New fuse box?

[stillp]

High local ambient temperature, too high a loop impedance, coil of cable covered in inches of sawdust...
Might have been some other factors as well but these were enough for the customer's solicitors to back off!

 

[Echo the husky]

I'd have one of these in my house (I'm totally keeping that when it comes out next week )

That's an awesome fuseboard! I'd keep it too if I took it out. Strangely I saw the exact same model of bell transformer on a T+I at the end of last week!

 

[Iggifer]

That's an awesome fuseboard! I'd keep it too if I took it out. Strangely I saw the exact same model of bell transformer on a T+I at the end of last week!

It's a beaut. Seems to be in near mint condition, bar the holes for the tails. I can't see plastic consumer units lasting as long as that must have (metal ones, maybe)

The little Bill one just out of shot on the left is in pretty good condition too.

And, tbf, I think we need to refer to that as a fusebox, as that's entirely what it is, and presumably the design that that name came from

 

[JohnW2]

High local ambient temperature, .... coil of cable covered in inches of sawdust...

Does that mean that the fire arose in the extension lead, rather than the fixed wiring?

... too high a loop impedance

As I said, that ought to be irrelevant as far as the safety of the fixed wiring is concerned. Unless BS7671 has got it seriously wrong (and, on the contrary, I suspect they are being very conservative), an appropriately-rated (per BS7671) OPD should protect the (fixed wiring) cable adequately.

As for the extension lead, it's obviously down to whether the OPD protecting it is appropriate to the way in which it's being used (and 'coiled under inches of sawdust' might require a pretty low-rated one ).

Kind Regards, John

 

[stillp]

Does that mean that the fire arose in the extension lead, rather than the fixed wiring?

That's the problem, the extension lead was being used to operate an item that was intended to be properly connected to the installation via fixed wiring. The OCPD had been selected for the load and would have been correct had the installation been completed as designed, but, believe it or not, the electrician was on holiday! A production manager fitted the temporary solution to get the plant running, and it was then a low priority for the electrician when he returned... until the fire happened.

 

[JohnW2]

That's the problem, the extension lead was being used to operate an item that was intended to be properly connected to the installation via fixed wiring. The OCPD had been selected for the load and would have been correct had the installation been completed as designed ....

Fair enough. I therefore suppose it's an example of one of RF's scenarios, in which a "properly designed/installed installation" would not have 'needed' an RCD to prevent fire, since the OPD should have protected the relevant cables, but in which an RCD would probably have prevented the fire in the actual situation in which the installation was not "properly designed/installed" (installed in your case). It's therefore a bit different from the sort of situations I was talking about.

Ironically, in relation to your case, RF appeared to be suggesting that RCDs were rarely needed in commercial/industrial installations since, unlike domestic ones, they were usually 'properly designed and installed'

Kind Regards, John