chasing stray voltage - need some help

[Cobra6]

That should work well. Make sure you establish a normal drop under load baseline by doing that test on a known normal circuit. This way you will have something to compare against on the drop test. You should only drop a couple volts on this for a good circuit.

Check the dirt drop while you are doing this too. Give us the dirt drop under load and with no load. I think you said you had 12.5 volts with no load. Measure across the exact same spots.

I plugged in a small heater - only dropped 3 - 4 V on the circuit, but the reading when I put the positive probe in the large slot, and the negative probe in the ground terminal was almost 2 volts at the tail end (.6V on the first outlet - then went to 1.1V - then to 1.9v on the last outlet) - I am thinking that the voltage from the neutral to ground should be les than .5 V.

On a good circuit, there was almost no drop, and the voltage between the neutral wire and ground was 0.

OK - the dirt drop - today I have about 12.5V between my pool water and the metal handrail, no change when I put a load on - but my "dirt load" drops from about 10V down to 8.5V (it is a little dry) - the whole voltage has been lower the last two - or three days - I have seen over 30 V in the ground a couple of weeks ago.

So - what does this tell me - should I replace and check the ground on the outlets where the drop starts? I have about a 3V drop with no load.

 

[Cobra6]

What consumers are on this circuit that are continuous?

You mentioned the "ADT". I don't know what this means. Is this device consuming power all the time?

Can you disconnect this ADT to isolate it from the problem/check to see if the problem goes away without the ADT?

ADT is a security alarm system - I disconnected it completely -

 

[Cobra6]

Bari,

Sorry to say it in this manner but . . . . how much longer are you going to be stupid and cheap ????? ...... Until someone gets killed ???????

Call an electrician and tell him to fix it ! Doesnt matter what the cost is, just fix it.

Just my worthless opinon,

Bill - I will add your $.02 to the jar - I have already had two electricians and the utility company here and it is painfully obvious to me that if I don't isolate the problem it won't get fixed - if they knew how to fix it, they would have been glad to charge me $$$ to do it.

 

[MrMark]

I plugged in a small heater - only dropped 3 - 4 V on the circuit, but the reading when I put the positive probe in the large slot, and the negative probe in the ground terminal was almost 2 volts at the tail end (.6V on the first outlet - then went to 1.1V - then to 1.9v on the last outlet) - I am thinking that the voltage from the neutral to ground should be les than .5 V.

On a good circuit, there was almost no drop, and the voltage between the neutral wire and ground was 0.

OK - the dirt drop - today I have about 12.5V between my pool water and the metal handrail, no change when I put a load on - but my "dirt load" drops from about 10V down to 8.5V (it is a little dry) - the whole voltage has been lower the last two - or three days - I have seen over 30 V in the ground a couple of weeks ago.

So - what does this tell me - should I replace and check the ground on the outlets where the drop starts? I have about a 3V drop with no load.

This could be a million things. Neutral wire touching a water pipe, problem outlet, loose connection, etc. But basically, you are completing the circuit through the dirt somehow, someway. Not much, but enough to give someone a shock and it only takes milliamps to kill if across the heart. This is the great danger of electricity.

You drop a hair over what you should on that circuit. This means a slightly high impedance path back to the transformer somewhere in that circuit. Because it is only slightly high it also suggests that maybe you have hot to ground leakage occurring.

Can you basically describe the entire circuit from the panel forward? Can you check the circuit at the panel to see that the neutral and ground wires from this circuit and landed on the appropriate buss bars and that they are clean and tight? Check your connections at the panel.

I hate to tell you this but the best way to troubleshoot at this point is to start disconnecting downstream outlets and working back to the source until you can isolate the problem.

Can you get a handle on the wiring diagram for this circuit. It may help to draw it out. You can look in each box and figure out the run of the circuit.

 

[MrMark]

Have you managed to completely identify everything that is on this circuit? Unless you have a hot to ground problem (and you may have), and for that you would probably need an amp clamp to see if any current is flowing with no known load on that circuit, then you have a neutral to ground problem and there shouldn't be anything flowing (and hence no drop across your dirt) if there are no consumers (loads) on that circuit.

So, are you getting voltage across of dirt with absolutely no known load?

 

[MrMark]

I would like you to put an amp clamp on your ground wires and the ground wire in your panel too. I think you will be very frustrated on this without using the amp clamp to trace and check for the ground current. It could be on your water piping too if that is bonded properly.

