correct size cable for range cooker

[2scoops]

i've just in the middle of having a extension built and want to put in a double oven and six burner hob [all electric]I'm assuming the new cooker will be over 12kw and should therefore use a 10mm supply cable the problem i've got is the distance from the consumer unit to the oven will be around 20m - will a 10mm cable be ok or should i use a 16mm cable as suggested in a diy book I've got.only that i cant find this recommended anywhere else

 

[plugwash]

there are 3 issues when sizeing cable

1: disconnect time
2: volt drop
3: cable rating

i very much doubt your cooker will be over 12KW as 50A is only 11.5KW and 50A is the larest breaker normally used domestically

10mm is within spec for 50A 20m but if in doubt fit 16mm better to oversize than undersize

 

[securespark]

Are the double oven and hob separate appliances?

If so, wire them as such, taking the max load of each to calculate cable size and breaker size.

 

[2scoops]

hob and double oven will be a single unit.i was concerned with the length of the cable run and was not sure whether to fit a 10mm cable or a 16mm cable.i'm not sure of the spec it will be around 20 meters

 

[securespark]

12K's is 52.17A @ 230V.

With no correction factors, 10mm2 will carry this current with a vd of 4.59v. max allowed is 4% of 240 or 9.6v. So this is OK, but if you have correction factors involved, insulation, ambient temp etc, then go for 16.

I'd double check the total possible load at any one time - the total of all ovens etc may indeed be 12kW, but is it possible to switch it on all together?

Use a 50A breaker and you should be fine.

 

[dingbat]

As many cookers come with terminals that can be difficult to terminate 6 sq mm into , has anybody considered the potential problems of trying to terminate 16 sq mm? And has anybody managed to successfully get 16 sq mm into and out of a cooker control unit without injury?

If it were me I'd check the actual rating of the cooker first, before you install cable that will cost a bomb, along with suitably rated accessories and may ultimately be impossible to connect up!

 

[securespark]

I'd double check the total possible load at any one time - the total of all ovens etc may indeed be 12kW, but is it possible to switch it on all together?

I did say double-check first.....

 

[2scoops]

went to currys to check ratings there half could be run on a plug and the other half a 6mm cable was reccomended(checked manuals)so i should be fine with a 10mm cable
just a thought. there must be some big cookers out there to draw more than 12kw r these standard cookers you can get from places like curry/comet

 

[securespark]

Just out of interest - what were the ratings?