Not sure if someone mentioned this but the first thing I do is visually inspect the outlet (30A or 50A) at the pedestal before doing any other checks. It's not uncommon to see burnt contact(s) inside the outlet. Inserting the plug from your RV with the nice, shiny contacts into that socket will quickly degrade the pins if used too long under high amperage conditions (running A/C, water heater, etc.). The resultant arcing will increase the electrical resistance of the pins, which in turn creates more heat and hastens the process. The only fix is to move to another spot or have the maintenance person change the socket.