Discuss AFDDs for single-socket circuits in the UK Electrical Forum area at ElectriciansForums.net

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Haven't been on here for a while, so sorry if this has been discussed before.

BS7671 2018 + A2 Regulation 421.1.7 recommends AFDDs for "single-phase AC circuits supplying socket outlets..." (requires in certain premises). My intention is that from September 27th I will recommend them to customers (in practice I already do in some situations) and require a signed waiver if they don't want the expense. At least I will do so for the actual Sockets Circuits - typically ring final, serving a number of sockets for general use and sometimes also fixed equipment via FCUs.

What I'm not sure about is circuits that serve just a single socket, such as a dedicated circuit for a fridge or an oven. In the case of a fridge, it will likely draw less than 2A, so an AFDD is unlikely to perform any useful function. In the case of an oven, one could justify cutting off the plug and connecting it via an FCU, in which case the circuit is no longer supplying a socket, yet with or without a socket it's still the same appliance and the same wiring. Yet in both cases if a socket is fitted an AFDD is recommended according to the regs.

BTW I understand a case could be made for AFDD protection for an oven and oven circuit. But for this question I'm just interested in the definition of 'circuits supplying socket outlets' for the purposes of this recommendation.
 
I'll be honest - you have more enthusiasm than me!

Personally I'm not in a hurry to make the manufacturers any richer and I only fit them if required. Quoting for them for other jobs just makes me look (even more) insanely expensive compared to the chancers who fit the cheapest dual-rcd board they can find at Screwfix and bang test it.

I don't quite understand why you'd require signed waivers for something that is just a recommendation unless it's a scaremongering technique.
How will this work in practise, will you double the admin and quote for the job with and without them and then ask for a signed waiver if they choose the cheaper option?
Will you also ask for a waiver for other recommendations in A2, such as adding an earth electrode to a PME system?
 
Until I can fit an AFFDDD board for roughly the same price as I can currently install a full RCBO board then I ain't fitting AFFDDDs

Speaking to other electricians locally we don't want them and don't want to be forced to use them
 
I'll be honest - you have more enthusiasm than me!

Personally I'm not in a hurry to make the manufacturers any richer and I only fit them if required. Quoting for them for other jobs just makes me look (even more) insanely expensive compared to the chancers who fit the cheapest dual-rcd board they can find at Screwfix and bang test it.

I don't quite understand why you'd require signed waivers for something that is just a recommendation unless it's a scaremongering technique.
How will this work in practise, will you double the admin and quote for the job with and without them and then ask for a signed waiver if they choose the cheaper option?
Will you also ask for a waiver for other recommendations in A2, such as adding an earth electrode to a PME system?
Thanks for reply timhoward.

So here's my thinking: I'm ideologically in favour of giving the customer as much choice as possible. For a while I have, where appropriate, quoted for a 'bare bones' job as cheaply as possible (to secure the job), and offered optional extras / pricier options that people can choose if they wish, that gives me the chance to make some actual profit instead of just keeping things ticking over. I do find there are some people who just want the cheapest, and other people who will tick every box so to speak for all the extras. It's not always obvious to me who will be which, and I do think it should be their decision. So I quite like these recommendations rather than requirements.

The challenges are two-fold: how to explain the advantages of the more expensive options in language they can understand so they can make an informed choice, and how to cover myself in case something goes wrong at some point and someone turns round and accuses me for not 'following official recommendations' or such like (hence the waiver). Not a scaremongering technique - just wanting to be sure I'm covered.

Yes, that's how I intend to do it in practice. As I see it doubling the admin goes with giving people the choice. When I started out I used to ask people a lot of questions about what they wanted when I visited, but quickly realised they couldn't answer until they knew how much each option would cost. As for the other recommendations, yes, I've prepared a 'delete as appropriate' waiver covering each of SPDs, AFDDs and earth electrodes.
 
