Melted shore power

J

joefish24

Active member
Joined
Jul 17, 2019
Messages
32
Fluid Motion Model
R-23 (Outboard)
Hull Identification Number
FML32C02F122
Non-Fluid Motion Model
Cutwater C32 CB
Vessel Name
Seaquel
MMSI Number
338426122
Today I found my shore 1 melted as seen in the picture. What could be the possible causes? I noticed I left my parallel on from a recent cruise where I had only one 30A outlet available to me. Could I have overloaded shore one and caused this problem?
985a46d1e16181eb3b06f8f148eaebcc.jpg





2a4c390a76c02c816ce46a28ecb1782a.jpg
 
The probable cause is that shore power connections suck and there are many possibly points of failure. I would argue it is inevitable. I’ve never owned a boat where the standard shore power plug didn’t fail. Back when I was a liveaboard anybody who could afford one bought a smartplug — unfortunately they aren’t as good as they used to be (no built in thermal sensor anymore), but they are still much better.

I would use this as an excuse to upgrade. Should take about 90 minutes start to finish if you follow the instructions.
 
I've worked with this issue on a couple of boats. I think sometimes the issue revolves around not getting the plug twisted enough to get full contact engagement. This leads to heat being generated at the poor contact point. The contact pictured is the 'hot' lead, which seems to always be the culprit. The smart plug mentioned is a good upgrade and it eliminates the need to get the proper twist in to ensure full contact engagement. With the smart plug, you just have to make sure it snaps in. I still have the Marinco type plug on my boat.
 
A bad connection causing arching. The smart plug will help with the issue if the bad connection is at the cord to shore power plug. There is another culprit. The actual shore power plug receptical mounted to the bulkhead. The connections to it could be loose. I had the same issue with my C26. My shore power plug was burnt looked just like yours. I checked the plug cord to shore power receptical mounted to the bulkhead. I tightened the black collar and it all seemed tight. Why the bad connection? I troubleshot further by removing the shore power receptacle from the boat. I found the black Hot lead terminal screw loose. This loose connection caused a rise in resistance, heat, and the result was a burnt connector. This condition was not continuous for me. Fortunately the ELCI would trip when heavier loads were applied. If the ELCI did not trip this condition could have caused a fire. It had generated enough heat to melt the plug. About a year after I found the loose connection at the shore power receptacle I was doing some electrical inspections because of hot water heater breaker trips. I was also installing an inverter. I had the breaker panel pulled and found all Hot leads on the shore power side of the panel loose and the hot water black lead burned with isolation melted.The indicator light wires (smaller gauge) had all the insulation melted off. I had to replace several wires that had melted insulation. The cause of this was loose terminal screws.
gallery2.php?g2_itemId=72576&g2_imageViewsIndex=1
gallery2.php?g2_itemId=72579&g2_imageViewsIndex=1

This may not be the culprit for you (Loose connections at receptacle ) but it is worth an inspection especially when looking at how the receptacle burned. If properly tightened ring terminals should never come loose that is why they are used in boats. Boats are built by people and people make mistakes. Quality control and final inspections are done to prevent this from happening. Unfortunately it does happen. Good luck with troubleshooting this issue. Electrical fires are in my book the number one cause of fires on boats.
 
Everything everybody else said it right. I may have missed it but there should be a switch that you turn off on the pedestal first. And if you don't have a switch, always, always unplug from the pedestal first and then from your boat. Reverse the procedure when reconnecting.

There is always an arc when you connect and disconnect, and you will always have some amount arcing and if the boat is under a bigger draw, you'll get a bigger arc.
 
Great information thank you everyone for the insightful answers. I “think” the problem might have been a combination of two things: 1) shore power to boat might not have been inserted and locked correctly (ya know how people try to “help” when docking?). 2) the parallel was left on from a previous trip so all power was going through shore 1 instead of being split between 1 and 2. New parts are on the way, Will get things fixed up and take more precaution!
 