 

[Cobra6]

Can you basically describe the entire circuit from the panel forward? Can you check the circuit at the panel to see that the neutral and ground wires from this circuit and landed on the appropriate buss bars and that they are clean and tight? Check your connections at the panel.

I hate to tell you this but the best way to troubleshoot at this point is to start disconnecting downstream outlets and working back to the source until you can isolate the problem.

Can you get a handle on the wiring diagram for this circuit. It may help to draw it out. You can look in each box and figure out the run of the circuit.

I was thinking about exactly the same thing - start at the end and disconnect outlets to see if anything changes. It is easy enough to check grounds and even replace receptacles.
The circuit comes out of my main breaker box, up through the garage ceiling (outlet for the garage door opener) then goes through the attic in the garage to the rear wall of my house, with two outlets on the rear wall of the kitchen, one in the laundry room, and two outlets in the den, all on the back wall of the house.
The only thing that would seem different is that the breaker is a 20A/20A tandem breaker, but I am not sure that it means anything. I looked at the circuit in the panel when I started this, and it seemed OK (electrician checked it too)

 

[Cobra6]

I would like you to put an amp clamp on your ground wires and the ground wire in your panel too. I think you will be very frustrated on this without using the amp clamp to trace and check for the ground current. It could be on your water piping too if that is bonded properly.

I will try to getan amp clamp tomorrow. I don't own one.

 

[Cobra6]

So, are you getting voltage across of dirt with absolutely no known load?

I have plugged in an extension cord on an outside outlet (not on the problem circuit) - I put the negative lead in the ground terminal of the cord andthe positive lead in the dirt, and was getting 12V - 15V

I am not sure if it proves anything or not.

 

[MrMark]

If this circuit is comprised of all outlets and there is nothing on those outlets then you have a hot to ground problem for the dirt to be energized. If you were to clamp the hot wire at the panel with nothing pluged in it should show some small leakage current (short to ground). You could have a nail through a hot wire touching something metalic that is ultimately grounded. You could have a nick in a hot wire barely touching a metalic box or ground within the box.

Work back by disconnecting until the problem goes away.

On the tandem breaker, I don't see that as a problem.

 

[MrMark]

I have plugged in an extension cord on an outside outlet (not on the problem circuit) - I put the negative lead in the ground terminal of the cord andthe positive lead in the dirt, and was getting 12V - 15V

I am not sure if it proves anything or not.

What I meant was that there was nothing plugged into any receptacle on the problem circuit and you were still getting something on the dirt?

Now that we have established that this is an all receptacle circuit and nothing is plugged in (open circuit), it has to be a hot to ground problem for you to have voltage across dirt.

 

[MrMark]

On the amp clamp, it is a cool tool to have, and I consider it an indispensible electrical troubleshooting device, you can get a very cheap one if you just need to measure AC circuit current. Any diagnostics I do, whether it be a car or house I pretty much use current measurements rather than voltage, but that's just me. I find it easier and more powerful generally.

If you would like to work on car diagnostics too, then you would need a different type of clamp, a hall effect type clamp that does AC and DC. I don't know your situation. Here, all you need is the cheapest AC only transformer style clamp for 30 bucks.

 

[Cobra6]

What I meant was that there was nothing plugged into any receptacle on the problem circuit and you were still getting something on the dirt?

Now that we have established that this is an all receptacle circuit and nothing is plugged in (open circuit), it has to be a hot to ground problem for you to have voltage across dirt.

Yes - I do still have voltage across dirt with nothing plugged in on the circuit. As soon as I throw the breaker on with everything unplugged, I have 12+V through the dirt.

 

[MrMark]

Just start disconnecting outlets. Do it methodically and record your results as you go. Confirm as you go that your understanding of the run of wires is correct. In other words, when you disconnect an outlet - and its pigtails - make sure that the outlets downstream go dead as you believe the run dictates it should.

You might have 12 years of paying for slightly energized (ohmic heating) of dirt. Unless some recent construction put a nail or something through a wire and somehow made a connection to dirt.

How long has this been going on? Does it coincide with some construction activity?

 

[jhelrey]

Just rip out the wires and rewire the circuit.

 

[Roots]

This really needs to be addressed with a quickness, as people could be harmed.

Ideally, you'd best be served by finding an electrician who's great at residential/commercial diagnostic work. I'd personally be inclined to start disconnecting and meggering all of the wires on that circuit and in the new addition. However that's time consuming, requires specialized test equipment, and a very knowledgeable and attentive technician; which may be hard to find.

