MCB, RCD & AFDD all in one

Zdb · Jul 7, 2018

These things are blooming huge!

Oh and £170

Rockingit · Jul 8, 2018

Wes1000 said:
Or is it aimed at blocks of flats too??

May also make sense since Grenfell but then you'd have thought they'd listed BMO's

rolyberkin · Jul 8, 2018

Recommended is too ambiguous to cause me any concern, by the time the reg becomes mandatory they will have tumbled in price and be the size of a single rcbo. Next!

Nigel · Jul 8, 2018

anthonybragg said:
That's my take on it.

I agree. Blocks of flats are dwellings. Not sleeping accommodation.

Wes1000 · Jul 9, 2018

Flats and HMO etc will be saved for the next book then?

Nigel · Jul 13, 2018

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.

??????

Pete999 · Jul 13, 2018

essex said:
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.

EalingBadger · Jul 15, 2018

Pete999 said:
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.

Can anybody throw any further light on this?

It seems a crazy limitation.

Deleted member 26818 · Jul 15, 2018

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.

EalingBadger · Jul 15, 2018

spinlondon said:
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.

Ah, yes. Good point. Obvious when one gives it the merest moment of thought.

Wes1000 · Jul 15, 2018

They will work on parallel arc faults on an RFC but won’t detect a series fault on the ring itself although they will detect both types of arc on any equipment connected to the ring or spurs etc as there is no additional leg to compensate.

Nigel · Jul 15, 2018

In conclusion if you are installing sockets in a building that requires AFDDs don’t install RFCs.

Marvo · Jul 15, 2018

Whilst AFD's don't detect series arc faults on a ring final cct that mode of fault is not as dangerous on a ring because of the parallel path available for the load current so it's kinda swings and roundabouts....

paullyons · Jul 17, 2018

This may shed a bit more light on what the future holds

johnduffell · Jul 17, 2018

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.

Bobster · Jul 18, 2018

johnduffell said:
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.

But if a fuse blows or an MCB trips you have test equipment to diagnose the fault quickly and reliably every time.

No such thing with these devices, one might keep tripping due to a natural arc in a circuit (something switching). How do you fault find that.... just start replacing parts at an unnecessary cost.