"Dedicated cooker circuit with a 32/40 amp MCB"?

QTPie

What does this actually mean?

We are purchasing a house (have exchanged, but don't complete until next month). There is a dual fuel range cooker in place and we want to replace with induction.

The electrical installation certificate states that there is a cooker circuit (that only serves that cooker). The Overcurrent Protective Device has a 32A rating.

Would this fulfill the requirement of "a dedicated cooker circuit with a 32/40 amp miniature circuit breaker"? Would we be wiser to upgrade the MCB to a 40 amp? Is that straightforward?

QT

lee111s

I had a similar issue. Previously had a gas oven and electric hob. Since changing to an Induction I had to convert the double socket that was protected by the 40a fuse into a single cooker style outlet using 2.5mm twin and earth cable solely for the induction hob purely because of how much current it can potentially draw (7.2Kw). I then ran a spur from another socket to create a single standard socket for my new oven.

Ben84

If the manual suggests a 32A circuit, which is what you have, and your electrician is happy with the condition and quality of the circuit, you should be fine.

It looks more confusing than it is, but the amp rating of the cooker doesn't have to match the amp rating of the supply. In practice it rarely does. The sizing of cooker circuits is treated differently to just about any other appliance I can think of, and many electric cookers are connected to lower amp circuits than their rating due to diversity - basically they assume nobody will turn on every element at once. I believe the calculation is that the supply must match the first 10A of the cooker's rating plus 30% of the remainder and 5A if you have a socket on the circuit (can be removed if needed to gain back the 5A). Presumably, as a 32A supply is recommended, your cooker falls within the range of a 32A supply when diversity is calculated.

Mark_Mark

lee111s wrote: »

I had a similar issue. Previously had a gas oven and electric hob. Since changing to an Induction I had to convert the double socket that was protected by the 40a fuse into a single cooker style outlet using 2.5mm twin and earth cable solely for the induction hob purely because of how much current it can potentially draw (7.2Kw). I then ran a spur from another socket to create a single standard socket for my new oven.

Are you sure 2.5mm is big enough?

lee111s

My qualified electrician installed it so I'd imagine so.

Mark_Mark

lee111s wrote: »

My qualified electrician installed it so I'd imagine so.

Seems small, I hope he got his maths right when he did it.

muckybutt

2.5mm is no where near big enough to cope with a load of 7.2Kw - I kid you not THAT IS A SEVERE FIRE RISK

2.5 mm is roughly rated to 20 A max on a radial circuit.

I would have put a 6mm cable in for a cooker circuit - always have done always will do as that has always been the norm.

DO NOT USE YOUR COOKER UNTIL THE CABLE SIZE HAS BEEN CHECKED.

sparkieguy

2.5mm is not big enough!
The fuse/mcb protects the cable not the appliance

lee111s

Aplogies, read through my texts and it was indeed a 6mm twin and earth he had me get so that's what fitted.

QTPie

Thanks very much.

So cooker requires a 32A dedicated circuit and has an electrical load of 11.7kW.

I have a 6mm dedicated cooker circuit (6mm live, 4mm CPC) with 32A MCB. This should be sufficient and safe? Even for 11.7kW?

Thanks

muckybutt

QTPie wrote: »

Thanks very much.

So cooker requires a 32A dedicated circuit and has an electrical load of 11.7kW.

I have a 6mm dedicated cooker circuit (6mm live, 4mm CPC) with 32A MCB. This should be sufficient and safe? Even for 11.7kW?

Thanks

NO ! 6 mm rated to roughly 8.5Kw 46A max if clipped direct.
11.7Kw you need to upgrade the wiring to 10mm might even be 16mm and the MCB to 50A

11700 / 240 = 48.75A which is over the max rating for 6mm cable

Use that cooker on full load and kiss goodbye to your home !