Until I can fit an AFFDDD board for roughly the same price as I can currently install a full RCBO board then I ain't fitting AFFDDDs

Speaking to other electricians locally we don't want them and don't want to be forced to use them
Ahhhh yes but the customer might want them and might be happy to pay for them. Who am I to make a value judgement on their cost/benefit analysis?

Personally if I was doing a CU in my own home I'd probably fit an AFDD for the kitchen sockets but not bother elsewhere.
 
It’s always interesting to hear how other people approach their business. Thanks for sharing.
We agree on the point of helping customers understand complicated things using simple non technical terms. I’m quite passionate about that - if they are going to pay more for an RCBO board (for example) I want them to understand the benefits.

I think my struggle is that I’m not personally convinced AFDDs are going to save many lives. I’m aware of the argument that one life saved anywhere makes it worthwhile. But when nothing I’ve worked on over the last 20 years has had a subsequent electrical fire it’s hard for me to tell people it’s money well spent.
It feels more likely to be properties that aren’t being tested, inspected, and upgraded that need the AFDD technology the most and of course they are the ones that won’t get it.

I’m trying to keep an open mind about them nonetheless!
 
if houses and flats were burning down left right and centre due to loose connections and arc faults then I would be the first to be pricing AFFDDDs to my board swaps. My clients for most part are very well off and wouldn't bat an eyelid to a new £2000 consumer unit.
I just haven't seen enough evidence in front of me to suggest AFFDDDS are really a necessary Evil
 
It’s always interesting to hear how other people approach their business. Thanks for sharing.
We agree on the point of helping customers understand complicated things using simple non technical terms. I’m quite passionate about that - if they are going to pay more for an RCBO board (for example) I want them to understand the benefits.

I think my struggle is that I’m not personally convinced AFDDs are going to save many lives. I’m aware of the argument that one life saved anywhere makes it worthwhile. But when nothing I’ve worked on over the last 20 years has had a subsequent electrical fire it’s hard for me to tell people it’s money well spent.
It feels more likely to be properties that aren’t being tested, inspected, and upgraded that need the AFDD technology the most and of course they are the ones that won’t get it.

I’m trying to keep an open mind about them nonetheless!
You're welcome! And thanks also!

You may be right that they will not save many lives. And I'm not a proponent of the 'one life anywhere' argument - it may sound callous but what do we all eat if we put all our resources into saving one life? Everything is a risk/benefit analysis. It's a difficult judgement call with a fair bit of uncertainty, but IMHO one that should ultimately be the customer's. They might want to consider risk of damage to property as well as risk to life.

For me the recommendation in the regs is for the customer - the property owner is the duty holder at the end of the day. So if I don't tell the customer about the recommendation they could reasonably argue that I had been negligent in not giving them that information. That's where my waiver comes in - to prove I've informed them and they have made the choice.

That's a good track record you have. Thankfully I can say the same for my 10 years. Bare in mind AFDDs may have more to do with dodgy white goods than the fixed installation. Something I'd probably say to customers verbally rather than putting in writing with named manufacturers!
 
if houses and flats were burning down left right and centre due to loose connections and arc faults then I would be the first to be pricing AFFDDDs to my board swaps. My clients for most part are very well off and wouldn't bat an eyelid to a new £2000 consumer unit.
I just haven't seen enough evidence in front of me to suggest AFFDDDS are really a necessary Evil
Yes, but quite a few white goods. Including some high profile cases.
 
if houses and flats were burning down left right and centre due to loose connections and arc faults then I would be the first to be pricing AFFDDDs to my board swaps. My clients for most part are very well off and wouldn't bat an eyelid to a new £2000 consumer unit.
I just haven't seen enough evidence in front of me to suggest AFFDDDS are really a necessary Evil
Arc Fault Finding Damage Detection Devices?
 
You need to give more info such as the nature of the premises and whether afdds are actually required. Are you getting some crossover confusion with spds.
 
