Cooker cable sizeq

[Blue Fox]

Hello all,

Been to look at a cooker today that the shop refused to fit. The landlord then called British Gas and they came round and also refused to fit. The reson is good enough the cable from the cooker switch to the connection block has been done in 2.5mm!! However the BG guy has said it needs fully recabling with 10mm cable and a 45A pop out fuse fitting to replace the existing 30 because the cooker is rated at a max of 9Kw. The cable from the c/u to the cooker switch is 6mm, so does it really need upgrading to 10mm or can I take diversity into account and replace the 2.5mm with 6mmfor the short run from the switch to the connection point. The cable coming out of the cooker is only 6mm anyway not 10mm.

Thanks for the advice.

 

[Andy™]

use diversity. as long as the fuse/mcb covers the 6mm, its safe

 

[steptoe]

???

not so sure if I would, (use diversity)

then again, its a personal judgement, if its 6mm and protected by a 30a then the circuit is fine,

protective device < cable capacity

so all is good.

just dont upgrade the fuse simply because it keeps blowing.

 

[tom1]

i would use diversity, on a 30 amp mcb

and you could get away with a 40 amp mcb

 

[Blue Fox]

Thanks for the replies. I wouldn't upgrade the fuse size without rewiring it in 10mm, just don't want to get a call back in a couple of days because it is continually blowing the fuse as the tiles are going to have to come off for me to replace the 2.5mm so don't want them to go back on again then have to have them off again to replace with 10mm!

Or could I replace 2.5mm with 10mm to cover that then if fuse does kepp popping rewire the rest? I know its not ideal as it would be 6mm to cooker switch and 10mm from switch to connection - I would never noremally put differing cable sizes on same circuit but is there a reg against it?

 

[tom1]

i know someone with a range cooker on 32 amp mcb 6mm

think its 12 or 13 kw, no problems yet

 

[kme]

could I replace 2.5mm with 10mm to cover that then if fuse does kepp popping rewire the rest? I know its not ideal as it would be 6mm to cooker switch and 10mm from switch to connection - I would never noremally put differing cable sizes on same circuit but is there a reg against it?

Yes, you could do that, without an issue.

KME

 

[Lurch]

Some of the larger all electric range cookers do occasionally take out a 30A MCB once in a while. If I'm wiring from new and I know one of these is going in I go for 10mm and 40-50A CPD. I've fitted a few on 30A circuits though without a major issue.

Suck it and see I think, what CPD is on it now, you mention 'pop out fuse', would you mean an old style Wylex plug in 30336 replacement? Pop out fuses sound hazardous, you could get hit in the head when walking past!

 

[Blue Fox]

Some of the larger all electric range cookers do occasionally take out a 30A MCB once in a while. If I'm wiring from new and I know one of these is going in I go for 10mm and 40-50A CPD. I've fitted a few on 30A circuits though without a major issue. Suck it and see I think, what CPD is on it now, you mention 'pop out fuse', would you mean an old style Wylex plug in 30336 replacement? Pop out fuses sound hazardous, you could get hit in the head when walking past!

Its the Wylex BS3871 type.

 

[batty]

As long as the cable is not to long, circuit could be replaced with 40 amp breaker job done. Why oh why do the installers make such a big deal of installing a cooker.

 

[Lurch]

Its the Wylex BS3871 type.

I'd be wary of sticking anything more than a 30A circuit in there as the older Wylex boards were only rated 60A total. If it has to be done in 10mm it's either arse about splitting tails or board change.

 

[Andy™]

As long as the cable is not to long, circuit could be replaced with 40 amp breaker job done. Why oh why do the installers make such a big deal of installing a cooker.

because they dont have any 6mm?

 

[Lurch]

Why oh why do the installers make such a big deal of installing a cooker.

Because they get paid either way so if they can get out of it then they're done.