With regard to my boat, on its 120 Volt AC System panel, I have a switch that turns Shore Power on and off. To my knowledge this is the first switch on the panel as 120 comes into the craft. Before I connect the boat to shore power I make certain this switch (and all of the other circuits as well), and the breaker for my pedestal connection are in the off position.

Before I remove the boat from shore power I reverse this procedure and make certain that there is no draw on shore power.

It is my understanding that arcing and surging are typically items that have negative consequences when dealing with marine power which is why I follow these routines.

CJ


rheimb1":2vh5xfah said:
Everything everybody else said it right. I may have missed it but there should be a switch that you turn off on the pedestal first. And if you don't have a switch, always, always unplug from the pedestal first and then from your boat. Reverse the procedure when reconnecting.

There is always an arc when you connect and disconnect, and you will always have some amount arcing and if the boat is under a bigger draw, you'll get a bigger arc.
Click to expand...
 
Had my new SmartPlug sitting in the garage, waiting to get time to install it. This thread spurred me into action so now I have a nice shiny new plug in my boat:

smartplug.jpg


Also took the opportunity to add a galvanic isolator as well:

galvanic_isolator_and_smartplug.jpg


Whole job was super easy and didnt take very long at all, and now I can sleep a little better at night.
 
Nice job, that looks great! We would do SmartPlug again in a second.

BTW for anyone wondering, the old grey or yellow Marinco 50' cord makes a decent extension cord for the SmartPlug cord (at the pedestal end) when the marina plug is far away. It often lets us run the cord along the dock rather than over the pulpit.
 
@Salty Lass, looks like a nice setup.
 
SJI Sailor":1gdgmggj said:
Nice job, that looks great! We would do SmartPlug again in a second.

BTW for anyone wondering, the old grey or yellow Marinco 50' cord makes a decent extension cord for the SmartPlug cord (at the pedestal end) when the marina plug is far away. It often lets us run the cord along the dock rather than over the pulpit.
Click to expand...

This is assuming you don’t make your smart plug cord out of your own Marinco cord. It’s easy (took maybe 20 mins), and much cheaper than a smart plug cord set — I recommend it!
 
I've seen this happen when the cord is removed/plugged in before turning off the 110v breakers on the boat . I've also seen due to poor shore power and the plug not seated properly, but more often the first above. You should replace the cord and also the male plug on the boat, it will often melt behind it.
 
I had the same issue with my cord. Was going to with the smart plug solution - but marina will not change the dock box hookup to smart plug. So I just got another Marinco. After reading this some things come to mind.

Change out my old plug in the boat to smart plug.
Use my old Marinco cord and change both ends to smart plug
Keep existing dock box plug and make a pigtail for the smart plug for the dock box

Does anyone have a pic of your Marinco cord to the smart plug?

thanks
 
tranmkp":3afykmcm said:
Does anyone have a pic of your Marinco cord to the smart plug?
Click to expand...

I don’t know of any marinas that have converted to the SmartPlug - it is just the boat end that gets upgraded usually. You can buy a new shore power cord with the correct standard marina end and new SmartPlug boat end, or cut off the end of your existing Marinco cord and just replace the boat end. @Submariner has a video about their upgrade and you can see how the end is replaced: https://youtu.be/sV9Z97-qHPA
 
Smartplug has decent videos on their site showing how to swap out the outlet on the boat, as well as how to replace the plug on an existing cable. https://smartplug.com/resources/videos/. I did ours and it was fairly easy, and everything was easy to reach for a change.
 
We completed our SmartPlug upgrade this afternoon.

After months of procrastination, it took a grand total of 8 minutes end to end.
 
You must log in or register to reply here.

  • Tugnuts.com is the community hub for Ranger Tug, Cutwater, and Solara owners. Since its inception in 2008, the Tugnuts forum has grown into an active and thriving community of more than 9,000 members. It serves as both a meeting place for the best boating community online, and an invaluable archive of information.

  • User menu
Back
Top