16A oven ok on existing set up?

[Fletch77]

Hi all,

I appreciate that this is a question that has been answered a lot but each response I could find was for slightly different set up to mine, so hoping you guys might be able to advise. If any work is needed I will get an electrician out, but don't really want to take time off work and waste his time if nothing needs doing.

I have just bought a new oven which has the self clean and realised that it is a 16A oven where my last one was 13a. The previous one was hard wired in.

The oven specs are:

Grill 3100W
Hot air heating element 2300W
Top Heat 1100W
Bottom Heat 1100W
Power Circuit 3600W

I also have a hob rated 5800W

My current set up is a dedicated cooker RCBO with 32A at the consumer unit, this runs about 2.5 meters to a dedicated oven isolation switch above the counter which then runs to a white junction box underneath the counter where it splits with one cable going to the hob and one to the previous oven.

So I am just trying to work out if anything what I may need to change to allow my new oven to safely work, I have a feeling the 32A RCBO might need changing but i'm getting confused if you have to lower it to 16A to match the oven or up it because of the KW output.

Not that it makes much difference but as its only me and the girlfriend occasionally, I have never used more than the standard oven and 1 hob ring at the same time in the 2 years I have lived there.

Any advice would be greatly appreciated and if any more info is required to make a judgement please let me know.

Thanks

 

[Blaspark]

Sounds like you should use a spark to wire it in if this is your question. It'll take him no time if you get the kitchen as ready as you can without touching the electrics

 

[Midwest]

Hi @Fletch77 & welcome.

For your new oven a diversity factor can be applied, which give its suggested maximum operating load, but it seems the manufacturer has already done this by suggesting max load of 16A?

Together with your existing hob of 5800W, which I calculate a load of 14.5A, so both appliances in use together would be just over 30A.

Does your cooker isolator have a socket outlet? If not, as your existing oven supply is 32A (I'm surmising it is a suitable 32A supply cable etc), I would say it would be safe to reconnect your new oven.

How old is your existing installation? It may just be worth verifying everything is in order, via an electrician before proceeding.

 

[Fletch77]

Hi Midwest,

Thank you so much for the help. The cooker isolator switch does not have a socket attached. The wiring looks to be 6mm so I’m pressuring this is ok? I think the wiring was probably done around 20 years ago when it was converted into a flat, howere the consumer unit was replaced in 2016.

I may well call an electrician then just to have a look over.

 

[Blaspark]

Your wires might be old colours too. If you're going to do it yourself check old wire colours compared to new. Might save you some confusion

 

[dksanders]

What size cable is the cooker circuit run in?
What does the manufacturers instructions for the new oven say regarding supply parameters?

 

[Fletch77]

What size cable is the cooker circuit run in?
What does the manufacturers instructions for the new oven say regarding supply parameters?

Actually looking at the cable, I think it might be 10mm.

Unfortunately the oven manual doesn’t seem to state the supply parameters, it is a second hand one that’s a few years old.

 

[Blaspark]

Actually looking at the cable, I think it might be 10mm.

Unfortunately the oven manual doesn’t seem to state the supply parameters, it is a second hand one that’s a few years old.

I thought it was new. Are you going to pat test it or just pump 16a through it?

 

[telectrix]

it should be fine to connect into existing circuit. don't be put off by the gloom and doom merchants. after all, it's only 3 wire..........

 

[Midwest]

What size cable is the cooker circuit run in?
What does the manufacturers instructions for the new oven say regarding supply parameters?

Think OP's already answered those.

 

[Midwest]

Common you lot, its a friggin oven. You gonna require an ECIR on the house, 'cos someone's given you their old tv!

 

[Fletch77]

It’s a family members old oven and is a pretty decent one and was working fine so it’s a known entity to an extent.

Thanks for your input though guys.

 

[dksanders]

Think OP's already answered those.

His answer wasn't there when I started my post so our posts crossed.

OP- where did you get 16A from?

If it's 6mm and clipped direct, or 10mm then the cable would be able to take the (max) 41A load, just replace the MCB for a 40A one if the cooker is a 16A max load, but given the oven load figures the OP quoted it would suggest a separate cooker circuit would be required.

