Cable for cooker andseparate hob?

Chris · Mar 2, 2019

Hi all,

When wiring a kitchen and the customer is buying a separate cooker and hob, which combined has too high a load for a single 6mm,
Do you wire two separate circuits with a 6mm for each or one larger cable and have both on same circuit?

dinger809 · Mar 2, 2019

Two separate circuits with local isolation

SparkyChick · Mar 2, 2019

I tend to get the specifications from the client and decide. I've done two kitchens this year and one had 3 new circuits (10mm for hob and 2 x 2.5mm, one each for fitted oven and microwave) whilst the other had one (10mm for range cooker).

And as @dinger809 says... local isolation for each.

telectrix · Mar 2, 2019

SparkyChick said:
I tend to get the specifications from the client and decide. I've done two kitchens this year and one had 3 new circuits (10mm for hob and 2 x 2.5mm, one each for fitted oven and microwave) whilst the other had one (10mm for range cooker).

And as @dinger809 says... local isolation for each.

and a fat wallet to pay for the electrickery.

Wilko · Mar 2, 2019

Hi - do you know what are the make / model of the hob and cooker?

telectrix · Mar 2, 2019

my cooker's a 1951 model, and goes by the name of 'er indoors.

Pete999 · Mar 2, 2019

telectrix said:
my cooker's a 1951 model, and goes by the name of 'er indoors.

Same age and model as mine Tel, know reason to replace or repair worked very well, they don't make em like that anymore.

GeorgeCooke · Mar 2, 2019

Chris said:
Hi all,

When wiring a kitchen and the customer is buying a separate cooker and hob, which combined has too high a load for a single 6mm,
Do you wire two separate circuits with a 6mm for each or one larger cable and have both on same circuit?

Redo you calculations and don't forget diversity. It is very likely the cooker and hob can both go on a single 4mm cable on a 32 amp MCB.

Chris · Mar 2, 2019

Wilko said:
Hi - do you know what are the make / model of the hob and cooker?

Hi,

It was more of a general question as i usually wire in two 6mm with local isolation for both but wondered if there was an easier way where I dont have to install two separate cooker isolators

GeorgeCooke · Mar 3, 2019

Yes. There is no requirement for isolators at all.

But assuming the customer requires it there is no reason why one isolator cannot switch both appliances. After all if the cooker and hob were not separate you would only use one isolator. You can get dual outlet cooker connection units too. You would also only need one cable and it would most probably be OK with a 4mm cable on a 32 amp MCB.

SparkyChick · Mar 3, 2019

@Chris , you should also take into account manufacturers instructions (nearly all the oven type appliances I've connected up have specified ratings for the OCPD they are connected to) and consider the general guidance in the regs about splitting the installation to minimise inconvenience in the event of a fault (as an example, the first kitchen I did this year suffered a failure of one appliance which resulted in the RCBO supplying it tripping - it wasn't an urgent issue as the hob and second oven had their own supply so the home owner was able to cook).

GeorgeCooke · Mar 3, 2019

Trouble is manufacturers instructions can be wrong as in this example here. This was with a B & Q oven.

[ElectriciansForums.net] Cable for cooker andseparate hob?

SparkyChick · Mar 3, 2019

GeorgeCooke said:
Trouble is manufacturers instructions can be wrong as in this example here. This was with a B & Q oven.

View attachment 48121

So in that case I would use what I like to call 'common sense' and install a 20A DP isolator near the device (so as to comply with the double pole isolation requirements) and supply it from a 16A MCB/RCBO so as to comply with the 16A fusing requirements.

In the event of something going wrong, you have then complied with the manufacturers requirements of double pole isolation and fusing. Thus your backside is covered.

telectrix · Mar 3, 2019

GeorgeCooke said:
Trouble is manufacturers instructions can be wrong as in this example here. This was with a B & Q oven.

View attachment 48121

deleted

Pete999 · Mar 4, 2019

GeorgeCooke said:
Yes. There is no requirement for isolators at all.

But assuming the customer requires it there is no reason why one isolator cannot switch both appliances. After all if the cooker and hob were not separate you would only use one isolator. You can get dual outlet cooker connection units too. You would also only need one cable and it would most probably be OK with a 4mm cable on a 32 amp MCB.

You're welcome to try and Isolate mine Mate. 4mm 2 is no good need something heavier, 70mm 4 core would just about manage it, providing you get a decent swing at it.