LED Christmas Light Glow When Outlet Is Switched Off-Phantom Voltage

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
  • Hope everyone has a wonderful and warm Thanksgiving!
  • Super Cedar firestarters 30% discount Use code Hearth2024 Click here
Status
Not open for further replies.
The hot supply to the switched outlet is from the switch, and there is no neutral wire along with the wires from the switch to the outlet. The neutral would have to come from the unswitched outlet.
That's how it should be done IMHO. Unless the switch is super convenient and it would save labor to do otherwise, an electrician won't run any more copper than necessary. I've got a few half switched outlets in my house and they are great for turning on room lights when you enter the room. Many people don't want room lights on the ceiling.
 
" It's weird that 3 other half-switched outlets on 3 other circuits also exhibit voltages."
Each of the circuits is on its own breaker. There is no voltage to the switched outlet when its breaker is opened. Neutral is not open.
 
Each of the circuits is on its own breaker. There is no voltage to the switched outlet when its breaker is opened. Neutral is not open.
That's why a few of us are suggesting that you have to turn off the breakers one at a time and test, or as I suggest turn all off, then one on at a time. Since all the neutrals and ground wires are tied together to neutral/ground lugs on a panel, if you have a hot/neutral or a hot/ground fault somewhere in the house, it will affect all your neutral or ground circuits. Yup, it gets messy.
 
It's not uncommon to have inductive or capacitive coupling from live wiring that's run parallel. With high impedance devices, such as LED,s as the only load, they will glow. That's why and how transformers work. Turn off the main breaker to the house and see.

But as others have said you can do some strange things with back feeding the neutral.
 
It's not uncommon to have inductive or capacitive coupling from live wiring that's run parallel. With high impedance devices, such as LED,s as the only load, they will glow. That's why and how transformers work. Turn off the main breaker to the house and see.
A definite problem in communications circuits, or with high transient loads, but I do not believe a 60 Hz line is going to couple sufficient CW power to an adjacent line, given spacing between hots and grounds versus potential spacing between adjacent Romex pairs, with any less than 12 million feet of parallel length.
 
Have to agree on that. It might make an LED glow but not put 40+ volts on a meter.
 
it was only found by isolating every line and running a wind-up voltage tester of some kind that created a current.
One common name for the device typically used now is "fox and hound". I believe you can even rent them in some places.
 
Have to agree on that. It might make an LED glow but not put 40+ volts on a meter.
Actually, other way around. Meter has very high impedance, so 41 volts is surely less than 1 mW. By comparison, it will take 7000 mW to get a full string of 100 LEDs to full brightness, so depending how bright they're glowing...
 
While lying in bed last night, I remembered where I had the 40-50v. reading. I was replacing some 3 and 4 way switches with the newer style and got confused about which wire went where. Often they use red or yellow on these lines. I got out the meter and got a reading of 40 -50v but I can't recall how that happened. That's why I suggested that the voltage might be related to a mis wired switch. I still get dizzy when I do 3 way and 4 way switches.
[Hearth.com] LED Christmas Light Glow When Outlet Is Switched Off-Phantom Voltage
 
The LEDs are irrelevant, other than that's how you discovered your short. 40+v is the problem. It won't kill anyone touching it but it's enough to cause problems. Then again, 120v won't kill anyone either, unless they are grounded - at least ASAIK. I've felt 120 plenty of times and it wakes you up. I know someone that had his arm stuck into an industrial conduit where the power was supposed to be off - he lived but had a 3 month vacation recovering.
 
I work on systems delivering up to 80 kW into 50 ohm loads (capable of 4 kV continuous RMS voltage), every day. I've hit myself with > 120V probably more times than I can count. Only hurts when you're sweating. ;lol

Ever light a lightbulb sitting on a table from across the room? :p
 
I believe you're in my general area and the other day we had an hour or so brown out with power at less than 80 volts. Not sure if this could of messed something up or if your house was even involved. Just a thought.

Dale
 
I believe you're in my general area and the other day we had an hour or so brown out with power at less than 80 volts. Not sure if this could of messed something up or if your house was even involved. Just a thought.

Dale
Nothing here. NYSEG trimmed the trees not too long ago and I think they also put a recloser on our line. Of course, that means instead of the entire line going out, it's just us and our neighbors, lol.
 
What was the findings, turning off breakers one at a time?
 
Did that. Just one breaker, the one the lights are on is affected. I disconnected wires at outlets, and MIGHT have isolated it to a 4' piece in the wall from switch box to outlet. The reality was that it was getting dark, Mrs. Velvetfoot was bitching at me, and I put it all back together with new outlets. Still a very faint glow. Note that I measured voltage on three other half-switched outlets in the house, each on their own breaker. Tearing up walls, chasing ghosts, not in the outlook.
 
I have been watching this one with interest. I have run into this problem in the past and it usually ends up being from induced voltage. Sounds like you probably have a string of wires running together. Good news is that normally it doesn't really cause an actual problem.
 
I have seen this many times. Is the on off wall switch lighted? If it has a light inside( so you can see the switch at night) these type of switched will cause leds to light very dimly. No one brought it up before or asked. It's not a wiring issue and no cause for concern if it is the issue, it's a known bug with leds
 
I have been watching this one with interest. I have run into this problem in the past and it usually ends up being from induced voltage. Sounds like you probably have a string of wires running together. Good news is that normally it doesn't really cause an actual problem.

If it's an induced voltage, why does the problem go away when he turns that breaker off?
 
If it's an induced voltage, why does the problem go away when he turns that breaker off?
Because it's not induced voltage like a few of us thought, he also has a lighten switch which was leaking voltage which was enough for the LEDs to have a phantom glow.. Merry Xmas
 
Status
Not open for further replies.