Re: Current in water pipe
Charlie,
Hope you had a good Thanksgiving.
I do question the " water pipe is a higher impedance path - - -.".
With-out looking-up the permit number/address info, - -,
had a house with a 2W 120V service off of a Poco pole mounted transformer with at least 8 other service drops, 2 of which were duplex(s) of a year or so old. An electrician contacted me after he seen another contractor changing the service to a 3W system after he had made trouble call to the site.
When it was a 2W system, the grounded conductor carried approximately 1/3rd the current of the ungrounded conductor and he had not yet figured-out why.
So-ooo, when I was called for the service change inspection, I took the readings on the new 3W 240/120V service which was still , temporarily, connected to the 2W service drop. The old service drop was a triplex with one conductor not connected at the pole. The grounded conductor was carrying 12A +/- and the ungrounded conductor had 42A +/-. The Water GEC was 30A +/-.
Notified Poco and the City Water Department.
Not sure what Poco actually did, but they did install a new service drop. When making a follow-up inspection, because of the above problem, the neutral service conductor was still only carrying a very low partion of the return current.
Turning off all of L1 and all of L3, L2 being the neutral, at different testing times, to simulate a 2W system, the grounded conductor was still only carry about 1/3rd of the ungrounded conductor under test. The water GEC was carrying the other 2/3rds of the current.
The City, that I worked for then, did not allow me to make further tests.
Assume it is still the same today.
The Poco transformer pole and two other secondary side poles where along an 8" cast iron water line.
Maybe a ground rod made contact with the 8" water line.
I would like to been able to check each of the other service drops.
gwz2