Re: Grounding the inverter question
i never ground my inverters to the chassis. I think it's a bad idea to give 110 volt current an opportunity to go surging through the bus chassis. I keep the high voltage isolated from the bus chassis. The concern is that the bus itself is not grounded. Stray voltage on the bus chassis is just gonna be looking for a ground, and the easiest path might be through YOU when you do something like open the refrigerator door while touching the ceiling.
*edit* I might have misunderstood the original question.....
if the question was where should the negative battery cable be connected I would agree it should be connected to the negative battery terminal.
There is usually a separate grounding terminal on an inverter, and that is what i never connect to the bus chassis. Obviously you have to connect your negative battery terminal to ground, or the battery (better choice)
Quis custodiet ipsos custodes (who will watch the watchmen?)