Okay, we are installing a normally closed contactor on the AC wire coming into the Xantrex inverter charger, following the very good idea from MrWizard. My question arises because the Xantrex usually passes the AC right through the Xantrex when no inverter is needed. If the contactor we are installing opens up because of high temp sensed by the BMS (which controls that contactor) then the Xantrex will go into inverter mode and the output wire is no longer simply shore power being passed through but is now battery power being inverted to 120v ac. This isn’t terrible because that’s what it is for. But our contactor is a DPDT, and I’d like it to open the power line to the Xantrex but close a circuit to the output wire from the Xantrex, which would normally be the AC being bypassed through the Xantrex anyway, but, with the contactor switched, the ac would be bypassing the Xantrex completely. In effect all that is powered by the 30 amp bypass current through the Xantrex would now just completely circumvent the Xantrex and continue to power everything vis shore power rather than the inverter. I know (at least I think I know) that I can safely do this with two DPDT contractors, with the second in line on the bypass wire coming out of the Xantrex, being NC letting the unit operate exactly as it does when all is well, but, when energized by the first solenoid because of overvoltage, it would open the line BACK to the Xantrex and close the ac current coming from the first contactor, thereby not only bypassing the Xantrex but also preventing any voltage from “back flowing” into the Xantrex through the output side. Does anyone know if I should be worried about power going back into the Xantrex via the output wire? If I don’t need to worry about that then the single DPDT will do the trick. Can anyone possibly follow what I’m attempting to explain? I’m not at all worried about all of you and your capacity to comprehend, but I’m totally convinced of my inability to explain with clarity what I’m doing. If anyone does understand please comment. Thanks.
