Jeffrey,
The AquaHot 120V heating element in your coach draws 15 amps (some latter model coaches have dual elements and draw 30 amps), so if nothing else is running like battery chargers, a 30 amp plug will handle the load. However if you actually use the coach while on this plug, you should consider a 50 amp plug, because charging low batteries or just turning on the microwave would overload the circuit if the AquaHot element was on.
Gerald