A precautionary tale or shore power near disaster.

[chrisings]

For reasons I don't need to go into here, we were never able to sail Trinity this season, sadly, she didn't once leave her slip. Upon disconnecting the shore power last month, in preparation for haul out, this is what we found. A VERY overheated plug and inlet. After reading Maine Sail's posts on his Compass Marine website a Smart Plug has been on the to do list. Foolishly it was towards the bottom of the list (honestly it's one of those things you just don't think about often). We were very lucky and should have known better! Check those shore power cable folks and always put safety first!

Fair Winds,

 

[WayneH]

Yeah, saw that on my old plug, too. Replaced it with a Smart plug two years ago and it is still performing flawlessly.

 

[rbringle]

The Smart Plug is a wise choice and an easy DYI project. I found a good deal on a Smart Plug and a new 50' cord combo on ebay--but I don't remember the supplier.

 

[Terry Cox]

We've had ours for several years now; check it periodically to make sure no issues at hand and it looks like this cord set here: http://www.ebay.com/itm/30-Amp-100-ft-Marine-Shore-Power-Cord-9506-/172389637009

No electrician, but I do have years of electrical experience and practice certain steps to keep issues at bay:

1. Turn the main boat breaker off before connecting/disconnecting shore power.
2. Disconnect the cord at the dock pedestal first when removing cord.
3. Connect cord on boat first when installing for service.
4. When connecting cord on boat/dock pedestal, twist plug firmly clockwise to lock the blades before securing locking ring.
5. A lanyard on the dock end of the cord is used to wrap around the pedestal to secure the plug to the socket. Most dock pedestals have no means of accepting a locking ring and the lanyard serves that purpose.

Boats move around when the wind pipes up and can, at times, put a strain on the cord set connections. I installed a strain reliever on the boat end that is clipped to a stanchion to take up any stress on the plug. One time, before the strain reliever, arrived at the boat to find the boat end locking ring broken and the plug hanging partly out of the socket.

A cord set was ruined early on in my boating days because I was not following the above steps. It looked just like the one pictured by the thread poster. Maybe some day a conversion to Smart Plug will happen. But as long as what we have works without issues...

 

[Sailm8]

I installed one several years ago after an article by Mainsail. I checked my plug and found it scorched. Very easy replacement and only took less than two hours to do. I understand that the newer versions do not have the high temp shut off that mine does.

 

[thinwater]

I will add:

1. Clean the tines several times per year.
2. Keep a thin coating of grease. Coorosion is the whole problem. Practical Sailor has a review coming out next month, I believe--not all are equal.
3. Keep the area dry. A cover is a good idea if the dodger doesn't cover it. They are supposed to be water resistant, but....
   
4. Test the plug for warming under load periodically. Put a couple space heaters on it and see if it warms.

 

[Gunni]

Since a change to SmartPlug would set me back $600 and still leave me with the same retro-fitted shore power cord and the same loosey-goosey dock plug I really question the cost/benefit for a change to SmartPlug.

 

[LeoLambert310]

How do you get $600 as it cost me only $225 to do mine last year.

 

[chrisings]

Since a change to SmartPlug would set me back $600 and still leave me with the same retro-fitted shore power cord and the same loosey-goosey dock plug I really question the cost/benefit for a change to SmartPlug.

Cost me nothing, it was a Christmas present I do know, however, the 30A is available on Amazon for $187.

 

[Gunni]

How do you get $600 as it cost me only $225 to do mine last year.

It is the hidden cost of a bigger boat. I have fore and aft dual shore power connections, 2 X 30 Amp 120 VAC. Small is Beautiful, n'est pas?

 

[agprice22]

1. Keep a thin coating of grease. Coorosion is the whole problem.

I think corrosion may be A problem, but certainly not the whole problem...
Poor connection between the plug and receptacle is also detailed in Mainsail's article. Without complete connection, the current is drawn through a smaller connection causing greater heating and eventual failure... and possibly fire.

 

[thinwater]

I think corrosion may be A problem, but certainly not the whole problem...
Poor connection between the plug and receptacle is also detailed in Mainsail's article. Without complete connection, the current is drawn through a smaller connection causing greater heating and eventual failure... and possibly fire.

OK. Perhaps 85%. I've investigated MANY failed exterior plug connectors in industry over the years, and corrosion is at fault more than 90% of the time. With boats, I'm sure more so. Then once the connector starts to heat the female side will loose tension. Wear can also be a factor, particularly if there is vibration (industry) or motion (boats); secure the plug so that is NEVER feels the motion. But even then lube helps. Just put it on the spring list.

Like any plug, it should feel snug and not rattly.

 

[jssailem]

I converted mine last month to the smart plug. They are made out of great materials. Package says you can do the conversion in 30 minutes. The Smart Plug and a 50 foot 30 amp cord were delivered by Amazon for $277. Took me 37 minutes to remove the old plug and install the new one. The new Smart Plug cord feels heavier duty than the Marinco which it replaced. The Marinco cord had a couple of chafe spots on the cord so even though it was still operational replacement felt better than waiting for failure. The plug connection is sure easier to make a secure connection on the boat.

 

[agprice22]

OK. Perhaps 85%. I've investigated MANY failed exterior plug connectors in industry over the years, and corrosion is at fault more than 90% of the time. With boats, I'm sure more so

Interesting stuff. I can see corrosion creating a lot of resistance. The one thing that bothers me is the condition of the shore-side receptacle. My marina just replaced all the receptacles on our dock, but some of the old ones were looking sketchy.
I upgraded my last boat to the smartplug. My current boat has no shorepower, so I will use a smartplug again.
This makes me wonder... what better technology exists, or where are we headed, when it comes to transferring power to vessels? Is there something that is a few years away?

 

[Ron20324]

[QUOTE="agprice22,...what better technology exists, or where are we headed, when it comes to transferring power to vessels? Is there something that is a few years away?[/QUOTE]

Yes !!! Lithium crystals in mini-photon torpedoes. One quick application, and you'll never have to worry about shore power again.

 

[Jim 5757]

No, Ron!!! Lithium won't work!!! What you need is Di-lithium crystals but you'll have to deal with the Ferengi to get it...

 

[agprice22]

Whew, those Ferengi are a b$&ch to deal with! Guess I will stick with AC shorepower... for now.

 

[jssailem]

those Ferengi are a b$&ch to deal with!

They are like puppies... Pull their ears like LBJ did to his beagles...

 

[agprice22]

Really like the way my MacBook Air power cord connects. It snaps on magnetically. I do not imagine this would work in higher voltage situations, as I fear the size of the magnets needed to ensure a strong connection would be huge... reminds me of the story of the guy with the magnet to retrieve metal items in the water at his dock...

 

[Chris & Lenore]

Whew, those Ferengi are a b$&ch to deal with! Guess I will stick with AC shorepower... for now.

I heard the Ferengi own West Marine...