Induction hob for preexisting 4mm T+E

[Jackster]

Doh, I just double-checked the oven and it is 2,075 watts not 1900 watts.
Think I was looking at another oven a few weeks ago trying to get a better one.

Maybe, maybe not, we haven't seen the actual installation to be able to make that decision.

Ah...

It goes from the understands cupboard to the kitchen in the ceiling cavity.
Don't believe there is any insulation up there. And it should be clipped?

 

[FatAlan]

Do your heat and smoke alarms work ok?

 

[telectrix]

Doh, I just double-checked the oven and it is 2,075 watts not 1900 watts.
Think I was looking at another oven a few weeks ago trying to get a better one.



Ah...

It goes from the understands cupboard to the kitchen in the ceiling cavity.
Don't believe there is any insulation up there. And it should be clipped?

bear in mind yhat thatis the total ratingof the oven. youprobably won't be able to use oven and grill elements together, and even so, it's under 9Amps. can'tseea problem on the socket ring unles you have a washing macine and tumble dryer on at same time as oven. anyway, we all plug a 3kW kettle in and nobody bats an eyelid.

 

[7029 dave]

Its been done for decades, everybody knows a dedicated 32amp cooker circuit should be run in 6mm minimum.

 

[Pretty Mouth]

Its been done for decades, everybody knows a dedicated 32amp cooker circuit should be run in 6mm minimum.

@7029 dave , I would install 32A on 6mm too, just because it's always done that way. But I often wonder why? I could see 6mm being necessary for voltage drop concerns, or if using rewireable fuses. In the absence of these, and assuming method C, why wouldn't a 4mm conductor suffice?

 

[Ian1981]

6 mm for a cooker circuit is a throw back to the older 3036 fuses, where 6mm on a 30 amp fuse was the norm as it dealt with the issue of the fusing factor of the 3036 fuses being 2 rather than 1.45 , I2 < 1.45 Iz.
So a 6mm for a cooker circuit has just been recycled down the line without any thought on actual design.
Considering that a 15kw load is fine for a 32 amp mcb with diversity taken into account, 4mm is quite adequate for a cooker circuit, obviously if the calculations allow it, the same as any other selected conductor.

 

[davesparks]

Its been done for decades, everybody knows a dedicated 32amp cooker circuit should be run in 6mm minimum.

But everybody knows that a 32A socket radial should be 4mm, so what's the difference? Same size OCPD, same calculation, different cable size?

'everybody knows' isn't always correct, it can just mean that a lot of people are wrong.

6mm is traditionally used for cooker supplies yes, but that is out of tradition, not calculations. It harks back to the imperial cable sizes where the size used for a 32A radial was nearer to 6mm and so people just started using 6mm.

 

[7029 dave]

@7029 dave , I would install 32A on 6mm too, just because it's always done that way. But I often wonder why? I could see 6mm being necessary for voltage drop concerns, or if using rewireable fuses. In the absence of these, and assuming method C, why wouldn't a 4mm conductor suffice?

The OP stated it is a new build so method C is out the window we have been told that, which will reduce the CCC thats why 4mm wont suffice.

 

[Ian1981]

The OP stated it is a new build so method C is out the window we have been told that, which will reduce the CCC thats why 4mm wont suffice.

Why is method C out the window?
Our company do new builds, method C is common to a lot of the circuits installed

 

[7029 dave]

But everybody knows that a 32A socket radial should be 4mm, so what's the difference? Same size OCPD, same calculation, different cable size?

'everybody knows' isn't always correct, it can just mean that a lot of people are wrong.

6mm is traditionally used for cooker supplies yes, but that is out of tradition, not calculations. It harks back to the imperial cable sizes where the size used for a 32A radial was nearer to 6mm and so people just started using 6mm.

I would use the term common sense other than tradition, out of interest given the info we have, what size cable would you select.?
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Why is method C out the window?
Our company do new builds, method C is common to a lot of the circuits installed

My understanding is that is a surface install.