Clarification of hob / oven wiring.

[STEVETATE]

I a newby to this site. (I am a qualified electronics engineer but need some clarification regarding hob / oven regs.)

My retired mother has just built a new house. Very nice, however the electrician has not finished completely and done a runner , as yet the house is not yet certified, but most of the second fit is done.

Now to the point.

He has installed a 6mm cable from the dist. board to the kitchen (about 4 metres in length. protected by a 40A breaker.) This goes through a simple but large isolation switch which is .5 metre from where the hob is.

Question 1. Does this meet current regs. for a new build?

The hob is 6.5 kw and the double oven / grill is also 6 kw. resulting in 12.5 kw. and thus 52 Amps without diversity.

Question 2. Can I fit a terminal junction box near the hob to split the supply to both the hob and the double oven unit? If so would a 45A junction box be OK ?


Please help, Steve

 

[sparkybird]

Hi there

You need to think about the cables that will be going from this isolator to the hob and over. Their only means of protection will be the 40A breaker at the board, so they need to be rated at 40A or above (ie 6mm cable or equiv). Is this what you've got?

It would be preferable for each item of equipment to be separately isolatable. However if you did use a JB it would need to be accessible and 45A would be OK (but I'm not sure if you can get them, so you might have to go up to 60A.

The diversity looks OK. At worst the breaker will trip when your mum puts all the rings and ovens on, but there's not much you can do about that because 6mm cable can be protected by a maximum 40A mcb.

Hope this is helpful

SB

 

[STEVETATE]

Their only means of protection will be the 40A breaker at the board, so they need to be rated at 40A or above (ie 6mm cable or equiv). Is this what you've got?

SB

Yes, The cable from the isolator is 6mm.

I have locked for 45A junction box and you seem to be right, I am aware of the requirement to ensure that the junction is avaliable for inspection. I see that 60A chocbloc is available, I could put that into a blanked back box. That should be OK.

Thanks for your help.

Steve

 

[Taylortwocities]

Scolmore (Click) make a dual outlet plate (PRW217) that is rated at 45A.
Allows one cable (up to 10mm in) and two cables (up to 10mm) out to connect to 2 appliances, It fits in place of the single cooker connx plate that your running sparky will have supplied.

Go to Scolmore.co.uk & u can download the brochure. Its in their POLAR range.,

TTC

 

[sparkybird]

Good idea Taylor - will look up that one myself!

SteveT - what I meant was that the cable to be terminated into the hob and oven will need to be 40A rated. Is there any exisitng cable/flex from the two appliances? If not you'll need to wire them into the 6mm from your isolator.

Good luck

SB

 

[shepsamiller]

nooooo,, the total load of both the oven and hob cannot be supplied off one 6mm cable, i,m afraid youll need to upgrade the supply cable,ideally 2 seperate circuits are required from the c.u. with the adequate protction.[/list]

 

[securespark]

Ideally yes, it is best to fit two circuits if possible.

However, previous posters are perfectly correct in their advice that diversity can be applied to the cooker circuit.

C'mon, you should know that, else you should refrain from posting advice here...