John Lussmyer via EV wrote:
On Mon Nov 11 09:47:56 PST 2019 [email protected] said:
[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
John, are these built as DC/DC converters? Or are the AC-input power
supplies that you are using with a DC input?
AC Power supplies
AC power supplies usually have noise filter caps, and resistors to
discharge these capacitors when unplugged to satisfy UL requirements.
It's common to find capacitors from hot and neutral to ground, and a
high-value resistor or two to ground to discharge them.
One has a ground, which isn't connected, and the case is on a plastic board.
If the supply has no ground pin (2-wire cord or wall-wart), then there
will be a capacitor and resistor from the AC input side to the output
side, in the hopes that the output negative side "might" be grounded.
The other is 2 wire only - but it a potted unit, no way to get inside.
So, it sounds like I need to find a real DC-DC converter that can take 330vdc
and make 13.8vdc.
Pretty much the opposite of every unit I've ever seen.
How about a Vicor module? They are US-made, and UL-listed (and actually
tested to comply). The noise filters and discharge resistors are not
inside the unit (which is a potted module). You are expected to add them
externally, if needed for your application.
Vicor modules are expensive new; but widely available at good prices on
the surplus market. I have a bunch; so let me know what you need. :-)
Lee
--
There is a computer disease that anybody who works with computers knows
about. It's very serious, and interferes completely with your work. The
trouble with computers is that you 'play' with them! (Richard Feynman)
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
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