Cooker cable sizing

[geezza]

I've got a 17.1kW cooker to install.
The cable run is 20m, can someone please confirm what cable size should be used.

Thanks

 

[malcolmsanford]

Erection method
Protection device intended to be used

When you answer these we maybe of better help

 

[geezza]

Under the floor and channeled in the correct zones.
40A MCB, and RCD protected

 

[malcolmsanford]

6mm should be fine, but I personally would use 10mm

 

[geezza]

Thanks, I was thinking 10mm also.

 

[wallyanker]

Have I missed something here, 17.1kw cooker on a 40a mcb? 17.1kw is approx 74a.

 

[needasparks]

I just know whats coming ! I'm off to the cafe quick.

 

[AP Electrical]

you gotta love diversity

 

[wallyanker]

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.

 

[AP Electrical]

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.

No diversity on shower as capable of taking full load, chances of cooker seeing full load of 17kw highly unlikley thats why diversity comes in.

 

[wallyanker]

So if the cooker in question has all functions running on full steam, it would still not reach 17.1kw. Why dont the manufacturers test the cooker on full power and indicate the exact figure, then the circuit could be deisgned and installed with the extra added confusion.

 

[AP Electrical]

So if the cooker in question has all functions running on full steam, it would still not reach 17.1kw. Why dont the manufacturers test the cooker on full power and indicate the exact figure, then the circuit could be deisgned and installed with the extra added confusion.

Not quite, the cooker is capable of outputting 17kw on full steam but the chances of someone turning the whole lot on full at once is slim and even then the thermostats are going to be switching the elements on/off intermitantley to reach temp. So although everything is turned on by operator it's the stats that call for power so once upto temp they knock off.

 

[Engineer54]

Not quite, the cooker is capable of outputting 17kw on full steam but the chances of someone turning the whole lot on full at once is slim and even then the thermostats are going to be switching the elements on/off intermitantley to reach temp. So although everything is turned on by operator it's the stats that call for power so once upto temp they knock off.

lol!! ...Not quite again!! ...the 17KW is the connected load, the fact is it CAN'T all be switched on at one time as there are elements within the oven section that can't be ultilised at the same time, a good example is the grill element, it can't be used during oven operation. then there are multiple oven elements in modern ovens, some can be utilised at the same time others can't.

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....

 

[AP Electrical]

lol!! ...Not quite again!! ...the 17KW is the connected load, the fact is it CAN'T all be switched on at one time as there are elements within the oven section that can't be ultilised at the same time, a good example is the grill element, it can't be used during oven operation. then there are multiple oven elements in modern ovens, some can be utilised at the same time others can't.

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....

Why bother ?

 

[fancypantsyeah]

i've got a 17.1kw cooker to install.
The cable run is 20m, can someone please confirm what cable size should be used.

Thanks

a big un ,,,,lol........

 

[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.