Electric oven and hob cable sizing

[jordanlm5]

Hello all,
I'm replacing a gas oven and hob for an electric oven and induction hob.
It will have it's own dedicated 32A cooker circuit which is wired in 6mm cable that leads to a double pole cooker switch with socket, which then leads to a cooker hardwire outlet.
My new oven is 3.5kw, my new hob is 6kw. I have done the diversity calculations and found that these will be fine on the 32A circuit.

I plan on hard wiring both the oven and the hob to a dual appliance cooker outlet.

My question is with the cable that comes from the oven to the cooker outlet and the cable that comes from the hob to the cooker outlet.
Both oven and hob have 3093Y 2.5mm heat resistant flex which is rated at 25A.
Will this be sufficient?

 

[JohnW2]

... My new oven is 3.5kw, my new hob is 6kw. I have done the diversity calculations and found that these will be fine on the 32A circuit.
My question is with the cable that comes from the oven to the cooker outlet and the cable that comes from the hob to the cooker outlet.
Both oven and hob have 3093Y 2.5mm heat resistant flex which is rated at 25A.
Will this be sufficient?

Yes. Even without invoking diversity, 2.5mm² flex is more than adequate for 3.5kW and very nearly adequate for 6kw, so that, when one does consider diversity, such cable would be more than adequate for both oven and hob.

It would be very strange if cooking appliances came fitted with cables which were inadequate to carry the current drawn by those appliances !

Kind Regards, John

 

[Murdochcat]

If the items come with cables provided then crack on.

What really annoys me is all the manufacturers who seem to shy away from making definite size recommendations for cables - this is an unacceptable practice

 

[JohnW2]

If the items come with cables provided then crack on.

Quite so. As I wrote ...

It would be very strange if cooking appliances came fitted with cables which were inadequate to carry the current drawn by those appliances !

What really annoys me is all the manufacturers who seem to shy away from making definite size recommendations for cables - this is an unacceptable practice

I must say that my experience is that most manufacturers of such items usually do provide recommendations (for both size and type of cable) these days, quite often even when the appliance comes fitted with a cable. Having said that, those recommendations can sometimes be somewhat OTT.

 

[Murdochcat]

I must say that my experience is that most manufacturers of such items usually do provide recommendations (for both size and type of cable) these days, quite often even when the appliance comes fitted with a cable. Having said that, those recommendations can sometimes be somewhat OTT.

Well, with the ones I've seen recently the type of cable has been mentioned but not the size - but you're not earning a living with this carp are you

 

[SUNRAY]

Hello all,
I'm replacing a gas oven and hob for an electric oven and induction hob.
It will have it's own dedicated 32A cooker circuit which is wired in 6mm cable that leads to a double pole cooker switch with socket, which then leads to a cooker hardwire outlet.
My new oven is 3.5kw, my new hob is 6kw. I have done the diversity calculations and found that these will be fine on the 32A circuit.

I plan on hard wiring both the oven and the hob to a dual appliance cooker outlet.

My question is with the cable that comes from the oven to the cooker outlet and the cable that comes from the hob to the cooker outlet.
Both oven and hob have 3093Y 2.5mm heat resistant flex which is rated at 25A.
Will this be sufficient?

What does manufacturers instructions state is required for each item?
Instructions are there for a reason.

 

[JohnW2]

Well, with the ones I've seen recently the type of cable has been mentioned but not the size

Fair enough - our experiences obviously differ.

- but you're not earning a living with this carp are you

No, but what has that got to do with anything?

Regardless of how I make my living, I am involved with the purchase of a fairly large number of domestic appliances, so see many associated MIs. In fact, unless you are a 'kitchen fitter' you may well not see more than I do.

 

[JohnW2]

What does manufacturers instructions state is required for each item? Instructions are there for a reason.

Indeed. Not only that but, as I wrote above, if an appliance comes supplied with a cable, it would be pretty extraordinary if that cable was not adequate in size for the appliance!

 

[SUNRAY]

Indeed. Not only that but, as I wrote above, if an appliance comes supplied with a cable, it would be pretty extraordinary if that cable was not adequate in size for the appliance!

It's not only the size of the cable involved.

 

[JohnW2]

It's not only the size of the cable involved.

Hmmm - the implication of what I wrote was obviously "... adequate in size and type" for the appliance in question !!

 

[EFLImpudence]

Most MIs state that the installation of the product must be done by a qualified (or similar) person.

It is obvious why they state that but stated it is so why do people never insist that that instruction must be followed and tell DIYers that they must not do the work?

 

[JohnW2]

Most MIs state that the installation of the product must be done by a qualified (or similar) person.

They do - although sometimes talk about 'competent', rather than 'qualified'.

It is obvious why they state that but stated it is so why do people never insist that that instruction must be followed and tell DIYers that they must not do the work?

Perhaps for a similar reason that we don't usually tell DIYers that they must feed fans through isolators and 3A fuses? ...i.e. our advice is given after "having taken the MIs into account" - which, as you know is ('all') what BS7671 now requires.

 

[SUNRAY]

Hmmm - the implication of what I wrote was obviously "... adequate in size and type" for the appliance in question !!

OK!
It's not only the cable that needs to be considered. If it comes without a plug it is considered to be a component (or whatever official term is used) and therefore is permitted to be correctly fused or otherwise protected external to the appliance.
It also needs to be installed correctly, with correct clearances, heat resisting materials, ventilation etcetera according to MI's

 

[SUNRAY]

They do - although sometimes talk about 'competent', rather than 'qualified'.

Perhaps for a similar reason that we don't usually tell DIYers that they must feed fans through isolators and 3A fuses? ...i.e. our advice is given after "having taken the MIs into account" - which, as you know is ('all') what BS7671 now requires.

But as I've just replied installation is not restricted to electrical.

 

[EFLImpudence]

"having taken the MIs into account" - which, as you know is ('all') what BS7671 now requires.

Yes, but some don't seem to accept that.