Some years back my daughter’s old trailer was plugged into our 30 amp house RV outlet beside our garage. One day I was at my workbench when a gullywasher went through, and I stepped to the rear garage door to check it out, then back to my bench. All was fine except for the super downpour. A second later I heard an odd sound and went to the door again. The adapter from our cord to hers was laying on the concrete nearby to my right shooting sparks and flame gloriously high. Surmising that the cord at the house outlet might be too hot to just grab and pull, I hurried to the nearby electric panel and flipped the RV breaker.
At first I’d assumed daughter had overloaded something in her trailer, but she wasn’t even home. The downpour was heavy enough to put the adapter slightly under water on the flat concrete and had shorted it, somehow without kicking the breaker. I learned a lesson and never let connectors lay on solid surfaces now. I moved her connection above the surface and under a makeshift “hood”.
If Norm’s place experienced a downpour while he was gone, and a connector was similarly exposed, that is also a possible culprit. I can attest that despite being underwater, sparks and flame can shoot in a show to rival fireworks. And if the connector was near the rear of the coach...
Joel