T8 light trips GFCI

[gar]

090418-0903 EST

PetrosA:

I would run the following experiment on the bench.

Use a new Leviton 7899 GFCI (the only reason for this device is I have experimental experience with it). Supply this with hot, neutral, and EGC.

Connect your motion sensor and controlled by the motion sensor an incandescent. The motion sensor EGC wire should connect to the GFCI EGC. Does this trip the GFCI?

If it does, then disconnect the motion sensor EGC wire from anything. Now does the GFCI trip? It will not. If the motion sensor with EGC connected caused tripping, then the motion sensor is a problem.

Without the motion sensor do the same experiment as above but with the LED fixtures. Use the same number of LED fixtures as in your application. What are the results.

If none of these caused tripping, then connect both the motion sensor and LEDs and see what happens.

My guess is that either the motion sensor or the LEDs had some filter capacitors or other leakage to the EGC, and this is what caused the GFCI tripping. Or you have a GFCI that has high frequency sensitivity that I have not found with the Leviton mention above.

.

 

[johnny watt]

All GFIs are not created equal.
I would try a different brand like the Levitron mentioned earlier.

Here is a paper by graduate students.
They are trying to improve a GFI so that it is more immune to nuisance tripping such as you might be experiencing:
http://seniord.ee.iastate.edu/may9906/design_review.html

 

[hurk27]

All GFCI's are not created equal.
I would try a different brand like the Leviton mentioned earlier.

Here is a paper by graduate students.
They are trying to improve a GFCI so that it is more immune to nuisance tripping such as you might be experiencing:
http://seniord.ee.iastate.edu/may9906/design_review.html

I agree with this as I just had an apartment building that had GFCI's tripping not just ones on the same circuit but ones on the opposite phase, it perplexed me that this could occur in the first place, I did a few test to see just what was tripping them, in my case it was inductive kick back, The three things tripping them was an old magnetic ballast 32 w T8 2 bulb fixture in the kitchen, the bath fan, and a series magnetic ballast bi-pin PL fixture in the hall. putting a test 130 MOV across each switch eliminated the problem with each one. so then I turned my attention to the GFCI and found they were purchased at Menard's (the ones that come 3 in a pack) and later found that the ones that come in a single box with a wall plate, both are very susceptible to transient surges and are questionable to whether or not they went through UL testing. they are so bad that, they would even trip on the opposite phase through the heating element of a water heater, after changing the GFCI's to the leviton the problem was eliminated.
Also that these apartment have a small 100 amp panel right in the middle of each apartment so the circuit runs are not over 25-30'
The maintenance department for them now only uses the leviton GFCI's.

Yes many of these shop fixtures might claim energy saving T8 bulbs but still have the magnetic ballast in them.
But non of the apartments that had newer fixtures in the kitchen with electronic ballest triped the GFCI's.

 

[brother]

I agree with this as I just had an apartment building that had GFCI's tripping not just ones on the same circuit but ones on the opposite phase, it perplexed me that this could occur in the first place, I did a few test to see just what was tripping them, in my case it was inductive kick back, The three things tripping them was an old magnetic ballast 32 w T8 2 bulb fixture in the kitchen, the bath fan, and a series magnetic ballast bi-pin PL fixture in the hall. putting a test 130 MOV across each switch eliminated the problem with each one. so then I turned my attention to the GFCI and found they were purchased at Menard's (the ones that come 3 in a pack) and later found that the ones that come in a single box with a wall plate, both are very susceptible to transient surges and are questionable to whether or not they went through UL testing. they are so bad that, they would even trip on the opposite phase through the heating element of a water heater, after changing the GFCI's to the leviton the problem was eliminated.
Also that these apartment have a small 100 amp panel right in the middle of each apartment so the circuit runs are not over 25-30'
The maintenance department for them now only uses the leviton GFCI's.

Yes many of these shop fixtures might claim energy saving T8 bulbs but still have the magnetic ballast in them.
But non of the apartments that had newer fixtures in the kitchen with electronic ballest triped the GFCI's.

What does MOV stand for??

 

[mxslick]

What does MOV stand for??

Metal Oxide Varistor

It is a device that has very high resistance to current flow below it's rated voltage...at or slightly above it's rated voltage it conducts with low resistance until the voltage drops below the rated or it burns up.

Common device in surge supressors, usually connected L-N, L-G and N-G to catch any spikes on any of the three.

 

[hurk27]

Metal Oxide Varistor

It is a device that has very high resistance to current flow below it's rated voltage...at or slightly above it's rated voltage it conducts with low resistance until the voltage drops below the rated or it burns up.

Common device in surge supressors, usually connected L-N, L-G and N-G to catch any spikes on any of the three.

Whats weird was I found that placing them from the hot to the switch leg produced the most reduction of the spike, kind of a L/R circuit that seems to draw off more of the spike then placing them from H-N or SL-N they SL-N did show quite a improvement then without them but still had the tripping of the GFCI's, just not as much.

also this is only a test method as leaving them in place would not be code compliant, and can result in some freaky behavior when the circuits experience's over voltage like in a lost neutral, lights turning on and pulsating by themselves lol (drives a home owner nuts) yea forgot to remove one, one time

 

[iaov]

I have seen flourecents trip GFIC's before. Randomly. Sometimes after 5 minutes, sometimes after 20 minutes. Replaced GFIC's> Tried different brands. Still tripped. Have come to the conclusion that it has something to do with electronic ballasts.

 

[PetrosA]

090418-0903 EST

PetrosA:

I would run the following experiment on the bench.

Use a new Leviton 7899 GFCI (the only reason for this device is I have experimental experience with it). Supply this with hot, neutral, and EGC.

Connect your motion sensor and controlled by the motion sensor an incandescent. The motion sensor EGC wire should connect to the GFCI EGC. Does this trip the GFCI?

If it does, then disconnect the motion sensor EGC wire from anything. Now does the GFCI trip? It will not. If the motion sensor with EGC connected caused tripping, then the motion sensor is a problem.

Without the motion sensor do the same experiment as above but with the LED fixtures. Use the same number of LED fixtures as in your application. What are the results.

If none of these caused tripping, then connect both the motion sensor and LEDs and see what happens.

My guess is that either the motion sensor or the LEDs had some filter capacitors or other leakage to the EGC, and this is what caused the GFCI tripping. Or you have a GFCI that has high frequency sensitivity that I have not found with the Leviton mention above.

.

gar, I would have loved to experiment with the setup, but this was one of those jobs with tons of callbacks, etc, and I just couldn't spend the time. The lights are like $400 a piece, so getting one to experiment with was also out of the question. I did test it without the motion detector in line and just connecting the lights tripped the GFI breaker as well. There were four lights fed off the detector, and by reducing the number to one I was able to get them to start sometimes without a trip, but not always. I'm guessing there's something magnetic going on in the circuitry that's using power that's somehow not returning through the neutral when the circuit powers up (maybe some magnetic field that gets absorbed by a grounded shield?). Sort of like those non-contact electric toothbrush chargers, which BTW aren't grounded like the LEDs or electronic ballasts are.

 

[gar]

090420-1907 EST

PetrosA:

Since the number of fixtures affects the probability I would suggest that there is capacitive coupling from the ballast or hot wire to ground. meaning to an EGC if it exists or just the building structure. There may be an RFI filter at the input to each fixture, possibly in the ballast, that thru shunt capacitors to ground provides the leakage path.

.