Calling all Live Aboards - Check your Connectors..

[Bluemansailor]

To all my fellow live boards in the cold Northeast and PNW area, PLEASE CHECK ALL your power cord connections this winter. There was a fire last winter at out marine due to the poorly maintained power cord connections.
BoatUS says that 1 cause of boat fires is AC and DC wiring/appliance - 55%

I noticed one day that my cord felt warm where it was plugged in to the boat, “thought that shouldn’t be” checked the connector and this is what I found!



A lot of corrosion and some of the plastic plug was melted.
Here’s how all my connectors looked ….



Time to replace them – nice new connectors, I really liked the new Furrion plugs – really well made.


Here’s an article I copied from the Marinco site..

“What to look for...

Examine the ends of the shore power cords. Look for discoloration or melting around the blades of the plug (male end) and around the slots on the connector (female end). Examine the face of the inlet on the boat and look for discoloration or melting around the blades and the inlet. Examine the receptacle on the dock and look for discoloration or deterioration around the slots.

What causes overheating…

If a device shows signs of overheating, it is generally caused by one or two conditions: corrosion on the metal blades or contacts, or bad connections between the wiring device and the wires connected to it. Severely corroded blades or contacts are a result of exposure to a corrosive environment, most commonly salt water. If the ends of the cord set are dropped into salt water and not properly cleaned and dried, the contacts will eventually corrode. Corroded contacts do not make a good electrical connection and overheating results. Bad connections between a wiring device and the electrical wires can be a result of loose termination, corrosion on the wires or terminals, or the wires not being stripped properly so the wire insulation is under the terminals. A bad connection will result in overheating of the terminal, and this will be visible on the face of the wiring device.

What to do…

If a wiring device shows signs of overheating, it should be replaced immediately. Do not wait for the problem to get worse. When replacing wiring devices, examine the electrical wire and make sure the wire strands are clean, and are not corroded. Even a new device cannot make a good connection to corroded wire.
Many boat owners think overheating is a result of over loading the circuit, but this is rarely the case. A bad connection in an inlet will also cause the mating connector to overheat. All too frequently a boat owner will merely continue to replace his connector, not realizing the inlet is causing the problem. Both devices should be replaced in order to prevent the problem from happening again.
The same is true for the plug and the receptacle on the dock.”
http://www.marinco.com/files/media/g...#39;sGuide.pdf

So please everyone who keeps their boat plugged in with electric heaters over the winter take a moment and check your connectors..

[Cheechako]

Very typical... especially if a small heater is being run. I used to go thru a 30A cord every winter while living aboard up here in the PNW.
If not living aboard do not use an electric heater. Light bulbs or a Golden rod/ Caframo unit will suffice.

[sabray]

A 30 amp cord is maxed at about 23 amps. That's if all your connections are good. It's not the heater but the load or bad connections burning up the cord terminations.
Most people ignore or are clueless about circuit load. They are happy to reset the breaker and go about business. Meanwhile the wires are baking and the termination is melting.

[DumnMad]

Originally Posted by sabray

A 30 amp cord is maxed at about 23 amps. That's if all your connections are good. It's not the heater but the load or bad connections burning up the cord terminations.
Most people ignore or are clueless about circuit load. They are happy to reset the breaker and go about business. Meanwhile the wires are baking and the termination is melting.

Terminal connections are a fire risk even if circuit loads are OK. When we were new on the boat we worked out the allowable loads but still burnt up the cord to boat plug. Cable could take the load OK but as the connection got warmer the resistance across the terminals started increasing with the points getting hotter and hotter until burnout. The reason being that while resistance across the terminals was very high it was for a very short length so not contributing much to the total resistance(R = sum of r x length) With the overall resistance over the remaining 15m cord still OK the overload switch did not trigger.
Would pay to make a regular check of plug warmth at times when power consumption is fairly high.

[valhalla360]

Summer also when the A/C is running.

Also, keep an eye on it even with the new connections.

[Snore]

Somewhat of a rookie question.... At my day job, we "shoot" all electrical connections once a year with an IR thermometer to check for loose/corroded connections.

Is that something done on boats?

[a64pilot]

Another Rookie question, this seems to be real common, would it be a good idea to replace the boat end of the connections with 50 amp ones and keep the contacts well covered in silicone grease to prevent corrosion? Pushing 30 amps through a connection designed for 50 leaves some headroom, and eliminate the corrosion would I think essentially eliminate the problem?

[s/v 'Faith']

Great reminder, thanks. :bigthumb

Replaced mine with a "Smart Plug" last year, very happy with it. Absolutely no signs of corrosion or heating.