In the next few months I feel AFDD's are going to be one of the most debated parts of AMD 2 and lets not forget our colleagues across the pond have had AFCI's for many years and there seems to be a consensus that they don't always work as they should over there
When the AFDD first appeared 4 - 5 years ago with an eyewatering cost attached I was curious as to the benefits and if there were any negatives so at one or two of the Elex shows I spent some time talking to the manufacturer's of the devices and also the test equipment manufacturer's
As you would expect the manufacturer's who had AFDD's on display were very pro fitting them ( they would at £200 each) but aside from the test button on the front they had no external test equipment to demonstrate them like you would an RCD and you had to accept with blind faith that they would operate as the manufacturer's expected under fault conditions
Then we come to the test equipment manufacturer's and with the different arc fault signatures they said they had no way of verfying the operation of an AFDD or identifying the existance of a potential arc fault on the circuit and it's location on the circuit

So we fit an AFDD or multiple AFDD's on an installation and one trips what is the course of action, does the householder just reset it and let the problem develop and at what point do they get the electrician in. No doubt if the AFDD tripping icreases to the point of being inconvienient the electrician will be called and then the question is what can we do to check the operation of the AFDD and then the integrity of the circuit the answer I got from one test equipment manufacturer was replace the AFDD if that doesn't solve the problem then rewire the circuit.
Earlier this year I came across the Hager AFDD that can be reprogrammed but having seen it in the flesh at one of the shows and now having thought a bit more about what they said at the time it brings up more questions which I hope to get answered at one of the upcoming shows

I have to admit after 40+ years on the tools I'm quite sceptical of these AFDD devices I can only think of a couple of faults I have been called to in that time that MAY have been detected a bit earlier with an AFDD but then they may not
Bare in mind AFDDs may have more to do with dodgy white goods than the fixed installation.
So why is the onus being placed on the installation to prevent dodgy white goods causing problems it starts to blur the lines when it comes to PAT as to whether appliances should be tested as part of the EICR
 
You need to give more info such as the nature of the premises and whether afdds are actually required. Are you getting some crossover confusion with spds.
Thanks for reply - I should have been clearer, this doesn't relate to a specific job but is just me thinking around the issues. Most of the premises I work on are not 'high risk' or otherwise required to have AFDDs.

I'm aware of the fact SPDs are required unless the customer opts out, while AFDDs are only recommended, but I still think liability could arise if one can't prove the customer was informed of the recommendation and made their own choice.
 
In the next few months I feel AFDD's are going to be one of the most debated parts of AMD 2 and lets not forget our colleagues across the pond have had AFCI's for many years and there seems to be a consensus that they don't always work as they should over there
When the AFDD first appeared 4 - 5 years ago with an eyewatering cost attached I was curious as to the benefits and if there were any negatives so at one or two of the Elex shows I spent some time talking to the manufacturer's of the devices and also the test equipment manufacturer's
As you would expect the manufacturer's who had AFDD's on display were very pro fitting them ( they would at £200 each) but aside from the test button on the front they had no external test equipment to demonstrate them like you would an RCD and you had to accept with blind faith that they would operate as the manufacturer's expected under fault conditions
Then we come to the test equipment manufacturer's and with the different arc fault signatures they said they had no way of verfying the operation of an AFDD or identifying the existance of a potential arc fault on the circuit and it's location on the circuit

So we fit an AFDD or multiple AFDD's on an installation and one trips what is the course of action, does the householder just reset it and let the problem develop and at what point do they get the electrician in. No doubt if the AFDD tripping icreases to the point of being inconvienient the electrician will be called and then the question is what can we do to check the operation of the AFDD and then the integrity of the circuit the answer I got from one test equipment manufacturer was replace the AFDD if that doesn't solve the problem then rewire the circuit.
Earlier this year I came across the Hager AFDD that can be reprogrammed but having seen it in the flesh at one of the shows and now having thought a bit more about what they said at the time it brings up more questions which I hope to get answered at one of the upcoming shows

I have to admit after 40+ years on the tools I'm quite sceptical of these AFDD devices I can only think of a couple of faults I have been called to in that time that MAY have been detected a bit earlier with an AFDD but then they may not

So why is the onus being placed on the installation to prevent dodgy white goods causing problems it starts to blur the lines when it comes to PAT as to whether appliances should be tested as part of the EICR
Lots of interesting info, thanks. The issue of how to track down a fault is one thing that concerns me, too. I think I'd probably proceed something like this:

1. Ask the customer to switch everything off and see if it will reset. If so ask them to try to note over time if it trips when a particular appliance is switched on etc. If suspect appliances found try to move them to another circuit if possible to see if the fault moves with the appliance.