You might very well be better off to have a licensed electrician just rewire that entire circuit, and than see if there's a still problem. I really wouldn't see it as a utility issue versus a house wiring issue.

 

[sdowney717]

We had a wire going under cement not in conduit and the wire eventually had an insulation break. Must have leaked current for a while till the flow got big enough to start tripping a non gfci 15 amp house breaker. I recall resetting it and hours later it would trip. I dug it out, cut that wire bundle apart and the copper had disintegrated for several inches looked pretty burned up.
So I would as your doing just keep disconnecting circuits. should be easy to find the offending wire.

I recall having a long interesting somewhat contentious forum discussion on how much current the earth can conduct.

Normal grounds are worthless to prevent shocking, good grounding hopefully blows the breakers when wires shorting but when not enough current flows then you can be killed since the line stays hot.
So much better are ELCI GFCI current interupters.

http://www.mikeholt.com/reprint_request.php?url=http://mikeholt.com/graphics/touch2.gif

 

[Cobra6]

Checked out and replaced 3 receptacles today on the circuit. No change, nothing unusual, except two were wired using the "push-in" connectors on the back (as opposed to the screws). Everything else looked good.

I also opened up my ADT security box, since I realized that it has a battery backup. Even thought the system is off the circuit, I unplugged the battery, remeasured voltage, no change.

I only have about 9.5V in my pool and in the dirt today.

 

[Teken]

Silly question for you . . . Have you tried to pour water around the area where the ground rods are for the garage to see if the voltage changes?

I know another member suggested this earlier but I did not see you reply that you did this to see if this made any difference.

Its interesting you noted that the voltage has dropped from 12 volts, to 9.5 volts . . .

Just so we are all on the same page: You're in fact measuring at the exact same place each and every time to ensure a consistent reading correct?

If not, then this will give you inaccurate readings and could lead to misdiagnoses of the fault thinking its getting better when its not . . .

Has it rained lately?? Or has it been bone dry in your area??? Just trying to get a big picture of your environment . . .

 

[Cobra6]

Silly question for you . . . Have you tried to pour water around the area where the ground rods are for the garage to see if the voltage changes?

I know another member suggested this earlier but I did not see you reply that you did this to see if this made any difference.

Its interesting you noted that the voltage has dropped from 12 volts, to 9.5 volts . . .

Just so we are all on the same page: You're in fact measuring at the exact same place each and every time to ensure a consistent reading correct?

If not, then this will give you inaccurate readings and could lead to misdiagnoses of the fault thinking its getting better when its not . . .

Has it rained lately?? Or has it been bone dry in your area??? Just trying to get a big picture of your environment . . .

I'm measuring at the same place every time, the same way with the same meter. It rained today for about 30 minutes, but it has been a little drier here lately, but not extreme - grass is still good and green.
I will try the water on the grounding rods - that is easy to do.
I don't think the problem is better, it has fluctuated from around 10V - 35V since I discovered the problem.

 

[Teken]

I'm measuring at the same place every time, the same way with the same meter. It rained today for about 30 minutes, but it has been a little drier here lately, but not extreme - grass is still good and green.
I will try the water on the grounding rods - that is easy to do.
I don't think the problem is better, it has fluctuated from around 10V - 35V since I discovered the problem.

I would soak the perimeter of the building from the house outwards to about four feet all around the home.

Please ensure that the breaker is indeed off during this process and then perhaps tomorrow turn it back on and see if there is a difference.

 

[Milton Shaw]

Tesla back in the 1890's had a lot of voltage coming out of the ground, I think he got 135 foot lightening before he burned out the power plant of the town. You haven't got any tesla coils around there have you. (Tesla was the founding father of Westinghouse and beat Edison out on electricity with AC instead of DC current. He also beat Marconi on radio. Most of today's electrical distribution is based on his patents.)

 

[MrMark]

You should be able to solve the problem by disconnecting outlets and working back (or forward). I doubt it is a problem with a receptacle. It is going to be some place on the circuit where the line side is touching something that makes its way to the dirt - somehow, someway. Wetting things just changes the conductivity/resistivity of the localized dirt, it will affect the voltage obviously but not lead you any closer to solving the problem.

You have the problem isolated to the one circuit and now it should be very simple to finish the puzzle. Just be methodical. If you get all the way back to the first receptacle - having disconnected everything downstream - and the problem still presents, then the problem is between the panel and the first receptacle. Find it then.

