arc fault combination breakers tripping

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c-pwhitson

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I have a 100 amp sub panel in garage.Garage plugs are on a dedicated circuit.There are two lighting circuits that serve an addition off this sub panel.When there is a large load like a chop saw or vacume plugged in to the garage plugs it trips both arc faults.The arc faults and garage breaker are all on the same phase.What is causing this? Could there be an existing plug on the same phase as garage and arc faults that has a nuetral and ground touching?I have checked for loose nuetrals every where.I also have another arc fault on a different phase that trips when another large load is plugged in.It doesn't trip right away.I think this might have something to do with the other problem.If I had a nuetral toughing a ground it would trip instant,this is not happening.Also a small load will not trip this either.
 
I had a problem like this once, I unplugged everything, lifted all neutrals and grounds, ohmed, nothing everything was good. Then I opened every receptacle, someone else had wired, they had stripped all the conductor back a little over an inch, I found one where only under load it was shorting, I don't remember exactly but I cleaned it up, everything works fine now. (Including the vaccuum.)
 
I found the problem there are flour fixtures in garage off sub panel but not on arc fault.These had electronic ballasts and the noise from ballsats were making arc faults trip.
 
You will have to explain to me why you believe fixtures that are not on the same circuit as the AFCI are causing them to trip. I have had the sparking brushes of a chop saw trip an AFCI. Shared neutrals are another problem.

Harmonics just doesn't sound right to me. Then again, cheaper than dirt Chinese made fixtures?
 
c-pwhitson said:
I found the problem there are flour fixtures in garage off sub panel but not on arc fault.These had electronic ballasts and the noise from ballsats were making arc faults trip.
Click to expand...

That is very interesting.
Is it correct that: you disconnected those ballasts , ran the saw and vacuum, and the AFCI held?

Then as soon as the ballasts were re-energized AND the saw or vacuum ran the AFCI trips?

What loads are directly fed by the AFCI, I didn't quite understand that from your first post?

I am curious to know if you believe that it may be a combination of noise generated by multiple loads that combine to cause the tripping? (even if these are not loads fed directly by the AFCI)
 
These breakers are siemens.I called them and told them what was going on,they said some of these electronic ballasts have radiated emissions well in excess of the FCC requirements,some 10 times the limits.When I changed out ballasts with different electronic ballasts it took care of problem.
 
c-pwhitson said:
These breakers are siemens.I called them and told them what was going on,they said some of these electronic ballasts have radiated emissions well in excess of the FCC requirements,some 10 times the limits.When I changed out ballasts with different electronic ballasts it took care of problem.
Click to expand...

Interesting I was just going to direct you to another thread with the same problem with GFCI's. Click here
 
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