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This is a follow-up to my previous question about a bad neutral. The dimming lights/fluctuating voltage problem mostly went away after the PoCo tightened the neutral connection on my side of the meter 'a few turns.' I still measure some current (.15A-2A) on the ground conductor connected to the copper pipe of the water service entrance. I have another ground conductor in my main panel that is connected to a ufer ground that measures no current. (edit: The conductor outside my house leading to the ground rod also measures no current.)

I turned off the main breaker and put a clamp ammeter on the water service ground wire (edit: and the service entrance neutral) and I'm still getting some current (~.1A). Is there any reason for this? From the pictures, you can see that the current is slightly lower near the water entrance. I'm not sure if that's significant. Is this still a PoCo issue?

.1A on ground at main panel (main breaker off) .1A on ground at main panel (main breaker off)

.08A on ground at water service entrance (main breaker off).08A on ground at water service entrance (main breaker off)

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    Did you try clamp testing the service neutral wire? Remember, the main breaker does not disconnect the neutral. Oct 4, 2022 at 15:30
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    @RobertChapin I just did. I'm reading .08A on the neutral and ground with the main breaker off. Updated post body to reflect this.
    – kton25
    Oct 4, 2022 at 15:40
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    So a fraction of an Amp with potential from the transformer and/or your neighbor's bad grounding system. Not bad. And believe me, nobody goes around clamp testing their water meter for fractions of an amp. I guess it's no concern but will let others answer. Oct 4, 2022 at 15:44
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    @RobertChapin Gotta agree, mostly in that it's not a worry. But I differ that the neighbors grounding system is bad, frankly, it's probably pretty good given that current is flowing via physical earth to the OPs ground. Using NEC terms, we have the "Grounded Neutral Conductor" and the "Equipment Grounding Conductor". Both are grounded. There is probably a tiny bit of resistance in the GNC that leads to the EGC to carry a bit of current. Really nothing to worry about. Oct 4, 2022 at 17:05
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    @GeorgeAnderson I may have been imprecise. The idea was that the neighbor has the same bad neutral connection by the same bad contractor resulting in inadequate ground-neutral bond. Oct 4, 2022 at 17:29

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Robert Chapin nailed it. This is stray current from somebody else's ground fault of some kind. They might have a lost neutral as you did, or they might have a failing appliance of some kind.

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