Cooker Cable Size

[diyomy]

Relocating where the electric cooker will be located for a new fitted kitchen. Not decided which oven to fit yet or exactly where in the kitchen it will be located, cable length is likely to be between 3m and 12m from the CU laid behind a few inches of insulation (basement kitchen at the back of the property, very cold so bringing the walls of the room in a few inches so it's better insulated).

Plan is to fit the cable and when the ovens fitted have an electrician connect it to the CU.

If I've understood the 'average' oven I'd fit 6mm cable, but some double ovens would need a 10mm cable if the cables at the 10+m range in insulation.

If I use 10mm cable and go with a single oven are there any possible issues with that? Basically is it OK to use 10mm cable when you only need 6mm?

David

 

[ban-all-sheds]

You can always use a larger cable than needed, just like you can always use V rated tyres on a car that can only do 100mph, or you can always put an LCD TV on a stand designed to support 60kg CRTs.

 

[PrenticeBoyofDerry]

If I use 10mm cable and go with a single oven are there any possible issues with that? Basically is it OK to use 10mm cable when you only need 6mm?

David

Should not be a problem, most cooker control units will be able to handle tho cable core size at the terminals.
and the oversized cable rating should not be an issue.

 

[skenk]

Normally 10mm is total overkill for a single oven, are you having an electric hob too? as these use much more. However seeing as the cable will be run in insulation then a good idea to up the size. The electrician who signs off will be able to calculate the current carrying capacity dependent on length and thickness of insulation etc. First thing you should find out is how much power (Kw) you are needing at the cooker point and you can work back from there to select protective device and cable, taking diversity into account of course.

You will need to agree what works you will be doing under the supervision of the electrician before you start work as finding an electrician who is willing to turn up and sign off you DIY efforts after the fact may prove difficult (not to mention it's probably illegal).

 

[mbga9pgf]

Normally 10mm is total overkill for a single oven, are you having an electric hob too? as these use much more. However seeing as the cable will be run in insulation then a good idea to up the size. The electrician who signs off will be able to calculate the current carrying capacity dependent on length and thickness of insulation etc. First thing you should find out is how much power (Kw) you are needing at the cooker point and you can work back from there to select protective device and cable, taking diversity into account of course.

You will need to agree what works you will be doing under the supervision of the electrician before you start work as finding an electrician who is willing to turn up and sign off you DIY efforts after the fact may prove difficult (not to mention it's probably illegal).

If you install 10mm, you are looking after anyone who wants to put a double oven in at a later stage, for example, if they were to install a new kitchen with fittings and made space for a double oven and halogen hob.

 

[skenk]

Well it depends on installation method but I think 10mm just for a cooker is overkill for anything but the biggest kitchen or heaviest insulation. 6mm will allow you cooking gear potentially up to 100A after diversity. . . . (40A MCB)

32A MCB will alllow 83A if full diversity is applied

Do you really need 10mm for a cooker circuit?

 

[ban-all-sheds]

It depends on how much you agree with diversity, how mandatory you consider it to be, and how much of a duty you see it to design the cheapest possible installation.

 

[skenk]

And how much of a duty you have to protect your customers' interests, it's a balancing act and if money was no object then of course you would put in 10mm every time. However the real world is a different place and IMO a 6mm cable not installed under insulation is not going to be overloaded by anything but the biggest kitchen on xmas day.

 

[ban-all-sheds]

Ah - but do those interests lie in having the cheapest possible design, or in having a circuit which can cope with induction hobs, multiple ovens being started at once, and a trend to home cooking which is much more ambitious than was the norm when everyone had single oven, 4-ring 60cm wide cookers?

If you're paying an electrician to rewire a kitchen, by what % does the price go up if you have 10mm² rather than 6mm²?

