Question about reverse Y adapter (50amp to 2 x 30amp)

[MichaelB1969]

I know that with the reverse Y, you need to find two 30amp connections that are out of phase. Couple of questions regarding this:

1. How often are the two 30amp connectors on the same shore power pedestals out of phase?

2. When not out of phase, and you need to find another connection, do you carry a length of 30amp cord to run from the adapter to the other pedestal?

Thanks!
Mike

P.S. For what it's worth, the last time I got a 50amp hookup (in Monterey and Half Moon Bay), it was the old type and I wasn't able to connect! The guy at Monterey said he had an adapter to convert the old 50amp to the newer 125/250 connector, but someone was using it. I still haven't found any such adapter.

 

[loungeitude]

Yes you would have to run one leg to another pedestal that was a different phase. Sometimes they are all wired incorrectly and you are stuck running your gen for several hours at a time.

 

[Bay Pelican]

If you are planning on using a smart Y at other than your home slip buy the additional 30 amp 50 ft cord initially. You will need it at a good percentage of marinas.

 

[Flatswing]

'Personal experience is that most marinas with quality pedestals have both legs on the 30A connections to deliver 240v with the smart Y. The practical problem is that often adjacent boats may be already plugged into them! The 30Ax50ft cord helps alleviate this. Remember, if you use a smart Y, you boat will still only get 30A (not 50A) so may need to dial back high demand appliances accordingly.

 

[psneeld]

'Personal experience is that most marinas with quality pedestals have both legs on the 30A connections to deliver 240v with the smart Y. The practical problem is that often adjacent boats may be already plugged into them! The 30Ax50ft cord helps alleviate this. Remember, if you use a smart Y, you boat will still only get 30A (not 50A) so may need to dial back high demand appliances accordingly.

Not sure about this......

I think in some cases if not most, each 30 will provide 30 amps to each leg/bus of the 50A boat panel. So it will matter if you are set up with 240V appliances I guess.

On my boat, no 240V breakers so I get 30 amps on two separate busses.

 

[caltexflanc]

I found the issue typically comes up at funkier marinas that do not provide 50/240 service, or only have it on one dock. First discovered that at Rio Vista as a matter of fact.

I think in some cases if not most, each 30 will provide 30 amps to each leg/bus of the 50A boat panel. So it will matter if you are set up with 240V appliances I guess.

No guessing needed. Yes you get 2 30/120 legs instead of two 50/120 legs off a 50/240 feed, and 30/240 for your 240v circuits.

 

[TJM]

Electrical for Dummy's question.
I am a pretty hands on guy and always understood the 30 amp x 120 VAC system. Am I correct in hearing that the voltage coming off of the 50 amp pedestal plug is 240 VAC ?
I have a Y splitter that plugs into the 50 amp outlet and then splits into 2 x 30 amp plugs. These two 30 amp feeds (with cords connected) go to each one of my inlets on the boat.
Where does the voltage get dropped down to 120 VAC / in the Y splitter ??

 

[DHeckrotte]

Easy enough to check. Measure the voltage between the two 'hots' at the pedestal. I'd expect that each pedestal's 30 amp receptacle is protected by a separate breaker at the dock's panel. With any kind of luck (and appropriate skill of the dock's electrician), the adjacent pedestal's receptacles are on opposite legs.

 

[Maerin]

Electrical for Dummy's question.
I am a pretty hands on guy and always understood the 30 amp x 120 VAC system. Am I correct in hearing that the voltage coming off of the 50 amp pedestal plug is 240 VAC ?
I have a Y splitter that plugs into the 50 amp outlet and then splits into 2 x 30 amp plugs. These two 30 amp feeds (with cords connected) go to each one of my inlets on the boat.
Where does the voltage get dropped down to 120 VAC / in the Y splitter ??

The voltage doesn't get dropped. 240V is derived from 2 legs of 120V. The 50A receptacle on the pedestal has 2 120V hot legs and a neutral. The voltage between the 2 hot legs is 240V, the voltage between either of the hot legs and the neutral is 120V. So the voltage doesn't actually change.
Keep in mind that when you plug your 30A cordset into a 50-30 splitter, you're plugging into a 50A source, so the potential for overloading the 30A cordset exists. You're really safer if you can plug the 30A into the appropriate receptacle.

 

[psneeld]

Yes and no......yes, only if the cord shorts and no because the main breakers on the boat panel should be 30 amp.

 

[caltexflanc]

no because the main breakers on the boat panel should be 30 amp.

Doesn't help your shore power cord, or anything else between dock and boat panel.

 

[psneeld]

And you are more likely to get hit by lightning from all the power cord failures I have heard of.

Burning up plugs is from resistance that may not trip any breaker on any set up.

If y cords were dangerous, lots of people would be letting us know, from the govt to the insurance companies.