Shore Power Cable Short Circuit ?

[Alecadi]

We had a bad surprise on Saturday when we went checking on DayOne at the Marina.
The shore power cable was burnt at the plug and so did the plug... Both plastics were totally carbonized....

Surely if we have not been there, a few hours more and a fire would have started !!

The cable and the plug have been replaced. The electric panel and connections checked and replaced if corroded or else...

But we don't have any idea of what provoked that plug burning... and we would like not to repeat any mistake..

Any help?

[speciald@ocens.]

The plug burned because of arcing. This could happen because of a loose connection, salt or water in the plug. Its not infrequent and can happen at either end of the cord.

[Alecadi]

Originally Posted by speciald@ocens.

The plug burned because of arcing. This could happen because of a loose connection, salt or water in the plug. Its not infrequent and can happen at either end of the cord.

I understand the arcing.. but what caused the arcing?
The cable was almost new. A year. And clean. I check it regularly.
And how to avoid that kind of problem?

[zeehag]

was the plug properly screwed into the socket? i noticed that after some work had been done on my dock connections--i was allowed to receive water to my dock, with a spigot built in..that the connection was disturbed and i didnt any longer have a ground. i went to check the plug and found thatr it had, indeed, not been screwed back into the socket. the plug was hot. mine doesnt get hot. so i fixed it. it did cool off. try making sure your plug is twisted into the socket.

[osirissail]

The salt water atmosphere provides the path for arcing should the plug/receptacle not be "perfectly' in contact. You will find in the older marinas that an awful lot of the dock power receptacles are blacked/arced/burnt and not usable anymore. It gets to be a real pain trying to find one that still works.
- -This arcing/burning/blackening of shore power cable is just a normal part of cruising -unless- you purchase some dielectric silicon grease and coat your shore power plug prongs with it. I normally put an extra amount on the plug and insert into the dock power receptacle and remove the plug several times to work the dielectric grease into the receptacle. This will prevent the salt water laden atmosphere from getting to the plug/receptacle mating.

[JusDreaming]

Originally Posted by speciald@ocens.

The plug burned because of arcing. This could happen because of a loose connection, salt or water in the plug. Its not infrequent and can happen at either end of the cord.

Yep arcing is the culprit. It only takes one little arc to begin the process
I have to replace the cord ends about every other year or so!!!!!!!!
There is a raeson Marinco and Hubbel both sell ends for cords

[zeehag]

i havent had to replace plugs, either male or female since 1998. when i am at a dock i make sure my connection is twisted together and no water gets to it.

[Alecadi]

Originally Posted by zeehag

i havent had to replace plugs, either male or female since 1998. when i am at a dock i make sure my connection is twisted together and no water gets to it.

You got it Zee... In all my boating life I never before twisted the plug.. I totally ignored that info... only yesterday a friend of mine at the marina explain to me that I have to do it ..
You learn at all age..

[zeehag]

some things are simple and overlooked--i didnt twist plug for many years--i musta been just plain ol lucky. didnt reallyknow it made a difference until i got this power strip with grounding and protection lights on it--- i saw last night that the ground was missing--went out and found the not twisted plug and turned it and ta daaa.... dang it worx!!!!! and i thunk i was smartzz.....

[senormechanico]

It's also a very good idea to have the master switch OFF before you connect the plug.
This prevents any arcing when the plug is inserted.

[AnchorageGuy]

9 times out of 10 the arcing problem is due to the plug on the dock not in tightly. This can be the result of a worn outlet or the plug not pushed firmly into the outlet and twisted to lock the cord. Push hard, twist and then pull on the plug. If it moves or easily comes loose you will have an issue. The boat moving around in the slip will make things worse. Chuck

[Lancerbye]

They are called twist -lok receptacles and plugs for a reason. I wish the marinas would install the higher quality receptacles with the locking weather proof screw caps, but the cost is higher, some do and most don't.

[Cheechako]

living aboard in seattle i had to replace the cord every year. One year I was going to just replace the end fitting. When it cut the cord, the copper was very dark colored all the way in. Over stressed with running a small space heater.... are you running AC?

[Alecadi]

Originally Posted by Cheechako

living aboard in seattle i had to replace the cord every year. One year I was going to just replace the end fitting. When it cut the cord, the copper was very dark colored all the way in. Over stressed with running a small space heater.... are you running AC?

YES but not continuously

[Intentional Drifter]

One of the best changes I've done is to put in a SmartPlug shore power connection. Much more secure than the Marinco type, with a thermal cut off in case things get out of hand. They're not cheap, but then nothing good is.

No, I'm not connected with them in any way; just a happy customer.

ID

SmartPlug Systems - Shore Power Products and Accessories