 

[SPECIAL LOCATION]

Hello all,Been to look at a cooker today that the shop refused to fit. The landlord then called British Gas and they came round and also refused to fit. The reson is good enough the cable from the cooker switch to the connection block has been done in 2.5mm!! However the BG guy has said it needs fully recabling with 10mm cable and a 45A pop out fuse fitting to replace the existing 30 because the cooker is rated at a max of 9Kw. The cable from the c/u to the cooker switch is 6mm, so does it really need upgrading to 10mm or can I take diversity into account and replace the 2.5mm with 6mmfor the short run from the switch to the connection point. The cable coming out of the cooker is only 6mm anyway not 10mm.

Thanks for the advice.

Erm....?

Do I understand this is a "New" cooker

& at a rented property?

I am assuming this is not a big all singing & dancing 'mega-oven',

just your fairly typical domestic oven to allow a basic provision of cooking appliance for the tennants.....

So I would bet that

1/ diversity can be applied

2/ a 30a / 32a will be fine

3/ 6.0mm will be perfectly adequate...

but all that said...

THE MOST IMPORTANT BIT:-

what does the manufactures instructions say..

e.g. the bit about electrical connections in the flimsy little booklet that is probably selotaped to the grill pan? ?:|

is there any specific guidance about cables & circuit ratings?

 

[steptoe]

Erm....?Do I understand this is a "New" cooker

& at a rented property?

I am assuming this is not a big all singing & dancing 'mega-oven',

just your fairly typical domestic oven to allow a basic provision of cooking appliance for the tennants.....

So I would bet that

1/ diversity can be applied

2/ a 30a / 32a will be fine

3/ 6.0mm will be perfectly adequate...

but all that said...

THE MOST IMPORTANT BIT:-

what does the manufactures instructions say..

e.g. the bit about electrical connections in the flimsy little booklet that is probably selotaped to the grill pan? ?:|

is there any specific guidance about cables & circuit ratings?

and that my friends puts everything else into perspective

BRC states,

follow manufacturers instructions (or somesuch like)

 

[Lurch]

and that my friends puts everything else into perspectiveBRC states,

follow manufacturers instructions (or somesuch like)

Yes, but it doesn;t say blindly follow them regardless, so you need to look at them and then draw your own conclusions.

Also, BRC?

 

[SPECIAL LOCATION]

Yes, but it doesn;t say blindly follow them regardless, so you need to look at them and then draw your own conclusions.Also, BRC?

nobody said it did...

But it does say..

"Electrical equipment shall be installed in accordance with the instructions provided by the manufacture of the equipment"

(second sentence of 134.1.1 pg 19)

and in the context of this thread,

If the manufacture recommends specific minimum cable size and/or fuse rating..

it would be rather foolish to draw yourself different conclusions!

"BRC" = steptoes name for 7671 = Big Red Comic!

 

[Lurch]

nobody said it did...But it does say..

"Electrical equipment shall be installed in accordance with the instructions provided by the manufacture of the equipment"

(second sentence of 134.1.1 pg 19)

and in the context of this thread,

If the manufacture recommends specific minimum cable size and/or fuse rating..

it would be rather foolish to draw yourself different conclusions!

Well yeah, what I meant was, use your head and do what's best using the manufacturers instructions and the BRB to arrive att he best conclusion.

"BRC" = steptoes name for 7671 = Big Red Comic!

Ah, I see, makes sense.

 

[steptoe]

sorry Lurch

what I should have said was

do whatever covers your ass the best,

if your calcs say 6mm, but the instructions say 10mm,

then 10mm it is.

if the instructions say 40a mcb, but your calcs say , max 32a(for the cable run)

then 32a it is.

does this make it clearer

 

[Lurch]

sorry Lurchwhat I should have said was

do whatever covers your ass the best,

if your calcs say 6mm, but the instructions say 10mm,

then 10mm it is.

if the instructions say 40a mcb, but your calcs say , max 32a(for the cable run)

then 32a it is.

does this make it clearer

Yeah, that's pretty much what I think I was trying to say as well.