Another AFCI question.

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IMHO all cases of signature based nuisance tripping of AFCIs (which by definition do not involve the GF detection component) are false series arc detections. Unlike parallel arc detection, a series arc signature trip only requires about 8A of current through the breaker.
On the other hand RF induced malfunctions of the electronics could affect a breaker even with zero current.
 
Field electricians can reliably observe most AFCI's trip by holding neutral and ground conductors in opposite dry hands, with light switch turned off, and hot wire capped.

Field observation demonstrates AFCI devices are monitoring this Neutral resistance to Ground, as it floats between AFCI breaker termination and load, to high resistance N-G in the hands. This observed AFCI trip mechanism is in addition to published electromagnetic wave-form signatures, with inherent nuisance trips from noise interference, RF, power-line transients, and some genuine arcing between appliances, wiring, and devices.

Building alterations by unqualified persons historically demonstrate the worst offenders of N-G wires spliced together, and finding multiple-circuit breakers (of same Leg) under same splice.

Therefore, IMHO remodel poisoned, open-permit renovations, and laborer-run track developments, are the battle-damaged buildings most likely to trip this N-G mechanism observed with AFCI's.
 
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romex jockey said:
would that be the 'supplemental afci' in 210.12?

~RJ~
Click to expand...

From the 2020:

https://imgur.com/QnXpRHv


The thing is all modern 15 and 20 amp circuit breakers have a 7-10X magnetic pickup which will work with their 50-70 feet home run restriction, where as older breakers have it set much higher or do not even have an instantaneous pickup altogether.

The code has never been explicit about this intent.

If an outlet AFCI is left interrupting a 6000 amp parellel arc fault it will in theory explode or catch fire. The idea (goal) of #3 being that if a parellel arc fault was in excess of a few hundred amps it would trip the breaker first protecting the AFCI receptacle.
 
mbrooke said:
From the 2020:

https://imgur.com/QnXpRHv


The thing is all modern 15 and 20 amp circuit breakers have a 7-10X magnetic pickup which will work with their 50-70 feet home run restriction, where as older breakers have it set much higher or do not even have an instantaneous pickup altogether.

The code has never been explicit about this intent.

If an outlet AFCI is left interrupting a 6000 amp parellel arc fault it will in theory explode or catch fire. The idea (goal) of #3 being that if a parellel arc fault was in excess of a few hundred amps it would trip the breaker first protecting the AFCI receptacle.
Click to expand...


But the 'intent' could be read into 210.12 A 3 b>>

(50 ft) for a 14 AWG
conductor or 21.3 m (70 ft) for a 12 AWG conductor.

Because it addresses 'mag trip' ......

Yet 406.3 D 4 (replacements) seems to not seem to specify this same supplemental ocpd

~RJ~
 
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