421.1.201

Assuming you have no large stock, why would you want to do that? However, as I largely see the alleged problem as a storm in a teacup with an unknown cause, possibly meter installers, and completely defective operational procedures, it does not really come under the heading of domestic does it? Where is the bathroom and kitchen for example, although small commercial premises have both (shops) so the definition is rather vague, to say the least. I say carry on.

It's arguable. On the one hand, the premises include the main building, outbuildings, and grounds. On the other hand, a (large) garage could be fitted out like a small unit on an industrial estate.

Or again, imagine a terrace in a market town. The premises in what amounts to one building could include dwellings, shops, and workshops. It seems odd that different types of CU would be permitted.

The problem is that “domestic” and “household” are not defined in BS 7671.

Hello Zoomup. I agree with David; the rationale for specifying non-combustible consumer units in domestic premises is flawed, but we are now stuck with it. In the circumstances you describe, I would choose metal rather than plastic for installation, but if I happened to have an unused plastic CU on the van, all things being equal, I would be quite happy to fit it to the barn section.

 Where is the bathroom and kitchen for example, 

The large barn has no bathroom and kitchen, they are in the adjacent house.

Z.

davezawadi (David Stone): 
 

Assuming you have no large stock, why would you want to do that? However, as I largely see the alleged problem as a storm in a teacup with an unknown cause, possibly meter installers, and completely defective operational procedures, it does not really come under the heading of domestic does it? Where is the bathroom and kitchen for example, although small commercial premises have both (shops) so the definition is rather vague, to say the least. I say carry on.

Meter installers connect up new meters to grossly undersized and single insulated tails in my experience. They probably would not care.

Regarding “why would you want to do that,” well one reason falls under the popular phrase coined by Maria Edgeworth in “The Parents Assistant”. (Clue: W.N.W.N.)

Z.

I am with David Z. Why the hell would you want to do that? 

Is it you have an old plastic consumer unit you want to unload and you do not give a monkey's  about the safety of the consumer?

Given that a fully loaded 12 way steel consumer unit from a decent manufacturer  is circa £125 inc VAT gut the components from inside the plastic carp and drop it in the bin!

Would somebody explain why LFB demand M/C CCUs but the DNOs happily continue with plastic.?

So would a M/C CCU stop the propgation of a fire when the cabling is PVC.?

Legh

John Peckham: 
 

I am with David Z. Why the hell would you want to do that? 

Is it you have an old plastic consumer unit you want to unload and you do not give a monkey's  about the safety of the consumer?

Given that a fully loaded 12 way steel consumer unit from a decent manufacturer  is circa £125 inc VAT gut the components from inside the plastic carp and drop it in the bin!

It is the customer's request to use a cream coloured plastic consumer unit. It is of good reputation and made by a well known maker. Previous regs. have insisted on the use of all insulated enclosures for a TT earthed installation. It will never be fully loaded, and is positioned where in the very unlikely event of fire it will not spread. The walls are brick, the floor is concrete and the location is remote from any stored items.

I have installed many all insulated enclosures over many years and not one has caught fire.

We do not hear of London consumer units catching fire in the press these days. I wonder why not? And I imagine that they have not all been updated to non flammable metal types.

Why are we still using flammable P.V.C. as cable insulation in installations. Have you ever seen it burn? I can tell those that haven't that it does.

Oh, and the choice of the new boxed all insulated consumer unit is not about cost, the customer is loaded.

Historical report

Electrical Products - Fired-up over consumer units (eponthenet.net)

Z.

Metal consumer units do not have to be fire sealed and normal IP ratings apply and we are told they are not to stop fire just delay it to enable occupants to escape. So in an environment with is not residential, not very flammable, not on a fire escape route and not directly attached to a residential property I would say why not fit  plastic one.

I am not convinced that a metal CU fitted under the stairs in a cupboard stuffed with coats, toys, shoes all in contact with the CU is going to delay the fire much or give the occupiers notice that it is getting a bit hot. My record for the longest time to get to a CU under the stairs is about 10 minutes of pulling stuff out and trying to stack it nicely, there was a lot of stuff. Has anyone taken longer?

 On loose connections: I recently had a customer who had a smart meter fitted. A month later he had “no electric". I found no neutral connected on the supply, a dead smart meter and 240V L and N to the supply earth (PME). I suspected the smart meter and the DNO later confirmed a loose neutral connection on the tails to the smart meter which had finally given up when he tried to boil a kettle. He has sent a complaint to his supplier who fitted the smart meter but I have not seen hm to see if he had a response. The suppler would not take a complaint from the DNO engineer for data protection reasons as he was not the customer!

Zoomup: 

. . . Meter installers connect up new meters to grossly undersized and single insulated tails in my experience. . . 

I suspect a lot of UK Meter Installers are just that. Without being electricians and members of a competent person scheme, they may consider it high risk to replace the tails. 

Regards,

Alan.