Oven and hob cable sizes etc

[Knownotall]

I have a friend who is having a hob and oven replaced. These are both electric. The hob believe it or not is 7.9Kw (induction type) and the double oven is 4.9Kw

Am I right in assuming it will have to be on two seperate circuits and will 6mm do it.

I have necer come across a hob with such a huge wattage

Any advice will be welcome

Thanks

 

[domestic spark]

run two seperate circuits. any thing over 2kw should be on its own dedicated circuit! and at 7.9kw i would personally wire hob in 10mm t&e!

 

[domestic spark]

oven in 6mm

 

[Spudnik]

Yup, two circuits, one for each, although you may get away with 6.

Cable calcs will tell.

This work will also need notifying so it may end up cheaper enlisting the services of a local competent registered electrician.

 

[domestic spark]

Yup, two circuits, one for each, although you may get away with 6.

Cable calcs will tell.

This work will also need notifying so it may end up cheaper enlisting the services of a local competent registered electrician.

go through calcs, with him if you have time, hell know then for future reference!

 

[Knownotall]

Thanks for the reply guys. I am currently doing the inspection and testing so dont want to get involved with it until I pass the exams. He only has a six way con unit so he will have to upgrade that aswell. All will need notifying.

 

[tonys]

Have a read of page 160 of the on-site guide, section 8.4 may offer a bit of guidance.

 

[Engineer54]

Up to 15KW, the age old diversity factor WORKS!! A 6mm cable and 32A breaker will cope with this cooking load. The cable and the breaker will virtually never see that 12.8KW loading.

Not all the elements for the oven will be connectible at any one time, like the grill and the main oven for example. Also like the oven, the hob elements will be switching on and off for the duration of the cooking time.

Both appliances can be connected via a single supply cable by using a twin CCU....

 

[Simlec]

Side note: beware that many of the new single ovens state in their manuals that they must be connected via a 16amp supply

 

[Knownotall]

I'm Confused, Not having as many years doing much on electrical installs I thought Diversity relates to the maximum demand load for the supply. The fuse and cable size should still be selected based on the full potential load of the appliance?

I think they say 10KW of the load plus 10% of the remainder and 5 amps if the switch includes a socket outlet

It has been a long day so I am probably way of the mark but no doubt someone will tell me

 

[tonys]

I'm Confused, Not having as many years doing much on electrical installs I thought Diversity relates to the maximum demand load for the supply. The fuse and cable size should still be selected based on the full potential load of the appliance?

I think they say 10KW of the load plus 10% of the remainder and 5 amps if the switch includes a socket outlet

It has been a long day so I am probably way of the mark but no doubt someone will tell me

Have you not read any of the above posts ?

 

[telectrix]

no it's 10AMPS +30% of remainder ( then 5A on top if a s/o)

 

[MFHEng]

GN1 Page 131

A circuit of rating exceeding 15 A but not exceeding 50 A may supply two or more cooking appliances where these are installed in one room. One switch may be used to control all the appliances. The control switch should be placed in a readily accessible position. Attention is drawn to the need to afford discriminative operation of protective devices as stated in Regulation 536.1.

 

[Knownotall]

The two loads combined would work out at 55amps i think Thanks for all the replies and yes Tonys I have read all the replies but perhaps I am slightly confused with some parts thats all.

 

[domestic spark]

back of bs7671 says any load over 2kw MUST be on its own circuit?