[Closed] Any electricians on board? I need to hard wire a cooker 6mm or 10mm cable?

You'll need to know what size has been run from the consumer unit.

When I put in new hob, I had to put a bigger cable in.

11.4kW is 49.5 Amps

You'll be needing a 10mm from the consumer unit plus new fuse/mcb and 50A cooker switch

30 amps is less than 8kw - you'll also need to calculate volt drop, if its as long cable run, you might even need 16mm

Sounds like you want to get a spark in . Too many questions in this post - scares me to give vague answers to vague questions incase you start a fire :/

you'll also need to calculate volt drop

10mm will do 50m at 5% volt drop.

Am with trail rat on this. If you have to ask then you shouldn't be attempting it. Are there rules against wiring yhem yourself if you aren't qualified?

@RD - I think there are now. Didn't used to be but its changed.

TBH with the kind of current that is involved consulting a sparky is probably very sensible....

call an electrician. It's life and death.

trail_rat - Member
Sounds like you want to get a spark in . Too many questions in this post - scares me to give vague answers to vague questions incase you start a fire :/

FFS! give him answers anything, it keeps me in gainful employment.

Haha - thanks to a bodger you were about 2 showers from coming to my gaff before i rewired.

Previous Idiot wired my 10.5kw shower in on 8mm cable( despite changing it to 12 from the fuse board to the pullcord....) and it had started to burn the live wire insulation back down the cable.

Its now on a real rcd system instead of wire fuses and 12mm cable from the box to the shower unit.

Yeah, I don't know how we've all lived this long before all the regs and HSE got involved. Every 9.5 kW shower ever fitted on 6mm cable should have burned and killed everyone within a ten block radius.

FFS! give him answers anything, it keeps me in gainful employment.

I presume you're a fireman. 😀

[Img] [/img]

What my shower looked like after tripping the fuse board. Worth the risk ?

TR that could well be due to a loose terminal which will cause overheating regardless of correct or incorrectly sized cabling.

Could also have been a small smurf starting a fire under it.

Ill stick with speccing the correct sized cable via the maths instead of guessing at what should be fitted from "experiance" or "its working isnt it shut up"

+1 for 'theotherjamie'.
chances are that your cable back to the consumer unit will be 6mm judging by your 30amp fuse. get a recommended sparky to sort you out.

@ trail rat - that cable in the pic looks like 2.5mm to me

You might be right - it was rediculously underspeced i remember that much .

Much like my entire garage being wired into a lighting circuit from the back bedroom - and being signed off by building control. Loved that part.

Buying someone elses house is awesome.

Errrr. Yea TR keep yer pants on there little fella. I wasn't saying it was right. Merely pointing out that even the correct sized cable overheat if the terminals aren't pinched up tight enough. It's as much the installation as the materials. Both have to be right..

Thanks guys, think ill get a sparky in.

6 mm

We bought one of these 2 weeks ago. The manual says use 6mm. You won't get 10mm into the connector in the back of the cooker, it's optimised for 6mm.

Bacuase of the decorative state of the house, I can still touch the cables. Not even warm with everything flat-out.

But, still get a sparky in.

It will more than likely be fine on 6mm, apply diversity then see what you get.

I wired in an AEG in last year. I cannot remember the model number of the unit but the fitting insructions specified a very unusual specification of 10mm 'flex' which I couldnt even find to buy despite hours of googling. Consequently its on 10mm twin and earth.

Astormatt - genuine question here as it didnt apply to my cooker at the time due to kitchen layout.

Diversity as i understand it is for things dual rated where you cant draw the max rated load as it would involve 2 or more systems working against each other. Hence why you cant apply it to a shower as its a single system drawing the load.

Surely i could cook on all 4 hobs and have the big oven and little oven on cooking a xmas dinner and draw 11.4kw

Unless of course they have added the grill system into that where it would be impossible to have it on when the ovens on.

trailrat is about right.
Diversity will apply to a cooker, so you will use the first 10 amps, plus 30% of the remainder to get your cable / overcurrent device size.

11.4kW is 49 amps.
So 10 A plus 30% of 39A = 10A + 13A = 23A
Your cable will need to be able to carry 23A continuous.
Current carrying capacity of 6mm T+E cable is around 47A if buried in plaster, with no insulation around it. If bunched with other cables, its capacity drops, so assume it has a little insulation, or is bunched, so it will now have a current carrying capacity of 32A.
Which is perfect for your existing installation, as your new cooker will be a direct connection to the existing installation.

There's a caveat that the Manufacturers installation instructions must be observed. They may require the use of a RCD to protect the cooker, so, in your case, having a fuse as your overcurrent device, I doubt if you have RCD protection on that circuit.

So simplistically, your existing installation will be fine, if the manufacturers instructions do not want RCD protection.

Trailrat to answer your question, it is very unlikely that all elements in an oven will be on at one time, and when they are, it is not for long, as they are all thermostatically controlled, so once up to temperature, they do not draw full power for long.
If you have an electric oven, this is easily seen/heard when the thermostat clicks to turn on/off the element.

There are occasions when all will be drawing full power, but the duration will be so short that it will not put enough load through the overcurrent device, for long enough, to trip it.

A 32A breaker will not trip at 33A. At 50A it will think about tripping after 15 minutes. You need to put 160A through it for near instant tripping, they are there for fault protection instantly, and overcurrent protection over time - the characteristics are that they trip before the cable melts.

cheers for that alan.

trail_rat - Member
Haha - thanks to a bodger you were about 2 showers from coming to my gaff before i rewired.

Previous Idiot wired my 10.5kw shower in on 8mm cable( despite changing it to 12 from the fuse board to the pullcord....) and it had started to burn the live wire insulation back down the cable.

Its now on a real rcd system instead of wire fuses and 12mm cable from the box to the shower unit.

POSTED 16 HOURS AGO #

Where do you get 8mm and 12mm twin and earth from?

10mm when I wired in our 10.8kw shower. Had to uprate the pull cord also. That cable takes some man handling too. 😯

Wasnt keen on wiring it in with old fashioned fuse wire type fuse, so bought a new consumer unit for it to go in to. (Was cheaper than a stand alone 50A unit).

In fact, must get round to wiring the rest of the house into the new consumer unit also. 😳

Thermostatic shower and a gas cooker Ftw. Best thing I ever did was ditch the electric shower. 🙂

If you can get away with using 6mm then it will be a hell of a lot easier to handle and install than 10mm cable not to mention cheaper too though the price should be the least of your concerns where electricity goes!

Try [url= http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html ]this calculator[/url] to work out what you *might* need

Sat wondering how much the sparky has charged or did he stand there making that sucking noise through his teeth whilst shaking his head then start his first sentence with "Well"