Confussed!!

[Monkeynuts2]

Hello Im looking to install my new electric cooker .

I have added up the following wattage

Hob 5.8
small oven 1.3
grill 0.6/1.7/2.7 low/med/high
main oven 2.0

The total is 11.8 at max but as you cant have the small oven on at the same time as the grill the max is hob 5.8 grill 2.7 and main oven 2.0 total 10.5

The problem is i have phoned belling the manufacture for the model and they have stated that i should hard wire to 6mm cable and use a 32amp fuse.

Reading through this forum i should be using a 45amp fuse and 10mm cable?

Although sparkymike stated somewhere that you apply a diveristy calc?

Thanks Tony

 

[Spark123]

If the manufacturer says 6mm with a 32A protective device is fine then it is fine.
Thermostats cut the elements in and out as required hence it is not on full demand all the time, if you did put it all on at once it may trip but likelyhood is you are not going to do that (unless on xmas day!)

 

[Monkeynuts2]

Thanks spark123 for your reply

Tony.

Im trying to understand why this is ok when the kilowatts are clearly high?

10.5 divided by 240 = 43.75 amps
10 amps + 30% = 23amps

But i could use like you say the oven on full power not just at christmas but at any time so will the 32amp trip keep poping?

Thanks Tony

 

[Steve]

No. The ratings you have posted above are the actual resistive ratings of the electric elements of the appliance.

When you set the oven at half-mast, the element will come on full power for a certain time. When the thermostat determines the oven has reached temperature, it will turn the element off until it drops below its set temperature again. The elements cycle on and off indefinitely, even when the temp control is on full.

With older ovens, they had a light on the front that went on and off with the element, so that you could see when it had pre-heated (element off = oven hot enough).

You can also see halogen / ceramic glass hobs doing this cycling, and they click too.

None of the heating elements of your cooking appliances have "variable power" settings. When they are on, they are on full.

This cycling though, is what allows us to put higher wattage cooking appliances on traditional 30 amp circuits. The only time it might be a problem is if you walk up to your oven and slam everything on at once from cold, because until things start cycling, it'll all be using full power for a few minutes.

 

[mikhailfaradayski]

it has a lot to do with how often and for how long the cable and protective device is subjected to a given level of current.
MCB's dont trip the instant their rating is exceeded.
There is suggestion that a 32A circuit is usually appropriate for cooking appliances upto 15kW.
Its unlikely that a 32A trip will keep popping
BTW, using your calcs, the design current would be more like 20A, not 23A

 

[electronicsuk]

None of the heating elements of your cooking appliances have "variable power" settings. When they are on, they are on full.

That's a little misleading. While each individual element doesn't have variable control, there are some appliances where there are a number of elements to heat a single section of the appliance. Therefore, the power can be varied in steps by altering the number of elements that are in use. I had a halogen hob in my kitchen where one single ring had three individual halogen heating elements to allow for different sized pans and, thus, adjustable power based on the size of the pan you wanted to heat.

 

[Monkeynuts2]

Thankyou for you the replies you have been very helpful

Tony