When recently checking on our travel RV, Sophie, we discovered the AC power had gone out. The breaker seemed to be okay which suggested the problem was ether the power cord, the surge protector, the transfer switch or something else.
Checking the power cord with a multi-tester showed it had mor problems.
That made me think the problem was the surge protector or transfer switch because after plugging the power cord back into the power pedestal there was still nor power to the RV as evidenced by the remote display not showing any readout.
After taking the many screws out to access the suspected culprits, it occurred to me that maybe the real problem was the 30 amp outlet itself. It turned out that was the case and later we learned from the people owning the nearby RV lots there had only ever been 50 amp RVs parked there. We are currently using a 50 amp to 30 amp adapter in the 50 amp outlet and all is well.