2. Try swapping the AFDD - with another in the same CU if one of the same rating is present. Then see if the fault goes with the AFDD or stays with the circuit.

3. Check for loose connections, dodgy switches etc. and tighten/replace as appropriate.

4. Examine all visible wiring of circuit in loft, basement etc.

5. Ask if the customer minds part of the circuit being temporarily disconnected to see if the fault persists.

6. Only rewire as a last resort.

A far from ideal situation for sure.

As for why the onus is placed on us, I have heard it said that it is because the manufacturers sit on the JPEL committee and essentially they want to keep selling Ch*n*se junk with western brand names on the front with impunity. Whether that is the case I have no way of knowing.
 
Thanks for reply - I should have been clearer, this doesn't relate to a specific job but is just me thinking around the issues. Most of the premises I work on are not 'high risk' or otherwise required to have AFDDs.

I'm aware of the fact SPDs are required unless the customer opts out, while AFDDs are only recommended, but I still think liability could arise if one can't prove the customer was informed of the recommendation and made their own choice.
Yes AFDDs are only a recommendation but after September will need a waiver signed by the client to say they dont want them, which will cover you when their tv blows up and they say you didnt recommend using one
 
My own belief is SPDs (and metal CU) are both good things to justify the cost and regulations behind them. The SPD is typically well under £100 now for the whole domestic installation* so not too onerous when doing a CU change or similar. Also SPD are likely to reduce the failure rate of some items, but probably not that much compared to not buying cheap crap in the first place.

AFDD are an item I am sceptical about for the reasons that @UNG has already outlined. I asked the speaker at the recent "18th AM2" event CEF held about it and he told us, perhaps a bit superciliously, just to trust the manufacturer's self-test on this. In my view if you can measure/verify something then it really fails on the purpose and specification front.

[*] If you have a big installation with multiple DB and it has a lightning protection system you might need type 1 at then incoming point and also type 2 SPDs at the other sub-DBs.
 
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In terms of the OP's original point I don't see any problem with offering AFDD as an extra-cost option for properties where they are not mandatory but it is going to be only a few who will spend the extra on them. Not sure anyone has written a fair and balanced guide for the public on this yet?

Perhaps in a couple of years they will be down at similar prices to RCBOs and then less of an issue, but we still have to see how well our AFDD fare in terms of unexplained trips versus the poor reputation the American AFCI have.
 
Although I get it that some people are reluctant to fit AFDDs partly because no testing can be done, bear in mind we don't test MCBs either.
 
Although I get it that some people are reluctant to fit AFDDs partly because no testing can be done, bear in mind we don't test MCBs either.
The fact we can't test them is neither here nor there Imo , as you say we fit millions of MCBs each month and have no idea if they work proper or not.
My issue with AFFDDDs is I honestly don't feel that they are necessary in the UK
 
The fact we can't test them is neither here nor there Imo , as you say we fit millions of MCBs each month and have no idea if they work proper or not.
My issue with AFFDDDs is I honestly don't feel that they are necessary in the UK

Yes, but I was specifically referring to the issue that gets raised about being unable to test them.
 
if houses and flats were burning down left right and centre due to loose connections and arc faults then I would be the first to be pricing AFFDDDs to my board swaps. My clients for most part are very well off and wouldn't bat an eyelid to a new £2000 consumer unit.
I just haven't seen enough evidence in front of me to suggest AFFDDDS are really a necessary Evil
Quite, AFDFs are a solution in desperate need of a problem.
 
