No cute title, this is a serious issue.
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.
My friend, August, suggested a few readability changes. Went there, did that! Shore Power Economics.2
I have added a page under Special Topics on Shore Power Economics. While the business case analysis clearly leaves out things like (non-electricity) business taxes and unusual peak hour billing schemes, the basic concept is accurate and the bottom line is even with 10-30 percent recapitalization costs, daily power appears to be a cash cow for most marinas. Most will not meter the electricity until one is on a monthly contract. At ICW (Maine to Texas) prices, gross profit margins appear to be on the order of 30-60%. Even if taxes and fees take half that, those are still music to an accountant’s ears.
The average coastal sailboat will have a very hard time using what they have paid for. Trawlers with their larger interior volumes and air conditioning systems may find it a bit easier. If one has a solar boat, as we do, we consume about 5-10% of the shore power we are paying for. Put another way, 75% of what we pay for electricity goes to the marina bottom line. When it is a one to two night stay, and the weather allows, we don’t plug in any more.
Well, having reached a point in life where pill minders serve a useful purpose, I was struck by just how useful they can be. Mine is yellow and blue, my wife’s is pink and blue. Since these three colors correlate nicely with wire crimp fittings, and since the bottoms have a curved corner to facilitate pill (fitting) removal, (additional of) these have now become small parts bins in my electrical kit.
Posted in 2011
I have an almost love-not quite hate relationship with technology. So when I find myself wishing for a technical solution to a problem, I have a developed a concept of dreadthusiasm. I know each new solution will cause new dependencies, and those will probably cry out for, you guessed it, a technical solution or more.
Such is the case with the inspection challenges of a 40 foot boat and a 6′ 2″, 250# captain. Think bear in a refrigerator carton…add the carnival ride of a following sea on the quarter… Continue reading