Installing two ovens

[singinmgr]

Missus has decided on two ovens both have leads for connection without plugs;
Oven 1: - Electrical connection rating (W) 3,650 W - Current (A) 16 A
Oven/MicroW 2: - Electrical connection rating (W) 3,000W - Current (A) 15A

The Hob is on its own dedicated circuit from the consumer unit using 6mm.

Can I connect the two ovens on a normal socket circuit or do they require their own dedicated circuit similar to the hob.
Thanks for any advice.

 

[Taylortwocities]

Normal sockets and connections to ring circuits are limited to 13amp.

your ovens are more than 13A EACH, so the answer is no.

You will need a new separate feed for the two ovens. A 32A feed using 6mm cablke would do it. Don't forget this new circuit will need to be notified. Plus it'll need to be RCD protected.


One small thought, though. The hob, I guess it is an electric one? What is the rating of the hob? And what value fuse/MCB is protecting the hob circuit?

 

[singinmgr]

Thanks TTC for the quick response and very clear answer.
The hob is 7200W and on 32 MCB which I am not touching.
Looks like a job for the electrician not me.

 

[Taylortwocities]

Yes, its a new circuit and will need notifying to the local authority + other stuff.
Use a registered electrician.. check he/she is listed here www.competentperson.co.uk

 

[PrenticeBoyofDerry]

Can I connect the two ovens on a normal socket circuit or do they require their own dedicated circuit similar to the hob.
Thanks for any advice.

The manufacturers instructions should inform you how they should be installed, but no factory provisions of a plug on flex/cable and ratings above 13A suggests that they cannot be plugged in via 13A plug.

So a new circuit is required, they can both be on this circuit, if a 32A radial is installed and the cable is sized correctly to the method of installation.
If this cable is buried within a wall less than 50mm (please note there are regulations concerning the maximum depth of chases in solid walls and often 50mm is not achievable under these regs) and not mechanically protected, then RCD protection will also be required.

 

[singinmgr]

Thanks all for your advice.

Just checked the Consumer Board and there are no empty slots. So from the the following options which is most desirable from a costs perspective but keeping with the rules etc? Or is there another way?

1. Replace the current Consumer Board with new one with enough slots.
2. Add a separate CB just for the Ovens etc.

 

[Taylortwocities]

Post a picture of your consumer unit, maybe there's a workaround...

 

[singinmgr]

Photos of my MCB

Untitled

• singinmgr
• 28 Apr 2014
• 1

Untitled

• singinmgr
• 28 Apr 2014
• 1

 

[Taylortwocities]

OK

The Smoke Alarm circuit does not need to be on its own MCB. In fact, smoke alarm companies like Aico recommend that it is better if these are on a regularly used lighting circuit. It then becomes quickly obvious if the MCB has tripped!

OK, so that frees up a slot on your consumer unit. Then you'll need an Ashley& Rock 32A MCB for the new circuit to the ovens.
If the cabling for the new ovens will be concealed (in walls etc) less than 50mm from the surface, then the breaker will need to be put on the RCD side of that split load board.,

That may mean messing around with the busbars of that split-load board.
A job for your electrician, i would suggest.

But it is easily do-able.

 

[EFLImpudence]

3650 + 3000 + 7200 = 13850 / 240 = 57.71A

57.71 - 10 x 0.3 + 10 = 24.3A

Say no more.

 

[Taylortwocities]

Too tight for my liking. Depends on your view of diversity.
On a busy day (eg Xmas) I would suggest that 10amps plus 30% for EACH appliance would be more certain for the turkey to still be cooking when you come back from church..

 

[singinmgr]

3650 + 3000 + 7200 = 13850 / 240 = 57.71A

57.71 - 10 x 0.3 + 10 = 24.3A

Say no more.

What's this mean?

 

[EFLImpudence]

What's this mean?

It means you can connect the ovens to the hob circuit.

 

[loosenup]

napit are requesting now that any cooking appliance over 2kw is on it's own radial , is this correct and is there a regulation to support this comment ?.
and if so . what size cable and mcb would be required ?

 

[EFLImpudence]

napit are requesting now that any cooking appliance over 2kw is on it's own radial , is this correct

Strictly speaking that may be correct; I have no knowledge of Napit.
However, it is not up to Napit to make rules - other than, I suppose, for their members but that probably is not allowed either.

and is there a regulation to support this comment ?.

No, merely a recommendation for the circuit's sake.

and if so . what size cable and mcb would be required ?

Well, it depends on several factors but assuming the ideal -
2kW is 8.33A so a 1mm² cable and 10A MCB would suffice but no one would install that because there may be a hob as well or a larger oven may appear in the future.
(for pedants - not future-proofing, common sense)