Discuss AFDDs are a massive fraud in the Electrical Forum area at ElectriciansForums.net

Cookie

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Derailed another thread with AFDDs, so I am starting this one. I will simply say that UK RCDs and MCBs provide arc fault protection as is. UL not only knows that, but extensively researched UK power systems in an effort to emulate the very same concept 40 years. One the simply fact (growing concern) that the US National Electrical Code does not prohibit a maximum earth fault loop impedance.
 
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Cookie

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Here is the theory that started it all in the US:



First few minutes of this video explain it. Remember, the US has nothing on loop impedance and some US circuit breakers did not even have a magnetic trip function 40 years ago where as breakers in Europe did.




The the thing is, these uncleared short circuits as a result of lacking earth fault loop impedance are being incorrectly called "arcs"
 

Vortigern

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I have looked at your contributions regards RCD as AFDD and on the surface it seems a compelling argument that it is true that RCD are AFD devices. The technicalities presented certainly superficially are a revelation and indicate a massive fraud if it is true. I note the report is from the 1980s' and wonder if further work or research has been done on this to your knowledge. A cursory search reveals only info on AFDD info.
 
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Cookie

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And at 9:20 in the video, notice the extension cord being used in a deliberate attempt to elevate the loop impedance.
 
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Cookie

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I have looked at your contributions regards RCD as AFDD and on the surface it seems a compelling argument that it is true that RCD are AFD devices. The technicalities presented certainly superficially are a revelation and indicate a massive fraud if it is true. I note the report is from the 1980s' and wonder if further work or research has been done on this to your knowledge. A cursory search reveals only info on AFDD info.

Further work was extensively undertaken by UL both in cords and building wiring. Here is but one example:
 

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Lucien Nunes

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I don't have time now to get caught up in this debate, but one quick thought;

We have to be a careful comparing US 120V circuits with European 230V. I appreciate that many US buildings have a few 240V circuits too, but numerically the 120V circuit prevails. Some important parameters vary as the square of the voltage or current, so there can be a factor of four differentiating the behaviour of US and UK general purpose circuits. Series arcs also have noticeably different characteristics and form in different situations at 230V vs. 120V. When looking statistically at the causes of actual fires, as well as detail differences in electrical technique, such as the kind of conduit used (or not), one has to allow for differences in building construction, climate and other external factors that affect how a particular electrical event relates to a fire outcome.

It is a complex subject and for the fireside observer, personal opinions about 'fraud' and 'rip-offs' are likely to heavily bias the view of what little technical information is available from controlled studies.
 
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Cookie

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Eventually US manufacturers lowered or added magnetic trip to around 10x the handle rating.





The first AFCI was proposed to simply be a low magnetic trip breaker.

Research was done and it was theorized that the lowest perspective short circuit current at the panel (consumer unit) plus the highest anticipated circuit impedance would result in a minimum short circuit current of 75amps at the furthest point in the circuit.

However a 75 amp magnetic pickup would result on tripping on inrush with vaccuum cleaners, window ACs and even incandescent light bulbs burning out.

Thus came the idea of an electronic AFCI. One that could discriminate between the current surge of a vacuum cleaner starting and that of a short circuit. Although come reality electricians were and still do get call backs on vaccum cleaners and tools tripping AFCIs.

Even Joseph C Engel, one of the main developers of the electronic AFCIs now has his doubts:



My reply from my other thread:

An AFDD is money secured for the manufacturer. Come time AFDDs will probably have self test logic, meaning they will lock out every X years and require replacement. Already being done with US GFCIs.


AFCIs got into the NEC because manufacturers (like Eaton) bribed the code making panels and UL. They want to and are grdually doing the same with the IEC through committees.


Manufacturers know electrical equipment is near perfected and cheap, I mean what else is capable of lasting 60+ years? But if you require products through mandates, especially products that will require replacement the financial reward is in orders of magnitude greater then before. Investing millions will give you billions, and investing billions will give you trillions. With millions and billions its not hard to cook up a lie one great enough that most everyone will believe.
 
