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LED Light Tripping GFCI

1330 Views 4 Replies 3 Participants Last post by  surferdude2

I recently purchased a couple of different canless recessed LED lights for a bathroom remodel. Before installing the light in the ceiling, I wanted to make sure I was happy with the color and quality of the light they produced, so I found a 3 prong appliance cord and hardwired the cord to the light. I had everything neatly laying on my kitchen counter. But when I plugged the light into a GFCI socket, it tripped the GFCI.

I can't really understand why that would be happening. I've even tried a similar light from a different mfg. and it does the same thing. I verified that I had the line, neutral, and ground wires all connected correctly and that nothing could be shorting out. If I plugged my setup into a non-GFCI plug, the light worked fine.

I know these lights don't require a GFCI, but I wouldn't expect them to trip a GFCI either. I have plenty of low voltage LED landscape lights running on GFCI.

Does anyone know what could be causing this???
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Some LED lights aren't compatible with GFCI breakers. You probably have that type.

I know that sounds like too simple of an answer, so I'll add a little so you can feel safe by using those lights or if you don't trust them or me, then you can return them for some that are compatible. They will likely cost more.

So... here's the deal, when the self contained power driver adapter for the fixture initially powers up, the switching circuit on it instantly throws an inrush current spike on the ac sine wave that only affects one excursion of the wave, either the positive side or the negative, depending on the instant in time when you flipped the switch. That little blip is enough for SOME GFCI breakers to see that imbalance and trip. That doesn't happen on some other GFCI's since they are made to ignore the that instantaneous blip and delay the response.

The LED light manufacturers are aware of this problem and some of them have responded by providing LED drivers that don't have that problem. How that works is that when you turn the LED light on, the driver has a sensing circuitry that actually connects the load when the sine wave is passing the neutral point. That eliminates the instantaneous inrush current that fools the GFCI into tripping. Now it is being fooled into not tripping, simple what?

You really don't need GFCI protection on those lights, so not to worry, OK?
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Like any new technology, it often gets off to a rough start. Then it tends to get over utilized. I try to sandbag until rises up to the occasion and proves itself. Presently, I'll stick to the self contained LED units that directly replace the old standard A19 incandescent bulbs.

I have no quarrel with those who have the need for the higher power LED types that require power adapters to limit their wattage as versus a simple series limiting resistor that would dissipate too much power at the higher LED requirements.

For those who are interested in fully understanding how the drivers work, Google it and there are some good presentations that make it easier to grasp. An example is below in the link. It only shows the DC portion of the driver so you may want to look for other videos that show the complete system, from converting the 120 line ac to the lower input voltage to the regulators. That requires a frequency converter, a transformer, a rectifier diode and an electrolytic filter capacitor. It runs in to money before you get to the consumer product! Makes the old A19 look like a bargain. :smile:

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