i have amps on ground wire

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shockey

New member
ran into something odd i had 18 amps on a ground connection in a house.the house was turn into two apts . the electrician who did the upgrade from from
the fuse box to circuit breakers never ran outside ground rod and didn't run a ground wire to the water meter.instead they ran a ground wire to water heater
which is right near the panel. told landlord that has be correct first!!!next i didn't find the circuit that was causing the feed back because i couldn't get in the upstairs space.i thick it could be ac window unit causing the problem or a back feed on from a neutral from a circuit because all hot wire were reading low amps.even turn off main breaker to main panel then the ground to water pipe read 7 amps. i think that there a back feed somewhere.and i think that circuits from the first floor go to second floor this one is old it will take time to trace. any idea anyone?
 
JohnJ0906

JohnJ0906

Senior Member
Location
Baltimore, MD
Does the house have metal water piping from the street?
Is the 7 amps reading with all power turned off?
This could be neutral current from another house on the same transformer finding a path back to X0
 
cadpoint

cadpoint

Senior Member
Location
Durham, NC
And mine since I've read that previous thread about amps in cold water pipe. I'd never heard of that before. I found that to be a truly fascinating read.
Click to expand...
I'm glad you said previous thread, but it still makes me want to for find my Amp Meter...
 
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gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
080810-1922 EST

shockey:

Find the water line that enters the house. Is it metalic going into the ground? If so and if you have a clamp-on ammeter that will fit around, then measure the current at that point. Also measure the current on the incomming neutral wire if possible. Do both measurements with the main breaker off or fuses pulled. Report results.

Still with no house load --- Measure the voltages L1 to neutral, L2 to neutral, and L1 to L2. Do they correlate? In other words does (L1 to N) + (L2 to N) = (L1 to L2)? Are the two line to neutral voltages equal? What is the difference. When doing these tests always identify the same side as L1. Apply a resistive load of about 10 A to one side of neutral and then move the load to the other side. What are these voltages. You can use a 1440 W heater, about 10 ohms. Monitor the water line current when doing the experiments.

Where is the supply transformer relative to this house and all others on the same transformer, and the distances? Does the primary supply to the transformer have one primary lead connected to ground at the transformer and thus to the neutral to the house?

With the house load completely removed the only source of current to the water pipe is the neutral from the transformer.

.
 
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