Fitting 16A hardwired oven to 32A cooker circuit

Phil W · Mar 31, 2022

Hi all, I'm new on here....

I have an existing 32A cooker circuit with a wall switch with 13A plug hole.The manufacturer says the new oven is hardwired and is 16A.

Can I just replace the breaker in the consumer unit with a 16A one and use the existing wiring?

Current breaker is a Proteus 2632B which is now obsolete. I haven't opened the consumer unit yet to have a look, but am guessing the 2632b is double pole, as they also used to do a 632b version, though can't see why it'd need to be double pole?
If it's din rail mounted, can I use any 16A b type breaker?

suffolkspark · Mar 31, 2022

Phil W said:
Hi all, I'm new on here....

I have an existing 32A cooker circuit with a wall switch with 13A plug hole.The manufacturer says the new oven is hardwired and is 16A.

Can I just replace the breaker in the consumer unit with a 16A one and use the existing wiring?

Current breaker is a Proteus 2632B which is now obsolete. I haven't opened the consumer unit yet to have a look, but am guessing the 2632b is double pole, as they also used to do a 632b version, though can't see why it'd need to be double pole?
If it's din rail mounted, can I use any 16A b type breaker?
View attachment 96489View attachment 96488

Connect straight into the cooker outlet where the old one was, no need to reduce MCB unless manufacturer specifically says protection by 16A mcb

littlespark · Mar 31, 2022

Ovens are fixed load, so won’t go over 16A… and having a socket could add another 12A to the load if you’re, say. Boiling a kettle and cooking at same time.

Dustydazzler · Mar 31, 2022

Some sparks and kitchen fitters are really ---- about reducing the mcb to 16/20amp as that is what most new ovens come 'rated at'

but in reality it will only draw 16 odd amps so it doesn't matter if its on a 16/20 or 32amp mcb imo

I never bother swapping out mcbs on old cooker feeds , but I know others who will stick any old 16a mcb in a board as an extra on a kitchen job and charge the poor home owner £100 just for the trouble

telectrix · Mar 31, 2022

assumint]gthe cableis 6.0mm, then you leave it on a 32A MCB as posted previously. although it's a proteus, might not work anyway so a 16A would only make it fail at a lower level.

Phil W · Mar 31, 2022

littlespark said:
Ovens are fixed load, so won’t go over 16A… and having a socket could add another 12A to the load if you’re, say. Boiling a kettle and cooking at same time.

Hi Littlespark
Thanks for the quick reply - I did think that the load on the socket + the oven being on at the same time might take it over 16A, so good point band thanks for confirming that. The oven hasn't arrived yet, so can't check the manufacturers install instructions. Just checked the oven I'm taking out and it's rated at 3kW, so same story there.

Phil W · Mar 31, 2022

suffolkspark said:
Connect straight into the cooker outlet where the old one was, no need to reduce MCB unless manufacturer specifically says protection by 16A mcb

Thanks Suffolkspark
Haven't got oven to check what manufacturer says, but it should arrive tomorrow. Hopefully should be ok, as you say.

Phil W · Mar 31, 2022

Dustydazzler said:
Some sparks and kitchen fitters are really ---- about reducing the mcb to 16/20amp as that is what most new ovens come 'rated at'

but in reality it will only draw 16 odd amps so it doesn't matter if its on a 16/20 or 32amp mcb imo

I never bother swapping out mcbs on old cooker feeds , but I know others who will stick any old 16a mcb in a board as an extra on a kitchen job and charge the poor home owner £100 just for the trouble

Thanks Dustydazzler
Funny you should say that, as the main reason I'm asking is that on the supplier's website and another supplier's website that I looked at before buying, every oven that needs hardwiring apparently needs to be supplied by a separate 16A fused spur and they offer their installation services for 100 quid. Maybe I've misinterpreted the bit about the separate fused spur, as I've already got the 32A cooker circuit and thought of it as a spur off the 32A one, whereas they're just meaning you can't wire it into your normal '13amp plugs' circuit, but it looks to me like they just want to sell you their installation service...

mike jones · Mar 31, 2022

Phil W said:
Hi all, I'm new on here....

I have an existing 32A cooker circuit with a wall switch with 13A plug hole.The manufacturer says the new oven is hardwired and is 16A.

Can I just replace the breaker in the consumer unit with a 16A one and use the existing wiring?

Current breaker is a Proteus 2632B which is now obsolete. I haven't opened the consumer unit yet to have a look, but am guessing the 2632b is double pole, as they also used to do a 632b version, though can't see why it'd need to be double pole?
If it's din rail mounted, can I use any 16A b type breaker?
View attachment 96489View attachment 96488

Just connect to the existing cooker supply no need to downgrade fuse

littlespark · Mar 31, 2022

The oven manufacturers are pretty woolly when it comes to installation manuals.

They could say “at least a 16A supply” but they tend to be international models, sold across Europe, made in some other country and translated into English by a 12 year old.
Only in the great United Kingdom that we reside do 13A fused plugs exist… so the majority of these ovens are wired into 16A radial circuits. The UK being a minority market.

