Wiring oven and hob?

The Ayatolla

Hi folks

QQ as I've received conflicting info on this.

I need to wire up a new integrated oven and a separate integrated electric hob.

Plan is to run a 6 square twin & earth from the board which will be on a 32AMP RCBO / breaker.

This 6 square will feed a cooker switch.
The tail/load of the cooker switch will go into a junction box behind the kitchen units.
The cables then leading from the oven and job will be joined together in connectors with the 6square in the junction box.

Would this satisfy installation requirements withint he current regs ?

I've heard feedback of:
a) Both appliances need separate 6sq supplies
b) One supply is fine, but they need two separate switches (so the supplies can be "linked" out.

Would (A) and/or (B) be required or is my explanation above sufficient?

From the 2008 regs,
has this changed ? I dont know.

In domestic and similar installations, an isolating device for a cooking appliance shall not be mounted either
directly above or behind the appliance.
Where the oven and hob are separate appliances, a common supply and isolator may be used provided:
- each appliance is within 2m of the switching device, and
- the fault-loop impedance value for each cable is sufficiently low to ensure the conect (sic) operation of the overcurrent
protective device in accordance with 4 1 1 .3 and Chapter 61.

Westernworld.

BrownFinger wrote: »

From the 2008 regs,
has this changed ? I dont know.

In domestic and similar installations, an isolating device for a cooking appliance shall not be mounted either
directly above or behind the appliance.
Where the oven and hob are separate appliances, a common supply and isolator may be used provided:
- each appliance is within 2m of the switching device, and
- the fault-loop impedance value for each cable is sufficiently low to ensure the conect (sic) operation of the overcurrent
protective device in accordance with 4 1 1 .3 and Chapter 61.

None of the above would have changed its mostly common sense anyhow

Strictly speaking on cable sizing and single isolator no-one can say for definite without knowing the cooking loads

Tuco88

Don't the ovens usually come with a plug top? what is the kW? Would you not be better off running 6mm^2 for the hob, and a 2.5mm^2 (If its normal size) for the oven.

Separate Isolators, separate supplies. Getting messy with J.Bs

The Ayatolla

Yep the oven has a 3-pin plug top so I think 2.5 supply for that from the board will suffice.

I'll go with a 6-square for the hob then and a 2.5 for the oven.

Thanks folks!

Tuco88

Yes, because you don't want a situation of a 2.5mm2 Cable protected by a 32amp MCB.

The Ayatolla

Tuco88 wrote: »

Yes, because you don't want a situation of a 2.5mm2 Cable protected by a 32amp MCB.

Could I just have a single socket behind the oven which is fed by the load of the cooker switch, and then utilise the 13a fused plug of the oven?

Tuco88

Id keep it seprate circuits.

If you use a 32amp RCBO, wire the socket in 6mm2 I couldn't see anything wrong, you'll have fun trying to get 2 6mm^2 into one terminal on the load side of the cooker switch?

The Ayatolla

I was thinking of having a 6mm2 load go to the hob and then a 2.5mm2 load go to a socket behind the oven. Then plug the oven into said socket?

Tuco88

You now have a section of 2.5mm^2 on a 32amp MCB not ideal.

Wearb

Tuco88 wrote: »

You now have a section of 2.5mm^2 on a 32amp MCB not ideal.

How about a fused spur for the oven section?

Tuco88

Fine once wired in 6mm^2 to the spur.

If you can run a seprate supply it really the better option.

The Ayatolla

So a 2.5mm2 from board to spur with a 13A fuse (fuse varied dependant on oven max load). Then supply a single socket behind the oven and plug it in there.

Tuco88

A 2.5mm^2 cable from the board to a 20amp isolator dp switch, to a single socket behind the oven. The oven will plug into the socket (It will have its own fuse in the plugtop) no need for a spur outlet.

The Ayatolla

Ideal. Thanks!

EHP

Double check the load required by the hob some of them now require 10sq in fact any new installations we do now we always run 10sq for the hob to allow for any changes in the future.

2011

EHP wrote: »

Double check the load required by the hob some of them now require 10sq in fact any new installations we do now we always run 10sq for the hob to allow for any changes in the future.

Yes, many induction hobs require this.

Pasteur.

Tuco88 wrote: »

You now have a section of 2.5mm^2 on a 32amp MCB not ideal.

Short bits connecting a load I think are ok

Tuco88

MCB/Fuse in relation to cable size, Its as simple as that for me.

Anyway the in art of terminating, I wouldn't be a fan of putting a 2.5mm^2 in with a 6mm^2.

The Ayatolla

So if the oven comes with a 13amp fuse in the plug, that should provide the overload protection, right?
Or a 13amp fuse in a spur?

Pasteur.

Tuco88 wrote: »

MCB/Fuse in relation to cable size, Its as simple as that for me.

Anyway the in art of terminating, I wouldn't be a fan of putting a 2.5mm^2 in with a 6mm^2.

It's common enough to use smaller cables than the fuse rating to connect loads

Different matter upstream on a circuit where the cable could be overloaded

Tuco88

Pasteur. wrote: »

It's common enough to use smaller cables than the fuse rating to connect loads

Different matter upstream on a circuit where the cable could be overloaded

Its common when its after being designed and calculated correct, like control or power distribution panels with tri-rated flex for very sort links etc.

I wouldn't use anything less than 4mm HR flex from a C.C.U its good for 37Amps open to air. If you ask me its just laziness and poor workmanship using 2.5mm^2 even a single 2.5mm^2 pvc/pvc even allowed to carry 32amps in ET-101?