Kilowattage question. Help please.

[jacksonscraft]

Fire doors? How many storeys does this house have?

If you're 'selling up', there is surely no obligation to leave any oven or hob inn the house when you sell it, is there? Why not just remove them and leave the buyer to install whatever they wish?

In your situation, can understand that pragmatic approach.

That's nonsense. Ask him if he understands anything about 'diversity'. However ...

That sounds like a sensible approach, which (one hopes ) BC could hardly complain about. However, as above, do you really need to leave any hob at all when you sell the house?

Kind Regards, John

John, I really cant be bothered getting in a row with this BC bloke. Maybe that's irresponsible of me, but if you were under the stress I am, you might do the same.

No, I dont need to leave them. I may choose to though.

Cheers
James

 

[JohnW2]

John, I really cant be bothered getting in a row with this BC bloke. Maybe that's irresponsible of me, but if you were under the stress I am, you might do the same.

As I suggested, there's no need to interact with BC in any way. Just remove the hob and sell the house without one - I'm sure that wouldn't have any significant impact on the selling price of the house.

Kind Regards, John

 

[flameport]

So the 10mm cable I ran under the floor was a waste of time.

It wasn't. 10mm² good for pretty much any domestic cooking appliances whether that's a double range cooker, single width cooker, 2x single ovens and separate hob, oven / microwave / hob or most other other combinations.
No significant difference between halogen, solid plate or induction hobs either.

I can't run a 10.8 KW induction hob/cooker on a 10mm cable. It has to be a 16

They presumably install grossly oversized 16mm² in every house they go to then - 99% of standalone cookers or double oven & hob combos are more than 10kW total.
Must be an absolute nightmare attempting to get 16mm² conductors into the isolator switch.

 

[wundaboy]

Thanks for your reply John. The thing is - we're selling up and I really can't be bothered arguing with my LABC bloke. I just want this situation sorted, so we can get the sign off and move. BC are insisting on fire doors and an induction hob. So that's what they're going to get. My Sparks got back to me saying : I can't run a 10.8 KW induction hob/cooker on a 10mm cable. It has to be a 16. So sod that. I'm getting a new worktop from Wickes, cutting a hole in it and we're getting a plug & play induction hob to go in it. Same with the elec' oven I now have to buy. I'll get one as cheap as possible to go into a Kitchen oven cabinet.




Ventilation wasn't mentioned by him, only the potential fire risk.

Sounds to me like your BC inspector and your electrician have **** in their eyes and/or for brains!

In particular, with diversity as others have stated, you can quite happily run it on a 6mm cable and a 32amp supply. The BC stuff is verging on the kafkaesque!

 

[ebee]

Fire doors? How many storeys does this house have?

If you're 'selling up', there is surely no obligation to leave any oven or hob inn the house when you sell it, is there? Why not just remove them and leave the buyer to install whatever they wish?

In your situation, can understand that pragmatic approach.

That's nonsense. Ask him if he understands anything about 'diversity'. However ...

That sounds like a sensible approach, which (one hopes ) BC could hardly complain about. However, as above, do you really need to leave any hob at all when you sell the house?

Kind Regards, John

And here`s me thinking I`d got most domestics covered, sometimes overkill, with the age old 6mm supply cables and say a min 32A protective device for just about any cooker or combination thereof that is likely to be met.

No wonder that there are millions of house-fires on Xmas day in the UK. The bodies are piled high in the streets you know

 

[jacksonscraft]

Sounds to me like your BC inspector and your electrician have **** in their eyes and/or for brains!

In particular, with diversity as others have stated, you can quite happily run it on a 6mm cable and a 32amp supply. The BC stuff is verging on the kafkaesque!

RE: BC and Sparks, I couldn't agree more. But they're the ones that are signing this off and I just want it done. I'm actually a bit relieved to not be using the 10mm cable I laid and having to buy a free standing oven with induction hob. They cost a small fortune for what they are.

Thanks for your reply, greatly appreciated.

 

[Murdochcat]

No I didn't. The instruction was very simple and straight forward. I am to put fire doors everywhere and swap my existing dual power cooker for an induction hob because, he said, of fire risk.

Is this an HMO ?

If not I would question the advice from this inspector

 

[morqthana]

Thanks for your reply John. The thing is - we're selling up and I really can't be bothered arguing with my LABC bloke.

And so he will continue to lie and to cheat and to visit his ignorance and incompetence on others. You don't just need to argue with him, you also need to write to the chief exec demanding that he be sacked. Get your councillor involved too

My Sparks got back to me saying : I can't run a 10.8 KW induction hob/cooker on a 10mm cable. It has to be a 16.

Don't pay him a penny.

For anything.

