Originally Posted by prairiecamper
not knowing how your RV is wired and not knowing where your portable surge protector is in the circuit, this is for certain, plug is melting because of heat, heat is created because of high resistance. Short term high power usage with high resistance creates heat almost instantly but might not trip a breaker or be sensed by surge protector! could be dirty or loose connection plug/receptacle or a bunch of other things?
Totally agree with above statement, would go further and say you are always running on the edge, and drawing 31-33 amps "just under the radar" of camper or shore breakers. I've had it happen to me where drawing just over the line= damaged plug. Remember the cord is rated to 30 amps, the intent is to stay just under that cause it is not a 100% efficient connection.