Shore Power Cord Fire

Shore power provides the all important trickle of electricity which keeps our batteries healthy, our bilge pumps with unlimited power in the case of a leak and energy to enjoy our boats at the dock.  While shore power is a beautiful thing the cord is one of many important items that requires inspection from time to time.  Corrosion on the contacts, those pieces of metal which transmit the energy, creates resistance.  Over time that extra resistance will create more and more heat until the plastic casing begins to break down and even burn.


The beginnings of a fire caught just in time.

The shore power connector shown above was replaced after it became evident that heat was beginning to build up due to corrosion on the contacts.  The owner noticed the issue mainly because their inverter/charger unit constantly monitors all incoming shore power to insure that the electricity is the right voltage, frequency and polarity.  While onboard the owner noticed that the inverter unit shut down the incoming AC power feed.  Inspection revealed that it only did this because the tiny smoldering fire inside the connector had done enough damage to make the incoming power feed unstable such that the inverter rejected the feed as being substandard.  It should be noted that most boats do not have a system that monitors incoming power and shore power cord corrosion often results a much more dramatic situation.  It is also important to note that this corrosion results in a persistent brown out and your onboard AC electronics will last much longer if you give them “clean” power.  So be sure to periodically inspect your connectors and repair or replace them as needed.  Your boat and budget will thank you!!!

Happy boating all!!!


Older electronics

On a recent survey I was powering up an older depth sounder in order to test it out and verify its function.  I energized the breaker and then turned on the power key on the face of the sounder.  Upon powering it up I heard a sizzling noise coming from inside the sounder base unit and immediately secured the breaker and set up a fire watch.  Upon closer inspection through vent holes I could see (and smell) where a large bug had climbed inside long ago.  This boat had been sitting for 8 plus years without use and many of the electronics were toast.

I did another survey of a large sailboat built in 1973 with electronics from the early 80’s.  This boat has seen consistent use over the years and had done two circumnavigations over its lifetime, carrying its loving owners all over the world.  This boat had an old Furuno radar system with the green phosphorous CRT screen.  Every piece of electronic hardware worked perfectly.

In both of these instances my client was very concerned about older electronics and insisted that everything had to be scrapped and replaced with thousands of dollars of new equipment.  As a surveyor it isn’t my job to tell people what systems are right for them but I encouraged the buyer in the second case to learn about the systems and try them out before making a decision.  I spent a short amount of time showing him the operation of the green screen radar and how the high contrast black and green makes it really easy to see vessels even if they have a poor radar return.  These older radars are also 100% pure data, completely unfiltered by computers designed to get rid of radar returns it thinks are not real boats and often times I have seen on my radar water getting disturbed by a powerful microburst ahead and even larger logs in the water.  These new units do a great job but there is also a romantic art to mastering an old green screen radar and the one on my boat served me very well in helping me steer through all of the other boats, ice bergs and large logs on my trips to Alaska.

So before you resign yourself to having to pay huge money on new gear I encourage everyone to just start by learning about the older system and then making the decision that works best for you.  If it sizzles when you turn it on then it is probably time to get new stuff.  If it works great then you will either like it or not.  If nothing else it will give you a better idea of the feature you like and don’t like.

Happy boating all!