Camper Trailer Inverter Setup Question

[nicklee]

HI everyone, I am looking at installing a Renogy 3000W Inverter/Charger with built in transfer switch in my camper. My plan is to install this with 4 6V 200Ah Golf cart batteries via 4/0 cables in the front locker. I currently have a 100W panel on the roof running through a Samlex MPPT but will be adding panels at some point. My questions is this... what I would like to do is take a small RV/generator extension cord (30amp, 3 prong), cut it in half, and then direct wire these into the AC input and output on the Renogy. This way I could plug my existing RV Cord into the generator output, and plug my Gas Generator's cord into the Input of the Renogy. I would then turn off the converter in the trailer's panel. Wondering if I'm on a feasible path here? My other worry is that the pass through grommets on the Renogy won't fit a 4/0 cable or the big 10 gauge generator cords.

Appreciate any input you might have to this.