High current on neutral with a balanced load

[jhardy13]

Okay, I am about ready to give up on this and just move across town. I don't have the free time to or will to continue pursuing the root cause of this. This might be my last question here unless something obvious comes up.

I found that we have ac current on our coax cables at the service entrance. We have network issues all the time even though our speeds are good and signal levels are in spec on the modem home page. Could this be related? Roughly .3amps to 1amp on coax and the home is drawing about 6amps total. The current is only on the coax cable on the ISP side of the ground bond and the current is also on the ground bond. I've read this can indicate a loose neutral, but all of our connections have been checked. Could it be a neighbor with a loose neutral and some of their current is returning on our coax cables to our neutral? Attaching some photos below. One above the ground bond and one below. The one with the current is going to the street.

 

[Hv&Lv]

.

I found that we have ac current on our coax cables at the service entrance. We have network issues all the time even though our speeds are good and signal levels are in spec on the modem home page. Could this be related? Roughly .3amps to 1amp on coax and the home is drawing about 6amps total. The current is only on the coax cable on the ISP side of the ground bond and the current is also on the ground bond. I've read this can indicate a loose neutral, but all of our connections have been checked. Could it be a neighbor with a loose neutral and some of their current is returning on our coax cables to our neutral? Attaching some photos below. One above the ground bond and one below. The one with the current is going to the street.

Yep, back full circle now..
Go back to Posts #18-20

 

[jhardy13]

Yep, back full circle now..
Go back to Posts #18-20

At the time we weren't seeing any current on the coax cables. Thanks for reminding me about those posts. The amperage is rather low. Haven't seen it above 1.1amps. Is 1.1 amps significant enough to be looked into?

 

[jhardy13]

The neighbor sharing our transformer is not bonded to the isp coax cables so it would have to be a neighbor further away if this were the case. Closest neighbor would be about a quarter mile away

 

[gar]

202024-1301 EDT

jhardy13:

You have put us all to this long post, and our time to try to help you. Now you want to quit.

Fundamentally you do not know how to troubleshoot an electrical problem, and do not provide the correlating information needed to help. I think you would have the same trouble working on a mechanical or chemical problem.

The problem of an unexpected high neutral current can be troubleshot in a relatively direct fashion.

.

 

[Hv&Lv]

202024-1301 EDT

jhardy13:

You have put us all to this long post, and our time to try to help you. Now you want to quit.

Fundamentally you do not know how to troubleshoot an electrical problem, and do not provide the correlating information needed to help. I think you would have the same trouble working on a mechanical or chemical problem.

The problem of an unexpected high neutral current can be troubleshot in a relatively direct fashion.

.

Be easy...
See post #9
Learning takes time.

 

[jhardy13]

202024-1301 EDT

jhardy13:

You have put us all to this long post, and our time to try to help you. Now you want to quit.

Fundamentally you do not know how to troubleshoot an electrical problem, and do not provide the correlating information needed to help. I think you would have the same trouble working on a mechanical or chemical problem.

The problem of an unexpected high neutral current can be troubleshot in a relatively direct fashion.

.

I am completely self taught on this stuff. I have no training or background in electrical theory. I'd say I know quite a lot now considering this. Obviously there will be gaps in my understanding, and my methods of troubleshooting aren't going to be 100% correct or professional. I just want to fix the issue my home is facing. I started this thread after paying multiple electricians to investigate the problem and no one could find the root of the issue, however all of them agree that there is an issue including the engineer at our local power company. Also, I can quit any time I want. I'm sick of dealing with a problem that can't be solved without throwing large amounts of money and time at it and I think you would be too if you were in my shoes. Regardless, thanks for your efforts.

 

[gar]

202024-1342 EDT

jhardy13:

At your class level you have had high school science, chemistry and physics. Likely by now chemistry, and physics in college. Also many college engineering specialities will require courses in other specialities.

Many electricians have nothing like your background to work from. Also many electricians lack good troubleshooting skills. In industrial plants I saw and worked with many different trades. In the electrical area were ones that could be classified as bulb changes, and others that were skilled troubleshooters.

