High current on neutral with a balanced load

jhardy13

Member
Location
Joplin Missouri
Occupation
Industrial Engineering student
I notice you have three different mfg meters. Did you happen to rotate them to check if they all read approximately the same?
Yes, we checked with several different meters and we checked in various positions. We also check with a single meter on all three cables and the results are the same.
 

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
I suggest putting your clamp meter around any Romex cable, conduit, or grounding electrode conductor that exits the breaker panel, to the extent there are clearances to do so. Somewhere there has to be a return conductor for the stray current that's flowing on the service neutral.
Also put the clamp meter around any cable or conduit attached to the service meter enclosure and check if there's any current present.
 

Another C10

Electrical Contractor 1987 - present
Location
Southern Cal
Occupation
Electrician NEC 2020
Are you able to lets say plug in a 60 w lamp off a breaker using a temp wired receptacle at a panel breaker, pick phase A then measure the .5 amp off the utility neutral and then the .5A off the utility phase A, then for the heck of it swap the power for the lamp to phase B of the utility check for the .5 A and confirm the same for the utility neutral.

That way you'd know the problem is or is not at the panel or if its after the branch breakers.
 

ramsy

Owner/Operator
Location
LA basin, CA
Occupation
Service Electrician 2017 NEC
..Whatever is causing this is damaging my electronic equipment, so it is getting past the ground rods and into our panel. I have lost several computer power supplys now.
In the mean time surge protection equipment might be appropriate.
 

ramsy

Owner/Operator
Location
LA basin, CA
Occupation
Service Electrician 2017 NEC
.. removed the meter to kill power completely and we were still seeing 1-3 amps on the neutral.
SWER demonstrates the earth can reliably conduct utility power at transmission or medium-voltage levels. The right soil formations may also conduct 120v for short distances.

If water-pump wiring fails Megger, then potential exists for current to find a neutral path through your house electrode grounding system.
 
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LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
You said two houses are sharing a single water pump. Whose house is powering it?

Has the same neutral integrity investigative work been done on the other house?

Even with plastic piping, a compromised neutral there could be energizing the earth.
 

oldsparky52

Senior Member
You guys are all very wise and I appreciate your comments. You have given me several ideas on ways to troubleshoot this. Is there any additional information I can provide that might help?
I would have my main turned off, check the neutral current and if it is there, ask the neighbor if I can turn their main off and check the neutral current at your house again. If it goes away, your neighbor's neutral from the PoCo may be compromised. Even the PoCo guys would have to admit this.
 

uwiring

New User
Location
Houston
Occupation
Master Electrician NEC 1996
I haven't seen this added:
Please verify the Neutral can carry the unbalanced load. Get one of L1 or L2 to at least 10 amps or more; such as running a microwave. then test the current on each L1, L2 and N. The N should be exactly the difference between L1 and L2. Ex: L1 10A - L2 5A = 5A. I have seen the N be 1 A off and found that the PoCo terminations was corroded. Also similar situation with customer having to replace circuit boards in appliances, we were able to access the service laterals at the PoCo and with the main off found the N measured .9A current at the PoCo . The lateral was in conduit so after we replaced lateral we cut the neutral and found corrosion throughout.
 

kwired

Electron manager
Location
NE Nebraska
I haven't seen this added:
Please verify the Neutral can carry the unbalanced load. Get one of L1 or L2 to at least 10 amps or more; such as running a microwave. then test the current on each L1, L2 and N. The N should be exactly the difference between L1 and L2. Ex: L1 10A - L2 5A = 5A. I have seen the N be 1 A off and found that the PoCo terminations was corroded. Also similar situation with customer having to replace circuit boards in appliances, we were able to access the service laterals at the PoCo and with the main off found the N measured .9A current at the PoCo . The lateral was in conduit so after we replaced lateral we cut the neutral and found corrosion throughout.
If there is a problem with the neutral then line to neutral voltages should unbalance as the current unbalances. I could be wrong but I think OP has stable voltages just stray neutral current that he hasn't figured out where it is coming from.
 

McLintock

Senior Member
Location
USA
Occupation
Electrician
Remove the power from the well and retest.
Kind of my thought too, if by some means the neutral/ground goes to his panel, if the pressure tank is in the house.

It would also be helpful if we knew at what point this all started, what were the conditions around it at that time.


“ shoot low boys their riding shetland ponies”
 

kwired

Electron manager
Location
NE Nebraska
Kind of my thought too, if by some means the neutral/ground goes to his panel, if the pressure tank is in the house.

It would also be helpful if we knew at what point this all started, what were the conditions around it at that time.


“ shoot low boys their riding shetland ponies”
Not saying one should completely ignore it, but submersible wells are almost always 240 volts and don't utilize the neutral, shallow well jet pumps or even similar used as pressure booster can be 120 but majority of those also are usually 240 volts.
 

McLintock

Senior Member
Location
USA
Occupation
Electrician
Yes most the time they are, but when I had a new well put in they asked me if I wanted a 120v pump or a 240v pump


“ shoot low boys their riding shetland ponies”
 

jhardy13

Member
Location
Joplin Missouri
Occupation
Industrial Engineering student
Here is another photo of the strange neutral current. I used different clamps this time and you can see that the results are the same. With an almost perfectly balanced load, we have over 4 amps on the neutral. When turning off the power to the house, the neutral current drops to 1 amp.
 

Attachments

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
What are those wires coming into the meter base on the lower left? POCO load control or something else?
 

Another C10

Electrical Contractor 1987 - present
Location
Southern Cal
Occupation
Electrician NEC 2020
When turning off the power to the house, the neutral current drops to 1 amp.
120 watts on the neutral when no power is applied what so ever, can you pull the meter to see if that 1 amp goes away, maybe there is leakage somewhere on the line side of the meter ... either way I'd have a lot of fun trying all the tricks of troubleshooting I learned from the past, you certainly need to tell us what the culprit is when discovered.
 
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