Cooker cable sizing

[fancypantsyeah]

i "nearly" understand the diversity calc, first 10a plus 30% of remainder, i just can not get my head around how 6mm cable and a 40a mcb is adequate for this size of cooker when if you installed a 10.5kw shower it wouldn't be.

thats because when you install a shower there is no ,,,, diversity allowed.....but in a cooker there is....that why see....lol...

 

[fancypantsyeah]

Ya have not seen our lass cook mate every ring on an over full wack mind there are 6 of us inour house...lol./...

 

[wallyanker]

But i agree that manufacturers should in this day and age state maximum KW loading, rather than the connected KW load.... As a 17KW cooker isn't really 17KW, it's more like a 15 or 15.5KW cooker....

e54... If you apply the basics of the cooker diversity of first 10a plus 30% of remainder, have i got this right...??

17.1kw = 74.35a
10a + 30% of 64.35a = 29.3a

So, the circuit you install must be designed for 29.3a = 6.7kw ??

 

[telectrix]

6mm clipped direct, 40A MCB. that's my opinion, for what it's worth

 

[telectrix]

But i agree that manufacturers should in this day and age state maximum KW loading, rather than the connected KW load.... As a 17KW cooker isn't really 17KW, it's more like a 15 or 15.5KW cooker....

e54... If you apply the basics of the cooker diversity of first 10a plus 30% of remainder, have i got this right...??

17.1kw = 74.35a
10a + 30% of 64.35a = 29.3a

So, the circuit you install must be designed for 29.3a = 6.7kw ??

it's worked for 60 odd years. no reason to think any different today. best thing is in the proof of the pudding, as they say. switch everything on and clamp meter it. initial current might be a little bit over, but bet it settles down to no more than 30(ish) amps.

 

[wallyanker]

So why dont the manufacturers just call it a 7kw oven and do away with the diversity... Would make a lot more sense, as the manufacturers would know exactly what the oven can draw at any one time.

 

[telectrix]

they can't do that, because then nobody would buy them. what customer would think of buying an oven less powerful than mrs. jones at no.47.

 

[wallyanker]

lol... good point

 

[Octopus]

If you've got to run a new circuit in commonm sense would suggest a 10mm is the way to go. Future proofing!

 

[telectrix]

why not go the whole hog and run a 25mm SWA to a sub-main. could plug the kettle in as well then.

 

[BES]

i take it this is domestic not a bussiness, hotel etc

 

[Jimmyb]

it's worked for 60 odd years. no reason to think any different today. best thing is in the proof of the pudding, as they say. switch everything on and clamp meter it. initial current might be a little bit over, but bet it settles down to no more than 30(ish) amps.

I totally agree with you but i get customer saying to me that the spur off a spur off a spur has been fine for 30 years and there not much chance of much being overload as they dont really use them anyway. what do u say when you say u only need 6mm for cooker because its been fine for 60 years

 

[Engineer54]

Can't see a problem for you Jimmyb, if they want you to install a 10mm cable when a 6mm will be adequate, then rub your hands together and provide them the 10mm!! And the extra cost...lol!! ....Simples!!!!

 

[telectrix]

@ jimmyb. when i said it's been fine for years, i meant also that it's compliant with regs. as well.

 

[Jimmyb]

totally agree with you telectrix.

I wasnt referring to the cooker circuit and beside if they install a 10mm instead of 6mm how im i going to make much if any because it will take about the same time so unless im going to rip people off which i anit it doesnt make much difference, I was talking about the spur off a spur off a spur