11kwh Induction cooker on 10mm2 and 40a MCB

[bassybert]

We've just moved in to a house and it's fair to say the cooker has seen better days and needs replacing. At the moment we have a separate gas hob and electric conventional oven. I would like to change this to either a duel fuel freestanding cooker or preferably an all electric dual oven and induction hob for efficiency and safety reasons.

I've just looked in our consumer unit and it looks as though our cooker circuit is using 10mm2 cable and is protected by a 40a MCB already. The cooker I have my eye on is a Belling FSE60DOi, which looking at the specs is rated at 10.97kwh.

Are we going to be able to change over to using an all electric cooker without any problems using the existing circuit? Seeing as we have just moved into the house (mid 70s build) I have no idea about the cable length and run but it's 13-14 metres from the consumer unit to the cooker as the crow flies, with both the consumer unit and cooker on the same floor.

Thanks, James

 

[ban-all-sheds]

The cooker I have my eye on is a Belling FSE60DOi, which looking at the specs is rated at 10.97kwh.

That represents a load of 21.3A - less if the rating is at 240V. Your 40A circuit will be fine.

http://www.tlc-direct.co.uk/Book/6.2.3.htm

 

[bassybert]

Thanks a lot ban-all-sheds.

The reason I asked is that I thought 10700/240 = 44.58A

How did you get to 21.3A? Is it due to 'diversity' that i've heard about?

I'm not questioning your reply at all, just wanting to understand how it all works

Thanks,

James

 

[JohnW2]

The reason I asked is that I thought 10700/240 = 44.58A ... How did you get to 21.3A? Is it due to 'diversity' that i've heard about?

[you initially said 10.97, not 10.7, and I assume you meant kW, not kWh]

Yes, BAS applied 'diversity', which takes into account that not all of the cooker will be using power all of the time. For a cooking appliance, the usual formula is "the first 10A pus 0.3 times the rest". BAS used 230V and 10.97 kW, which gives a current of 47.7A. Applying diversity, that becomes 10A plus (0.3 times 37.7A), which works out as 21.3A.

Using your 45.58A figures (using 240V and 10.7 kW), application of diversity turns that into 20.37A.

Kind Regards, John

 

[bassybert]

The reason I asked is that I thought 10700/240 = 44.58A ... How did you get to 21.3A? Is it due to 'diversity' that i've heard about?

[you initially said 10.97, not 10.7, and I assume you meant kW, not kWh]

Yes sorry John, my mistake. 10.97kW

Makes sense - I can't remember ever using everything at the same time, not even on Christmas day.

Thanks for your reply, much appreciated

 

[winston1]

I would like to change this to either a duel fuel freestanding cooker or preferably an all electric dual oven and induction hob for efficiency and safety reasons.

An induction hob is probably more efficient than a gas hob i.e. less heat losses but I don't think it is cheaper to run simply because electricity per kWh is around 3 times the cost of gas.

 

[JohnW2]

Yes sorry John, my mistake. 10.97kW ... Makes sense - I can't remember ever using everything at the same time, not even on Christmas day. ... Thanks for your reply, much appreciated

You're welcome. Even if you were 'using everything at the same time' on Christmas Day, each of those 'eveythings' (hobs, oven elements etc.) are separately thermostatically controlled, and are therefore not drawing current all of the time. The only time that could happen is if everything is switched on simultaneously from cold - pretty unlikely and, even if it did happen, the resulting high current would only be short-lived (until things started heating up) and would not do any harm.

Kind Regards, John

 

[ban-all-sheds]

How did you get to 21.3A? Is it due to 'diversity' that i've heard about?

I'm not questioning your reply at all, just wanting to understand how it all works

http://www.tlc-direct.co.uk/Book/6.2.3.htm

 

[SimonH2]

Also, don't know about the model specified, but many have a programmed setting that limits maximum power. The one a mate installed can be set to several values - the lowest allows it to run off a 13A socket.

As mentioned, it only makes any difference if you put several pans on to heat up at once. As soon as any of the "rings" starts to back down on power then that means more power available for the others.

 

[JohnW2]

As mentioned, it only makes any difference if you put several pans on to heat up at once. As soon as any of the "rings" starts to back down on power then that means more power available for the others.

True, but in the OP's case, he doesn't really even need to invoke diversity. His cooker represents a maximum load of about 45.7A (10.97kW @ 240V). A B40 MCD will allow about 45.2A to flow indefinitely, and about 58A for an hour. His 10mm² cable will, if 'clipped direct', take 64A. ... so, even without diversity his B40/10mm² circuit would be only a hair's breadth away from being fine.

Kind Regards, John