Power outages are eventually followed by power restorations, but the voltage supplied at restoration may not be what it should be. The wrong voltage can damage AC powered equipment and can cause overheating that can lead to fires. This is not a boat/marina issue nor is it exclusively an away from the US issue.
This morning, early, we lost AC power to the boat. I know because I heard our transfer switch solenoid release. Later, I just happened to be sitting in the nav station looking at weather information when the power was restored. I looked up at the battery charger and saw negative amps (discharge) while the status panel indicated bulk charge. WRONG. I also realized the charger cooling fan was already operating. WRONG. My first thought was, “the Xantrex charger is at it again.”
I looked up at the AC Watt/Volt/Amp/Hz meter, and there was “73.6 VAC.” NOT GOOD. I flipped the main breaker, and then realized I could hear loud humming from the dock. When I went topsides, the loudest hum was coming from an unhappy transformer 50 yards away.
While this is not just a boat/marina nor a foreign issue, it does tend to be an edge of the infrastructure one. When in these areas, consider setting up the equipment you can to not restart on power restoration at non-spec voltage. If you can’t do that, set up a lost AC alarm and use it as reminder to switch AC equipment off until you can personally assess the voltage.
We have also decided we will no longer leave AC powered equipment on when we are away from the boat. Flipping that one big switch isn’t that hard, and we can wait for hot water if we have too.