Home Made Shorepower Cords

[Cheechako]

Originally Posted by thinwater

There are some smart people on this thread and some good responses, but...

... would someone explain to me why people without a 10th grade understanding of electricity would post opinions? Without any knowledge of resistance, heating, NEC, or ohms law? It's plain dangerous. We worry about fires; I saw a guy get completely toasted by unfused 460/3 because he tried something he didn't understand. He lived, but his hand was melted to a pair of pliers.

I refuse to post on diesel engines, because I don't run them. It's kind of like that.

I think people relate their experience.... it's up to the reader to decipher all the posts and think it thru. That's true whether the writer is a novice or an expert in the field.... after all.. have you read the posts from people who have paid those "experts" to get their boats fixed! The satisfaction rate is pretty low.... it aint all theory...

[GordMay]

Originally Posted by Garrettw

... I don't know the history of Marinco's "standard" and what ultimately led to its USA installed base over other standards.

The North American 30A 120V Twist Lock* (NEMA L5-30) configuration is a standard of the National Electrical Manufacturers Association (NEMA).

* “Twist Lock” was first patented by Harvey Hubbell in 1929.

[rwidman]

This appears to be a "home made" shorepower cord:



There does not appear to be any strain relief on the cord, it is hanging by the wire connections. Any strain placed on the cord is transferred to the wire connections which were not designed for that purpose. Also, it is obviously not waterproof or even rain proof.

Yes, it will "work" and supply power to the boat (for a while). If someone pulls on the cord or trips over it, the wires may loosen or even pull out. If it rains, the connections will begin to corrode or there could be an arc between the connections and overheating or a fire.

I once observed a drunk fall down behind my boat and attempt to pull himself back up by pulling on my power cord. I yelled at him to let go of my power cord and he denied that he was holding on to it. He was that drunk.

[rwidman]

Originally Posted by thinwater

There are some smart people on this thread and some good responses, but...

... would someone explain to me why people without a 10th grade understanding of electricity would post opinions? Without any knowledge of resistance, heating, NEC, or ohms law? It's plain dangerous. We worry about fires; I saw a guy get completely toasted by unfused 460/3 because he tried something he didn't understand. He lived, but his hand was melted to a pair of pliers.

The other side of the coin is the person who posts a bunch of extraneous technical language in an effort to impress everyone with his/her knowledge rather than explain something in a manner that can be understood by the not so technical person.

[Garrettw]

Originally Posted by GordMay

The North American 30A 120V Twist Lock* (NEMA L5-30) configuration is a standard of the National Electrical Manufacturers Association (NEMA).

* “Twist Lock” was first patented by Harvey Hubbell in 1929.

Gord, it's not necessarily the genesis of the twist lock that I was getting at, rather it's the adoption of it by the US marine industry. But I think if the Hubbell connector had been around since 1929 like you pointed out, then it was probably the most convenient thing to adopt since IEC 309 only came about in the late 1960s, I believe. Add that it was probably in use by the RV industry since well before electrified pleasure boats, then I guess there you have it.

[valhalla360]

Originally Posted by rwidman

This appears to be a "home made" shorepower cord:



There does not appear to be any strain relief on the cord, it is hanging by the wire connections. Any strain placed on the cord is transferred to the wire connections which were not designed for that purpose. Also, it is obviously not waterproof or even rain proof.

Yes, it will "work" and supply power to the boat (for a while). If someone pulls on the cord or trips over it, the wires may loosen or even pull out. If it rains, the connections will begin to corrode or there could be an arc between the connections and overheating or a fire.

I once observed a drunk fall down behind my boat and attempt to pull himself back up by pulling on my power cord. I yelled at him to let go of my power cord and he denied that he was holding on to it. He was that drunk.

It's hard to tell but either the strain relief is inside or the owner intentionally removed it. Every end I've ever bought includes a strain relief mechanism.

I have mixed feelings on the idea of water proofing. In theory it's good but unless it's complete, it's worse than doing nothing because any water that gets in, is trapped. If it makes no attempt at waterproofing any water that gets in tends to run right back out. Unless submerged, it's usually not a big issue.

Probably the worst thing you could do is install a non-waterproof end and goop it up with silicone. Odds are you won't get a good seal and after a few times in the rain, it will always have water inside.

[1 desert rat]

G'day to all as this is my first post.
I would like to submit that in my 49 years of age I feel I have been well traveled and have experienced life's trials and tribulations and hope to contribute to discussions with well thought out and concise additions to the forums.

I have had many hobbies and as much pairs of socks and now pointing my focus and direction to sailing..
I have been a general contractor for 25+ years, a Padi certified rescue diver since 91 and have a inquisitive nature to want to know everything.
Did I mention I change hobbies like socks ? lol

My contribution to this discussion is despite the failure of waterproofing at the junction? There is still a breaker that will trip at any fault at the pedestal if connected to shore power. The failing points in my experience with 50 amp service in RV's is the transfer switch and excessive amperages though a single circuit leading to a failure because of minimal torque on the terminals.
In fact it is required to retorque the connections periodically to manufacturers specs .

I will go on pursuant to discussion.



PS
10 ga is good for 50 amps depending on run.

[GordMay]

Greetings and welcome aboard the CF, Desert Rat.

[rwidman]

Originally Posted by 1 desert rat

............ My contribution to this discussion is despite the failure of waterproofing at the junction? There is still a breaker that will trip at any fault at the pedestal if connected to shore power. ...........

Yes, the circuit breaker will trip, your batteries will discharge and your food will spoil.

Counting on a circuit breaker tripping to make up for shoddy workmanship is poor practice at best.

[poiu]

Originally Posted by rwidman

Yes, the circuit breaker will trip, your batteries will discharge and your food will spoil.

Counting on a circuit breaker tripping to make up for shoddy workmanship is poor practice at best.

That's a good outcome, but maybe a little kid fiddles with it just after a rain shower for no particular reason. He is standing on the wet dock in his bare feet and his wiggling of the plug just makes that internal connection between the live wire, the internal puddle of water, his hand, body and wet dock connected to the sea.

Nice knowing you kid.

[rwidman]

Originally Posted by poiu

That's a good outcome, but maybe a little kid fiddles with it just after a rain shower for no particular reason. He is standing on the wet dock in his bare feet and his wiggling of the plug just makes that internal connection between the live wire, the internal puddle of water, his hand, body and wet dock connected to the sea.

Nice knowing you kid.

I think you missed the point of my post. Your issue would be with "1 desert rat", not me. I'm all for doing it right and minimizing the danger.

[poiu]

Originally Posted by rwidman

I think you missed the point of my post. Your issue would be with "1 desert rat", not me. I'm all for doing it right and minimizing the danger.

Understood. No issue with anyone. Just making a point.

[GrowleyMonster]

Originally Posted by rwidman

Well I would too. I guess there's not much you can do about it at that point. You're in a foreign country and a guest of the marina.

I would think if a marina wanted to hardwire the shore ends they would just wire every pedestal. Or at least supply the cords. Actually, I don't know why they would want to. That's what plugs and sockets were invented for - to make electric power portable.

This is probably because replacement receptacles are expensive and hard to come by in Cuba. Hard wiring is safer than using worn out old receptacles. The electrician's hourly wage is hardly even an issue. Keep that cut off cable for your next visit! Maybe tin the ends if you don't want it chopped off a couple inches shorter next time.