|Plug Into Fire Safety|
By John Strong, Principal Surveyor
WHAT YOU NEED TO KNOW ABOUT SHORE POWER CONNECTIONS TO HELP REDUCE FIRE RISKS.
As pleasure boats have become more complex, onboard electrical safety has become more important. Although this may be something boaters don’t think about very often, here is a critical thought to consider: A major percentage of fires on pleasure boats are electrical in origin.
A likely place an electrical fire can start is at the boat’s inlet receptacle. The inlet receptacle is the fixture on the side of the boat, with the hinged cap, where you connect the shore power cable. Since it is often exposed to the elements, the inlet receptacle’s condition can deteriorate.
The receptacle can be damaged in a number of ways, including the simple action of plugging the cord into it. Over the years, the clips in the cord that contact the prongs in the receptacle wear out, which can result in a loose connection. If the cord end feels loose when you plug into the receptacle, it may be time to buy a new cord.
If the receptacle is in a location where it gets wet, corrosion often occurs, especially if the locking ring on the cord end is missing, or if it isn’t properly attached to the receptacle. If rain, salt water or washdown water gets into the connection, the metal parts will corrode and that corrosion will cause resistance, which results in heat that can melt the insulation and lead to a disastrous fire. That locking ring is important. If your cord doesn’t have one, get one and use it! If you can’t find a ring for your cord, get a new cord.
You can’t depend on circuit breakers to provide protection against this kind of damage. A corroded, loose, worn-out receptacle can generate enough heat to start a fire with very little current flowing. In one case, where a receptacle fire destroyed a nice 44-foot motor yacht, the cord and fixture were part of a standard 30-amp shore power connection, and only 12 amps were actually flowing at the time of the fire—less than half the rating of the breakers on the boat and on the dock!
How can a boater protect against this type of risk? The first, and most important, step is inspection. Every time you unplug and plug in your boat, take a good look at the inside of the receptacle, under the cap. The three prongs protrude from a plastic base, and in most newer boats, the base is white. If a prong has been overheating, the plastic around the base of the prong will discolor from the heat, turning light brown at first and darkening over time.
The second step in the process is replacement. If you ever see any sign of darkening around the base of one of the prongs, replace the damaged parts immediately! It’s not good enough to just clean the corrosion from the prongs. Corrosion is often the culprit, but it may be a worn-out cord end that’s causing a loose connection, or a loose connection at the back side of the receptacle, where the boat’s wiring connects. The electrical loads on boats tend to change as thermostatically-controlled devices, like water heaters, block heaters and electric space heaters, turn on and off. Overheating that begins due to corrosion, and then goes through countless cycles as components turn on and off, will cause metal parts to expand and contract, which can lead to loose connections. This means that a minor problem can lead to a major catastrophe if enough time and cycles pass.
For more fire prevention tips, get a free Fire Extinguisher brochure from ACE Recreational Marine Insurance at acemarineinsurance.com. Click on the Safety & Loss Prevention link, then click on “Fire Extinguishers” to download and print a copy.
Fire aboard a boat, especially in a crowded marina with covered moorage, can result in an enormous disaster. Vessels, marina property and lives are all at risk. Do your part to keep your boat safe, and your marina’s management will thank you for it. In fact, many marinas are establishing electrical safety and inspection programs. Good for them!