Your use of the term "by directional meter" is not clear. Please confirm the following:
- You will have have a single 400A service drop and meter from the utility.
- You will have 2 x 200A feeders from that service drop, one for the house; one for the RV garage.
- You have a Solar PV system, presumably on the house, and presumably with a NEM (Net Energy Metering) contract to where excess energy produced by the Solar PV system is pushed back to the utility through that 400A meter.
- You want to know if the Solar PV feed will go only to the house, not the RV garage?
If all of those are true, the answer to #4 is NO. The Solar PV system will just feed your "service", and anything drawing FROM that service will be drawing from the Solar PV, until/unless you need MORE than it can provide, in which case the utility power is pulled in through the service meter. The energy only goes BACK to the utility when your entire service is using LESS energy than the Solar PV system is producing. So at night for example, you will have all of your power coming from the utility (unless you have a battery system). In the middle of the day, if nobody is home and the energy use is minimal, the Solar PV system will be pumping energy back to the utility grid. But if someone is in the RV using energy, the Solar PV energy will go there.
If you WANT them separated, then you would need to have TWO SEPRATE 200A METERS, one for the house that has the NEM contract, then another meter for the RV garage that does not.