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Cookie

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I don't have time now to get caught up in this debate, but one quick thought;

We have to be a careful comparing US 120V circuits with European 230V. I appreciate that many US buildings have a few 240V circuits too, but numerically the 120V circuit prevails. Some important parameters vary as the square of the voltage or current, so there can be a factor of four differentiating the behaviour of US and UK general purpose circuits. Series arcs also have noticeably different characteristics and form in different situations at 230V vs. 120V. When looking statistically at the causes of actual fires, as well as detail differences in electrical technique, such as the kind of conduit used (or not), one has to allow for differences in building construction, climate and other external factors that affect how a particular electrical event relates to a fire outcome.

Of course. And do you seriously believe the IEC/BS7671 has not addressed the risk of of having a higher voltage to ground long ago?

Have a look at this:






The poster admits that it blew the 16 amp fuse the circuit was run for but not the 32 amp fuse. Further if that circuit had an RCD, the RCD would also have tripped since there is an earthing conductor sandwiched between the live and neutral.


Loop impedance, disconnect times and RCDs are not just about protecting people, but also mitigating fires as well.


The US on the other hand has never had disconnect times or loop impedance requirements...


It is a complex subject and for the fireside observer, personal opinions about 'fraud' and 'rip-offs' are likely to heavily bias the view of what little technical information is available from controlled studies.


The studies in of themselves show the history, one which says the UK system in its current state does the exact same thing as an AFCI.

Remember that this all started with people trying to emulate the British/EU system and thats stated on black and white.
 
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Cookie

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Wow. Its really antiques. Were you found it?

This site:





Reason I keep linking to him is that manufacturers were not only inspired by his theory, but UL also repeatedly sites his findings using it as a bases for picking up where he left off.
 
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Cookie

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To backup my claim about UL's desire for a 75 amp magnetic trip breaker, starting on page 8 with "Lowering the Instantaneous Trip Level of Circuit Breakers":




Page 11

The results of the study sponsored by the EIA determined that lowering the instantaneous trip level below 105 A rms would provide a greater potential reduction in fire risk. Lowering the instantaneous trip level to 75 A rms to cover all receptacles would also increase the possibility of nuisance tripping. AFCI technology, on the other hand, has the ability to detect the current signatures of parallel arcs so that the effective in stantaneous trip level can be lowered to 70 A rms without the increased risk of nuisance tripping.
 
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Pete999

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Derailed another thread with AFDDs, so I am starting this one. I will simply say that UK RCDs and MCBs provide arc fault protection as is. UL not only knows that, but extensively researched UK power systems in an effort to emulate the very same concept 40 years. One the simply fact (growing concern) that the US National Electrical Code does not prohibit a maximum earth fault loop impedance.
 

Vortigern

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The above states emphatically AFDD and RCD detect different events RCD does NOT detect arcs AFDD do. End of case? Not being an electrical engineer I would not like to hazard any conclusions on this but certainly something to think about.
 
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Cookie

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The above states emphatically AFDD and RCD detect different events RCD does NOT detect arcs AFDD do. End of case? Not being an electrical engineer I would not like to hazard any conclusions on this but certainly something to think about.
RCDs do not trip on a current ripple, but if the arc is going to ground you bet it will trip the RCD.
 
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Cookie

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That's what an RCD is designed for isn't it???

Yes, and if twin and earth is damaged a parallel arc is between two points: live to earth or live to neutral. Live to earth is covered with the RCD and breaker coil, live to neutral via the breaker's magnetic trip coil.

So any parallel protection an AFCI offers is redundant at best.
 

marconi

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Does anyone in the EF know what the 'tipping point' was to introduce the recent BS7671 requirements for AFDDs? Or did the technology and products become available and were then (necessarily) introduced into the B7671 requirements? Or has the requirement come from a fire brigade investigation and report as did the metal CUs.
 

Pete999

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Yes, and if twin and earth is damaged a parallel arc is between two points: live to earth or live to neutral. Live to earth is covered with the RCD and breaker coil, live to neutral via the breaker's magnetic trip coil.

So any parallel protection an AFCI offers is redundant at best.
Some sensing an Arc before it can produce any sort of heat makes it redundant does it? mind if I ask you a question? firstly you come on the Forum with a legitimate question about possible brown out in a Hospital complex, which turns into a thread comparing US and UK OCPDs RCDS and concluding your argument by saying AFDDs are redundant, Question what is your game?
 
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Cookie

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Some sensing an Arc before it can produce any sort of heat makes it redundant does it?
Well, I don't think you would be to happy if I told you arcing is the end stage of joule heating...


mind if I ask you a question? firstly you come on the Forum with a legitimate question about possible brown out in a Hospital complex, which turns into a thread comparing US and UK OCPDs RCDS and concluding your argument by saying AFDDs are redundant, Question what is your game?

