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Flourescent Shop Light Trips GFCI

bmw57isetta

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Joined
Apr 27, 2010
Messages
268
Location
Austin, Texas
Hello from Central Texas! I recently bought a new house and, among other things, gutted the garage, installed second subpanel, added multiple outlets for equipment, audio, video, Internet, compressed air, etc. All circuits are 20A. Reputable electricians did the work and everything tested fine.

I have an eight year old Craftsman shop light. It's the extruded aluminum housing with two 4' T-8 bulbs. It's worked flawlessly in two previous locations although they were older houses with no GFCI outlets in the garage. The new garage has two, one for each main 20A circuit.

Any time I plug the light in and turn it on, it trips the GFCI breaker. I had one GFCI removed and replaced with a new, hospital grade 20A duplex outlet and it works like a champ at any outlet on the non-GFCI circuit. I also have a completely restored '50's Craftsman 150 drill press that would trip the GFCI breaker every time but never on the non-GFCI circuit.

I replaced the switch in the shop light with an exact replacement, no difference. The electronic ballast is original and appears to be fine. Sometimes, if I turn the light on, breaker trips and I reset it, the light comes on fine but if I turn it off and back on again the breaker trips. Then it won't reset at all if light is still in "On mode". What could be the problem? I'm at the point of having the second GFCI outlet deep-sixed and moving on down the line.

Any GJ wisdom will be appreciated. By the way, I'm no electrical guru and all work has/will be done by a licensed electrician.
 
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Aceman

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Jan 28, 2007
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Eastern Oregon
Hello from Central Texas! I recently bought a new house and, among other things, gutted the garage, installed second subpanel, added multiple outlets for equipment, audio, video, Internet, compressed air, etc. All circuits are 20A. Reputable electricians did the work and everything tested fine.

I have an eight year old Craftsman shop light. It's the extruded aluminum housing with two 4' T-8 bulbs. It's worked flawlessly in two previous locations although they were older houses with no GFCI outlets in the garage. The new garage has two, one for each main 20A circuit.

Any time I plug the light in and turn it on, it trips the GFCI breaker. I had one GFCI removed and replaced with a new, hospital grade 20A duplex outlet and it works like a champ at any outlet on the non-GFCI circuit. I also have a completely restored '50's Craftsman 150 drill press that would trip the GFCI breaker every time but never on the non-GFCI circuit.

I replaced the switch in the shop light with an exact replacement, no difference. The electronic ballast is original and appears to be fine. Sometimes, if I turn the light on, breaker trips and I reset it, the light comes on fine but if I turn it off and back on again the breaker trips. Then it won't reset at all if light is still in "On mode". What could be the problem? I'm at the point of having the second GFCI outlet deep-sixed and moving on down the line.

Any GJ wisdom will be appreciated. By the way, I'm no electrical guru and all work has/will be done by a licensed electrician.

Flourescent lights and GFCI's don't mix. Hardwire in a proper lighting circuit rather than plugging a portable light into a receptacle.

GFCI and motors do not get along very well.

What do you base that on? Most of the customers I do work for get nothing but GFCI's installed, with no issues, some of them for motor circuits. Not to mention, construction sites are all GFCI protected. If they don't work well with motors, how do all the workers use their tools then?

I hate GFCIs, waste of time and money in a shop

I'm guessing you had some trip but never figured out why?
 
OP
B

bmw57isetta

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Apr 27, 2010
Messages
268
Location
Austin, Texas
Thanks for the input Aceman. I've got to get someone over here anyway and that thought entered my mind. Your comments are interesting and well-taken.
 

TheEquineFencer

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Jan 15, 2009
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9,278
Location
Farmville, NC 27828
Flourescent lights and GFCI's don't mix. Hardwire in a proper lighting circuit rather than plugging a portable light into a receptacle.



What do you base that on? Most of the customers I do work for get nothing but GFCI's installed, with no issues, some of them for motor circuits. Not to mention, construction sites are all GFCI protected. If they don't work well with motors, how do all the workers use their tools then?



I'm guessing you had some trip but never figured out why?

Experience.
I know where this is and going and I'm not going there.
 
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GS-Louie

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Dec 10, 2013
Messages
135
Your lights are not compatible with the GFCI you have. Replace one or the other. I had the same problem about 10 years ago in a new installation. Replacing the GFCI with another brand solved my problem. You could also wire the light to the line side of the GFCI. If I were you I would replace the light.
 

Kevin C

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Joined
Aug 4, 2011
Messages
1,653
Location
Portland OR
Arc producing motors, voltage leakage through capacitors or ballast, hermetically sealed motors, are prone to tripping GFCI receptacles.

One thing to add is the harmonics of ballasts seem to fool the GFCI's. My theory is that consumer ballasts that lack power factor correction are a lot more likely to cause a problem. Experience in my own shop is that three double bulb T8 fixtures would consistently trip the GFCI.

Any device using a switching power supply can cause similar problems.

Similar lamp loading using commercial fixtures with power factor correction did not. Small sample of fixtures, but it did appear to make a difference. The down side is most commercial ballasts dont have consumer EMI ratings.

Harmonic voltages and currents can also cause false tripping of ground fault circuit
interrupters (GFCIs). These devices are used extensively in residences for local protection near
appliances. False triggering of GFCIs is a nuisance to the end user.

http://shodhganga.inflibnet.ac.in:8080/jspui/bitstream/10603/9782/4/chapter-1.pdf

Short story.... If you want to keep your light on a GFCI, try putting in a commercial rated ballast (typically they have a 120-277V rating). Then you can start a thread about how your FM radio stopped working. :)
 
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