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]

when did this rule change, open to corrections

 

[Dcf]

I do loads of kitchens and would do the oven in 6.0mm and the hob in 10.0 if possible
Induction Hobs take about 40a when 2zones are on boost which is entirely feasible on normal usage. normal diversity rules do not really apply with these bad boys I'm afraid
Wouldn't go back to a gas hob now tho

 

[domestic spark]

I do loads of kitchens and would do the oven in 6.0mm and the hob in 10.0 if possible
Induction Hobs take about 40a when 2zones are on boost which is entirely feasible on normal usage. normal diversity rules do not really apply with these bad boys I'm afraid
Wouldn't go back to a gas hob now tho

thats what i have said also

 

[Engineer54]

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.

NOT using the diversity factor!!! The cooker diversity factor in BS7671 has been in existence now for getting on for 40+ years ...Why, ...because it Works and works well!! It's probably the only diversity factor in the Reg's, that a professional design Engineer will always use for cooking loads up to 15KW.... So learn it, and remember it!!...lol!!!

 

[tonys]

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.

No probs mate, I'm sure your work something out from everyone's input.

 

[domestic spark]

NOT using the diversity factor!!! The cooker diversity factor in BS7671 has been in existence now for getting on for 40+ years ...Why, ...because it Works and works well!! It's probably the only diversity factor in the Reg's, that a professional design Engineer will always use for cooking loads up to 15KW.... So learn it, and remember it!!...lol!!!

where will i find it??? page num or reg num please ill look now

 

[Knownotall]

Table 1B on site guide page 97 ?

 

[Engineer54]

Sorry, ...as mentioned before, still waiting for my soon to be out of date 17th ed.... But it has been quoted already in this thread....

 

[Engineer54]

I do loads of kitchens and would do the oven in 6.0mm and the hob in 10.0 if possible
Induction Hobs take about 40a when 2zones are on boost which is entirely feasible on normal usage. normal diversity rules do not really apply with these bad boys I'm afraid
Wouldn't go back to a gas hob now tho

I also have an induction hob, and electric oven, combined total stated load 13.4KW, Wired in 6mm singles in PVC conduit with 40A MCB. Never had current draw near 40A. Those quoted ratings on hobs and ovens can be sometimes be tongue-in-cheek with some of these manufacturers. ...And yes i did clamp them to check!!!

 

[Knownotall]

According to my "limited Knowledge" Your oven and hob would draw 58 amps on max load. I assume you have never had everything on at once, which would be unusual but could be possible. should the cable and fuse/mcb be selected for full load? Sorry but I am hungry for knowledge!

 

[Doomed]

thats were diversity comes in - in theory the max draw could be approx 58A, but that will probably not ever happen as unless you are playing silly buggers not all elements will be turned on and warming to the desired setting at the same time.

 

[Engineer54]

According to my "limited Knowledge" Your oven and hob would draw 58 amps on max load. I assume you have never had everything on at once, which would be unusual but could be possible. should the cable and fuse/mcb be selected for full load? Sorry but I am hungry for knowledge!

Take a closer look at your own oven for example. You may have a main oven element, a fan element, a grill element, Depending on the type and oven you have, you will probably not be able to have the grill element on at the same time as the oven element. you will probably have a choice of fan element or normal oven element!! ....Are you getting the picture?? Stated loads, do not necessarily mean you can use them all at the same time....

 

[Knownotall]

Thanks for all the replies. I am going to get the installation books of him (if he has them) and will let you know.