Arctic Traveller wrote:
koliver wrote:
According to the T&T post, the cause was a shore power connectionat the boat end.
Being livaboards, we have seen more than our share of burnt electrical connectors on our boat. We have a washer and drier, and it's not unusual for us to be drawing 30 amps for several hours at a time.* The trouble with the current design of 30 amp twist lock cord connectors is that they rely on what I'll call spring loaded connections.* By that I mean that the tempered steel blades of the female part of the plug are designed to maintain contact with the male blades by spring force.* As the plugs age, corrode, get dropped in the water and in general get dirty, the electrical resistance is increased.* This resistance causes heat to develop in the plug.* As time goes on, they can get hot enough to take the temper out of the metal, causing the plug to loose it's spring force and contact with the male blades causing even more heat.* Eventually, the plug can begin to burn.* I'm sure most folks have seen a blackened, burnt out shore power cord before, and it's easy to imagine how this sets the boat on fire.* I have a multi pronged attack to the problem though.* First I inspect our plugs on a regular basis.* Almost every time I think of it, if there is a load on the system, I'll feel the plug for excessive heat.* I also will check it with my infrared thermometer that I use in the engine room.* In the rare occasion that the plug falls in the water, I immediately unplug it, rinse it with thoroughly with fresh water and dry it completely.* Despite all this, we have had our share of burnt plugs.* Here is a little known seceret, (don't tell anyone) Several times I have taken my burnt cord into West Marine and said "gosh, this doesn't look right, is this cord ok"? They have always replaced it under warranty.*
Better yet, there is an easy solution to this problem.* I have no connection with this company except for being a customer.* I no longer worry about burning up any more cords.* See here:
http://www.smartplug.com/
This new design totaly eliminates the problem, and the boat you save may be yours and your neighbors.............Arctic Traveller
Artic,
I saw the Smart Plug as an ad a couple of months ago and thought it was a great idea.* A little pricey but not unreasonable.
I presently and for the last several years have used Dielectric Grease on all of my shore power cords and it has done an outstanding job of keeping everything dry and connected.* I have several different types but it can be bought at any Radio Shack.
Several cords have gone bad in our marina and one of the reasons sighted by an electrician was there is a fair amount of stray current running through the ground system.* But the marina says it is not a problem and chooses to ignore it.
*