Farm water troughs using a 3 prong 120 volt A.C. electric heater often have a slight voltage leakage. The heater used was newly purchased, as the farmer thought the original heater was defective. A Fluke digital meter type 117 on the "Lo Z" scale measured 1.7 V.A.C. from the water in the trough to a driven ground rod that was 8" away from the trough. With the heater unplugged, the Fluke DMM measured 0.0 V.A.C. This heater was energized from a G.F.C.I. outlet, which did not trip when a jumper wire was connected from the electric heater metal jacket to the driven earth ground rod. The current flowing in the jumper wire to the earth driven ground rod was 20 mA. I assumed the G.F.C.I. outlet did not trip because this was actually a capacitive current. Would you agree with this assessment? The water trough was made of a vinyl, plastic, or rubber material. The non metallic trough would be the dielectric, while the water and the earth serve as the two capacitor plates. With the jumper wire connected from the heater metal jacket to the earth ground rod the voltage measured was 0.0 V.A.C. (from water in the trough to earth ground rod.) Dave Baylor April 4 2018, 1:30 pm EDT
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