Oven connection options

[Bumber]

Hello

I hope someone could kindly give me some advice.

I have a small U shaped kitchen, where the gas hob is located, to the left is a cooker socket with a cooker plate behind the cabinet the hob is fitted to. Nothing is using the cooker connection.

I have bought a new oven which the manufacturer has stated can be connected either to a 13amp fused plug or fused spur both via 2.5mm BUTYL flex or to a cooker plate using 2.5mm TE.

The oven will not be going under the gas hob but to the right in a oven housing unit. The distance from cooker on and off socket to the oven on and off socket is 1.7m point to point.

My questions are how long can the 2.5mm TE cable be from the cooker connection plate to the oven?

Can the cable run behind the kitchen cabinets along the floor which will have plinths covering the fronts or does it need to be put in trunking?

If the above is ok when the cable enters the oven housing unit can it connect directly to the oven with a certain amount of extra cable so the oven can be pulled out for maintenance or does it need connect to another connection plate then the cooker ?

The alternative i was thinking was to use a single 13amp socket which is available 30cm to the left of the oven housing unit and convert it to a 13amp FCU. Would it be ok to chase some of the wall put some plastic electrical trunking to the FCU which would lead out behind the oven and then feed the 2.5mm BUTYL cable into the trunking? or do i need to use some sort of connection plate in the oven housing?

I have attached a technical birds eye view picture of my kitchen in my album not sure how to attach to post
Here is a link
https://www.dropbox.com/s/crypcnhub7f82qi/KitchenMod.jpg?m

Thanks for your time

 

[phatboy]

I would run a 2.5mm from the cooker connection plate under the units loosly, and back up into the cooker unit. The cable can be as long as you like, as 2.5mm is easily capable of a 13amp load, especially if its not trunked or buried in a wall

 

[EFLImpudence]

You will need to use 4mm² flex if connecting directly to the cooker connection plate (assuming 32A supply) otherwise you will have to fuse down to 13A.

Being buried in the wall has no effect on the Current Carrying Capacity of a cable.

 

[EFLImpudence]

duplicate

 

[PrenticeBoyofDerry]

AS above, if circuit is 32A you would require to fuse down or use 13A plug, if not using 4.0mm flex. Any flex or cable installed in trunking/conduit will have a reduced current carrying capacity, but cable clipped direct or buried in walls will not. Any newly installed cable/flex buried in walls less than 50mm will require RCD protection, unless mechanically protected and any additional socket outlets will also require RCD protection regardless.
Cables buried must be in permitted safe zones, chase depths must comply to part A of building regs. (no greater than 1/6th of depth of skin/leaf of wall horizontally, 1/3rd vertically)

 

[Bumber]

I would run a 2.5mm from the cooker connection plate under the units loosly, and back up into the cooker unit. The cable can be as long as you like, as 2.5mm is easily capable of a 13amp load, especially if its not trunked or buried in a wall

Thanks i think this sounds like then neatest solution as i really wanted to use the cooker connection which is not being used by anything at the moment.

I have another question, currently i have a hob which is gas but has a battery operated ignition. i will be getting a new gas hob in the future which will be fitted by a gas safe plumber however this new gas hob needs a 3 amp connection for ignition. My understanding is that this socket has to be easily accessible and it does not make sense to have a socket hidden behind the cabinet (please correct me if i am wrong)

Out of the following which would be the best way/best practice to do this.

Run a FCU of the existing kitchen ring main above the worktop to the left of the hob , run gas hob cable through wall in trunking to FCU

Run a FCU of the cooker circuit above the worktop to the left of the hob , run gas hob electric cable through wall in trunking to FCU. If this is acceptable can i connect the FCU via 2.5 TE to the cooker control switch (it is a double socket width type with one 3 pin socket and 1 cooker switch) or should i should connect the FCU via the cooker plate?

cheers

 

[Bumber]

AS above, if circuit is 32A you would require to fuse down or use 13A plug, if not using 4.0mm flex. Any flex or cable installed in trunking/conduit will have a reduced current carrying capacity, but cable clipped direct or buried in walls will not. Any newly installed cable/flex buried in walls less than 50mm will require RCD protection, unless mechanically protected and any additional socket outlets will also require RCD protection regardless.
Cables buried must be in permitted safe zones, chase depths must comply to part A of building regs. (no greater than 1/6th of depth of skin/leaf of wall horizontally, 1/3rd vertically)

Phatboy mentioned that 2.5mm TE could be run behind cabinets loose do you recommend clipping them to the wall ?
So if i do this and not bury any cables i should be ok without a RCD ?
I wont have to fuse down if i am using 2.5mm TE via the cooker plate to back of cooker ?

 

[EFLImpudence]

I would run a 2.5mm from the cooker connection plate under the units loosly, and back up into the cooker unit. The cable can be as long as you like, as 2.5mm is easily capable of a 13amp load, especially if its not trunked or buried in a wall

Thanks i think this sounds like then neatest solution as i really wanted to use the cooker connection which is not being used by anything at the moment.

I'm afraid that suggestion is not correct.
Read the two following replies.

