2.5mm cable for induction hob

[fulham]

Hi have a problem, lookin for answer, have run a 2.5mm 2core + earth cable from consumer unit (cable not connected yet) to point /area for worktop hob pref induction not yet purchased.
Cable route above ceilings have just been plastered + painted !

Have been looking at hobs ideal 1 is 32amp + 15 amp / 10.8 kw ! ? looking at 2nd choice now 8kw.

Can I use a 20 amp rcd with the cable to protect cable as will never use all hobs on full. Presume if to much power will trip on such an occasion..

Cheers . . . .. . .

 

[electronicsuk]

Basically, no. You don't design a circuit that wont take the diversified load current of the appliance, and with an induction hob, 20A isn't likely to even come close.

 

[sparkwright]

Is there an alternative route to get a larger cable in?
eg
Behind kitchen units, under floorboards, through another room, etc, etc...

Is there an existing cooker cable in the kitchen that can be 'adapted'?

 

[Lectrician]

How did you originally arrive at 20amp/2.5mm for the initial install

Did you pop into a Wilts wholesaler today

 

[ban-all-sheds]

Cable route above ceilings have just been plastered + painted !

Well - you'll probably be quicker at it 2nd time around.

Or you could always buy a gas hob.


I'm curious - are there any other areas of human endeavour where you know full well that you know nothing about them but still decide it'll be perfectly OK for you to have a go at them and only try to find out about them after you've screwed up?

 

[ban-all-sheds]

How did you originally arrive at 20amp/2.5mm for the initial install

 

[loosenup]

Are you also connecting an oven to this circuit??

I would say that if you just have the induction hob on this circuit the minimum cable requirement would be 6mm.. check your manufacturers instructions .. they usually state in them the minimum requirements for installation.. no diversity on induction hobs .
Get a pro sparky in if you are unsure how to proceed . These appliances need to be installed correctly . Incorrect installation will void any guarantee from the manufacturer and possibly invalidate you insurance if something does go wrong .. insurance companies will try anything to not pay out >

 

[ColJack]

I've said it before and I'll say it again..
you can't use diversity to design a circuit in a house.. it's for the whole installation only ( in my opinion and I'm sticking to it.. )

I can get 16KW on 2.5mm T+E if it's installed so that it's max CCC is the full 27A...

27 - 10 = 17
17 / 0.3 = 56.6666(recurring)
56.666666 + 10 = 66.666666
66.666666 x 240 = 16000W ..

which is just rediculous..

 

[loosenup]

we just put in an induction hob with a double oven in the kitchen . I ran 10mm for the hob with 40amp mcb 6mm for the oven with 32amp mcb .. there was an existing 100amp 30ma rcd and a main switch at 100amp. In my opinion this is the way to go . And in my opinion a kitchen should have it's own circuit protected by an mcb at the CU.

 

[ColJack]

kitchen needs at least 3 circuits..

1 radial for the cooker ( suitably sized, recomend 10mm with 50A breaker, can downsize breaker if needed later )
1 for general sockets ( 32A 4mm² radial )
1 for appliances (32A 4mm² radial )

if you're feeling a bit flush with the cash or have lots of large appliances, seperate 16A, 2.5mm² radials for each appliance.
if you're strapped for cash, then a 32A 2.5mm ring for the appliances, and a 20A 2.5mm radial for general sockets (

 

[loosenup]

I agree coljack...but

most clients are reluctant to spend the extra dosh on electrics when they have spent megabucks on a new kitchen... the amount of clients that say to me .. well it's been ok for the last 30 years. never blown a fuse !!!.

we have to try and make the installation as safe as possible , and in an ideal world everything would be done with separate circuits .

I asked a client a coupla months ago if there had been any work done on the property recently .... oh yes she says.. our Norman was 21 when we had some sockets added and a few lights fitted in the lounge.. Norman was watching tele at the time and he was about 55 years old . lol.

phill

 

[securespark]

Actually, Norman's 22, but because he spent his life in front of the TV, he aged beyond his years.

 

[Corgigrouch]

Do induction hobs not have a nasty habit of causing RCDs to trip?

 

[aptsys]

No

 

[Risteard]

I've said it before and I'll say it again..
you can't use diversity to design a circuit in a house.. it's for the whole installation only ( in my opinion and I'm sticking to it.. )

Of course you can apply diversity when designing a circuit. You can use your own judgement in the application of diversity - you don't have to use the suggestions in the On-Site Guide if you know differently how the installation is to be used. In fact it says this in the OSG.