On Sun Nov 10 15:05:24 PST 2019 [email protected] said:
>You do not really have a ground fault, it seems your power supplies have an
>input circuit that causes a small current to ground, possibly they have a
>MOV or other protective device on their input or a discharge resistor that
>takes care of the required removal of voltage from input capacitor when the
>power supply is unplugged, so you can't be shocked by the prongs of the
>cord after unplugging?

In this case, the leakage is from the Pack +/- to the output -12v connection.
The pack circuit is open mid-pack, so there is NO voltage on the supply HV 
inputs.
When the ma meter is going through a 1K resistor between either side of the 
pack, and 12v Gnd, I get a solid 0.34 ma that holds steady.  This is from about 
the 32v point on either the + or - side of the pack.  Current polarity is the 
opposite between the sides.
So, the only conduction path is through the power supply from either HV input 
to the -12v side of the output.
If I do NOT open the pack, so the DC-DC are powered, AND check at higher 
voltage point in the pack, the leakage current goes up significantly.
There is no "ground", as one of these power supplies is a potted plastic box, 
with no input ground lead, and the other is a metal box that is sitting on a 
chunk of plastic with no connection from it's case to the metal of the truck.


--

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