LED Christmas Lights Won't Turn Off

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nuckythompson

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Hi there, so I have a GFCI receptacle controlled by an electronic Lutron switch. From this receptacle I plugged a string of LED lights together using extension cords. When I turn the switch off, a set of the LED lights stays lit. With the switch off, I measured 37V to ground at this receptacle. Any ideas what is going on here?

I was thinking maybe faulty receptacle or switch, maybe incorrectly wired. A colleague mentioned that if you plugged an incandescent light bulb into the circuit the problem would go away, but he could not explain why.

Thanks,
 
(quick and simple answer)
Leakage current is why. Since an electronic switch does not physically disconnect the line a tiny current is able to sneak through, and small LEDs require very little current to operate. The higher load soaks up the available current which reduces the voltage (Ohm's Law).

(And measuring to "ground" is not correct, measure line to neutral.)
 
zbang said:
(quick and simple answer)
Leakage current is why. Since an electronic switch does not physically disconnect the line a tiny current is able to sneak through, and small LEDs require very little current to operate. The higher load soaks up the available current which reduces the voltage (Ohm's Law).

(And measuring to "ground" is not correct, measure line to neutral.)
Click to expand...
So with these electronic switches, I am using power even with the switch off? Would it amount to any $?
 
Lutron electronic switch. I agree it's leakage from not actually disconnecting.

I believe their 6 amp caseta disconnects the load entirely

1) it has specific line/load designations (required for the electronics to have constant power) - and

2) I think it can be wired in standard configuration with a regular 3-way switch.

 
hbiss said:
You can't put a receptacle on a dimmer. But I don't know if this is a dimmer he's talking about.
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Come on that takes the fun out it.
Can we call it a voltage drop device and be ok. 🥴
Could this considered a 406.3 (E) situation.
Just having some fun.
Wait untill morning and see if it's still on.

Did you hook up the netural that came with the switch. I do believe that switch required a grounded conductor.
 
James L said:
Maybe 2 or 3 pennies per year
Click to expand...
people don't always realize how low that leakage is or how little it takes to get an LED to create some illumination.

watts = V x A

totally off top my head figures - say we are leaking 5 mA. voltage will be low as well otherwise current will be higher, so lets just say 3 volts

that is 3 x .005 = .015 watts.

will need to run that way for about 67,000 hours to use one kilowatt hour of energy.
 
Don't forget about all those new breakers that consume power with no load other than internal load. Penny's do add up.
100 unit apartment complex with ten in each load center.
 
kwired said:
people don't always realize how low that leakage is or how little it takes to get an LED to create some illumination.

watts = V x A

totally off top my head figures - say we are leaking 5 mA. voltage will be low as well otherwise current will be higher, so lets just say 3 volts

that is 3 x .005 = .015 watts.

will need to run that way for about 67,000 hours to use one kilowatt hour of energy.
Click to expand...
Yeah but this is a string of christmas lights, so multiply the usage by 50.

Probably more like a dollar or two a year than a penny.
 
I thought the leakage in these smart switches is from the current to run the electronics (especially the no neutral required ones). To use an RF remote to turn it on means that radio controlled switch always needs the radio on. I believe the triac inside it that actually turns on to run a higher power load is actually biased off when the switch is off. Its just the brains that needs a current return path and an incandescent light would never light up with that small current needed to run the radio.

At some point, I think UL allowed a certain amount of current to be leaked down the equipment ground instead of sending it through the load, so that allows a design that doesn't leak out the load wire. The switch linked to above in post #8 requires a neutral wire which gives the electronics a proper return path. I would not expect it to leak and is the proper way to do this. But many older houses don't have neutrals in switch boxes, just switch loops. OP did not state how many leads this smart switch has and whether it requires a neutral or ground.

I've been replacing some occupancy sensor switches in my house. They were old no neutral required types. If I only had LEDs in the fixtures they would never turn off either, they'd just keep blinking or pulsating. If I replaceed just one with an incandescent, it works just fine. I got tired of trying to find replacement incandescents now, so I'm changing those switches out for new Lutron ones that require either a neutral or ground. It is kind of a funky switch in that there is a white wire with a green sleeve. If you have a neutral, you pull off the green sleeve and connect the neutral to that wire. If no neutral, you pigtail that green sleeved wire to the bare ground in the switch and to the EGCs in the box.
 
suemarkp said:
It is kind of a funky switch in that there is a white wire with a green sleeve. If you have a neutral, you pull off the green sleeve and connect the neutral to that wire. If no neutral, you pigtail that green sleeved wire to the bare ground in the switch and to the EGCs in the box.
Click to expand...
I first saw that green sleeve about 2 months ago when I was troubleshooting some occupancy sensors at my son's school. Maintenance man had swapped out some, but didn't connect the neutral/ground lead 🤪
 
suemarkp said:
I thought the leakage in these smart switches is from the current to run the electronics (especially the no neutral required ones). To use an RF remote to turn it on means that radio controlled switch always needs the radio on. I believe the triac inside it that actually turns on to run a higher power load is actually biased off when the switch is off. Its just the brains that needs a current return path and an incandescent light would never light up with that small current needed to run the radio.
Click to expand...
There are really two specifications in play.

One is the switch-off power consumption of the device itself. This has no unavoidable effect on the load side of the circuit, but may cause problems with some upstream switching devices. But if the device does not have its own neutral connection that power has to come from current passed through to the load. This is one of the motivations for the NEC requirement for a neutral in some switch-only boxes.

The other is the switch-off let through current. That comes from the fact that some semiconductor switching devices do not completely cut off all current when they are in the off state. This may be temperature dependent and may have an effect on low current loads like LEDs. In the worst cases (no load) it can produce a voltage close to line voltage on the output side, with very low current capability but enough to cause a false reading in a non-contact voltage detector.
 
Interesting. Doesn't NEC require the "switched" BC to be an actual switch/disco? If the switch leaks both voltage and current when "off", is it really a disco? 5mA is on same order of GFI level.

Also, I have built many solid-state switches for 120vac-60Hz, and when the silicon is off, it's hard off, not leaking mA, not even uA. If Lutron is leaking 5mA, I would call that a crappy switch and would seek out something better.
 

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