Did you ask the people in the know at FW if they had any electrical issues in that loop during that time period, surges, outages, what have you? One time while we were there, there was an outage in the middle of the night, and the technician who came out told me that FW techs know EXACTLY what's going on with the electric there at all times.
On the other hand, could it be some kind of user error with the renters not using the electric in the camper right? I can't imagine how they could "throw" it repeatedly, but who knows?
I know that I can't run the a.c. in the motorhome when I have it plugged into our house's electric supply because the voltage isn't high enough, but I can't imagine that would be the case at a place like FW.
Please let us know what you find out!
Terri