Shore Power - SmartPlug vs. Circa 1938

Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
During my research I came across many comments like this and NOT posted on SmartPlugs web site..

Ron Rogers / Panbo Site said:
I have had one since the catastrophic marina fire here in January. I never have a question as to whether my inlet plug is firmly attached and it never gets warm. Because the shoreside connection is the insecure conventional 30 amp connector; I use black wire ties to secure it.

The construction is excellent with sturdy blades considerably larger than conventional ones. The boat is always in motion and this secure connection and the LED is most reassuring. Flawless performance for a year now.

The fire here started at an inlet and destroyed 52 boats - mostly in a covered shed outboard of me. The VFD stopped the fire 3 slips from me and they fought it for 10 hours. You do not want to experience this.
 
Oct 2, 2006
1,517
Jboat J24 commack
On land in a wet industrial environment the use of twist lock plugs is a never ending disaster


It is still possible to have issues with the pin and sleeve units BUT the wire is now more likely to fail then the plug
 

Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
Am I the only person who has both a twist-lock plug AND a threaded locking ring to hold the power cord plug to the boat? My inlet power plug has ZERO movement.

I just wonder if these electric problems are just operator error - someone neglecting to secure the plug with the threaded locking ring.
 
Nov 26, 2008
1,970
Endeavour 42 Cruisin
Sounds like you just need a couple of 30A inlets and a couple of 30A retro fit plugs and the boat end is fixed...;)
Not quite!

I have that 12' cord that I use from my Honda to the inlets. I have my 2 battery chargers on separate 30 amp circuits so I use a Y cord to feed both sides of my system to power both chargers from the Honda.

So I'd need:
2 new inlets
3 new plugs
1 new Smartplug Y cord (do these even exist off the shelf?)

That's over $700!
I replaced all my inlets and plugs 3 years ago and so far have not seen one bit of burning, arcing etc. I keep the load well under 20 amps and use locking rings everywhere. And I am very careful to make sure all connections are good and tight. So far so good.


I still think code should be changed to reflect reality and require 20 amp breakers dockside.
 
Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
Not quite!

I have that 12' cord that I use from my Honda to the inlets. I have my 2 battery chargers on separate 30 amp circuits so I use a Y cord to feed both sides of my system to power both chargers from the Honda.

So I'd need:
2 new inlets
3 new plugs
1 new Smartplug Y cord (do these even exist off the shelf?)

That's over $700!
I replaced all my inlets and plugs 3 years ago and so far have not seen one bit of burning, arcing etc. I keep the load well under 20 amps and use locking rings everywhere. And I am very careful to make sure all connections are good and tight. So far so good.


I still think code should be changed to reflect reality and require 20 amp breakers dockside.
Keep it under 20A and you should be okay for a while...
 
Oct 22, 2005
257
Hunter 44DS Redondo Beach, CA
Am I the only person who has both a twist-lock plug AND a threaded locking ring to hold the power cord plug to the boat? My inlet power plug has ZERO movement.

I just wonder if these electric problems are just operator error - someone neglecting to secure the plug with the threaded locking ring.
I think most of us have these. I always secured mine, see the attached photo for what it looked like when I finally replaced it with a smart plug.
 

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Nov 6, 2006
10,214
Hunter 34 Mandeville Louisiana
Other End Of Story

A 15A shoreside adapter.. going to a 30 A connector..
Different subject, but ...
 

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Jan 4, 2006
7,643
Hunter 310 West Vancouver, B.C.
That's What I Used to Have ........

Am I the only person who has both a twist-lock plug AND a threaded locking ring to hold the power cord plug to the boat? My inlet power plug has ZERO movement.
.............. until the plastic threads on the ring finally wore smooth after a few hundred cycles of ON and OFF.

After 14 years of UV, bird crap and other contaminants, the vinyl surface of the old cord is pretty bad as well so for an additional $140.00, it's time to get a SmartPlug cordset and inlet. This time I'll wipe down the cord every year with Meguiars vinyl and rubber protectant to see if the vinyl on the cord lasts a little longer. I know it's kept my rub rail like new.
 

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RECESS

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Dec 20, 2003
1,509
Catalina 27 . St. Mary's Georgia
This will be my next purchase from defender. I will be going with the 50 ft smartplug cord and the boat receptacle.
 