You have come to this forum looking for help, and many have tried to help. The time of those that have helped is worth something, probably more than what you have expended.

Your problem(s) can be found by proper troubleshooting. The problem may or may not be solvable based on the origin of the problem. Don't give up and go away. It will be interesting find your cause, and it may help others.

Number one. Can you recreate the problem?

Number two. Can you make the problem disappear by turning off everything, and disconnecting all other things, like TV links. If so? Then reconnecting things what restores some or all of the problem?

.

 

[jhardy13]

202024-1342 EDT

jhardy13:

At your class level you have had high school science, chemistry and physics. Likely by now chemistry, and physics in college. Also many college engineering specialities will require courses in other specialities.

Many electricians have nothing like your background to work from. Also many electricians lack good troubleshooting skills. In industrial plants I saw and worked with many different trades. In the electrical area were ones that could be classified as bulb changes, and others that were skilled troubleshooters.

You have come to this forum looking for help, and many have tried to help. The time of those that have helped is worth something, probably more than what you have expended.

Your problem(s) can be found by proper troubleshooting. The problem may or may not be solvable based on the origin of the problem. Don't give up and go away. It will be interesting find your cause, and it may help others.

Number one. Can you recreate the problem?

Number two. Can you make the problem disappear by turning off everything, and disconnecting all other things, like TV links. If so? Then reconnecting things what restores some or all of the problem?

.

Yes I can recreate the problem. It doesn't need to be "recreated" because it is always present when all of our breakers are on and my family is doing normal everyday activities such as using the kitchen appliances and watching tv. The problem being a large neutral current compared to the current draw on each phase and flickering lights unrelated to something kicking on such as an AC unit. It doesn't require special circumstances to be present. If it did, this would be a nonissue. Turning things off does NOT make the problem go away.

 

[oldsparky52]

I would ask the PoCo to put a recorder on your service for a while.

If you can recreate the problem, do you know where it is coming from? From what I remember about this, that has been a moving guess.

So it seems like now it's the cable? If you disconnect the cable at the demark box, does it go away?

 

[jhardy13]

I would ask the PoCo to put a recorder on your service for a while.

If you can recreate the problem, do you know where it is coming from? From what I remember about this, that has been a moving guess.

So it seems like now it's the cable? If you disconnect the cable at the demark box, does it go away?

What kind of recorder are you referring too? They've already set up a power quality analyzer that showed large amounts of harmonic currents. THD% greater than 70%. They're recording equipment didn't capture large voltage drops or fluctuations. If I knew where the problem was coming from I wouldn't be on this forum. I'm not saying it's coming from the coax. I'm simply stating that we have ac current on our coax. Nothing more nothing less. Is AC current normally on the coax? Pretty sure the answer is no. That's why I brought it up. In the photo I provided you can see the coax has 0.475 amps on it. I'm asking a yes or no question. Is it normal to see ac current on
the ISP coax cables? If no, what amount of current would you consider concerning and why?

 

[gar]

202024-1640 EDT

jhardy12:

I believe in the past, somewhere, you have said that with all breakers off that there is no excess neutral current. Is that correct? If so, then what breaker being turned on causes some or all of that unwanted neutral current to appear? Note that turning on a single 120 V breaker will cause the same current magnitude to appear on the hot and neutral. Further these two should be of nearly identical waveform (including magnitude) and phase position.

.

 

[oldsparky52]

202024-1640 EDT

jhardy12:

I believe in the past, somewhere, you have said that with all breakers off that there is no excess neutral current. Is that correct?

I remember (correctly or incorrectly) that it was reported that with the MB off there was still neutral current, then I thought later it was reported that with the MB off there was no current.

This whole troubleshooting exercise has been all over the board. It sounds like there may be multiple issues.