He is not an electrician - he is an imposter.

 

[ebee]

Well I`d usually be happy to run a 13Kw cooker on a 32A MCB with 6.0 (even 4.0 though I don`1t because I never stock it as standard) cable for a 13Kw cooker unless I consider it is going to exceed the domestic cooker rule of thumb diversity calculations and consist of of a bog standard family type setting with two adults and 2.4 children or thereabouts. Is there some critical info you are not tell us that your electrician is aware of?

 

[JohnW2]

Well I`d usually be happy to run a 13Kw cooker on a 32A MCB with 6.0 (even 4.0 though I don`1t because I never stock it as standard) cable ....

I would imagine that most (sensible) people would say the same thing.

... for a 13Kw cooker unless I consider it is going to exceed the domestic cooker rule of thumb diversity calculations and consist of of a bog standard family type setting with two adults and 2.4 children or thereabouts. Is there some critical info you are not tell us that your electrician is aware of?

Indeed - and I would frankly doubt that the 'assumptions underlying diversity' would ever be significantly incorrect is a domestic situation (other than an incredibly rare 'domestic situation') to invalidate the approach. In fact, I doubt that even if it were 4+ adults and 5.4 children would make a lot of difference - ity's more a question of the duty ratio of the various elements than the number of people who are being cooked for.

Kind Regards, John

 

[ebee]

I would imagine that most (sensible) people would say the same thing.

Indeed - and I would frankly doubt that the 'assumptions underlying diversity' would ever be significantly incorrect is a domestic situation (other than an incredibly rare 'domestic situation') to invalidate the approach. In fact, I doubt that even if it were 4+ adults and 5.4 children would make a lot of difference - ity's more a question of the duty ratio of the various elements than the number of people who are being cooked for.

Kind Regards, John

Yes agreed John, I might start to re-evaluate some instances, example what is effectively approximating two or three families living in one household off one mains supply and I would begin to consider if the age old rule of thumb needs tweeking a little bit in this instance or not. If one of them had a habit of cooking to excess as , for instance, meals on wheels volunteers or running what is effectively a business involving copious amounts of cooking.
But, apart from extremes, I would usually consider the tried and tested approach seems reasonable unless we find otherwise - bodies piling in the streets and homes burnt out etc etc

 

[jacksonscraft]

An update for all concerned. I've gone and bought a plug and play induction hob and electric oven. Both are less than 2.5 KW each. This meant buying a new length of worktop to sink the hob into and a oven cabinet. So that's that. It's done.

This also meant that running that 10mm cable under the floor to the CU, was a waste of a day and of my flooring which is now knackered because of it.

Thanks for your advice. Needless to say I won't be using this particular electrician ever again.

Jack..

 

[morqthana]

If previous victims of this dreadful BCO had bothered to argue with him then you might not have ended up with knackered flooring.

 

[JohnW2]

Yes agreed John, I might start to re-evaluate some instances, example what is effectively approximating two or three families living in one household off one mains supply and I would begin to consider if the age old rule of thumb needs tweeking a little bit in this instance or not. If one of them had a habit of cooking to excess as , for instance, meals on wheels volunteers or running what is effectively a business involving copious amounts of cooking.
But, apart from extremes, I would usually consider the tried and tested approach seems reasonable unless we find otherwise - bodies piling in the streets and homes burnt out etc etc

As I implied, my first reaction is to be far from convinced that 'the amount of cooking' has all that much impact on the concept of diversity since, as I said, I think it's far more about the cycling on and off of elements etc. (under thermostatic control) than about how many of the elements are 'switched on'and for how long.

If my think were right (which, as below, it may well not be!), then if all bits of the hob, and all ovens/grills were left 'switched on' 24/7, the 'average' (i.e. 'after diversity') power consumption might well still be broadly the same as is assumed by the 'standard' diversity calculation.

In fact, given that the greatest deviation from the calculated 'after diversity' consumption will usually be when bits of the cooker are switched on from cold (particularly if several are 'switched on from cold' simultaneously), one might expect to get closer to the calculated after-diversity figures if 'everything was on continuously'.

Having said that, some people obviously disagree fairly strongly with my suggestion, since the diversity guidance in the OSG is far lless 'generous' in relation to cooking appliances in non-domestic settings, imply that they believe that 'the amount of cooking' is an important part of the equation - so I don't know, and suspect that my thinking must be flawed!

Kind Regards, John

 

[ebee]

No I think it is not so much flawed as such john but there are times, even in "high usage" where everything is off, therefore sufficiently cooled, to start all at once scenario repeatedly too, so that might factor in also to varying degrees of usage I suspect.
I reckon that someone cleverer than us might be able to inform us better on this topic.