I am confused about whether or not to ground my inverter to the trailer chassis (it is a military trailer with a steel floor). It is a Xantrex 1000 watt pure sine wave inverter, and the directions say to ground it to the chassis. But before I get into it, let me describe my setup.
First, the trailer's tail lights are grounded to the trailer frame, and are run of course from the tow vehicle's battery. The tow vehicle's battery is not connected at all to the trailer's electrical system. (I did not set it up to charge the trailer's batteries, so there is no isolation switch.)
That being the case, if I install a ground strap from the inverter's grounding tab to the trailer chassis, and from the trailer frame to the trailer battery's negative terminal (as it says to do in the inverter's manual), am I not potentially mixing up the tow vehicle's ground with the trailer's ground, in effect connecting their negative terminals together? I am thinking this would not be a good situation. What do you think?
Second, I have an automatic transfer switch for switching between shore AC power vs. the inverter's AC power. When connected to shore power, I should be grounded via the campground's electrical system (in theory). If on inverter power, there would be no grounding rod in the equation (although the trailer does have a steel jacking foot). What is the advantage to grounding the inverter to the chassis, and then to the battery's negative terminal? Are we not talking about 120 volt AC being grounded, not 12 Volt DC? Which kind of current is the inverter's grounding tab actually for?
Also, I have a GFCI outlet in the inverter, and a GFCI outlet just downstream from my shore power inlet. So both sides of my 120 VAC power system are fault protected. My 120 VAC system is fused at 15 amps just like a simple household circuit.
So, does it make sense to ground the trailer's inverter & batteries to the trailer chassis or not, given the considerations above?
Thanks for your help!