Can certain fluorescent fixtures trip a GFCI circuit?

In my main work area, I have two lighting zones each operated by a 3-way switch. Both zones feed from a single 20 circuit. Zone 1 is pulling roughly 6.0 amps and zone 2 is pulling 7.5 amps with the light fixtures installed. Zone 1 contains all magnetic ballast fixtures. Zone 2 contains a mixture of magnetic (much cheaper models than zone 1) and some electronic ballast fixtures. I have been running this setup for about 4 years now without problems. If you follow my build thread, you will recall I acquired a pallet full of new electronic ballast fixtures that will be installed sometime in the future.

I'm in the middle of revamping all my electrical wiring and since some of these fixtures plug into switched outlets, I decided to add a GFI outlet to this circuit for protection. I wired it all up and turn on zone 1 - everything was fine. I then turn on zone 2 and the GFI trips. At first I figured I was overloading the 15amp GFI outlet since the breaker was 20amp, but then I tried switching on zone 2 first and the GFI still tripped. My conclusion is the GFI doesn't agree with some or all of the fixtures in zone 2.

So the question is: Can some types of fluorescent fixtures trip a GFI protection regardless of the the amp draw?

Any electrical device or wire can trip a GFCI if it is defective. If you have power leakage, it will trip the GFCI. A tripping GFCI here points at a problem that should be found and fixed.

They can be funny but normally lights are not wired gfci, mainly accessible receptacles.

the RFI filters in the electronic ballasts can leak enough current to ground to trip a GFCI. One might not, but parallel 10 and its not hard to get over 4ma of leakage.

This doesn't answer your question, but , separate the lights, they shouldn't need gfi protection.

Gary S said:

Any electrical device or wire can trip a GFCI if it is defective. If you have power leakage, it will trip the GFCI. A tripping GFCI here points at a problem that should be found and fixed.

Click to expand...

Now that you mention a defective part, I have noticed that the 3-way switch for zone 2 feels warm (not hot) to the touch after being on for hours while the other zone 1 switch in the same box was not. I always thought this zone was pulling more power so that might be the reason, but should a switch ever get hot? Is it worth replacing the switch to see if it makes a difference?

I've had cheap fluorescent shop lights tripped a breaker out of the box, and it only took one fixture. I had two of them, and they were leaking so much to ground that it almost seemed like something was wired wrong. I took them back, replaced the $6 housings with $8 ones, then they worked fine. These were from Lowes.

If you have a switch or receptacle that feels warm, change it.. Much cheaper than putting out the fire..

Just a followup:

First, I unplugged 4 of the fixtures to see if the wall switch would still get warm - it did, but not as warm as before. I then removed the old 3-way switch and found all screws very loose. After replacing the switch with a new old, the switch remained cool to the touch, even with all lights plugged in. First problem solved

I guess I will never know if it was the loose screws or a bad switch causing the heat, but my findings makes me want to tear apart the more boxes to check for more loose screws.

Next, I will try installing the GFI in the circuit again and report what happens...