AFDDs are a massive fraud

[Cookie]

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":

https://www.cpsc.gov/s3fs-public/AFCIFireTechnology_0.pdf

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.

 

[Pete999]

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.

What you need to know about Arc Fault Detection Devices (AFDD’s)

New to the 18th Edition Wiring Regulations is the recommendation of AFDD's. We have put together a complete guide to help you understand what an AFDD is.

www.electriciancourses4u.co.uk

 

[The Ghost]

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.

 

[Cookie]

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.

 

[Pete999]

RCDs do not trip on a current ripple, but if the arc is going to ground you bet it will trip the RCD.

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

 

[Cookie]

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]

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]

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?

 

[Cookie]

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]

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?