2 x Ovens and a hob - can anyone help?

[Tattyt]

Hi,

I have had an electrician out to look at at what needs to be done to install two new ovens and a new hob.

Existing: 6mm cable which was used for a double oven & hob previously, with one isolating switch. 40A breaker (think it should be 32A)

Two new ovens: Neff 2 x 2.99KW 13A
New hob: 6.5 KW

I just want to confirm that his recommendations are correct as it involves running some new cables so carpet, floor boards up etc etc.

If anyone could advise that would be brilliant

 

[SparkyChick]

Hi,

I have had an electrician out to look at at what needs to be done to install two new ovens and a new hob.

Existing: 6mm cable which was used for a double oven & hob previously, with one isolating switch. 40A breaker (think it should be 32A)

Two new ovens: Neff 2 x 2.99KW 13A
New hob: 6.5 KW

I just want to confirm that his recommendations are correct as it involves running some new cables so carpet, floor boards up etc etc.

If anyone could advise that would be brilliant

Hi, welcome to the forums.

What has he recommended?

 

[telectrix]

you have a total load of 9.5kW. a 6.0mm cable on a 32A MCB can cope with 15kW, once you allow for diversity. running new/additional cables is just a waste of money.

 

[Tattyt]

Hi SparkyChick,

Thanks for a prompt reply.

To run two new 2.5 cables, 2 x new 20 amp breakers with two new isolation switches.

Regards, Tattyt

 

[Tattyt]

you have a total load of 9.5kW. a 6.0mm cable on a 32A MCB can cope with 15kW, once you allow for diversity. running new/additional cables is just a waste of money.

Would it not be 12.5kW in total? as its for 2 x new ovens (3KW each)

Regards, Tattyt

 

[telectrix]

Hi SparkyChick,

Thanks for a prompt reply.

To run two new 2.5 cables, 2 x new 20 amp breakers with two new isolation switches.

Regards, Tattyt

crazy. unless the appliances are in separate areas. and depending on installation methods, 2.5mm may not be up to it.

 

[SparkyChick]

I'm inclined to agree with @telectrix .

I'm guessing those two cables are for the two ovens... it's interesting that 20A breakers are specified for a 13A load (when 16A breakers are available)

 

[SparkyChick]

How far from the consumer unit are these appliances?

 

[Tattyt]

How far from the consumer unit are these appliances?

They are approx 4 metres from the consumer unit but I have no idea the path of the cables.

The ovens are on top of each other and the hob is about 35cm away from them.

 

[telectrix]

They are approx 4 metres from the consumer unit but I have no idea the path of the cables.

The ovens are on top of each other and the hob is about 350 away from them.

350 what? miles, yards, poles, furlongs?

 

[Tattyt]

350 what? miles, yards, poles, furlongs?

Apologies, I have corrected it to read 35cm.

 

[telectrix]

that's just over 1 foot. no reason not to feed all 2 ovens and the hob from existing 6.0mm (32A MCB/RCBO) via a 45A isolator and a dual connection unit. from the dual connection unit, feed hob in 4.0mm or 6.omm and each oven in 2.5mm (fixed loads do not require overcurrent protection for the 2.5mm).

 

[Octopus]

If you were having a rewire or refit I would recommend a 2nd supply ....

But as others have said your existing set up could be adapted .....

 

[Tattyt]

If you were having a rewire or refit I would recommend a 2nd supply ....

But as others have said your existing set up could be adapted .....

Thanks Murdoch, no rewire or refit so new cable(s) would require a lot of work and stress!. If it does need to be done then so be it but it would appear not by the replies I have had.

 

[robd]

I agree with above on face value. If it's in the onsite guide (as was) it's good enough for me...6mm cable 32a MCB up to 15kw...unless there's something else he is thinking of.

Edit..for cooker circuits obviously not showers

 

[Gavin John Hyde]

Has anybody else noticed the ever lower current demands for new ovens and hobs, fitted one last week, manual said put it on a 16amp breaker. was a nice fancy one with steam and other functions. all part of the new energy conscious world

 

[robd]

Had my double oven out today for the first time since we moved in..bit of 10mm behind there, goes into a one gang double pole isolator. Some people

 

[Tattyt]

Many thanks to everyone that has taken the time to reply. There is so much conflicting advise out there.

Another electrician has said:

"you will either need to upgrade your current circuit to 50amp and use 10mm cable, or put in an additional circuit using 4mm for a 32amp. Your current circuit is fine with the cable size and breaker but both your ovens have a max load of 26am
(together), and the hob on its own has a max of 28amps. Please bear in mind that these levels are the maximum, ie, everything all on at the same time at max, which I doubt will ever happen?

Taking Diversity into consideration, you should be fine with the current circuit and personally that is the approach I would take unless you begin to have overload tripping issues. And then review the idea of upgrading or adding an additional circuit."

You try to do the right thing by getting an electrician in but it feels like the 1st one was trying to make it a bigger job than it probably is.

Special thanks to telectrix, I will be following your advice.

 

[Wilko]

Had my double oven out today for the first time since we moved in..bit of 10mm behind there, goes into a one gang double pole isolator. Some people

One place I was at, the cooker had 10mm and the shower 6mm. You don't have to guess why I was called ...
Re the Kitchen - I'd get another Electrician out .

 

[johnduffell]

I think the first electrician has forgotten about diversity in cooking appliances. And the second shouldn't be suggesting to wait until things trip.
they should confirm that on site in accordance with the regs