AFCI

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tadavidson

tadavidson

Senior Member
Location
Georgia
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Electrical Contractor
During an in house training session regarding the "how's and why's" of AFCI circuit breakers we tested a Square D AFCI combination type breaker. In the test we used a jumper cord and a screwdriver on the ungrounded leg and made and broke the circuit using the screwdriver. The rapid "make and break" of the screwdriver to the screw on the breaker with the attached load of a vacuum cleaner with a "12 amp motor" never produced a trip condition. We did this for about 30 seconds continually. We had a lot of arching but no trip. What say you?
 
Gotta love it . . . and I'll bet the AFCI breaker "Test" button worked, BOTH before and after the screwdriver spark trial.
 
Two possible problems with the test:
1. Is the current seen by the AFCI above the (7A?) threshold for serial arc detection long enough to qualify? I would not necessarily believe the 12A figure, and the screwdriver connection will reduce the average current. The breaker will probably look at peak current on a cycle by cycle basis though.
2. The intermittent spark may not produce a large enough number of consecutive arc signature to qualify as a series arc event.

What you are doing is not a good simulation of what is expected of a series arc. Although some will argue that there is no such thing as a 120V series arc in the wild. :)

mobile
 
GoldDigger said:
Two possible problems with the test:
1. Is the current seen by the AFCI above the (7A?) threshold for serial arc detection long enough to qualify? I would not necessarily believe the 12A figure, and the screwdriver connection will reduce the average current. The breaker will probably look at peak current on a cycle by cycle basis though.
2. The intermittent spark may not produce a large enough number of consecutive arc signature to qualify as a series arc event.

What you are doing is not a good simulation of what is expected of a series arc. Although some will argue that there is no such thing as a 120V series arc in the wild. :)

mobile
Click to expand...
'
It was like Independence Day at the County Fair for a good 30 seconds. Idk
 
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