You can also get some supplied with 5 core flex, copper links and numerous connotations of connecting to 2 phase or 3 phase supplies.

Phil W · Mar 31, 2022

telectrix said:
assumint]gthe cableis 6.0mm, then you leave it on a 32A MCB as posted previously. although it's a proteus, might not work anyway so a 16A would only make it fail at a lower

Phil W · Mar 31, 2022

telectrix said:
assumingthe cableis 6.0mm, then you leave it on a 32A MCB as posted previously. although it's a proteus, might not work anyway so a 16A would only make it fail at a lower level.

Phil W · Mar 31, 2022

telectrix said:
assumint]gthe cableis 6.0mm, then you leave it on a 32A MCB as posted previously. although it's a proteus, might not work anyway so a 16A would only make it fail at a lower level.

Thanks for the reply - I take it that means I should probably think about a new consumer unit

Phil W · Mar 31, 2022

mike jones said:
Just connect to the existing cooker supply no need to downgrade fuse

Thanks for your reply, Mike - this is a great site, everyone's so helpful.
I just need the cooker to arrive tomorrow now!

UNG · Mar 31, 2022

littlespark said:
Only in the great United Kingdom that we reside do 13A fused plugs exist… so the majority of these ovens are wired into 16A radial circuits. The UK being a minority market.

I think you will find there are a few other countries around the world that use the BS1363 sockets and plugs

pc1966 · Mar 31, 2022

UNG said:
I think you will find there are a few other countries around the world that use the BS1363 sockets and plugs

The UK might be the origin for BS1363, but as you say also in ROI and several other countries:

AC power plugs and sockets - Wikipedia

en.wikipedia.org

littlespark · Mar 31, 2022

UNG said:
I think you will find there are a few other countries around the world that use the BS1363 sockets and plugs

yea... probably, but i was just trying to make the point that the instructions aren't very good

Mohoboto · Mar 21, 2024

Im going to piggyback this post as im in a slightly same position. I have a 45amp cooker switch with socket on a 6mm t&e to a 32amp breaker with rcd protection. The mrs wants to get the hisense oven and a built in microwave. The oven is 3kw and the microwave is 900watt, the oven says fuse rating 16amps, can i wire the oven to the 45amp cooker outlet and plug the 900wat built in microwave in the same socket on the original setup of 32amp breaker on 6mm t&e on the 45am cooker outlet with sockets
Thanks

Other_Tucker · Mar 21, 2024

Mohoboto said:
Im going to piggyback this post as im in a slightly same position. I have a 45amp cooker switch with socket on a 6mm t&e to a 32amp breaker with rcd protection. The mrs wants to get the hisense oven and a built in microwave. The oven is 3kw and the microwave is 900watt, the oven says fuse rating 16amps, can i wire the oven to the 45amp cooker outlet and plug the 900wat built in microwave in the same socket on the original setup of 32amp breaker on 6mm t&e on the 45am cooker outlet with sockets
Thanks

By 'hisense oven and a built in microwave' do you mean the microwave is built into the oven? I doubt it's got 2 separate cables then. Put a 13A plug on it and if you're lucky there'll be an ignition outlet behind there also to plug it into.

If they're separate, your plan has the microwave on a 13A plug in the cooker isolator socket which is fine, and the oven wired straight to the cooker outlet plate which I would do at my house but change it to a fused spur with outlet if you're worried.

A 900w microwave doesn't mean it draws 900w from the supply, I thought it meant 900w 'microwaving power' to the food. Cooking times would be all over the place if all microwaves used 900w supply but all had different efficiencies, and grill functions etc. I'd guess 2kW-2.5kW for a 900w microwave.

mainline · Mar 22, 2024

Other_Tucker said:
By 'hisense oven and a built in microwave' do you mean the microwave is built into the oven? I doubt it's got 2 separate cables then. Put a 13A plug on it and if you're lucky there'll be an ignition outlet behind there also to plug it into.

If they're separate, your plan has the microwave on a 13A plug in the cooker isolator socket which is fine, and the oven wired straight to the cooker outlet plate which I would do at my house but change it to a fused spur with outlet if you're worried.

A 900w microwave doesn't mean it draws 900w from the supply, I thought it meant 900w 'microwaving power' to the food. Cooking times would be all over the place if all microwaves used 900w supply but all had different efficiencies, and grill functions etc. I'd guess 2kW-2.5kW for a 900w microwave.

If your microwave is rated at 1000 watts it uses 1 kilowatt (kW) per hour

Other_Tucker · Mar 26, 2024

mainline said:
If your microwave is rated at 1000 watts it uses 1 kilowatt (kW) per hour

The 1000W refers to the actual power emitted by the magnetron in the form of microwaves for heating into the chamber. That is the energy output not the power consumption.

A 1000W microwave probably uses 1400W when running, likewise one drawing 1000W is maybe an 800W microwave. Otherwise the 900W written on my one could be any value of heating, based on its efficiency, and all food packet instructions are meaningless