 

[skenk]

For most customers they want the cheapest that is adequate for their needs, maybe not in some shire with 2 jags in the drive (or whatever) but for MOST people. I've yet to meet a customer that says, 'give me the best, money no object', even the ones who are clearly not short of cash, maybe it's a Scottish thing!?

10mm costs more and is unnecessary in the vast majority of kitchens, what more would a customer need to know? I'd rather try and convince them of the need for RCBO's, cpc's in their lighting circuit and other things which are more important than a bloated cooker circuit. Most of the properties I work in have a 60A cutout, so designing-in a cooker circuit to handle induction hobs, multiple ovens being started at once etc is usually a non-starter anyway.


Still not heard of any actual true stories of 32A MCB's tripping out on xmas day

 

[mbga9pgf]

Ah - but do those interests lie in having the cheapest possible design, or in having a circuit which can cope with induction hobs, multiple ovens being started at once, and a trend to home cooking which is much more ambitious than was the norm when everyone had single oven, 4-ring 60cm wide cookers?

If you're paying an electrician to rewire a kitchen, by what % does the price go up if you have 10mm² rather than 6mm²?

Depends how much the leccy wants to thieve off the owner for "parts" markup.

 

[martinxxxxxx]

Depends how much the leccy wants to thieve off the owner for "parts" markup.

Bit uncalled for.

Most electricians won't be able to mark up more than a few percent, as everyone checks the prices on screwfix or b&q site. I add five percent, but then I have to guarantee the parts I fit. Which means if they fail I will come and fit new ones. The mark up will never cover this if I were to use substandard parts.

Also; outside of communist countries making a profit is not called thieving.

and guess what Tesco's Asda and Argos markup thier goods too, are they all theives in your book too comrade.

Martin

 

[mbga9pgf]

Depends how much the leccy wants to thieve off the owner for "parts" markup.

Bit uncalled for.

Most electricians won't be able to mark up more than a few percent, as everyone checks the prices on screwfix or b&q site. I add five percent, but then I have to guarantee the parts I fit. Which means if they fail I will come and fit new ones. The mark up will never cover this if I were to use substandard parts.

Also; outside of communist countries making a profit is not called thieving.

and guess what Tesco's Asda and Argos markup thier goods too, are they all theives in your book too comrade.

Martin

Funny, last time I got a reciept at tesco, it said "Strawberry Jam" nor "Rasberry Jam".

If I get a reciept from a tradesperson, I expect to see what they paid on the bill,not some frigged figure.

I wonder how many leccies would reccommend the bare minimum knowing that if the owner ever intends to upgrade to a larger cooker,they will have to pay for a full installation, plus the potential hassle of re-plastering chasing etc?

Personally, I would prefer to pay the relatively small amount (£1.68/metre) rather than go to the hassle of having to upgrade later on. "Fitted with" rather than "fitted For thanks".Each to their own I suppose.

 

[martinxxxxxx]

I find most customers want 10mm whether they need it or not at the moment. They figure as you do; a bit of future proofing is worth the uplift in cost. £2.60 per meter is what I charge. A bit more than your £1.68 ( where are you buying 10mm for that btw)but then I don't work in a commune, brother.

Martin

BTW what do you mean by
Funny, last time I got a reciept at tesco, it said "Strawberry Jam" nor "Rasberry Jam".

 

[mbga9pgf]

I find most customers want 10mm whether they need it or not at the moment. They figure as you do; a bit of future proofing is worth the uplift in cost. £2.60 per meter is what I charge. A bit more than your £1.68 ( where are you buying 10mm for that btw)but then I don't work in a commune, brother.

Martin

BTW what do you mean by
Funny, last time I got a reciept at tesco, it said "Strawberry Jam" nor "Rasberry Jam".

Sorry martin, I was quoting the difference between 6mm and 10mm.

http://www.tlc-direct.co.uk/Products/CA10G.html

2.60 a metre is a pretty good deal to be honest, if my leccy quoted that, I would be more than happy. Benefits of bulk I suppose.