpoint ET6124X rated at 6.6kW

Double Oven is currently connected to a cooker plate then on to a cooker switch with a built-in 13A socket then over a length of 5-7m to a 32A MCB...

Should I/can I be asking for the sparky to wire the induction hob into this circuit and the double oven into a new circuit using 6mm2 wire, a cooker switch with no socket and on to a 16A MCB.

Assuming that's ok the wiring will need to go under the floor is this something I can do in advance the guy?

Final questions, the manual also talks about using an onmipolar circuit breaker. I've googled this but I'm not sure what this really means, what should I be expecting when the work is carried out, how much should I expect it all to cost and what's the best way of finding a good sparky (SE London)?

 

[Taylortwocities]

You're best getting the sparky to respond to all the queries as he/she may have their own way of doing things.

Get a registered spark from www.competentperson.co.uk

From your description, a hob/oven of the combined rating you state would be OK offa 32A mcb. In the UK they are usually onmipolar.

He may need to do something else if (eg) the manufacturer requires a separate feed or separate fuse at 16amps.

 

[ericmark]

I am weary of induction hobs as it may require protection with semi-conductor fuses so give the spark all the paper work and let him decide at to best method.

 

[EggMella]

ok thanks guys.... here's the deal.

I brought a new house recently and I had a builder in to finish a significant amount of work on it whilst I was away on business (wife at home). He's basically left the place in a right mess, no longer contactable, lied about work being completed (for payment), messed up other work (measurements, quality and such) + carried out work on gas & electrics (kitchen) and then refused (failed) to issue certificates for this. I'm pretty sure the reason for the latter is that he shouldn't have been carrying out the work.

I'm trying to get the mess sorted and one of the issues was leaking gas hob (underneath babies room) which gas safety has now disconnected. I'm no longer comfortable getting people in to do work that I don't understand hence these questions & others. This forum is proving to be very helpful, regarding the general scenario I described in this post does that sound correct (right ballpark) etc.

 

[Taylortwocities]

As I said previously

Get a registered spark from www.competentperson.co.uk

All people on this site are registered members of the several "Part P" schemes. They are traceable and their work carries guarantees with come back on the scheme provider if they dont perform.

Use one in your area - its the best and only advice i can give you.

 

[JohnD]

onmipolar.

 

[Taylortwocities]

One white bear in the snow

 

[ericmark]

I have already be banned from using DIYdoctor due to giving information which should not be given to the general public. As a result I am careful as to what I say. You must remember a guy on the job may see things which have not been relayed to those on the forum so it is very easy to say some electrician is totally wrong when he is right due to missing information so you can’t take what we say on here as being 100% correct.
Now to questions. The whole idea of the ring main and 13 amp socket was to supply heating in post war houses. However since the war things have changed and now we would normally only supply items using over 5 amp from a ring main when they are portable and any fixed units would be supplied independent of the ring main. However there is no law stopping one from plugging a 3Kw oven into the ring main although not recommended.
In your case both items are over 3Kw so should not be connected to the ring main. The book, which we use as a bible BS7671:2008, although not law, can be used in a court of law. And in real terms Electricians who are members of one of the overseeing clubs have to abide by BS7671:2008 or risk being refused membership which in turn would mean they were only able to do a limited amount of electrical work in domestic dwellings.
Because of the way induction hobs boost the output when all rings are not used there is very little diversity so the supply will need to be good for 10Kw or 43 amp there are no 43 amp MCB’s so either 45 or 50 according to make of consumer unit (CU).
As a result 6mm² to 16mm² will be required according to the route and type of cable. As a result it is very likely best practice would be to use two separate circuits to supply the two items.
We also have to follow manufactures instructions and these will normally limit the maximum size of the supply and again likely to mean we need two supplies.
So yes I should think you will need two supplies.
As to an onmipolar circuit breaker that means single pole and only the line is protected which is permitted in most domestic supplies.
I hope you can see why people are a little weary of answering your questions. If you intend to DIY then you can if you first inform the local authority building control and pay their fees. But in North Wales that’s £115 for up to £2000 worth of work. So unless it is a full rewire it is often cheaper to get an electrician who is registered to do the work. What I am unsure of is extra charges. If what you do does not come up to standard and has to be redone the rules on charges are not too clear and they could charge you a second time? The problem is no electrician is likely to submit work that fails and even if they did are not likely to admit it. So we have little knowledge on how the LABC will treat those who get it wrong.

However now for some good news. There have been a few cases where builders and electricians have been taken to court by the LABC and have received huge fines and settlement charges. You may be able to get items corrected by involving the LABC.

I have seen where building have been signed off by the LABC where the work has not been checked and where the builder has completed work which should have been completed by getting an electrician to return including where he could not get the electrician to return because of non payment. In these cases it can become very complex and here Part P is really a god send as all you need to do is involve the LABC. Of course if you have also broken the law then this option is no longer open so if I was in your position I would follow rules to the letter!

Click here to down load the Part P document in layman's terms.

I do hope you get it all sorted.

 

[ban-all-sheds]

I have already be banned from using DIYdoctor due to giving information which should not be given to the general public.

No - you got banned from there because they are a bunch of lying patronising c**** who think they know best what people can be allowed to be told, who give false information to people asking for advice because they refuse to accept reality, and who get rid of anybody who won't go along with it.

If you really want to get them riled start writing to the companies who advertise on their site telling them how it does their image no good whatsoever to be associated with such a site....

 

[Stoday]

Have you been banned too BAS?

 

[Taylortwocities]

ASBOs for sparkies, what fun!

Good post, Eric

 

[EggMella]

Ericmark,

Thanks for taking the time to write this..

I'm suprised by this comment

"I have already be banned from using DIYdoctor due to giving information which should not be given to the general public"

In most cases dissemination of information isn't illegal and in this case given that anyone could pick up a book or read this stuff on the internet it's a bizzarre thing for them to say.

Regarding the situation with the builder I'm in the process of taking him to the small claims court.... I haven't yet spoken to trading standards, CORGI or the LABC but will do so this week, particularly after the gas hob incident. Bottom line though, I don't hold out much hope of getting my money back and I doubt CORGI or LABC are going to have much impact on his life. If he was worried about these bodies I can't see him putting himself in this situation.

Regarding my situation am I think I'm going to have to ask the sparky to redo the kitchen ring main as well because the builder moved parts of this. The kitchen is 3m x 2m area with 3 double sockets, 5 fixed appliances and 2 cooker units.... Again I appreciate that this is a wooly area and that various different things will come into play but what sort of range should I be expecting to pay (SE London area). Is this a £200, £400, £800 job 1day, 3 day?

 

[ban-all-sheds]

Have you been banned too BAS?

What makes you think that?

Ericmark,

Thanks for taking the time to write this..

I'm suprised by this comment

"I have already be banned from using DIYdoctor due to giving information which should not be given to the general public"

In most cases dissemination of information isn't illegal and in this case given that anyone could pick up a book or read this stuff on the internet it's a bizzarre thing for them to say.

It's not that.

The people who run the DIYdoctor website have some very definite ideas about what people should be told, and what they should be allowed to do. These ideas conflict with the reality of what people are allowed to do, so to promote their desires they lie about what the law says regarding DIY electrical work, and when anybody tries to correct their lies they ban them.

They really are despicable.

 

[EggMella]

The induction hob wiring ended up costing £170.. Both the hob and the double oven are provided on separate 32A feeds from the CU on 6mm2 cable.

thanks to everyone for their advice