Cable size for new oven

[adventcarpenter99]

Can you tell me what size cable I will need to run a new Lamona 3200
conventional oven. the existing old oven has a 2.5 T&E to the cooker point
but i'm not sure this is suitable the info on the new oven its max output 2400w. So what cable should i use its a clear run of about 8m along the joists and 1.2m down the wall to the cooker point
thanks

 

[PrenticeBoyofDerry]

The Lamona 3200 is rated at 2400 watts, so only needs 10A.
A 13A supply will be standard procedure, this can be done by the use of a 13A plug (if fitted to cooker flex) or by the means of a 13A switched fused connection unit.
2.5mm T&E will carry a maximum of 27A, but other variables such as the route and length of the cable and the installation method, should be taken into consideration.
It is not normal to have a individual/dedicate cooker circuit on 2.5mm cable, is this part of either a socket (ring or radial circuit?
The appliance should have come with installation instructions, if not you can call the Howdens customer services line for their recommendations of installation.
But the spec does state 13A supply.

 

[adventcarpenter99]

Just measured and the cable will run 8m clipped to joists and above the insulation and down the wall 1.2 through pvc conduit to the cooker point
so am I right in thinking 2.5 t&e will be ok
thanks

 

[PrenticeBoyofDerry]

What current rating is the MCB/fuse protecting this cable.
As the cable is contained within trunking, I would expected a 20A or less device.

http://www.howdens.com/compPDF/category/46.pdf

 

[ColJack]

if it's connected to a "cooker point" then what is the fuse / breaker rating for that circuit in the board?
I read from the OP's post that there is no kind of fusing down going on so if it's fed with, say, a 32A breaker then it needs cable capable of taking that or some kind of local fuse rated at 13A as stated above..
you could fit a surface single socket to the end of the existing 2.5mm cable and then a 2.5mm heat resistant flex and plug to the new oven..
This also makes it easier in future should you want to change the oven again..

 

[adventcarpenter99]

Its an MK B32 so I suppose its a 32 amp breaker the existing cooker point
is an un fused cooker switch
thanks

 

[PrenticeBoyofDerry]

That wants changing then:
Are you sure there is no fused connection up stream of this 2.5mm cable?
Are you sure this is not part of a ring final circuit, is there only one set of cables connected to the cooker switch?
Are you sure it is 2.5mm and not 4.00 or 6.00mm cable.
If it a 2.5mm radial circuit supplying the cooker switch only, the 32A MCB needs to be changed to either 20A, 16A or even 10A.
At what point was the old cooker connected?
Directly to the cooker switch via cable or by an outlet plate of some kind?

 

[PrenticeBoyofDerry]

The kind of set up you require is:
* 2.5mm circuit protected by either 20A or 16A device.
* A 13A accessory such as 13A socket outlet or 13A FCU to be installed after the cooker switch and a heat resistant flex of either 1.5mm or 2.5mm to be installed to cooker, using either a 13A plug or hard wired to 13A FCU, conveniently located.
* Alternative to the above would be to change cooker switch with 13A switched FCU, then connect flex directly to that or have either a socket or a flex outlet plate conveniently located to use for cooker flex/plug connection.
* You could install a 10A MCB, as that is all the cooker needs and providing this circuit only serves the cooker, hard wire cooker flex to cooker switch.

I assume the cooker switch does not also have a socket on the outlet plate.

 

[adventcarpenter99]

OK, so what we've got is one old white 2.5 cable connected to a MK B32 breaker on the consumer unit this cable runs to a switched double pole
cooker point above the work top the oven is connected via a flexible
white cable coming out of the plaster below the work top

 

[adventcarpenter99]

Thanks for your last post that's exactly the info I was looking for
cheers

 

[PrenticeBoyofDerry]

The 2.5mm cable can carry a maximum of 27A as it is contained within trunking this is now reduced to 20A.
So you need to change 32A accordingly.
So your 32A MCB should be changed to that of a value that does not exceed 20A.

Your cooker is required by the manufacturer to by supplied by a 13A supply.
You then need to either install a socket outlet or a 13A FCU to the end of the flex that is currently entering the cooker, this can then be used to connect your new cooker by either plug or hard wire.

*You could actually replace the 32A with 10A B type and just connect straight up to new cooker, using what you have in place. As the cooker will operate on 10A. But I tend to go with the MI of 13A