I have another question, currently i have a hob which is gas but has a battery operated ignition. i will be getting a new gas hob in the future which will be fitted by a gas safe plumber however this new gas hob needs a 3 amp connection for ignition. My understanding is that this socket has to be easily accessible and it does not make sense to have a socket hidden behind the cabinet (please correct me if i am wrong)

It would be better if it were accessible but behind the oven is 'normal'

Wire a socket (or FCU) to the cooker connection plate and then it will be controlled by the cooker switch.

 

[Bumber]

I would run a 2.5mm from the cooker connection plate under the units loosly, and back up into the cooker unit. The cable can be as long as you like, as 2.5mm is easily capable of a 13amp load, especially if its not trunked or buried in a wall

Thanks i think this sounds like then neatest solution as i really wanted to use the cooker connection which is not being used by anything at the moment.

I'm afraid that suggestion is not correct.
Read the two following replies.

Hmm the instructions for the oven state i can use PVC 2.5mm twin earth with a certain fuse rating which i assume is the fuse rating at the fuse box.
They don't mention anything about 4mm cable.
Are you saying i am better off using 4mm flex from the cooker plate direct to the cooker ?
Here is a picture of the instruction page
https://www.dropbox.com/s/hw2bvstfqdw1z0h/oven electric.jpg?m
Also in album

cheers

 

[EFLImpudence]

Hmm the instructions for the oven state i can use PVC 2.5mm twin earth with a certain fuse rating which i assume is the fuse rating at the fuse box.

It is likely that you have a 30A or 32A at the fuse box.

Therefore if you use 2.5mm² cable you will have to insert a lower rated fuse.
Either in a plug or FCU.

They don't mention anything about 4mm cable.

Either a smaller fuse or larger cable.

Are you saying i am better off using 4mm flex from the cooker plate direct to the cooker ?

Not a question of 'better off'. You will have to do one or the other.

 

[Bumber]

Hmm the instructions for the oven state i can use PVC 2.5mm twin earth with a certain fuse rating which i assume is the fuse rating at the fuse box.

It is likely that you have a 30A or 32A at the fuse box.

Therefore if you use 2.5mm² cable you will have to insert a lower rated fuse.
Either in a plug or FCU.

They don't mention anything about 4mm cable.

Either a smaller fuse or larger cable.

Are you saying i am better off using 4mm flex from the cooker plate direct to the cooker ?

Not a question of 'better off'. You will have to do one or the other.

Ok think i got it so i have 32amp fuse at the fuse box for the cooker circuit, i need to use 4mm butyl heat resistant flex to connect the oven directly to the cooker plate, i should pin the cable to the wall using clips but its is ok to have it behind the kitchen cabinets.

In the picture of the manual it says
Oven control circuit 2.5mm PVC Twin Earth 15A/20A min
In what scenario could you do this for example if i had a 20amp fuse in the fuse box on the cooker circuit

cheers

 

[EFLImpudence]

In what scenario could you do this for example if i had a 20amp fuse in the fuse box on the cooker circuit

You could do that but it is easier to fit the 4mm² cable.

 

[PrenticeBoyofDerry]

Phatboy mentioned that 2.5mm TE could be run behind cabinets loose do you recommend clipping them to the wall ?

All cables should be fixed securely, sometimes it is impossible when access is restricted but if you can, clip them

So if i do this and not bury any cables i should be ok without a RCD ?

That will depend if a socket outlet is installed the outlet requires protection, even if the cable does not. It may be that you already have RCD protection at the consumer protecting this circuit, if so that is fine, if not either protect from the point of new cable being installed (which would be hard on a 32A circuit) or protect socket or replace MCB with RCBO.

I wont have to fuse down if i am using 2.5mm TE via the cooker plate to back of cooker ?

As it's a radial circuit and suggestion are this is a 32A circuit, 2.5mm T&E cable, can safely carry no more than 27A, so is underrated for circuit.
So installing 4.0mm heat resistant flex ,which can carry 35A would be a sensible step.
If the appliance only requires as again suggested 20A, it could be possible to replace existing MCB for one rated for appliance. If this was to be done, then consideration of exchanging for 20A RCBO(30ma) would in my opinion improve the installation.

 

[Bumber]

I wont have to fuse down if i am using 2.5mm TE via the cooker plate to back of cooker ?

As it's a radial circuit and suggestion are this is a 32A circuit, 2.5mm T&E cable, can safely carry no more than 27A, so is underrated for circuit.
So installing 4.0mm heat resistant flex ,which can carry 35A would be a sensible step.
If the appliance only requires as again suggested 20A, it could be possible to replace existing MCB for one rated for appliance. If this was to be done, then consideration of exchanging for 20A RCBO(30ma) would in my opinion improve the installation.[/quote]

That is a good suggestion about the RCBO but only the electrician will be able to do that for me and i believe i have to notify the council of this.
I will ask him in a few weeks when he comes round.

Thanks for the explanation about using 4mm cable i did realise a few posts earlier that without a fuse on the 2.5mm TE, the cable would be underrated for the circuit. It is the first time i am using a electrical oven always used gas just wanted to make sure the new oven was connected safely to existing electrics.