Bravo30,
Wiring the external AC source (Shore Power) to a Pass-Through, Inverter/Charger is different than other systems. All three of the shore power wires (Hot, Neutral, and Ground) should be wired directly to the Multiplus. Other than a breaker/fuse for the Hot wire, do not connect them to any thing else (Ground/Neutral Buses, etc.). The MultiPlus AC out should be the only source of power for AC loads. Also, do not manually bond the AC out Neutral to Ground. The MultiPlus has an automatic transfer switch that controls the Neutral/Ground bond. I have attached copy of the Manual for your Inverter/Charger. I strongly recommend you read it before wiring the system. I would hate to see you fry a thousand dollar plus device.
I have years of experience with these types of systems and am just trying to help.
Hope you take this in the spirit in which it is offered.
Pat