Which charge controller are you using? On the base unit the following pins are tied together:
PWR1 - PWR2 - One side of the switch input. The remaining pins are all reasonably isolated from each other, with varying amounts and types of isolation. For instance, PWR1+ and PWR2+ have no direct connection to each other. Measurement-wise they are both very lightly tied to ground through around 310K of resistance. The power to the rest of the circuit is through two blocking diodes which should effectively prevent cross-shorting as long as there isn't more than around 100V of difference between the voltage inputs - which are rated at 60V, so that should never occur. The reason why I asked about the charge controller is that many now have the following warning: [image: Inline image 1] The other question has to do with what voltage is the panel running at? Barring that, maybe you have a defective unit. If you have an ohmmeter, can you measure the resistance between Vin1+ and Vin2+? On Tue, May 9, 2017 at 4:31 PM, Bill Prince <[email protected]> wrote: > 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 > -- *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 [email protected] | http://www.packetflux.com <http://www.linkedin.com/in/fwchristian> <http://facebook.com/packetflux> <http://twitter.com/@packetflux>
