Pwr1 negative, pwr2 negative, shunt negative and I believe one of the
switch input legs are all common.
On 5/9/2017 8:42 PM, Adam Moffett wrote:
The only thing that comes to mind is a short through ground.
------ Original Message ------
From: "Bill Prince" <[email protected] <mailto:[email protected]>>
To: "Motorola III" <[email protected] <mailto:[email protected]>>
Sent: 5/9/2017 6:31:30 PM
Subject: [AFMUG] SiteMonitor II: Independence of PWR1 & PWR2
I think I have a SiteMonitor II with a problem, as I always thought
that the two power sensors (PWR1 and PWR2) were independent of each
other, and should have a pretty high impedance between then.
We set up a new solar site, and put our load on PWR1 and the
batteries on PWR2. As soon as we hook up either one of the sense
wires, the breaker to the batteries (30 amp) pops, and all the lights
go out.
We can monitor one voltage on PWR1, or the same or different voltage
on PWR2. However, if both are connected we blow the 30 amp breaker to
the batteries.
We've checked the polarity (both voltages are negative ground), and
they are both "about" the same voltage (although we have monitored
radically different voltage in the past (like 12V on one and 48V on
the other). This is a 48VDC system, so we are seeing ~~ 56V on both
right now,
BTW, when we hook up just one of the sensors and leave the other
open, we see ~~ 43 volts between PWR1 and PWR2. I haven't checked
other SiteMonitors, but this doesn't seem right to me.
--
--
bp
part15sbs{at}gmail{dot}com
