Shore Power Pigtails

[rick&sue]

I am planning a trip along the gulf ICW (departing in February). It appears that some of the marinas have only 50 amp (boat is 30 amp) shore power available. Digging through the marine supply website for a pigtail adapter, I see there is two types of 50 amp connections; one is a 50 amp 125 volt, and another is a 50 amp 125/250 volt connection. Obviously I do not want to be connected to 250 volts, but it also lists 125 volts. From what I'm reading (Hubbell catalog) the 125/250V adapter has one prong removed to assure only 125 volts will be transferred. I'm confused as to what type of pigtail adapter I should purchase?? Or should I stay away from using a adapter pigtail? Will the 50 amp 125/250 volt work in a 50 amp 125 volt socket? Or do I need both adapters depending on what the marina has? I've searched the archives but not found info related to the two types of 50 amp plugs. Hopefully someone can shed some light on my poor pea brain??
Thanks!
Rick

 

[LADYBUG TOO]

Rick,

We made a round trip from Pensacola to Apalachicola and most marinas had 30 amp shore power. At St. Joe Marina (Port St. Joe, FL) we needed our adapter. It is a 125 volt and is wired so that you only get the single 30 amp connection to your cable. It was a bit fussy about connecting to our 30 amp cable but we did fine. You should have a "Polarity" warning light on your panel so check it before you fire up your breaker.

Pat
Ladybug, Too

 

[Jake]

Hope you don't mind if I tack on my general question to this thread. I don't currently have a boat with shore power. The power source at my marina looks just like the GFI outlet in my house. It is used to power the boat lift and my battery tender. I am not charged for power use. So this is quite different from what you guys normally see as shore power. Discussions here talk about 50 amp and 30 amp service . My simple question is: why does it matter? Is it just because of what the electrical panel in the boat is designed to handle or is there more to it than that. Thanks for helping out the novice.

Jake

 

[knotflying]

Usually larger boats with more power requirements require more amperage and their panels are set up for it. The amperage is just the limit of the draw. So if you were to draw more than 50 amps the circuit will blow. Having excess amperage available is not the issue it is not having enough. So you can hook up your 30 amp to a 50 amp with the proper adapter and still be protected at 30 because that is the size of your main breaker. The other important thing is the voltage. You want to make sure you are only on the 110 to 125 volts side of a leg. Here is a link to an adapter from defender. http://www.defender.com/product3.jsp?path=-1|328|2290035|2290037&id=1353018

 

[Todd]

All of the plugs are different and will not interchance. They are based on the power that would be available to the boat, not based on what you actually are using at any point in time.

Your standard house/GFI plug is 15 amps. The marinas typically use 30 or 50 amp twist lock plugs. The 50 amp 230/115 volt plug has 4 pins, 2 are hot, 1 is a natural, and the other is a system ground. To use 115 volts your adapter will connect to one of the hots, the natural, and the ground. You actually have less current available on this connector because each of the hot legs will be 25 amps. You only get 50 amps when using 230 volts. The 30 amp twist lock delivers 30 amps at 115 volts.

As a note I have seen it refered to it as 110 volt, 115 volt, or 120 volt its all the same, as is 220 volt. 230 volt, or 240 volt, it is just double whatever the single hot leads are providing. The utility company's power varies a bit.

 

[stwendl]

All of the plugs are different and will not interchance. They are based on the power that would be available to the boat, not based on what you actually are using at any point in time.

Your standard house/GFI plug is 15 amps. The marinas typically use 30 or 50 amp twist lock plugs. The 50 amp 230/115 volt plug has 4 pins, 2 are hot, 1 is a natural, and the other is a system ground. To use 115 volts your adapter will connect to one of the hots, the natural, and the ground. You actually have less current available on this connector because each of the hot legs will be 25 amps. You only get 50 amps when using 230 volts. The 30 amp twist lock delivers 30 amps at 115 volts.

As a note I have seen it refered to it as 110 volt, 115 volt, or 120 volt its all the same, as is 220 volt. 230 volt, or 240 volt, it is just double whatever the single hot leads are providing. The utility company's power varies a bit.

Interesting that we have now a

natural

pin, your spell checker did not let you use

neutral

?
Also, 50 amps are 50 amps no matter if you use 115 or 230v. You may only get less if they went cheap and undersized the neutral wire. Another matter is if the so called 50A plugs are really a 25+25A configuration and your boat/Rv has two separate 115 circuits. But this means you don't get 50A even at 230v. It's either 230*25VA or 125*25VA + 125*25A which are both the same power.

My recollection of the electrical code is that anything over 30A needs to be hard wired. Which means that so called 50A plug will never provide 50A and is mislabeled as such :mrgreen:

 

[knotflying]

Todd said,

"Also, 50 amps are 50 amps no matter if you use 115 or 230v."

This is true, however, a device that can be used at 110V and be changed over to 220V, which is possible with some motors etc. will require half the amperage. This is because you are splitting the load between two hot legs instead of one.

 

[Jake]

Thanks Todd (and others) for clearing that up in my head. Makes sense now. Guess it would have been self explanatory if I had ever been to a marina and faced with the 30/50 amp situation. Especially if I was standing there with a 30 amp cable in hand looking at the 50 amp connection. 🙂

Jake