The fact we can't test them is neither here nor there Imo , as you say we fit millions of MCBs each month and have no idea if they work proper or not.
My issue with AFFDDDs is I honestly don't feel that they are necessary in the UK

Yes we do, but MCB's are batch tested and generally proven to be a pretty reliable technology. Plus they are a fairly basic mechanical device which doesn't rely on electronics.
Plus if an MCB is tripping it is almost always possible to find the cause with regular test equipment that we all have. We can pretty easily test whether an MCB is over-sensitive.

Afdds are presumably also batch tested, but they rely on sophisticated electronics to work which increases the opportunity for failures, especially when engineered down to a price.
We have no way of realistically testing for what may have caused an afdd to trip at the moment, and no way to work out if it is being over-sensitive.
 
I remember a few years ago watching a YouTube video of an electrician trying to get to the bottom of a tripping AFCI on a socket circuit on a new house. He couldn't get the AFCI to hold in SO guess what he did...

Removed the AFCi and put the circuit on a standard MCB

If that is the American solution to a tripping AFCi then why bother in the first place ?
 
Although I get it that some people are reluctant to fit AFDDs partly because no testing can be done, bear in mind we don't test MCBs either.
True, although at least in the event of an MCB trip we can break up and test sections of the circuit to find the location of the fault.
 
Although I get it that some people are reluctant to fit AFDDs partly because no testing can be done, bear in mind we don't test MCBs either.
If we wanted to spend a lot of money there is test equipment available for MCB's, I have done many searches for AFDD test equipment and found none
The fact we can't test them is neither here nor there Imo , as you say we fit millions of MCBs each month and have no idea if they work proper or not.
My issue with AFFDDDs is I honestly don't feel that they are necessary in the UK
MCB's are so cheap that no one really bothers if a suspect one is replaced, a suspect AFDD replacement is a considered cost and the decision can't be taken lightly
From what I have seen on YouTube from America the more expensive AFCI / AFFDDDs are Self Testing
How do you have faith and trust in a self test, the AFDD says it is working correctly so it must be right and the circuit is faulty and so the pantomime starts. It says it all with AFDD's when Hager has produced an AFDD that can be reprogrammed to ignore circuit noise that the AFDD may inadvertantly react to
Afdds are presumably also batch tested, but they rely on sophisticated electronics to work which increases the opportunity for failures, especially when engineered down to a price.
And firmware / software that could become corrupt from mains noise or voltage spikes is that why the SPD came before the AFDD
We have no way of realistically testing for what may have caused an afdd to trip at the moment, and no way to work out if it is being over-sensitive.
As previously mentioned Hager do have monitoring tools and their AFDD can be reproogrammed but I can't help but feel it's a kings new clothes situation you programme out the senstivity and all you end up with is a fancy bit of kit in the box to meet the requirements of the regs but it performs no other function

In recent years we have had requirements to fit SPD's and now AFDD's but nowhere have I seen any documentation, facts or real world reasons / case studies to support there introduction or to enable us to better inform our clients and customers as to the benefits of having them installed in their installation
 
Rather than messing about with Waivers

I will probably end up doing 2 quotes for future board changes

Quote 1 - The expensive option with AFFDDDs

Quote 2 - The slightly less expensive option without AFFDDDs

On the bottom of quote 2 , it is say that AFFDDDs were offered as an upgraded option but declined
 
3 mins into vid
1660581698457.png
None of that text is in the regs.
They have made it look like it is, but it isn't.

All the regs say is:
"For other premises, the use of AFDDs conforming to BS EN 62606 is recommended for single-phases AC final circuits supplying socket-outlets not exceeding 32A"
 
None of that text is in the regs.
They have made it look like it is, but it isn't.

All the regs say is:
"For other premises, the use of AFDDs conforming to BS EN 62606 is recommended for single-phases AC final circuits supplying socket-outlets not exceeding 32A"
If you dont want to cover your backside....... You carry on then.......
 
