Advice re oven and hob wiring

[john Stevens]

I’m hoping that somebody could give me some advice.

We recently had a new kitchen fitted, we had an excising double which is 4.1kw. This was wired into a consumer unit and a deducted cooker ring MTN132 B32 - 32amp breaker.


Our new induction hob is 7.4 kw.


The contractor has used the same feed from this supply to provide power for both my oven and induction hob. There are switches that isolates both appliances.


It is now been suggested somebody else, that this is incorrect, and that they should have ran a totally new power supply to the board. Reason being that it could trip the board if we use all our appliances, for example at Christmas or worse may be dangerous.


I have tested the system, in the best way I can by having all the appliances on and using all the hobs over a prolonged period. So far, all is good with no obvious issues.


Please can anybody advice me on weather I should start again and have a new supply to the induction fitted?


Thanks in advance.

 

[The Ghost]

You lost me at

excising double

and

a deducted cooker ring

 

[Spoon]

It is now been suggested somebody else, that this is incorrect

Out of curiosity, who is this 'somebody else'? Are they an electrician?

 

[telectrix]

assuming that the circuit cable is 6.0mm, then it will be fine. that's because you never have all elements drawing current simultaneously, due to the fact that, even if all options are turned on, the stats willl be switching on and off, so the average load is well under the max. rating of the appliance/s.

 

[john Stevens]

Vortigern - you are correct, I need to check my spelling. Induction and existing.

Spoon - it was another election who when I was speaking to him over the phone re another matter expressed concern stating that the hob alone was 32amp so how could the 32amp circuit handle the oven too which was 4.2kw.

Telectrix - thank you for your reply. Yes it is 6mm cable. I have been having a few sleepless nights thinking I’m going to have to run a new supply to my hob/and or oven.

 

[Randy Addae Jnr]

Please try t run a separate supply from the board to the cooker

 

[DPG]

Please try t run a separate supply from the board to the cooker

What are your reasons for this?

 

[Spoon]

Please try t run a separate supply from the board to the cooker

Please can you explain why

 

[telectrix]

maybe they don't have diversity in Ghana.

 

[Spoon]

maybe they don't have diversity in Ghana.

They can have ours...

 

[Midwest]

Just add, when checking the maximum load for a new induction hob for a client, the brochure mentioned 'zoning' of the heating rings. It would appear this particular hob is able to run two rings together. Why, I have no idea! The manufacture, Neff gave slightly higher ratings, than the normal diversity calculous would normally give.

 

[Randy Addae Jnr]

My reasons was that the Oven pulls a lot of current and because of that, it should have its own MCB which will control only the Oven to prevent overload.

 

[telectrix]

domestic ovens do NOT generally pull high current. in fact, most come fitted with a 13A plug top these days.

 

[john Stevens]

Thanks again for all your posts. My particular oven is 4.1kw, the induction hob (AEG) is 7.4kw, 32 amp in its own right.

At the moment, and having tested with all jobs in full power and both ovens on full heat, the board had not tripped.

My primary concern of course is safety. It’s seem that their is a split opinion on if there should be a separate cable required.

Talking to another electrician earlier he could not understand the theory diversity. He had a black and white view of if your hob is 32amp and your board breaker/fuse is 32amp how can this be right?

You have probably gathered, I have no idea about electrics so pur my faith in those who have this trade craft and expertise.

 

[telectrix]

cooker diversity works like this:
say your total rating comes to 40A.
load (A) = 10A + 1/3 of remainder
i.e 10 + 10 = 20A (+5A if cooker isolator incorporates a 13A socket).

this is due to the fact that, even if all elements are switched on, each will be cycling on/off at different times.

 

[john Stevens]

Right, thank you. So in my case both my combined appliances, oven and hob equates to 11500kw. Taking that into account and factoring in that 6mm is in use makes the 32amp rcd prictected board breaker/fuse suitable?

 

[john Stevens]

Right, thank you. So in my case both my combined appliances, oven and hob equates to 11500kw. Taking that into account and factoring in that 6mm is in use makes the 32amp rcd prictected board breaker/fuse suitable?

 

[telectrix]

i hope you meant 11500watts, not 11500kW. .
in which case, it's 10A + 13A = 23A design current. ( add 5A if a socket is on the isolator ).

 

[Spoon]

i hope you meant 11500watts, not 11500kW. .

It's a super fast cooker if it's 11500kW

 

[pirate]

...or a small nuclear reactor, with rings?