Wiring of new double oven and hob

[Snagrat]

Hi.

I am replacing my kitchen so am buying a new double oven and hob.

I currently have a free standing electric cooker wired into a 32a switch.

How would I wire my new double oven and hob with the existing connection? The hob is 7kW and oven 4.5kW?

 

[telectrix]

assuming your existing cooker is wired in 6mm T/E through a D/P Isolator Switch, then you can connect both oven and hob to the existing circuit. 11.5kw = 48A. Apply diversity, 10A + 30% of 38A = 22.4A. Add another 5A if socket outlet on Isolator. Perfecftly OK on 6mm cable . MCB can be 32A or 40A

 

[telectrix]

In an ideal world it would be good practice to run a separate circuit for each, so that if one appliance or circuit failed, you would still have the other appliance working, but that is not part of the regs. Might be an idea though to have the circuit tested to make sure there are no problems.

 

[Snagrat]

I will check if it is 6mm but it should be. It certainly is from connection to cooker as I can see it. When you say D/P isolator what do you mean? The electrics hav been updated recently to a new trip fuse box (rather then old style fuse wire).

 

[telectrix]

D/P isolator is what you would call the cooker switch, a double pole switch that breaks both live and neutral. absolutely essentil for more than one reason. 1. it isolates both live and neutral for maintenance purposes. 2. if you get a Neutral? Earth fault on the cooker, by isolating both phase conductors, you remove the fault which would otherwise trip your RCD

 

[Snagrat]

Yes I have one of them. Also has a socket on although that may go when I replace it with new one.

 

[telectrix]

beat without socket, then you won't put your electric kettle on a hot hob. just make sure that the isolator/switch is a minimum distance from the hob of 6" (regs.)

 

[Snagrat]

Currently 12in away and it's moving further away so will be fine.

What is best - wire both hob and oven directly into socket which will mean channeling both cables into wall or channel only one cable in the put a junction box behind oven and wire both into that?

I am assuming I'm allowed to do this as I am not playing with the ring at all?

 

[telectrix]

from the switch you should have a 6mm cable to a cooker outlet behind the existing cooker. should not go direct from switch to cooker. if you have then wire both into this. otherwis, i would fit one.

 

[Snagrat]

No currently it goes from switch to cooker. But I can put a 45a cooker connection in as per this one 45A Cooker Connection Unit - Switches & Sockets - Electrical -Tools, Electrical & Plumbing - Wickes ? And then wire both into this. Make sense to me as that what I hve seen before.

 

[Stu Too]

Currently 12in away and it's moving further away so will be fine.

Hey Snagrat,

Apart from beiong over 6" away. The DP isolator (cooker switch) shouldnt be more than 2 metres away from the appliance though (OSG p160, 8.4) Not sure if this is Reg or Guidance. Also it shouldnt go in a cupboard.

 

[peterb2428]

Hey Snagrat,

Apart from beiong over 6" away. The DP isolator (cooker switch) shouldnt be more than 2 metres away from the appliance though (OSG p160, 8.4) Not sure if this is Reg or Guidance. Also it shouldnt go in a cupboard.

Where does it state that it can't go in a cupboard?

 

[Stu Too]

You are right - it doesnt specifically say "Not in a cupboard", but guidance is that they should be "readily accessible" . For me - readily accessible would mean that anyone would be able to access them without having to go and find them. Although if you did put them in a cupboard (especially the upper cupboards) you wouldnt need to worry about BS7671 - you would probably be breaking Part M regs for accessibility as they would be above 1200mm.

 

[peterb2428]

You are right - it doesnt specifically say "Not in a cupboard", but guidance is that they should be "readily accessible" . For me - readily accessible would mean that anyone would be able to access them without having to go and find them. Although if you did put them in a cupboard (especially the upper cupboards) you wouldnt need to worry about BS7671 - you would probably be breaking Part M regs for accessibility as they would be above 1200mm.

Stu 450mm - 1200mm is guidance and new installs - you can put switches and sockets relative to the existing.

 

[Stu Too]

Hey Pete. I thought 450mm to 1200mm was build regs, not guidance and based on if you are moving current switches sockets, then it is a new kitchen install, then you would need to adhere to build regs. Willing to put my hands up if I'm wrong! I'm always learning Stu.