Source of ground current.

Originally Posted By: dguizzetti
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Here’s a toughie. I put my clamp-on ammeter on the cold water pipe between the cold water ground clamp and the point where the galvanized water line enters the home. I read 1.7 amps. I opened the main disconnect just under the meter on the garage and still read the same amps. I had the utility company pull the meter and still had 1.7 amps on the cold water line. There is no other source of electrical service to the property. Telephone and cable grounds are attached to the ground rod at the meter. Phone ground only shows .2 amps. Where can the ground current be coming from?


I ran across a post somewhere that had a similar case and the current was coming from a unintentional ground in a ungrounded conductor on an electric water heater three houses away. Any ideas? TIA.
Don


Originally Posted By: jjackson
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It almost has to be coming from another water line if the meter was pulled. If you are just inspecting the house, you just need to report it. If you need to try and find out where it’s coming from, I would shut the water off and disconnect the water meter.



jj

Originally Posted By: Greg Fretwell
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My guess;


a neighbor has a bad neutral connection. The path is from their main bonding jumper/EGC to the water pipe, through the dirt to your customer’s house, his EGC/MBJ and out his good neutral to the transformer. You could prove it by opening the ground clamp but be aware a voltage will be present then and the neighbor may see lights dimming/brightening.