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Work out oven kw to determine whether i can put a hob on the same cooker circuit

I'm changing my freestanding cooker for a separate oven & hob as part of a kitchen renovation. I have one cooker circuit (32amp at fuseboard). I already have a double oven - AEG Competence D4100-1 - from an ebay lot I bought and am choosing which hob to get. I really would prefer ceramic, but am concerned that there will be too much load on the circuit, and so will go for gas if necessary (as I can't afford to get a second cooker circuit put in as I'm sure that will be expensive). How do I work out whether I can get an electric hob on the same circuit? Obviously I will get a local electrician to come and install both, but don't want to buy a hob and then find it won't work out. I have found the manual for the double oven, and it lists various kW figures - but I don't understand which figure is the worst case scenario (which is what I assume matters) as the numbers listed under wattage are not equal to the sum of the parts. I will try and copy and paste the figures in here. Many thanks for any assistance:
Voltage: 230/240 Volts AC 50 Hz
Loading info:
Second Oven: 2.0kW
Dual Grill: 2.8kW
Base Element: 1.3kW
Main Oven
Fan Element: 2.5kW
Fan Motor: 0.03kW
Dual Grill: 2.8kW
Base Element: 1.3kW
Oven light: 0.05kW
Wattage: 5.6/6.2kW

Thanks for the responses. I can't see a way to reply beneath this, so I am not sure if you will see this! Just to respond to the calculation by M Bloomfield. You mention there would be 16amp left for a hob. But would not diversity also apply to the hob too? And therefore allow for a more powerful hob - as it would be the total of the hob and oven that would then have the 10a+30% applied (no socket)?
Yes, the figures listed were for the model number I gave, copied from the manual. I wasn't sure if I was supposed to add the 5.6 and 6.2 together to get the load total, so it is good to see that it is either.
My cable is 6mm and only travels a short distance from the consumer unit.
Thanks for your time.

2 Answers from MyBuilder Electricians

Best Answer

The regs say, household cooking appliance, using diversity:
The first 10 Amps of the rated appliance, plus 30% of the remainder of the rated current plus 5 Amps if a socket-outlet is incorporated in the cooker control.
Amps is worked out by dividing the Total Wattage by volts (230)
In your case you take the Total Wattage which is 6.2kw, or 6200 watts,(this is total wattage as your oven which doubles as a grill can not be used as oven and grill at same time, hope you understand this part hence take total wattage) then divide 6200 by 230 = 26.95 Amps.
So take the first 10 Amps that leaves 16.95Amps
then 30% of that = Approx 5.085.
Then Add that to your first 10 Amps so 10 + 5.085 = 15.085 Amps
This is for your total load on the cooking circuit, if as you have stated you have a another appliance you must add the total for both appliances together to get your total Amperage. The model number you have provided above i presume is the details you have provided for wattage, therefore this leaves you approximately just over 16 Amps total for you Hob , not a lot left!! for a hob. Yes please get an electrician in to connect and also verify you have the correct size cabling and isolating switches.Personnally you need to seek advice from an electrician first!!


Answered 25th Apr 2015

so you have approx 6 amps left on the circuit. You also need to factor in the size of the supply cable. Please get your local qualified electrician to test and examine this circuit for you. Thanks


Answered 25th Apr 2015

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