AFCI/GFCI Lighting Issues

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
When I ran the carpenters circular saw, my two lighting circuits tripped in the GF position even though the outlet I was using was on a separate circuit.

Do you have a breaker with only a GFCI function in the panel? If so, you might try putting one of the LED lights on a GFCI breaker instead. If it also trips then that would confirm that it 's a GFCI type issue and not an AFCI one.

It's possible that the LED lights have some capacitance to ground,. Then if a noise voltage is induced on the bus by the circular saw, it could cause some common-mode noise current to flow through the capacitance and trip a GFCI. A suggestion is to temporarily disconnect the EGC to an LED light and see whether it still trips.
 

macmikeman

Senior Member
Ok, so sadly for you, you didn't put an Eaton load center in . Then we shall move on from that to asking if you tested the integrity of the insulation of the wiring using a Megger testing device. If the insulation tests out ok , and it is only when questionable "motor" devices are plugged in to the circuit, circular saws or some vacuums that the afci device trips, well then, welcome to hell since 1990.
 

Squish

Member
Location
Poughkeepsie, NY, Dutchess
Occupation
IBEW Electrician
Can you put a few amps more on the circuit like was mentioned before with a heater or dryer? I think it's picking up the arc signature through the buss and feeder. But this can rule out if it is a nuetral issue but just under the line for the 5ma
Plugged in a dryer and no issues. This combo breaker doesn’t seem to like this saw.
 

Flicker Index

Senior Member
Location
Pac NW
Occupation
Lights
http://www.arrl.org/news/arrl-helps...ve-arc-fault-circuit-interrupter-rfi-problems
Y'all might find this interesting.

The microprocessor is listening to the shunt or transducer output. If you were to link the transducer to an amplifier and put it through the speaker, you can hear what a certain load sounds like or what it's doing. Some can interpret things as a fault induced arc when it is not much like some but not all people mistake backfiring sound as gunshots.

If you were to rig in (downstream of a regular breaker) a different brand of AFCI in the place of a nuisance tripping GFCI in the same location and that AFCI doesn't trip, it could be the AFCI's design. Of course the solution isn't that simple if you can't find an AFCI without issues that is compatible with your panel...
 

mopowr steve

Senior Member
Location
NW Ohio
Occupation
Electrical contractor
Contractor saws are always tripping afci’s, and drywallers (well maybe more due to the condition of their cords)
Seems to be more prevalent with high current start up these kind of saws.
 
Top