Terminating an electric cooker

[DTR]

Afternoon all,

We're changing over from gas to electric and our cooker has just been delivered. Here is a photo of the terminating panel:

In my usual line of work, I'd crimp those terminations (the screws are M6). But as domestic is a bit of change of scenery, I though I'd double check with you guys.

For what it's worth, the cooker circuit isn't live yet. It's all run in but not terminated at the CU. I've got a qualified sparky coming next week to do that and sign it off.

Thanks

 

[lurker]

Assume you are going to use a flexible cable between there and the fused wall "box"
When I did mine I put in a longish length of heat resistant sheathed cable so I could slide the oven in and out of the housing cabinet without disconnecting which has been useful later
It's quite expensive I think, although I "borrowed"a length from work
What is the oven wattage?

 

[DTR]

Does it have to be flex? The likes of Screwfix etc don't sell heat resistant flex in a heavy enough gauge. I don't know what the wattage is off hand bit I think it's in the region of 11kW. The specs ask for 6mm cable. The fused box is about 2' from the cooker.

 

[lurker]

Flat cable is usually 6mm but you can't use it unsupported
Could you check the wattage as 11sounds a but high

 

[DTR]

The retailer says it's 11.3kW, which is a bit high when you run it past Ohms Law. Zanussi's website does specify a 30A breaker though:

http://m.zanussi.co.uk/Products/Cooking ... ZCV68310XA

 

[HarryJ]

A bit off topic, but I think I have this oven and unless it's just mine, the grill pan expands when used due to the heat and gets wedged in... so much so that the oven moves before it comes free

Just something to check I guess...

Edited to add; I didn't see it being wired, so unfortunately can't help with that...

Harry

 

[Silas Gull]

A 10 kw electric shower requires a 10mm cable because it is drawing close to 45 amps on start up.
Your cooker might come close to this,but only with every ring, hot plate, grill and oven combination going at full chat -
which is where the manufacturers 11.5 kw figure comes from.

 

[Phil Pascoe]

I've never seen 6mm flex. Is there such a thing?

 

[bugbear]

I've never seen 6mm flex. Is there such a thing?

I thought it was always this stuff:

http://www.wickes.co.uk/Wickes-Twin-and ... H/p/156183

Not at all flexible. I worked with some recently. Not easy.

BugBear

 

[n0legs]

I've never seen 6mm flex. Is there such a thing?

Used regularly on bigger machines.
http://www.industrialextensionleads.co. ... 9868-p.asp

 

[Boatfixer]

I bought 6mm flex from a proper electrical factors with no problem. It is readily available but the guy behind the counter reckoned most electricians use twin and earth because they cant be bothered to carry 2 sorts of cable on the van......

Graham

 

[DTR]

I've never seen 6mm flex. Is there such a thing?

Used regularly on bigger machines.
http://www.industrialextensionleads.co. ... 9868-p.asp

That's the kiddie. It's very tempting just to use a T&E offcut but if a job's worth doing....



So back to the original question.... can I crimp the terminations at the cooker-end?

 

[mjcann]

Crimp is probably best job, no loose strands, as long as you use decent lugs and a good crimper, not one of those that just puts a dent in it.

 

[n0legs]

So back to the original question.... can I crimp the terminations at the cooker-end?

I would say yes to crimp on lugs.
But it would have to be the quality ones like the ones in the link below:-
http://www.neweysonline.co.uk/cembre-tu ... on.raction.

Nice bit of heatshrink up and over the barrel for some insulation.

If not those then a twist of the conductor, in the direction of the lay :wink: (do you like that ?) and a 'U' loop around the termination screw.

 

[DTR]

So back to the original question.... can I crimp the terminations at the cooker-end?

I would say yes to crimp on lugs.
But it would have to be the quality ones like the ones in the link below:-
http://www.neweysonline.co.uk/cembre-tu ... on.raction.

Nice bit of heatshrink up and over the barrel for some insulation.

If not those then a twist of the conductor, in the direction of the lay :wink: (do you like that ?) and a 'U' loop around the termination screw.

I'm all for heavy duty, but are the coloured crimps not ok? They're rated high enough. I have easy access to a ratchet crimper, but I can't borrow a heavy duty crimper or the crimps without some agro....

 

[Deejay]

Afternoon Dave

If you can't get a crimper, have you thought about soldering them?

Cheers

Dave

 

[n0legs]

I'm all for heavy duty, but are the coloured crimps not ok? They're rated high enough. I have easy access to a ratchet crimper, but I can't borrow a heavy duty crimper or the crimps without some agro....

I know which ones you mean but to me they always look a bit flimsy when crimped onto the larger conductors.
I think of it like this--
If I squashed that type of lug/crimp and made into a cylinder would it's cross sectional area be equal to that of the conductor being terminated in it. Also the bit where it goes from the barrel to the ring/fork/spade always looks a little 'skinny' to me, if you know what I mean.
But although I've just said all of that, if the manufacturer has given them a set of ratings then they must be okay. My trouble is I'm used to dealing with mahooosssive cables and terminations, so everything else looks small :lol:

Afternoon Dave

If you can't get a crimper, have you thought about soldering them?

Cheers

Dave

Ah ! =D>
Now you're talking, I frigging love soldered on lugs. It's just done, fitted, soldered and done. There's always a place for some solder :lol:

Though seriously.
Very little chance of or no vibration at all and a good cable clamp for a nice rigid hold on the outer sheath, and yes solder the lugs on. Job's a good 'un

 

[jolly1]

Regarding calculating the load (amps) cable sizing should include the diversity factor, ie not likely all the load shall be in use at the same time. Should be 10 amps plus 5 amps if the cooker unit has socket plus 30% of the total load.

 

[DTR]

Also the bit where it goes from the barrel to the ring/fork/spade always looks a little 'skinny' to me, if you know what I mean.

I do know what you mean, but then I've seen far too many heavy-duty crimps fail at that location! (admittedly they were all subject to vibration...)

Afternoon Dave

If you can't get a crimper, have you thought about soldering them?

Cheers

Dave

Ah ! =D>
Now you're talking, I frigging love soldered on lugs. It's just done, fitted, soldered and done. There's always a place for some solder :lol:

Though seriously.
Very little chance of or no vibration at all and a good cable clamp for a nice rigid hold on the outer sheath, and yes solder the lugs on. Job's a good 'un

Soldering, of course! #-o I really like that idea, I think I'll do that!

 

[DTR]

Regarding calculating the load (amps) cable sizing should include the diversity factor, ie not likely all the load shall be in use at the same time. Should be 10 amps plus 5 amps if the cooker unit has socket plus 30% of the total load.

Interesting to know, thanks.

So... 11.3kW @ 240V = 47A

10A + 5A + (47A x 30%) = 29.125A