ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades AFDD's coming to the UK

In our latest lot of regulations and standards, these things are mandated to be installed in new installations.
I can hear the cries of safety for the sake of money gathering, just like it was when RCD's had to be installed on everything but a dog kennel.
It doesn't matter that the wiring is poor, just throw an RCD on it.

AFDDs did a lot of good in places without RCD protection. If there's already an RCD fitted for the whole house, it seems to be a case of diminishing returns.

Let us just remember Children,
The reason they have AFFD's in the US, is because it has a voltage of 120VAC to the sockets and the lighting circuits.
This would require twice the Cross-sectional area of circuit conductors, as opposed to 230VAC.
Some could also be Aluminium conductors.
There has also been anecdotal evidence in the US, that if you are unfortunate enough to live next door to a radio ham that uses RF power in excess of 500W eirp, you can have your AAFD's trip, when they use SSB modes.
Shnieder and other manufacturers have been trying to sort this out, with, seemingly no luck, thus far.

I don't see how a lower voltage could cause greater incidence of arcing faults. Most are traced back to bad connections, not failures of the conductors. I am not going to say there is a proven benefit to AFCIs but in theory they do add a level of safety. I also know they were sold to NFPA by Cuttler Hammer with a lot of snake oil. In fact they hit the 99 code, to be implemented the 02 before C/H even had a working model in the market place. After almost 20 years of field experience and development, they do seem to be working as intended. The early ones were dodgy tho. Only one company I know of (SqD) actually recalled marginally performing units and I doubt half of them were actually replaced on the recall although I suspect many more were simply thrown away and replaced with a regular breaker. Some will argue they prevented "X" number of fires but that is like proving a negative. You just have to believe those fires didn't happen and they would have without the AFCI, then let your damage estimates run wild.

I've read rather convincing arguments that blanket 30 mA RCD protection in domestic installations would catch most arc faults because even inline arcs and L-N faults quickly lead to insulation breakdown.