Flourescent/GFI problem

[szyg6h]

I have an overhead flourecent light that when I turn it on, turn it off, sometimes, not consistent, it kicks off a GFI that is on a totally different breaker and circuit. That GFI circuit is just for bench outlets. ....and again a totally different breaker and circuit. The flourecent circuit checks proper for polarity, grounding, etc with the little 3 prong device that plugs into a grounded circuit.
The fixture probably came from HD, Lowes, ACE- don't remember.
Any ideas?
Maybe a capacitor could be wired into it? ....but what capacitor specs?

 

[nehog]

Maybe replace the GFI that is tripping?

 

[Falcon67]

Maybe replace the GFI that is tripping?

That first.

 

[jpinca]

Are the two circuits proximate, especially running together for any length?

 

[szyg6h]

Are the two circuits proximate, especially running together for any length?

yes they are.

 

[shoturtle]

What type of wire are you using in the run?

 

[jpinca]

yes they are.

You could be experiencing inductive-coupled EMI caused by a overshoot/undershoot transient from the light.

While it would be a fun science project to figure it out exactly, you may be time ahead trying a new GFI- especially another brand. Otherwise you can start by separating the cables.

 

[szyg6h]

You could be experiencing inductive-coupled EMI caused by a overshoot/undershoot transient from the light.

While it would be a fun science project to figure it out exactly, you may be time ahead trying a new GFI- especially another brand. Otherwise you can start by separating the cables.

the EMI transient is exactly what I have been thinking.

Went to Home Depot this afternoon and talked to a guy I respect for his electrician knowledge- have had good conversations with him before.

And, yeah, I could make a science project out of it. HD electrician suggested just replacing the old "fat" tube fixture, with the new T8, cold start, different starting device. I did. So far so good with many on/off cycles. Plugged in the old fixture, into a circuit next to the switch for the problem light, and it tripped the GFI.

Thanks to all for the suggestions.

 

[jbberns]

Possibly the two are sharing their neutral?

 

[Norcal]

Flourescent lamp ballasts do leak a small amount current to the case,perhaps the leakage was enough to trip the GFCI, worked on a office building years ago that none of the 2X4 recessed troffers were grounded, each suite had 8 fixtures & touching the ceiling grid & a gas line while working in the ceiling I would get bit, the reason was some non-code compliant work when they were built in 1979, but anytime I worked were there was a large # of ungrounded fixtures, always got a tingle, but have not seen any info on the current electronic ballasts & their leakage, if any...

 

[Shocker]

T8 or T12 fixture?

T12 ballasts seem to leak a lot more current as they age. T8 ballasts seem to be better.

 

[szyg6h]

T8 or T12 fixture?

T12 ballasts seem to leak a lot more current as they age. T8 ballasts seem to be better.

It was the T12.
Very interesting. Heard at HD that the T12 is history soon. Also heard that the T8 is (did he say) electronic and that is why they start at lower temps.

 

[jbberns]

The fixture is on a separate breaker and it was causing the GFI to trip?

 

[szyg6h]

The fixture is on a separate breaker and it was causing the GFI to trip?

Yep!

 

[Dick in Wisconsin]

Maybe replace the GFI that is tripping?

It is true that GFIs and GFCIs "wear out" after time? I've heard that from a reliable source a few years back.

 

[nehog]

It is true that GFIs and GFCIs "wear out" after time? I've heard that from a reliable source a few years back.

People say that, but it has not been my experience. They are solid state devices that have no wear components other than the contacts.

 

[szyg6h]

...and this is a 2 year old GFI, and this has been going on for a year or more.

With the new T8 fixture, still no porblems. But I plug in the old fixture to an outlet, GFI trips.

I see no constant Voltage leak when on, but I see spark when I plug it in. Transient jolt....