Discuss MCB, RCD & AFDD all in one in the UK Electrical Forum area at ElectriciansForums.net
May also make sense since Grenfell but then you'd have thought they'd listed BMO'sOr is it aimed at blocks of flats too??
I agree. Blocks of flats are dwellings. Not sleeping accommodation.That's my take on it.
Also according to the NIC presenters, ADDS will not work on a RFC, they didn't give a very good explanation on the film they produced, but the fact that AFDDs won't work on a RFC according to them was something that stuck in my mind.Seems these things are elusive.
Eaton are quoting £160 per combined unit and a 16 day lead time.
They also do not do 3 phase units.
??????
Also according to the NIC presenters, ADDS will not work on a RFC, they didn't give a very good explanation on the film they produced, but the fact that AFDDs won't work on a RFC according to them was something that stuck in my mind.
Ah, yes. Good point. Obvious when one gives it the merest moment of thought.Perhaps they work by detecting the gaps in the flow of current caused between arcs.
An RFC would have the gaps in current on one conductor filled in by the current flow on the other conductor.
Things can be in the regs even without a tester - after all there's never been a tester for the magnetic or thermal parts of an MCB/RCBO, only for the residual current part. Dame goes for fuses for that matter. so we have no idea if they still work when doing inspection and testing.
'premises with sleeping accommodation' is a bit ambiguous, though. I'm assuming they mean hotels?
Yes, you can just look at the switch or at the melted fuse. But the same applies to the afdd. I thought people meant testing the device itself for correct operation, which you can only do with rcds.But if a fuse blows or an MCB trips you have test equipment to diagnose the fault quickly and reliably every time.
Yep.It is very ambiguous. The Oxford Dictionary says 'Accommodation' is "A room, group of rooms, or building in which someone may live or stay. ‘they were living in temporary accommodation’ "
Doesn't that put every house down as having "sleeping accommodation" ?
With fuses and mcbs you can only test the circuit.
With afdds not sure! Maybe neither?
Yep.
Fortunately 421.1.7 has two softeners for now. It says "If used..." and then gives "Examples of where such devices can be used...". This will change to "shall be used" at some point I guess.
If there is a fire and it goes to court and the court says "BS7671 recommend that you use Arc Fault Detection Devices. Why didn't you fit them?" Where would you stand from a legal point of view?
I think if you could demonstrate you'd suggested it to the customer and that they'd nearly choked on their tea when told the price, you'd be fairly safe as you would have done your part.
Good point @SparkyChick .
So you would have to do two quotes. One with AFDD's, explaining what they are and why you recommend them and a quote without. Then the responsibility is shifted to the customer.
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