Hi Folks,
I've been watching the videos of John Ward as of late, on YouTube.
His latest video struck me as strange, because I was not aware that AFDD's (AFCI's that our US members know so well), are now mandated in the latest change to the Regulations in the UK.

Here is a link to the video, where he tests one of these devices and gives his thoughts on it.

JW- AFDD's

They're slowly spreading across Europe. Germany's had (and cursed) them for a few years, although I've gathered they're no longer required, only recommended. I'm quite curious about Austria's new regs, I'll hopefully get some info on them next week. The last thing I've read about AFDDs is that there isn't much evidence of advantages in fire safety over blanket RCD protection. Most of the data seem to be from the US where, as we all know, earth leakage protection of entire circuits is fairly uncommon.

Germany got a new national standard in 2016 requiring them for special places like laboratories, childcare, retirement homes, museums, public buildings with irreplaceable goods (like a historic library), wooden homes (which are the minority here), wood working businesses etc.
The standard is applicable for new planning. There is no obligation to update existing buildings.

Of course we had discussions about the new standard only being implemented because the manufacturers want to sell afdds... I haven't had any experience yet and don't know about any nuisance tripping.

In the second video that JW posted, which I will link to below,
he tried the over-voltage test (device is meant to trip @ 270VAC)
and then there was the actual arc-fault trip test, where loose connections SHOULD
cause the device to trip.
The results are quite disappointing, especially from a company that I thought made quality
electrical controls equipment.

Have a look:
JW 2nd set of tests

They're coming to Austria as well... the new standard (OVE E-8101) is already published but not yet mandatory. They're required in sleeping quarters of nursing homes and kindergartens (essentially any building where the inhabitants are considered less likely to escape a fire, not that that makes much sense, no one is likely to survive a fire while asleep) and recommended for essentially the same building types as in Germany.

They've been introduced in the recent update to wiring rules in Ireland too IS 10101 (a rather heafty 700 page tome or digital download!)

There was also a change to the wiring regulations being controlled by the NSAI (National Standards Authority of Ireland), whereas previously it had been a managed by a body called the ETCI (Electrotechnical Council of Ireland) which has been scrapped. Also the CRU (Commission for Regulation of Utilities) has taken over parts of the inspection regimes etc.

AFDDs are recommended for all circuits where there is a particular risk. Now required in all sleeping accommodation and in areas with things like fuel storage, wooden structures, irreplaceable valuables etc etc.

It also extended RCDs to all circuits in residential type premises. Lighting circuits (other than outdoors and in bathrooms) had not required RCDs in previous rules.

AC Type RCDs are banned in residential and similar work.

We've also banned plastic distribution boards (consumer units). From this point on they must be made from materials that are completely non-combustable, which in practical reality means metal boards from now on in residential and small business etc.

Other than that the major updates are a requirement for cables to be CPR compliant, with a minimum rating of Class Dca s1b,d2,a2 as per EN 50575

There's some extra specifications for residential / small commercial electric vehicle charge points.

Also inspection and testing processes have been completely redesigned to bring them into full alignment with CENELEC standards and residential installation sign off must now also include checks for compliance with the Electromagnetic Compatibility (EMC) Directive 2014/30/EU.

Rings were banned in kitchen / laundry rooms in previous revisions back in 2008, so now the minimum requirement for a kitchen is two 20amp radials (with a recommendation of at least 10 sockets). Obviously this does not include fixed appliances etc.

The old British-type "Twin and earth" is no longer allowed either (previous updates to the wiring regs). The earth conductor must be the same size as the live and neutral conductor and must be separately insulated.

The other recent changes (going back a few years at this stage, I haven't posted here in a while!) has been the banning of DIY work other than like-for-like replacement of fittings and minor additions to existing circuits. Anything involving the distribution board is now off-limits, other than to licensed Electrical Contractors and you can be charged in court for doing so. There have been a few €3000 fines and one 6 month prison sentence so far, but this was for someone falsely portraying themselves as an EC and leaving a system in a highly dangerous situation, but at least the regulations are tightening.

These gimmicks of marketing hubris will not prevent a single fire. They were literally (in their full entirety) created to emulate the advantages of the British wiring system in a country where code legally lets you run circuits beyond a length which a short circuit will trip a breaker. They are now being touted as providing advanced fire protection in the IEC world when in reality the IEC standards have already been providing complete line to neutral and line to earth arc fault protection for at least the last 40-60 years.

This leaves series arcing claims, where arcing is the end stage, not the initiating trigger of joule heating- assuming building material has not already ignited. The down falls are furthered in that commercial AFCIs lack the computing power to accurately detect series arcing phenomenon due to a limited number of computing power having to take into account normal high frequency ripples produced by brush motors and switched mode power supplies.

Their spread has only come from manufacturer and IEC UL committee influence on the development of codes and standards.

I feel sorry for the misfeasance and malfeasance humanity lets itself endure...

My impression is that almost everything the AFDDs have done for the electrical fire statistics in the US could have been done much more cheaply with blanket 30 mA RCD protection, provided all fixed wiring contains a CPC (ground wire). Unless you're talking K&T wiring, a series arc due to a poor connection will involve the CPC within a very short period of time as insulation breaks down from the heat and trip the RCD.

I've grown up with TT supplies and therefore whole-house RCDs, first 100, then 30 mA and consider them the cheapest form of electrical fire and life insurance. The only non-RCD supplies I've ever seen were ancient setups that used the city's mains water network as a giant earth electrode. This practice was legal until 2001 but despite the low earth impedance, RCDs were usually added as early as the mid-1960s.

Very much so- early AFCIs had 30/50ma GFP protection built in which caught frequent code violations and damage to NM during rough in. In the last 10 years several manufacturers have taken it out- ironically over wiring errors causing nuisance tripping.

The CPSC's original concern regarding cords could have been met with fuses built into the cord cap. The level of protection would have been higher- AFCIs stop looking for parallel arcs below 75 amps. This value was based on the lowest anticipated short circuit levels in building wiring. However, beyond that at the zip cord level it is possible for short circuit levels to drop below 75 amps.

I'm not sure how goods are vetted over the pond, but i do know how they're tested here reveals a lot about their true functionality

this doc does that>

http://www.combinationafci.com/resources/doc_ieee_combination_afci.pdf

~S~

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.