The only thing that comes to mind is a short through ground.
------ Original Message ------
From: "Bill Prince" <[email protected]>
To: "Motorola III" <[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