Not so much comparing as showing proof of my claims. Manufacter backed UL and others were literally researching UK/EU power systems with the intent of emulating the system here in the US leading to electronic AFCIs. Now these same manufacturers turn to the IET/IEC claiming they have a new product solving a problem that no technology has ever tackled before.

I derailed in the hospital thread- but since the subject was touched I might as well let knowledge on this hot button issue spill out.
 

Pete999

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Well, I don't think you would be to happy if I told you arcing is the end stage of joule heating...





Not so much comparing as showing proof of my claims. Manufacter backed UL and others were literally researching UK/EU power systems with the intent of emulating the system here in the US leading to electronic AFCIs. Now these same manufacturers turn to the IET/IEC claiming they have a new product solving a problem that no technology has ever tackled before.

I derailed in the hospital thread- but since the subject was touched I might as well let knowledge on this hot button issue spill out.
Without going back over the entire thread, What or Who is UL?
 

Pete999

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Well, I don't think you would be to happy if I told you arcing is the end stage of joule heating...





Not so much comparing as showing proof of my claims. Manufacter backed UL and others were literally researching UK/EU power systems with the intent of emulating the system here in the US leading to electronic AFCIs. Now these same manufacturers turn to the IET/IEC claiming they have a new product solving a problem that no technology has ever tackled before.

I derailed in the hospital thread- but since the subject was touched I might as well let knowledge on this hot button issue spill out.
Well, I don't think you would be to happy if I told you arcing is the end stage of joule heating...





Not so much comparing as showing proof of my claims. Manufacter backed UL and others were literally researching UK/EU power systems with the intent of emulating the system here in the US leading to electronic AFCIs. Now these same manufacturers turn to the IET/IEC claiming they have a new product solving a problem that no technology has ever tackled before.

I derailed in the hospital thread- but since the subject was touched I might as well let knowledge on this hot button issue spill out.
Regarding your statement about joules and heating, the AFDD detects an Arc fault before it reverts to combustion, doesn't it?
 
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Cookie

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Regarding your statement about joules and heating, the AFDD detects an Arc fault before it reverts to combustion, doesn't it?

That what they claim.

Joule heating (aka high resistance connection) are responsible for most electrical fires and in of themselves do not produce arcing. When they do, it is often near the end stage (terminal is already glowing and falling apart), not the start.
 

Pete999

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That what they claim.

Joule heating (aka high resistance connection) are responsible for most electrical fires and in of themselves do not produce arcing. When they do, it is often near the end stage (terminal is already glowing and falling apart), not the start.
That would be when the AFDD trips the circuit Off then before that happens.
 
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Cookie

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That would be when the AFDD trips the circuit Off then before that happens.

Assuming 1) a fire has not started prior 2) the current is over 5 amps 3) the AFDD has successfully determined it to be dangerous arcing and not a drill or LED lamp waveform.
 

Midwest

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Wouldn't worry too much; not many are going to be installed over here
in a residential setting, anytime soon at £200ish a pop ( :) ). And the premises that can afford it, will have their own design consultants, paid to worry over such issues.
 
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Cookie

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Perhaps now, but give it time. They will not only become mandatory, but eventually require self test logic (planed obsolescence) with a slew of devices to also follow. The American NEC is already a product catalog and getting worse each cycle. 2020 is going to be raunchy.
 

Midwest

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Perhaps now, but give it time. They will not only become mandatory, but eventually require self test logic (planed obsolescence) with a slew of devices to also follow. The American NEC is already a product catalog and getting worse each cycle. 2020 is going to be raunchy.
What time is where you are? Sun's over the yardarm here, I'd recommend a stiff drink, or whatever trips your device.:)
 

telectrix

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Yes, and if twin and earth is damaged a parallel arc is between two points: live to earth or live to neutral. Live to earth is covered with the RCD and breaker coil, live to neutral via the breaker's magnetic trip coil.

So any parallel protection an AFCI offers is redundant at best.
what about an arc L-L or N-N? e.g. on a fractured cable.
 
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Cookie

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Here is how fast they are supposed to trip per UL1699 (in 8 half cycles) and IEC-62606:

 

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