Electric Oven and Induction Hob cable requirements

[eyeofthebeholder]

Hi Guys,

We have a 10mm cable going to our oven at the moment. On installing a new kitchen later this year, we might want to install an induction hob as well on the same cable.

Looking at the requirement I think it falls very close to the limits of the cable, and just wondered what you guys thought. An induction hob we are looking at has a maximum draw of 7.2kW and the oven 3.5kW, which comes out at 47A. We also wanted a 13A plug, but I don't think that is going to happen, if we go for the hob.

Looking at these regs as previously posted by someone on this forum (http://www2.theiet.org/Publish/WireRegs/2001_Amd_1.pdf) is it at the top end. The cable itself is capped and plastered over for about 2.5m (including up to the switch and the rest of the 5m goes through the joists (total ~7.5m).

Is 10mm cable OK??

Could I also use a 13A plug, or is this out of the question?

Thanks for your help

Adam.

 

[sparkyspike]

Do you have the option to use a separate circuit for the oven? You could use a 16A radial circuit for the oven and leave the hob on its own switch (with socket outlet) on the cooker circuit.

 

[eyeofthebeholder]

Afraid not, we have just had our ceilings skimmed downstairs under the kitchen

Yes, I know we should have thought about it before hand..

 

[rebuke]

That's 10.7kW at full usage though, if you apply diversity (which for a cooking appliance you can generally say first 10A plus 30% of remainder, plus 5A if a socket-outlet is incorporated), it's less.

In your case, oven at 3.5kW is 15.2A, so first 10A plus 30% of remainder is 11.56A. Hob at 7.2kW is 31.3A, so first 10A plus 30% of remainder is 16.39A

Add on 5A for the socket outlet that you want, and that gives you 27.95A, i.e. a lot less than your 47A. I would probably recommend putting it on a 40/45A breaker, which should be fine depending on the installation method of the cable (e.g. if its under more than 100mm of insulation you'll have a problem), and I don't think you'll have a problem...

 

[eyeofthebeholder]

Hi,

Thanks for the information - puts my mind at rest for when the wife insists on the induction hob!

Thanks

Adam.

 

[ColJack]

can you use diversity on induction hobs?

i didn't think you could because of the way they work..

although, what are the odds you'll use all 4 / 5 "rings" at the same time?