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AFDDs - when do they work?

alanblaby

I'm struggling to see the benefots of fitting AFDD's.

I've searched the web, but cannot find any compelling evidence that they actually help in safety.

 The Proffesional Journals all say they are a good thing, but with little content to show the data used to show they make a difference.

As we know, many fires are not caused by arcs, the build up of fluff in a tumble dryer is a typical example.

When I did my Social Housing work, I found many burnt out shower switches, along with washing machine sockets and occasional cooker switches that were totally burnt around the terminals, yet, in many cases would still work until the switch finally fell apart. Clearly some of these switches had been arcing, then had fused the cable to the terminal, others showed black terminals with only a small contact area, thus heating the terminals and causing the 'fishy' smell, which was quite typical.

Is there any evidence that AFDD's would stop these failures?

What about internal appliance faults?

Wasnt Grenfell started in a fridge? If so, would AFDD detect that fault?

And, what are appliance manufacturers doing to make their goods safer? From what I see, there are still thin tin plate terminals on cookers,and poor, loose spade terminals inside firdges and other appliances.They are made to be as cheap as possible, and it shows when you tighten up a terminal, and it bends the back plate as it is so thin.   

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  • 0

    The Electrical fires part of the USA statistics is interesting in that they are significantly increasing over the last 13 years. They seem to stay at about 0.5% or so of all domestic fires, presumably the overall increase is loosely related to increased population. There is immediately a serious problem with the data, and that is that fixed wiring and appliances are not differentiated. Now as we seem to be saying that adding AFDDs may combat appliance fires (many caveats there)and I am not one to lie with statistics, surely there should be some determinable decrease, but there is not, and the data is really fairly random, year on year. This, and the small number of electrical fires implies that there is not a good statistical significance to these counts and we would have to apply multi-variate analysis to make much headway. As this is a significant computer task and there is not really a lot of data, I suspect that any answers would not be much use. If we had the data for each state or even each City FD, a much better and more useful result could be expected. Overall my only simple conclusion is that AFDDs do not make a useful difference, and overall because of the small number of fires involved do not noticeably save lives or costs of fires. It looks that if cooking were changed to induction in place of gas (most of the USA tend towards gas cookers) we would probably make a bigger difference to the statistics overall, quite possibly at less cost. I mention induction hobs because I have some and they are MUCH less likely to overheat pans with inflammable contents, because the actual temperature can be controlled, rather than just the power input (as with normal gas and electric cookers). To fry something 180C is usually adequate, yet does not evaporate the oil sufficiently to ignite oil vapour. Woks from experience can be made to catch fire but only above about 240C! One for you too Chris.

  • 0 in reply to David Stone

    So to summarise, BS7671 mandated the fitting of AFDDs without evidence of any positive effect they might have, and are now waiting for the evidence to build up over time to prove that they work, so that in the end the story will fit the narrative.

    And of course, someone makes a lot of money in the meantime.

    Do I have that correct?

Reply
  • 0 in reply to David Stone

    So to summarise, BS7671 mandated the fitting of AFDDs without evidence of any positive effect they might have, and are now waiting for the evidence to build up over time to prove that they work, so that in the end the story will fit the narrative.

    And of course, someone makes a lot of money in the meantime.

    Do I have that correct?

Children
  • 0 in reply to whjohnson
    whjohnson said:

    So to summarise, BS7671 mandated the fitting of AFDDs without evidence of any positive effect they might have, and are now waiting for the evidence to build up over time to prove that they work, so that in the end the story will fit the narrative.

    And of course, someone makes a lot of money in the meantime.

    Do I have that correct?

    Not really, but if you want to be a journalist, go ahead.

  • 0 in reply to gkenyon

    Nothing journalistic about it Graham. Just a mere attempt at getting answers to some questions.

    Can you highlight the errors in my previous post and perhaps correct them?

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