99 percent of all homeowners/electricians would rip it out or bypass it and start over. I admire you for trying to solve the problem the proper way.

 

[Cobra6]

You have the problem isolated to the one circuit and now it should be very simple to finish the puzzle. Just be methodical. If you get all the way back to the first receptacle - having disconnected everything downstream - and the problem still presents, then the problem is between the panel and the first receptacle. Find it then.

99 percent of all homeowners/electricians would rip it out or bypass it and start over. I admire you for trying to solve the problem the proper way.

Well,
Thanks - IMO - ripping it out and rewiring doesn't solve the problem, just fixes the symptom.

 

[Teken]

Another question no where are the studs metal are they?? This is all a stick building structure?

 

[Thruxton]

Well,
Thanks - IMO - ripping it out and rewiring doesn't solve the problem, just fixes the symptom.

No, rewiring solves the problem. The proper analysis of the problem is that it is a dangerous situation, the solution to the problem is to correct that situation, not anything else. If you want to fix the problem by correcting your current wiring, that's fine, but stop theorizing and go to it. You have had some good advice here, and so far it seems to me (could be wrong) you haven't pursued it. Get on it, and get 'er done.

 

[Cobra6]

I finally isolated the problem area on the circuit -
it is between the 1st and 2nd outlets in the circuit.

Luckily that is the circuit between my garage opener outlet and the kitchen outlet, so most of the wiring is exposed in the attic - so no drywall has to come down.

 

[Cobra6]

Another question no where are the studs metal are they?? This is all a stick building structure?

stick building structure - no metal studs - I have some French pocket doors in on eof the walls that may have a metal frame around it.

 

[MrMark]

I finally isolated the problem area on the circuit -
it is between the 1st and 2nd outlets in the circuit.

Luckily that is the circuit between my garage opener outlet and the kitchen outlet, so most of the wiring is exposed in the attic - so no drywall has to come down.

Great! Be sure to post what you find.

 

[Thruxton]

Glad to hear it! BTW, just got a HF coupon for a clamp-on AC ammeter for 9.95.

 

[Cobra6]

Glad to hear it! BTW, just got a HF coupon for a clamp-on AC ammeter for 9.95.

Thanks - I jumped all over that at lunchtime - $7.99 with the 20% discount coupon.

 

[65cayne]

...You should be able to solve the problem by disconnecting outlets and working back (or forward). I doubt it is a problem with a receptacle. It is going to be some place on the circuit where the line side is touching something that makes its way to the dirt - somehow, someway. ...

My money is on THIS.

And you dont have to "rip out all the wiring". Just inspect the circuit (to the greatest extent possible).

Try this (like you need any more advice), find the halfway point in the circuit, pull the plug/receptacle out of the box and disconnect the hot wire so it does not feed the latter half of the circuit. Now go measure the pool water....

Problem gone? Fault is in latter half of circuit
Not gone? Problem in in first half of circuit (still connected). Find the halfway point and repeat the process.

 

[65cayne]

I finally isolated the problem area on the circuit -
it is between the 1st and 2nd outlets in the circuit.

Luckily that is the circuit between my garage opener outlet and the kitchen outlet, so most of the wiring is exposed in the attic - so no drywall has to come down.

My money is on THIS.
...blah blah blah.....

Forget everything I just said....Good job.

 

[Cobra6]

Latest update - (long)
I turned the circuit off completely for a couple of weeks since I was TDY -
I finished running my new subpanels to my pool house and garage, just to be sure I didn't have a voltage leak somewhere else.

Anyway, after going through the entire circuit, I discovered that a couple of pieces of an ADT security system were in the circuit - a siren alarm and a smoke detector were actually hard-wired in. I did not realize this since both of these were not close to the rest of the circuit - the smoke was in a room that was added to the house after the new alarm system was installed, and the alarm siren was upstairs.

I had problems with these last April after the tornadoes when the power was out for a week. Problems = I cut one of the wires because the alarm was going off (battery power even went out).

And.... I got a deal through USAA to upgade to a PULSE system through ADT, so I have been in line to get the techs out here to do an upgrade, but between my schedule and theirs (cancelling twice) - we have not been able to get together to get the old stuff out and replaced.

I am 97% sure that this is the problem, but I will post another update when I get it all cleaned up.

Later............

 

[PSEUDOSENTIENT]

Great thread.... I read it all the way from page one.
Lots of helpful folks, I love it. God bless you guys.
Subscribed for the final answer when you have it!