Question Best Posts in Thread: LED Lights

When a light switch is in the open position there is voltage when tested from the line side to the open side due to reading from the neutral, through fixtures, one way to test a switch. A switch with a pilot light uses this to show when it is off, it uses the neutral through your light fixtures.

I have 3-way switches in my hallway with pilot lights and do not have glowing lamps (LED fixtures). I've spent a day thinking about this and really think the problem is that your neutral is not properly grounded, the pilot light is putting a voltage on the circuit beyond the switch, a very low voltage as they are just glowing and both LED lamps and CFL have a pretty interesting voltage ranges.

Replacing the switch to a normal toggle switch seems to be an easy solution if you are renting, if you own it is one of those things when you need to think about why this is happening. I would be willing to bet that a few of the folks chiming in about glowing lamps do not have pilot lamps in any of their switches as the are not that common here.

Shawn

 

A LED or CFL does not "store" power. If the switch is off and the lamp is glowing dimly, you have voltage present from some source. In the perfect world your voltage should be 0.

Possible causes could be an improperly grounded neutral, most homes here only ground the neutral via pole ground at the transformer; with 10+ houses coming off the transformer with very long secondary runs. The main panel is not grounded with the neutral and ground bonded and you have no 3rd wire (green, grounding conductor) for your branch circuits.

Are the lights on their own circuit or do they have receptacles on the circuit? I ran 3 separate lighting circuits at my house, even though if I turned all my lights on at once they are probably pulling less than 2 amps combined but it was mostly for ease of maintenance. With all the electronic equipment in use today there is a possibility of some issues, though a properly grounded neutral should fix that unless you have an extremely heavy electronic load.

Another possibility could be a shared neutral, though it is a two wire system here (phase to neutral) if you had 2 different breakers and only one neutral between them perhaps a problem, especially if you have any lose neutral connections somewhere. Another thing I've seen is all neutrals tied together from different circuits that happen to be in the same J-Box as well as neutrals going back and forth (circuit "A" to circuit "B" and then to circuit "A" again).

A light circuit that switches the hot wire in 1 room and the neutral in the next room could make for some funky stuff. Least likely is a bad switch but with the "quality" of some devices here it would not be a complete shock.

With over 27 years of doing electric work I have never personally witnessed it but have read about it on a couple forums based from the Philippines. My house has mostly LED lamps or fixtures with a few fluorescent fixtures (T-8 lamps) and 2 halogen lamps in the ceiling fans for our bedroom and the living room with no "lamp glowing" issues. I also built a small duplex in the village for a couple sister in laws as well as redoing the in-laws house, did the electric work myself (other than some things they've changed around) the duplex has CFL's and the in-laws have mostly LED now and some CFL's...no bulbs glowing there either and this is village secondary, but with almost no load and very little electronic devices (TV and cell phone chargers are about it).

As I said, I've never troubleshot this before, but everything leads me to think an issue with the neutral. I would suggest your electrician (sparky...hate that term) look at the neutral as the most likely culprit. I would love to hear a solution.

The "pilot light" on a switch in the off position uses the hot wire and the neutral through the fixture. If you read across the terminals on a switch in the off position and you will read the line voltage, good way to test if a switch is bad or not. I have three way switches in my hallway with pilot lights (US switches as I could not find what I wanted...rated at 120-277 volts) and the 2 LED fixtures are straight. I don't discount this as a possible part of the cause as most CFL's and LED's lamps operate at a pretty wide range of voltages, but think there is also an something going on with the neutral.

A CFL is self ballasting (no exterior ballast or starter) and LED switches AC to DC so they act differently than an incandescent lamp. I am quite curious to why folks are reporting glowing lamps here but have not heard of it elsewhere. Over a year ago I ordered my Mother enough LED lamps and a security light for her entire house and she has not seen it happen and her house is very old.

Great conversation and a post I will be following.

Shawn

 

I found out what the problem was when i arrived here 7 years ago with a florescent bulb i installed.

If you have a lt switch with a pilot light take it out and cut the wire to the pilot light . if therre is no wire replace it with a new switch with no pilot light. problem solved!

Dave

 

This is a great topic and there are many wiring issues that cause this. A neutral should not be used to switch things, it needs to be the hot wire. Someone tapping off of a switched hot to feed another fixture...tell tale is if you need to flip 2 or more switches to get your lights working...a switched neutral will cause all kinds of issues as the return path can be through the fixture.

I do not have these issues as I did the majority of work myself in our house. I have also spent a bit of time in the village with the family adding things or changing things and have seen things that make my head shake as the wife's brother in law did his best...when we left tonight I think it is pretty much straight.

A luminesce glow for a few minutes is due to the chemicals used to make the lamp (not LED)...if it is more than 5 minutes then there is another issue. I would say it is easy to fix, but it is not easy to find local labor to troubleshoot things. An LED should be on and off without any glowing afterwards.

Shawn

 

Jack. I have seen this phenomena several times and found no wiring faults. If you find a sparky that can identify the root cause of the glowing LED lamp I'd like to hear it.
My guess is that a very small amount of current leakage between conductors would give the slight glow.
The leakage could be the result of moisture in the switch and wiring. I have discounted inductive coupling and capacitive coupling because in both installation I observed there were no other electrical circuits near by.
In hind sight I did not check to see if the light switch was in the hot side of the supply or the common side. Maybe your sparky could look at that aspect.
On a side note if the switch is on the common side you can get a bloody good schock when you go to change the bulb...been there...didn't enjoy that...LOL
Good luck finding the ghost.

 

Not sure if I got a household wiring problem but............. After 3 years of fairly constant use, I am starting to change as they expire (fail/ break) The Energy (saving bulbs (akari?) around the house, I have gone for LED Lights and here is the problem? When the Light is turned off, the bulb stays on although not Bright.
I was talking to a friend only last week about this and he said maybe it could be Residual power to the Bulb socket from the way Noreco deliver the power, They say No and Polaris say No, it must be a Wiring fault of something at the Circuit Breakers.

Any Ideas anyone before I send for a Sparky?

JP