May 24, 2004
7,213
CC 30 South Florida
I don't think we have to worry about the usual Honda 2000 generator found in pleasure boats exceeding 20A, the bloody thing is hard pressed to produce 15A. Don't let the 20A capacity receptacle fool you.
 

Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
Lee and kloudie - note that you both have Charnockite granite slabs, it is often sold as "Ubatuba granite" Beautiful.
 

Tom J

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Sep 30, 2008
2,325
Catalina 310 Quincy, MA
When I worked at a large marina, it wasn't unusual to have to replace pedestal receptacles. One boat owner complained when the pedestal receptacle to his boat burned up for the second time. The yard manager had told him he needed a new cord, and wouldn't let him hook up to the second new receptacle until he replaced his cord.
Last fall, my boat receptacle burned when I was running a small electric heater. I had heard about Smartplug and checked online for prices. They are indeed not much more money than the old substandard crap. My first project in the spring is to replace the boat receptacle and the cord. Thanks for the excellent article, Main Sail.
 
Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
When I worked at a large marina, it wasn't unusual to have to replace pedestal receptacles. One boat owner complained when the pedestal receptacle to his boat burned up for the second time. The yard manager had told him he needed a new cord, and wouldn't let him hook up to the second new receptacle until he replaced his cord.
Last fall, my boat receptacle burned when I was running a small electric heater. I had heard about Smartplug and checked online for prices. They are indeed not much more money than the old substandard crap. My first project in the spring is to replace the boat receptacle and the cord. Thanks for the excellent article, Main Sail.

Electric heaters and AC's are two culprits that draw lots of current and can lead to these failures. Boat owners often forget they already have a 1200w to 1500W water heater on the shore cord and then add an electric heater, or two, or the AC in the summer..

A good AC install includes a second dedicated 30A service for the AC so as to limit over loading..
 

Levin

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Apr 7, 2007
165
Hunter 340 San Diego
ALCON:

Dielectric grease is your friend. While I can't argue with MainSail's article that if you want the best protection that you should go with a "smart plug" I can say from experience that liberal use of dielectric grease on the prongs of your twist lock plug going into your boat can do wonders for decreasing problems with plugs burning up. I had a huge problem with this a bunch of years ago and after a long thread here I came to the discovery that if I used dielectric grease this would be less of a problem. I ended up replacing the entire receptacle with a new twist lock receptacle (wish this article would have come out earlier and I would have gone with the "smart plug"... but alas I didn't really know about it then) and covered the blades with dielectric grease and have had no more problems. Now mind you I had gone through two shore-power plugs in 2 years prior to making this change with the plugs "burning" up (charred but no fire... like the one Lee showed only wore) and since I made the change, absolutely no problem. So if you don't want to put the money in for a "smart plug" put a few bucks out for dielectric grease and you be doing something very helpful for improving your safety.

Take care,
-Levin
 

Sailm8

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Feb 21, 2008
1,751
Hunter 29.5 Punta Gorda
I changed mine out after seeing Mainsails Hall of Fail. Easy switch out with great instructions and even a tool to help threading the cord through plug.
 
Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
BTW... Below is a link to the thread I had a bunch of years ago on this topic...

http://forums.sbo.sailboatowners.com/showthread.php?t=104961&highlight=Levin+shore+power

Hope this helps.

Take care,
-Levin
Don't know how I missed that one.. The real answer, with the old twist lock standard, is a max of about 20A on a 30A shore service. As the connections age drop that to 15A.....

If you live aboard, and have air conditioning, you really NEED a second 30A service or a full conversion to 50A......
 
Mar 23, 2011
30
Down East Yachts Downeaster 38 040 Milford, CT
Gee, thanks Main Sail, another project to add to the list! :bang:

Ha! Just kidding, great write up as always. I replaced the 30A outlet on Argyle a few years ago when I was doing the major refit, so at least it's relatively new. I keep her on a mooring mostly anchor when I cruise, so it will not be a top priority, but this is something I will definitely have on the to do list.

Thanks for doing all the work to put that together. :)

-Argyle
 
Mar 21, 2004
2,175
Hunter 356 Cobb Island, MD
Smart plugs and cord set on order. Soon as the ICE melts the installation begins....
 
Mar 21, 2004
2,175
Hunter 356 Cobb Island, MD
Well, this is a bummer. Ordered the SmartPlug and it is on BACK ORDER and won't arrive until the second week of March.

Guess this thread overloaded the factory....nice going Mainsail :)