Range Cooker Connection Refusal.

Well certainly not at all sensible in the way explained.

I wouldn't dismiss the (unlikely) possibility that the manufacturer's instructions stipulate a max 40A OPD and the terminals are only good for 6mm2 and those on the sharp end have been given a set of rules to follow without much background information …. but perhaps I'm in a generous mood today.

    - Andy.

Lol… fortunately a little knowledge is, in their case, not a dangerous thing. I would have thought that a stiff letter outlining the difference between supply and load would be sufficient to make them see sense.

Legh

Zoomup: 
The reason given was that the supply is too big and will overload the new cooker.

You couldn't make it up!

I agree with Andy's analysis.

Could be a C2 though! ??

Note. The old cooker had been connected up to 10.00mm2 T&E cable and worked well enough.

Z.

It is likely that much has been lost in translation from the company supplying the cooker via the customer. 

I agree with Andy that it is likely that the manufacturer’s instructions state a smaller mcb, and that the terminal block on the rear of the cooker is designed for 6mm cable, not 10. To get to the rating, most manufacturers just add the values of all the installed elements, regardless of whether it is possible to use them all at the same time. 

Regards,

Alan. 

Alan Capon: 
 

It is likely that much has been lost in translation from the company supplying the cooker via the customer. 

I agree with Andy that it is likely that the manufacturer’s instructions state a smaller mcb, and that the terminal block on the rear of the cooker is designed for 6mm cable, not 10. To get to the rating, most manufacturers just add the values of all the installed elements, regardless of whether it is possible to use them all at the same time. 

Regards,

Alan. 

It might indeed be the case that the installation instructions require a 40 Amp M.C.B. rather than a 32 Amp M.C.B. as often found with old cooker circuits. The instructions often quote a minimum rating, such as in shower installation instructions. Why can't installers provide some new suitably sized cable from the wall cooker connection point to the new cooker? I understand that changing the M.C.B. might be beyond their capabilities though.

Z.

This is ridiculous, why are some comments trying to justify the unjustifiable? This is another manifestation of the “Manufacturers Instructions” problem, or at least is likely to be. If the manufacturer wants the supply fused at some value, they should fit the MCB to the product, or a fuse. If the design is so bad as to need a 40A rather than 50A breaker it is fundamentally flawed and should not be offered for sale. This costs very little money, much less than demanding a particular supply configuration. The idea that a cable can be “too large” is simply daft, and fundamentally untrue. 

I find that manufacturers' instructions are less and less satisfactory by the week. They are often written for multiple countries, whose supplies differ, without any account taken of this. They are often “get out of jail” kinds of nonsense. Retail packed electrical accessories often say something like “refer to an electrician”, when not doing this is why they sell retail packed items! For major products, they are often worse, with comments like “caution hot surfaces, may cause serious burns” on a cooker! The same is written on some 6W LED lamps, they hardly get warm. As above, showers now seem to have strange instructions too. They try to specify a cable size, a breaker rating but do not mention the bonding requirements for bathrooms, or the cable installation method, and are based on 24/7 operation that cannot be sustained by the shower itself. They often require RCD protection which BS7671 may not. This is all very bad indeed.

Yep True Dave.

As an aside, remember I`ve mentioned that a customer was slating a previous contractor over “wrong cable size (the man from the council told me he had done that”. When I looked at it, it turned out the contractor had gone over the minimum size required an I suspect the council chappy had remarked something like “it`s larger than it needs to be” and this got wrongly translated as wrong cable size. I`ve seen other instances of such things in electrically unrelated speak too

davezawadi (David Stone): 
… comments like “caution hot surfaces, may cause serious burns” on a cooker!

I put this in the same league as, “walnut cake - danger, may contain nuts” and, “whole salmon - danger, may contain bones”. May or does? ?

davezawadi (David Stone): 
 

This is ridiculous, why are some comments trying to justify the unjustifiable? This is another manifestation of the “Manufacturers Instructions” problem, or at least is likely to be. If the manufacturer wants the supply fused at some value, they should fit the MCB to the product, or a fuse. If the design is so bad as to need a 40A rather than 50A breaker it is fundamentally flawed and should not be offered for sale.

Nonsense. According to this, even for a new circuit or new build, the customer has to pay for two breakers (the one specified by David in the appliance, and the one required by BS 7671 and common-sense at the CU) and potentially larger cable where selectivity is required … looks like that could turn into ill thought-through legislation or guidance.

The circuit should be arranged to suit the load, not some arbitrary assumptions.

It's like saying that everything connecting by BS 1363 FCUs should be capable of being protected by a 13 A fuse because that's what most new BS 1363 FCUs come with …