Replace oven and a half and gas hob to induction

[Ihmix]

Morning All,

We are in the process of replacing our kitchen and on the new design we are replacing our siemens 1 and a half oven with two neff single ovens that have an output of 3.45kw B47CR32NOB model number, we are also looking to replace our gas hob with an induction hob that produces an output of 7.45kw.

My question is can these all be wired to the same circuit which has a B32 rating without issue, the induction hob does have the ability to change the output for 20A to 16a or even 13a. would diversity allow this and could I use a double split type socket from the main oven isolater switch to connect the ovens if this was 6mm T&E but what about the induction hob, how would i incorporate this into the circuit.

As a side note I will be installing a built in warming draw and microwave but these have plugs and only pull around 900 watts each.

Thanks again and any advice or help guiding me in the right direction would be great.

The house is 4 years old and the consumer unit was upgraded to a 16 way only 6 months ago allowing for 3 spare ways.

Thanks

 

[ericmark]

With a B32 MCB or RCBO if there is an overload it will fail safe, so personally I would connect and cross fingers. My stand alone cooker has double oven, both multi elements and 4 heat areas so rating way over 32 amp but my 32 amp trip has never tripped in either of the two houses it has been fitted into, over some 15 years, so would not really worry about it.

 

[Ihmix]

Just watched a video on Diversity and doing the calculations using the following and allowing for an additional socket at 5A I get a total of 29.94Amps. @240v and 30.72@ 230v

First oven 3.45kw
Second Oven 3.45kw
Induction Hob 7.45kw

total is 14.35kw

14350 divide by 240v = 59.8Amps (Using Diversity first 10Amps then 30% of remainder plus 5amp for socket)
(59.8 - 10) then 30 x 49.8 divide by 100 = 14.94Amps + 10amps from before = 24.94 + (5amp additional socket = 29.94) using 230volts = 30.72amps

My last question is how do I wire these up, as mentioned I have two double ovens and a induction hob, now I know they do a 45a dual appliance outlet plate, but how do I apply three appliance to this. I presume I wire two in series and have the supply going to the first plate with one appliance from there and use the second appliance space to connect to the second dual appliance outlet plate of which I run the other two appliances from, is that correct.

 

[ericmark]

Personally I would use a twin back box (not double)

and two duel cooker appliance outlets

but I have never tried doing it, so would go to an electrical outlet so I could test at the counter two outlets would fit.

As to diversity with induction the waste is less, to both halogen and gas, so average use of power must drop, main reason for induction is a cooler kitchen, so even if on boost it can use 3.7 kW on one heat area, in real terms I found rarely uses more that 1 kW, the stand alone one I had, defaulted at 1 kW although could supply 2 kW and in the main found I turned it down not up. So except for initial warm up, likely using 500 watt per heat area, so unless your going to do some thing like beer brewing using all rings at max. It will use far less power than would ever open a 32 amp overload.

 

[EFLImpudence]

My last question is how do I wire these up, as mentioned I have two double ovens and a induction hob, now I know they do a 45a dual appliance outlet plate, but how do I apply three appliance to this.

Just put two in one side - OR
install two outlets.

I presume I wire two in series

No, not series - Parallel.

and have the supply going to the first plate with one appliance from there and use the second appliance space to connect to the second dual appliance outlet plate of which I run the other two appliances from, is that correct.

Not sure I follow that.

It shouldn't really be Twin&Earth on the outlet side.

 

[EFLImpudence]

Personally I would use a twin back box (not double)

It's called a 'dual' box.

 

[Ihmix]

So I could use one 45a dual appliance outlet send one of the cables to a dual box and plug the ovens to each of those sockets (basically a double socket I presume) and then send the other cable to the induction hob or a single socket for the hob. I also presume 6mm cable for the hob but is 4mm sufficient for the two ovens.

 

[EFLImpudence]

So I could use one 45a dual appliance outlet

Yes.

send one of the cables to a dual box and plug the ovens to each of those sockets (basically a double socket I presume)

No, You cannot use plugs on ovens and hobs of the ratings you have given.

You would have to use another dual outlet plate but there isn't much point.

Just connect all three to the one outlet.

2.5mm² flex for each oven and 4mm² for the hob.

 

[Ihmix]

Yes.


No, You cannot use plugs on ovens and hobs of the ratings you have given.

You would have to use another dual outlet plate but there isn't much point.

Just connect all three to the one outlet.

2.5mm² flex for each oven and 4mm² for the hob.

Thanks that makes sense. Not all the appliances cables will reach the dual socket
so I guess I replace the appliance cable with my own for example 4mm for the hob to the desired length required to reach the dual appliance outlet.

 

[EFLImpudence]

Thanks that makes sense. Not all the appliances cables will reach the dual socket

Dual cooker outlet. It's not a socket.

so I guess I replace the appliance cable with my own for example 4mm for the hob to the desired length required to reach the dual appliance outlet.

Yes, or a second outlet near the hob wired from the first.

 

[Ihmix]

Dual cooker outlet. It's not a socket.


Yes, or a second outlet near the hob wired from the first.

sorry a slip of words there. Outlet not socket. Perfect. Thanks