 

[Fletch77]

Hi dksanders,
I got the oven figured from the manual. Photo attached. I presume that I have read them properly?

 

[Midwest]

if the cooker is a 16A max load, but given the oven load figures the OP quoted it would suggest a separate cooker circuit would be required.

What?

Its a friggin domestic oven.

 

[dksanders]

What?

Its a friggin domestic oven.

..and many domestic ovens require a dedicated feed, especially double or multi purpose ovens. Until the OP just posted the manufacturers information, he'd listed the power consumption which totalled 11.2Kw which would draw 48Amps.

 

[dksanders]

What?

Its a friggin domestic oven.

..and many domestic ovens require a dedicated feed, especially double or multi purpose ovens. Until the OP just posted the manufacturers information, he'd listed the power consumption which totalled 11.2Kw which would draw 48Amps.

 

[dksanders]

Hi dksanders,
I got the oven figured from the manual. Photo attached. I presume that I have read them properly?

View attachment 47958

Thanks Fletch, is there a section describing the electrical connection requirements?

 

[Fletch77]

Thanks Fletch, is there a section describing the electrical connection requirements?

The only thing it says is the wording on the picture attached. But not sure what that really means?

 

[dksanders]

Thanks Fletch, although the English is somewhat questionable, ("the power mains....") that confirms that the oven needs a 16A supply so my previous comment about changing the MCB to 40A as long as the cable is suitable applies.

 

[Midwest]

Thanks Fletch, although the English is somewhat questionable, ("the power mains....") that confirms that the oven needs a 16A supply so my previous comment about changing the MCB to 40A as long as the cable is suitable applies.

I must be getting my maths wrong.

If I was calculating max load using diversity, for the listed W loads, then I would be going for 40A supply. However, as previously posted, the manufacturer of the new oven, has listed a max supply requirement of 16A. Presumably they have applied their own 'diversity', due to the users limited selection of elements by control knob. But in any case we agree on a max load for the new oven at 16A.

The only other unknown is the hob, which is rated at 5800W. Which I obtain a max load in A's (after diversity) of 14.5A.

So why the need to change the ocpd, when the existing 32A appears suitable?​

 

[telectrix]

think some members think a domestic oven is a pot bank kiln.

 

[dksanders]

I must be getting my maths wrong.

If I was calculating max load using diversity, for the listed W loads, then I would be going for 40A supply. However, as previously posted, the manufacturer of the new oven, has listed a max supply requirement of 16A. Presumably they have applied their own 'diversity', due to the users limited selection of elements by control knob. But in any case we agree on a max load for the new oven at 16A.

The only other unknown is the hob, which is rated at 5800W. Which I obtain a max load in A's (after diversity) of 14.5A.

So why the need to change the ocpd, when the existing 32A appears suitable?​

Not knowing enough about how the oven can be used i.e. if all those items can be on at the same time, (think Xmas dinner cooking), and likewise for the hob, I didn't apply diversity.

 

[Fletch77]

Thanks everyone for the feedback.

I can use the fan oven on its own, or the grill on its own, then either the top or bottom element on their own or together or the grill plus fan. So I think it’s probably fair to add diversity into the equation.

 

[Midwest]

Not knowing enough about how the oven can be used i.e. if all those items can be on at the same time, (think Xmas dinner cooking), and likewise for the hob, I didn't apply diversity.

You need to go back to school.

We had a range cooker, who's installation 'engineer' would only connect to a 40A supply. It had a facility where the all the (could be turned on) ovens could fast heat for 7 mins. I clamped it, along with switching on the grill & side oven; never got more than 14 A.

 

[dksanders]

You need to go back to school.

We had a range cooker, who's installation 'engineer' would only connect to a 40A supply. It had a facility where the all the (could be turned on) ovens could fast heat for 7 mins. I clamped it, along with switching on the grill & side oven; never got more than 14 A.

and why do I need to go back to school..?

 

[Midwest]

and why do I need to go back to school..?

Cos I think you got your maths wrong? No offence (someone's else just called me rude).