T5 fluorescent not compatible with GFCI? - Page 1
Forum section: electronics / general

author: rdl
author_rank: Super Contributor
timestamp: April 28, 2016, 07:46:14 pm
content: I've been looking for some lighting to go under a cabinet in my kitchen. All the outlets in my kitchen are GFCI protected. I ran across this light on eBay. Not that I want to buy this particular one, but why would it be incompatible with a GFCI circuit?http://www.ebay.com/itm/T5-HO-Indoor-Grow-Light-4-ft-1-Lamps-DL8041-Fluorescent-Hydroponic-Fixture-Veg-/222094831362/

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: April 28, 2016, 07:57:36 pm
content: http://forums.mikeholt.com/showthread.php?t=159075

author: Zero999
author_rank: Super Contributor
timestamp: April 28, 2016, 08:12:37 pm
content: I've never heard of this but where I live we use RCDs which have a trip current of 30mA and power many circuits, not just one socket. I believe in the US, RCDs trip at 5mA and protect only one socket.Why do you want fluorescent tubes?Have you considered LEDs? The house I've just bought has LED lighting under the kitchen cabinets and my parents have recently installed an LED strip light in their kitchen.

author: rdl
author_rank: Super Contributor
timestamp: April 28, 2016, 08:25:18 pm
content: What I got from reading that thread was that GFCIs will frequently trip from just about any random transient, but the old style ballasts may be worse than usual. The lamp I linked to uses an electronic ballast.I spent several hours shopping for lights at HomeDepot and never once read anything about this.I want to use the light as a grow light for lettuce (yes, lettuce. Stop smirking) and I'm not finding any LED type in that form factor (4 Ft. strip/shop light) as cheap as T5HO fluorescent with equivalent light output.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: April 28, 2016, 08:35:09 pm
content: Yeah but the ebay seller is just covering his ass if you buy it and it trips your breaker and then attempts to give negative feedback.

author: cvanc
author_rank: Frequent Contributor
timestamp: April 28, 2016, 08:56:18 pm
content: I can't speak to the GCFI issue, but damn, 5,000 lumens? That's one bright light... might not be too pleasant in a frequently occupied room like your kitchen?

author: rdl
author_rank: Super Contributor
timestamp: April 28, 2016, 10:35:54 pm
content: I agree, it's probably just that ebay seller doing a cya.I'm thinking I would need two. Yeah, it would be pretty bright.I don't use the kitchen much, but this half of the apartment is basically one big room, about 26' x 22' with the kitchen/dining side only partially separated from the living room area by 8 ft of wall and a short snack bar thing. I would probably have block it off somehow with foam insulation board.That's what I did in the dining area where there's two 3200 lumen LED shop lights and 200 watts (actual) of those blue/red LED grow lights hanging in some 36" x 18" x 72" wire shelving.I did find a Chinese company selling 3 ft. T5 HO grow lights on Amazon. They don't specify a lumen rating, but it should be around 3500 per tube. Two of those would probably work fine.

author: ConKbot
author_rank: Super Contributor
timestamp: April 29, 2016, 02:38:00 am
content: Yep. Got a nice new bench at work, overhead light with quad T5 tubes, and the damn thing trips the GFI that all the benches are on unless I only have 1 tube on. I was planning on working on it, but I didnt have time to play electrician and replace the ballasts or gut the whole thing and install LEDs. Eventually the GFI failed, and got replaced with a standard outlet. I ohmed out the light, and inspected the wiring for any faults and couldnt find any. Ohmed out infinite with a meter (no megger though)Do electronic ballasts put out high frequency that could be coupling to the metal reflector and causing leakage current that way?

author: KE5FX
author_rank: Super Contributor
timestamp: April 29, 2016, 03:49:17 am
content: The GFCI-tripping phenomenon is real and annoying and I wish I knew exactly what caused it. My best guess is that the failure mechanism is like the trigger electrode on a flashtube, only backwards: when the fluorescent tube(s) fire up, the sudden appearance of a current path along the length of the fixture dumps some energy into the grounded metal reflector. Assuming ground and neutral are bonded at the service entrance, the energy coupled to the reflector will preferentially come from the line side, and the resulting imbalance looks like a ground fault to the GFCI supplying the fixture.Might be possible to test this hypothesis by running the reflector's grounding wire through a current transformer but I've never been annoyed enough to spend that much time on it.

author: Red Squirrel
author_rank: Super Contributor
timestamp: April 29, 2016, 05:55:23 am
content: Technically, I don't think lighting has to be GFCI protected in a kitchen, so you could run a separate non GFCI outlet inside a cabinet or something and power it from there.