Wednesday, November 24, 2010

Shore power plugs

One of our suppliers passed on this article (picture below) that was published in Latitude 38 magazine.
I found it interesting and wanted to post it here for others to read.
As a marine surveyor I often go to a meticulously cared for vessel to perform a survey and find the ends of the shore power cord to be badly worn and in need of replacement.  It amazes me how something that gets handled every time the vessel leaves the dock can be left to deteriorate to the point where it causes so much resistance that it causes a melt down or in the extreme case in the article, almost kills someone.
If your plug is worn it would serve you well to replace it. I have seen insurance claims denied for fire damage caused by faulty receptacle plugs, it is often considered a maintenance issue and as such is not covered.
When unplugging the shore power cord from the vessel turn off the main circuit breaker on the vessels electrical panel before unplugging the vessel. Ideally this should be done on the dockside panel but they are often locked or otherwise inaccessible. When the plug is disconnected while energized it creates little arcs that cause minute pitting on the connectors. The pits fill with carbon deposits that are created when it arcs, the carbon creates resistance that leads to more arcing, more pitting, more carbon, etc. Before to long you have created significant resistance in the connection and are well on the way to a melt down.

Monday, November 8, 2010

Moving along

Lately the focus has been on finishing up loose ends.
A wash-down fixture was mounted on the foredeck and tied into the water pump for the toilet inlet. The toilet inlet water pump does three jobs now; provides water for the toilet, the deck wash-down, and a faucet at the head sink. There is no discharge  thru-hulls anywhere near the intake so their is no threat of contaminating the incoming water. The head discharges directly into the holding tank and is pumped overboard from time to time when permitted, or drawn thru a deck suction fitting when required. 
I plumbed a tee into the toilet discharge line and took it up to a deck fitting so that when pumping the holding tank the deck cap can be removed and a water hose used to flush the holding tank.

A ball valve was placed on the discharge side of the holding tank  and a macerator pump was plumbed in.
I got the pump from a customer who wanted a replacement pump as he considered this one to be too noisy.
I took it apart and cleaned, sanitized, and rebuilt it, put in new check valves and installed it my boat.
The disassembly and cleaning was a thoroughly disgusting job as there was a significant buildup of foul deposits that needed to be scraped and picked at to remove them from the orifices. Even though I saved a few hundred bucks on the pump I don't think its a task I'd care to repeat!
A two way valve was installed and the discharge line plumbed into it. From there one side of the valve went up to a deck suction fitting and the other through a vented loop to the overboard discharge thru-hull.
The last connections were made to the holding tank vent and filter and now the toilet system is finished and operational....although not tested at this time. It feels good to have another system completed and struck from the "to-do" list.