DUAL APPLIANCE OUTLET PLATE

Ira Jag · Mar 18, 2021

Hi everyone,

I have read few posts about dual appliance outlet and wonder now if it can be used in my case. I have 32a 6mm cable to 45a switch supplying 6200w hob. Current oven is 2,4kw 13a plug. It will be replaced with 7,4kw induction hob and 3,6kw oven. Can hob circuit be used for both appliances connected to dual outlet plate and using same 45a switch? We were told by an electrician 6mm cable will be ok for both appliances, but when we had a quote for new kitchen they builder told us he would not connect both appliances to one 6mm cable and we heed to add new circuit. In our case it has to run outside around house and we would like to avoid it if possible.

Any advice is appreciated

mattg4321 · Mar 18, 2021

Why are you listening to a builder where electricity is involved.

What you propose sounds fine to me all being as it sounds.

i=p/u · Mar 18, 2021

As above , but could be old colours or anything , and new kitchen going in and builder thinking I want a new cable too, you know how they put it across

i=p/u · Mar 18, 2021

All new no problems

telectrix · Mar 18, 2021

builder should stick to slopping bricks.. 6mm on a 32A into a 45A isolator is good fot cooking appliances upto a rating of 15kW. end of.

Dustydazzler · Mar 18, 2021

Agreed , some of the BS I hear builders/kitchen fitters come out with is ridiculous.

i=p/u · Mar 18, 2021

They have deal done before the spark even hears of it

Ira Jag · Mar 18, 2021

mattg4321 said:
Why are you listening to a builder where electricity is involved.

What you propose sounds fine to me all being as it sounds.

Good point, if I was not told by electrician first I would believe builder, but he supposed to discuss the issue with his electrician. I don’t know what his electrician said, but we have extra cost £325 for new circuit and 85 for rcbo. Our house built 2000 and we are rcd protected, of course I don’t want extra cost if possible.

Ira Jag · Mar 18, 2021

i=p/u said:
As above , but could be old colours or anything , and new kitchen going in and builder thinking I want a new cable too, you know how they put it across

I thought that, I was put off buying the kitchen just because of conversation with their builder. But we shell see.

Dustydazzler · Mar 18, 2021

Builders are wombats when it comes to electrical installations.
OP, please dont pay an extra £400 on work that you don’t need

Ira Jag · Mar 18, 2021

Thank you all, for your advice.

Dustydazzler · Mar 18, 2021

Builders are wombats when it comes to electrical installations.
OP, please dont pay an extra £400 on work that you don’t need

i=p/u · Mar 18, 2021

Get a spark.out to test the cable or play it safe and go with new 1 ??????

Ira Jag · Mar 18, 2021

Now your answers made me wonder, what else I was told wrong by the builder. When we had kitchen ceiling insulated an electrician had to extend some cables including 6mm hob circuit. My spouse got involved in the conversation with electrician and he got confused thinking we wanted move the hob to opposite side. We decided not to remove the cable, in case we want to move hob or oven to opposite side. Please see how it ended up, if I remember correctly. Again builder said, that electrician was wrong to do it, as line to another side should not come out from junction box, but after 45a switch. Where circuit must have two module enclosure with two circuit breakers, one for hob, one for oven. Now I also wonder if it is so necessary to do or it can be left the way it is now.

Ira Jag · Mar 19, 2021

telectrix said:
builder should stick to slopping bricks.. 6mm on a 32A into a 45A isolator is good fot cooking appliances upto a rating of 15kW. end of.

15!!? When I said, we wanted 11kW for both appliances and were told by electrician it would be ok, our precious builder said, that appliances can not be installed, as cable will be running on it limits and can over hit. After his words I lost interest talking to him. But two month later he send us his quote with lots of possible extras. After it, I said buy kitchen in Wickes and left over spend in pub. I guess last me for long with current lockdown.

telectrix · Mar 19, 2021

what you have to bear in mind is diversity. with cooking appliances yo won't usually have all elements on at the same time, and they cycle on annd off with the thermostats, so a cooker /hob rated at say 11kW total rated power ( 48A) will have an average current of only approx. half of that (24A).

Ira Jag · Mar 19, 2021

telectrix said:
what you have to bear in mind is diversity. with cooking appliances yo won't usually have all elements on at the same time, and they cycle on annd off with the thermostats, so a cooker /hob rated at say 11kW total rated power ( 48A) will have an average current of only approx. half of that (24A).

11kW was total 7,4 hob and 3,6 oven and it what I said to the builder that that both appliances will not be run on full, but he said it would be dangerous and illegal. I want everything to be done according regs in case I have to sell or rent house in the future.

telectrix · Mar 19, 2021

not to worry. as i said, both oven and hob will be fine on a 32A MCB, 6.0mm cable (if cable is not smothered in insulation) . this application of diversity has been in use for 60+ years and found to be compliant. only reason to install separate circuits for oven and hob would be to isolate either if faulty and still have use of the other.

Strima · Mar 19, 2021

Ira Jag said:
but he said it would be dangerous and illegal.

As previously stated, let him worry about slopping bricks together and let the electrician deal with the electrics. TBH if a builder that I had employed started coming out with comments like that he would be looking for business elsewhere.

telectrix · Mar 19, 2021

the only illegal thing here is a builder sticking his snout into something about which he knows bugger all (and probably due a nice backhander from his tame ~~sparks~~ odd job man to install an uneccessary circuit).

Ira Jag · Mar 19, 2021

telectrix said:
not to worry. as i said, both oven and hob will be fine on a 32A MCB, 6.0mm cable (if cable is not smothered in insulation) . this application of diversity has been in use for 60+ years and found to be compliant. only reason to install separate circuits for oven and hob would be to isolate either if faulty and still have use of the other.

(if cable is not smothered in insulation) - we have vaulted ceilings so cables runs between roof and 100mm celotex and in the walls between terminal bricks and plasterboards without conduits. Roof can get hot in the summer, but there is a air gap between roof and celotex to prevent condensation.

telectrix · Mar 19, 2021

cables warm up in use. this is normal. as long as the heat can dissipate, there's no problem. covering cables in insulation reduces their current capacity, the derating factor dependent on how thick the insulation over the cables is.e.g. 6mm cable with no insulation is rated at 47A continuous. derating due to insulation can be as much as 40%. a reasonable air gap around the cable is recommended where cable is heavily loaded.

Ira Jag · Mar 19, 2021

telectrix said:
cables warm up in use. this is normal. as long as the heat can dissipate, there's no problem. covering cables in insulation reduces their current capacity, the derating factor dependent on how thick the insulation over the cables is.e.g. 6mm cable with no insulation is rated at 47A continuous. derating due to insulation can be as much as 40%. a reasonable air gap around the cable is recommended where cable is heavily loaded.

Because of vaulted ceilings our cable runs in air gaps between insulation and roof, I don’t know building regs for air gap in roof but I believe it minimum 50mm or more. Maybe it is not same as no insulation, but there is good air gap.