ECN Forum Forums General Topics of the Trade General Discussion Area Checking Unit Sub before...

Before starting a unit sub we checked for continuity between phases and ground and kept getting continuity b/w red & grnd. It turns out that it was not a ground fault but only something electronically at the meter. Has anyone encountered this problem before and how do you dertermine if it is a true fault or just this electronic equipment causing this? We determined this by simply turning equipmwnt on after not physically seeing any fault in or around the equipment.

Cinner,
What sort of meter is used there?.
My understanding of an energy (KWh) meter, is that it has two coils in it.
One is the Potential coil and that connects across Hot and Neutral.
The other is the Current coil and that connects in series with the Hot wire before it feeds the load.
I'm thinking maybe that the Potential coil may have upset your continuity readings, because of a reference to Ground through the Neutral.
Can't say that I like the idea of that technique, because if there had have been a genuine fault on the circuit, things could have happened.