 

[oldsparky52]

What kind of recorder are you referring too? They've already set up a power quality analyzer that showed large amounts of harmonic currents. THD% greater than 70%. They're recording equipment didn't capture large voltage drops or fluctuations. If I knew where the problem was coming from I wouldn't be on this forum. I'm not saying it's coming from the coax. I'm simply stating that we have ac current on our coax. Nothing more nothing less. Is AC current normally on the coax? Pretty sure the answer is no. That's why I brought it up. In the photo I provided you can see the coax has 0.475 amps on it. I'm asking a yes or no question. Is it normal to see ac current on
the ISP coax cables? If no, what amount of current would you consider concerning and why?

I do not know for sure but agree with you that NO there should be no AC voltage or current on the coax. That (to me) suggest a neutral issue somewhere (I'm sure you are tired of hearing that).

Did you ever disconnect the coax completely at the demarc box and determine if there were any changes on the neutral conductor of the service?

BTW, I completely understand your frustration with this. I'm sorry if I contribute to your stress.

 

[oldsparky52]

In post #4 jhardy said

Okay I was able to quickly test the neutral current with our mains power turned off. It reads 0 amps.

Then later.

I have tried that. In fact, when we had the power company here a week ago, they removed the meter to kill power completely and we were still seeing 1-3 amps on the neutral. We do not have any form of solar power or battery that would cause this. Our home is small and simple. We only have one neighbor and we share a well pump and transformer with them.

This kind of thing makes it difficult to troubleshoot this.

 

[jhardy13]

In post #4 jhardy said Then later.



This kind of thing makes it difficult to troubleshoot this.

Those measurements were taken weeks apart. Maybe months apart, I'd have to look at the dates. If someone has an open or loose neutral and their current is finding it's way to my neutral via the coax cables, that would explain the measurements taken back then. Back then I didn't know nearly as much as I know now. I've been learning along the way. I dont think we checked the coax cables at the time. It never occured to me that I should back then because I didn't know that a neighbor with an open neutral could have current taking the coax cables.

I'll respond to everyone tomorrow, I have a lot going on today.

 

[ptonsparky]

I don’t know why there would not be some AC current on the coax. It would be in parallel with the neutral conductor from house to house. Assuming they are bonded to the GES of each home. Granted, I have never amp clamped a coax.

 

[synchro]

I'm attaching a couple photos of the Neutral to Earth voltage referenced from a remote ground rod 10 ft from the bonded ground rod at the meter. The voltage is usually between 1.5v to 3v. Just happened to take this while it was low. The DC offset on this voltage is real. I was sure to zero both channels before testing. The second photo doesnt show the offset because I had it set to alternating coupling in the scope which filters out dc components. This voltage is present with the 200amp breaker turned off.

How far from your meter is the power company's transformer? Is it possible to put a screwdriver in the ground about halfway between the meter and the transformer, and then measure the voltage between the screwdriver and neutral? You had mentioned measuring the voltage at 10 ft. spacings in different directions, but it would be interesting to see if the voltage "gradient" you measured continues over a longer distance and builds up the voltage even higher.

 

[jhardy13]

How far from your meter is the power company's transformer? Is it possible to put a screwdriver in the ground about halfway between the meter and the transformer, and then measure the voltage between the screwdriver and neutral? You had mentioned measuring the voltage at 10 ft. spacings in different directions, but it would be interesting to see if the voltage "gradient" you measured continues over a longer distance and builds up the voltage even higher.

The meter is roughly 25 yards away from the transformer pole. I'll test this later today and report back.

I have a hypothetical question for you. If a circuit has a high resistance/impedance neutral, will the current waveform be distorted or will it retain its normal shape? I'm not just referring to home circuits. In general, if I were to set up a small circuit with a battery to power a light bulb, would the current waveform be altered in any way by raising the impedance of the return path?

 

[ptonsparky]

The meter is roughly 25 yards away from the transformer pole. I'll test this later today and report back.

I have a hypothetical question for you. If a circuit has a high resistance/impedance neutral, will the current waveform be distorted or will it retain its normal shape? I'm not just referring to home circuits. In general, if I were to set up a small circuit with a battery to power a light bulb, would the current waveform be altered in any way by raising the impedance of the return path?

I would think with a DC circuit you just have a straight line. Reduced in amplitude because of the resistance. Intermittent would cause changes but again only in amplitude. My SEWAG.