use 6mm2 for 3.2 kw?

[diydad888]

Hi,

Just bought a john lewis own brand electric oven that has absolutely no info on wiring ! eventually I found a sticker saying it is 3.2 kw, I think this is over the limit for a 13 amp circuit.
I had a 6 mm cable with a 40 amp mcb fitted thinking I would need more power for an electric oven, I have this fitted to the oven outlet plate ready for connection, I am not sure if this cable too large for this oven so, should I just connect more 6mm cable from the oven outlet plate, and use the 40 amp mcb or reduce the mcb or use 2.5 mm and reduce the size of the mcb to ??16 amp??
I can't believe the total lack of information, nothing in any handbook, even the connection plate at the rear gives no more info but the cables leading off it into the cooker look like 2.5 mm or smaller.

 

[plugwash]

In the absense of guidance from the manufacturer you have to make a judgement call about what is reasonable. Personally I don't think it's reasonable to assume that a 3.2KW cooker has been designed to be safe when connected to a 40A supply.

Personally I'd probablly use a 20A breaker. It's low enough that it should provide reasonable protection for the oven and yet high enough to leave some spare capacity for a socket on a cooker control unit.

 

[imroberts]

You'll probably struggle to wire a 6mm cable into the terminals on the oven if it's only 3.2kW. My oven is about 7.5kW and needed the thicker cable and it was a challenge!

I'd agree with plugwash, use a 20A breaker (14A for the oven, 5A for a socket if you have one built into your cooker switch) and 2.5mm cable.

Also, most people use T&E but a lot of oven manufacturers recommend heat resistant flex such as this

 

[securespark]

What do JL say about how it should be connected?

 

[PrenticeBoyofDerry]

diydad888
Replace 40A MCB at board with 20A one (remember to get the same model type as installed on the board or required by the board, as they are type tested and isolate installation prior to doing this)
Then put heat resistant flex between outlet plate and oven either 2.5mm or 4.00mm 3 Core will have you well covered.
But I would be calling JL's customer service/ tech helpline and be asking questions. There should be manufacturers instruction with this appliances.

Technical support
If you have any queries or problems with an electrical or technology product, call our JL technical support line on 0330 123 0106 or email
[email protected] from 8am to 9pm weekdays, 8am to 8pm Saturday and 10am to 6pm Sundays – calls are charged at a local call rate. To help us handle your query promptly, please have your model number available.

 

[diydad888]

Thanks everyone,

I called john lewis to ask for more info they gave the standard reply of...the rules and regs say we cannot provide this kind of info in case it is used !!! but I did get them to tell me the manufacturer (electrolux) and the confirmed to me it is indeed 16 amp.
So I will put the MCB down to 20 amp as it is on single cooker switch with no 13 amp socket as per the advice and I can get some 2.5 mm2 heat resistant flex to connect up.
I guess the only fuse in the cooker system is the mcb, is that standard?

I may need post this next question in another part of the forum but maybe some opinion can be found here, this oven is quite large and almost fills the entire 600mm oven base unit, I will be fitting a gas hob above but there is not a lot of room left (30mm rear clearence) for a gas pipe to be fitted, it will be quite close to the rear of the oven, just thinking about any heat to the gas supply pipe that will be fitted, my old gas oven was fine with a rubber pipe connection being very close to the oven/cooker.

thanks again

 

[PrenticeBoyofDerry]

30mm gap/space is not a great deal, when you consider you will need room for a 15mm gas pipe and it should be clipped, so that will take up a little more space. Is there access behind an adjoining cupboard? a
As that maybe a better route for the vertical length of gas pipe, then elbow off to the hob connection.
But the gas engineer will be in better position logically and regulatory to tell you, I find a lot just squeeze them in!
But separation of gas pipes and electrical cable must be given, for a 15mm pipe it should be at least 25mm.

 

[kai]

From the power rating of 3.2.kw, it comes to about 14amps design current, making a B16 breaker just the job to protect the oven, use a minimum of 2.5.mm.cable for optimum performance (reduces voltage drops), and connect the oven to that.