I guess the other thing to possibly consider , if if you fit a fully RCBOs board as the customer can't afford the upgrade to AFFDDDs , should we make sure that we are fitting boards that at a latter date the home owner could swap out some of the RCBOs for AFFDDDs. Will all makes of consumer unit offer a AFFDDD that will fit in a single way in their current board models
 
As AFDDs are recommended in all other situations than those specified in the regs, some installers would choose to pass on the recommendation (along with the cost).

But there are many uses of the word "recommended" in the regs. Should we follow the same logic of covering our own arrses and pass on these recommendations as well?
 
If you dont want to cover your backside....... You carry on then.......
I don't actually feel any need to when page 18 of the regs clearly defines normative and informative elements.
As @loz2754 points out it would be a long list to get waivers signed for everything that is recommended that we don't do.

I prefer to tell customers what is required and what is recommended and help them make informed choices. Making them sign something is (to my mind) creating a false impression of severity relating to the consequences.
 
Ahhhh yes but the customer might want them and might be happy to pay for them. Who am I to make a value judgement on their cost/benefit analysis?

Personally if I was doing a CU in my own home I'd probably fit an AFDD for the kitchen sockets but not bother elsewhere.
You should also point out to the customer that the device will fail at some point, but you don't know when :)
 
Ha that’s a good one! Must be a manufacturers video

what works are not primarily designed and engineered around cost 🙄

so how much is a CU change going to be now approx?

8-10 type A rcbos, SPD, 12way board with main switch, approx 3 afdds for socket circuits, plus bits and pieces, days labour for fitting and testing, plus allowance for returning to site for further investigation if afdd starts playing up on an appliance that you couldn't detect during testing

must be talking £1000-1200 plus a bit of VAT

thats going to be a hard sell for most electricians I would guess depending on your area in the country

like others have said, I think I will be offering budget, mid-range and premium versions of a consumer unit change
 

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Just now a quick search for the Fusebox brand has RCBO for around £15+VAT and AFDD for around £105+VAT, so around £110 extra parts cost per circuit to the customer (inc VAT), and a bit of margin for returns and call outs for odd trips, so say £150.

Not sure what is typical for a home these days, but it is looking like £300-450 extra if you have 2-3 RFC and if not much else (couple of lights, couple of fixed kitchen appliances), then it is probably adding 50% to a CU change?

Some folk won't have issues with the cost but I bet the majority of customers do! More so when it is a hard sell as to what they really offer in terms of improved safety. We see general fire stats quoted from time to time but so far I have not seen an analysis of what AFDD would have likely stopped versus stuff they would not have detected.

Sure if the were down to £20 versus £15 for RCBO then nobody is going to have a big issue with them, but just now it is going to be a problem for many.
 
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More so when it is a hard sell as to what they really offer in terms of improved safety
There's a certain amount of chicken and egg here, until they end up in more installations we won't see if electrical fire statistics fall in general terms.
What could completely throw the stats is lockdown and the amount of time people spent working at home, and then people returning to workplaces, leading to a rise and fall in domestic fires.

I've had a quick look at some publicly available data:

Percentage of fires, non-fatal casualties and fire-related fatalities in accidental dwelling fires by selected sources of ignition, England; year ending March 2020
1660640070695.png

So electrical-appliance ignition source caused 13% of fires and accounted for 4% of fatalities.
Electrical distribution ignition sources are in fact killing more people.
(Space-heating source fatalities are really quite scary - people plugging in a fan heater in one room and not running the CH is going to be a real issue)

But maybe more relevant is this graph (same year)
Percentage of fires in accidental dwelling, fires by cause of fire, England; year ending March 2020
1660640751021.png

My conclusion for now - If 15% of fires are being caused by faulty appliances then maybe our advice should simply be that AFDDs are an attempt to bring down that number. The reality is that we won't know if it works for several years.

What could help would be some government funded TV adverts, like the original "Wake up - get a smoke alarm" campaign.
 

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