i built a RV pad for my brother. I also built a small laundry/storage room next to pad. I wanted him to pay for his own electricity so I ran 4 wires (2 hots, neutral, ground) from a 200 amp outside main panel (already bonded) to a meter box then to an outside 125 amp sub-panel. Both mounted to outside of storage room. The ground wire runs from 200 to 125. The sub-panel will be used as main disconnect.
Do I install the bonding screw in the sub-panel?
Note: the only other thing the main panel runs is the well and a booster pump. The wires were run underground in non-metallic electrical pipe.