Hard wiring electric cooker and oven

[Pask]

I am installing a new electric induction cooker and a single oven in my kitchen. Connection present at the moment is from 40amp fuseway in consumer unit, to control unit on the wall (the one with switch and a socket) to the terminal outlet box situated below the worktop level.
My question is can I connect electric hob AND oven to this outlet box? Or do I have to create another connection starting from the consumer unit in order to keep the 2 separate?
Apparently the max power of the hob is 7.2Kw and the oven's is 2.4Kw.

Thanks

 

[riveralt]

Do a search on this forum - loads of examples with answers. There has been a lot of cooker and hob connecting in the past week - must be contagious.

 

[PrinceofDarkness]

Yes, Pask. You can connect both of those items to a common outlet (providing the terminals are up to it - and they should be).

You should consider these two items as though they were a free-standing cooker, albeit that you have two cables to connect......


Lucia.

 

[AWSpark]

the hob cannot be connected to any outlet as it is over 3KW (13 amps). you say its 7.2kw this will draw in 32 amps which would be fine on a 40amp fuse, on its own circuit. the oven on the other hand can be plugged in on a 13amp plug as it is only 11 amps. you cannot though plug the oven onto the outlet box of the hob as you will blow the fuse. they need to be on 2 different circuits.

 

[ricicle]

the hob cannot be connected to any outlet as it is over 3KW (13 amps). you say its 7.2kw this will draw in 32 amps which would be fine on a 40amp fuse, on its own circuit. the oven on the other hand can be plugged in on a 13amp plug as it is only 11 amps. you cannot though plug the oven onto the outlet box of the hob as you will blow the fuse. they need to be on 2 different circuits.

Why are you dragging up an old post ?

 

[ban-all-sheds]

And why did you say "the hob cannot be connected to any outlet as it is over 3KW (13 amps)" when it could quite easily be connected to a cooker outlet plate?

And what does "you cannot though plug the oven onto the outlet box of the hob as you will blow the fuse" mean?

What fuse?

What does the "Spark" part of your user name signify? Do you believe that you are a competent electrician, by any chance?

 

[AWSpark]

the hob can be connected direct to the cooker unit but the unit also has a switched socket on it, the oven can not be plugged into this socket as it will blow or trip the 40amp fuse/mcb as it will be overloaded.

 

[ban-all-sheds]

Does the equation

(flc-10)*0.3+10

ring a bell?

 

[Pask]

Does the equation

(flc-10)*0.3+10

ring a bell?

Hello ban-all-sheds!

I read your replies to AWspark. I don't know what the equation is, but going to my original question, are you saying that the hob and oven can be wired into the same place?

Thanks!
Pask

 

[PrinceofDarkness]

Blimey Pask! Haven't you done that little job, since posting it originally, a month before last Christmas Eve?

AWSpark: Are you for real?


Lucia.

 

[ericmark]

I was rather surprised when I replaced my stand alone cooker to see the manufacturer recommended a 32A supply.

The ovens one likely just 2.2Kw but the other has rear, bottom, and top elements so likely around the 5Kw mark. One ring takes 3.7kw and on other side 3kw for single ring of a pair so one could be drawing close on 12kw or 52A. Since I have not got a circuit diagram I don't know if there is any circuitry which turns off the oven when rings are used or turns of rings when oven calls for power.

But we are told to follow manufactures recommendations and Belling say use 32A supply.

So looking at my mothers separate hob and oven the latter uses a lot less power than my stand alone oven. When using top and rear elements it alternates between the elements rather than using both so has a lower max demand than my stand alone. The original induction hob also was just 3kw on boost against my stand alone with 3.7kw on boost. So all in all it would seem the demand is less than for my stand alone.

I have always in the past said an induction hob should have a dedicated supply mainly as supply failure will also mean the cooling fans fail and it could overheat. And the auto boil then simmer plus boost means the induction hob can draw 8.8kw (4 x 2.2kw all rings on auto boil then simmer) which without the oven is over 32A. However these auto boil then simmer setting have a limited time and 7 minutes is max time.

As electricians we have to consider if we want to take the responsibility of connecting an oven and hob to the same 32A supply. And personally even though looking at the Belling instructions it seems there would not be a problem I would not really want to take the chance.

Induction hobs are not cheap and if it failed and the manufacturer was to blame it to loss of supply and resulting overheating it's a lot of money to replace. As to danger as long as the oven has a FCU then no real problem. However I have heard of a few induction hobs especially where mounted above the oven failing due to overheating problems. So is it really worth the risk?

 

[ban-all-sheds]

I don't know what the equation is, but going to my original question, are you saying that the hob and oven can be wired into the same place?

Thanks!
Pask

The thing about cookers is that they don't run flat out at maximum power all of the time - in fact often never. Think how many times you put a large pan of cold water on each ring and turn them all on at once along with the oven.

So traditionally the assumed loading for a cooker is 10A + 30% of the remainder of the full load current.

In your case you have a 9.6kW load, i.e. 42A, so the load the circuit has to support is 32 x 0.3 + 10 = 19.6A. And you're supposed to add 5A if the cooker switch has a socket. But basically your hob+oven is viewed as a 19.6A load, not a 42A one.

How valid is this? YPYMAYTYC. I'm not a big fan, because people are more adventurous with cooking these days and use cookers more extensively than when that diversity guideline was worked out (probably not long after WW II), and induction hobs complicate things because they can have a boost function whereby if you aren't using all of the zones the others can get more power, which does affect the validity of a calculation which assumes you won't have everything going flat out very often or for long.

That said, there is a lot of headroom between 19.6A and 40A - even with an induction hob you would be on solid-as-a-rock ground to say that the design load for the circuit is no more than 40A.

So - what would happen if you turned every knob up to 11?

SFA. A 40A breaker will let 45A through indefinitely - a fact which anybody who thinks they are justified in calling themselves an electrician ought to know.

 

[jimsky007]

I would connect the hob to the cooker outlet (connection at rear) and leave it with the 40amp mcb protection then you could run another 2.5mm t&e radial circuit from your consumer unit from a 16amp mcb to a 13 amp socket in the unit adjacent to oven and fit flex and 13amp plugtop with 13amp fuse to oven
as it is rated at 2.4kw (10amps) it will require this fuse for protection of flex.

 

[riveralt]

I would connect the hob to the cooker outlet (connection at rear) and leave it with the 40amp mcb protection then you could run another 2.5mm t&e radial circuit from your consumer unit from a 16amp mcb to a 13 amp socket in the unit adjacent to oven and fit flex and 13amp plugtop with 13amp fuse to oven
as it is rated at 2.4kw (10amps) it will require this fuse for protection of flex.

Then stop hijacking an old post and start a new one.