@CapsEngineer is correct, you have to use an adapter wired for EV charging use. The reason is that internally RVs have a 240V split phase electrical panel to power an air conditioner. But that adapter plugs into a 120v TT-30 receptacle. As a hack, the adapter will provide the same 120V phase to each of the 240V split phase side of the RV’s electrical panel. This will power all 120V appliances, but not the air conditioner, which is fine as a hack. But it does it by providing the same 120V phase to each of the 240V split phases. So if you were to read the voltage from the NEMA 14-50 receptacle part of the adapter‘s two hot pins, it would read zero volts (same 120V given to both hots).
And puts the neutral on the other hot pin. Anyone who makes one of these adapters (I have one) should make sure that it doesn't get used with an RV (or any other 14-50 appliance).
Your correct. I wasn’t thinking.
Yes, this. I've talked with some people who use RV's frequently. It's a little odd how many people in the EV community are using the 240V connection in a 14-50 type of outlet, when the actual RV's that those plugs are generally meant for do not use the 240V connection across the two hot lines at all. They are only using the 120V connections for everything, but they have to spread the appliances out somewhat evenly across those two circuits, so they don't overload something.
