Only one power cord is getting power from my shore power.

[Privilege]

I wonder if anyone can help me troubleshoot a problem? My transom has two 125v 30 amp twist lock inlet fittings which provide power to each side of the distribution panel. My shore power has a 50 amp socket. My normal set up is that I have a splitter from the 50 amp supply which leads to two 30 amp power cords, one of which goes to each of my inlets. Everything works fine.

This week I spent a few days at a different marina. I plugged in to the 50 amp supply but was only getting power supply to one side of my distribution panel. The LED's on both cables were illuminated suggesting that I was getting power to both. When I swapped them over, I got power to the other side of the panel which suggests that the boat set-up is O.K. Why would only one of the cables be providing power even though the LED was lit?

[Sailmonkey]

Reverse polarity on one leg of the 50 amp 125/250 dockside connection?

[MicHughV]

there is typically a breaker at the hull where the power cord attaches to the boat....if you have two 30 amp cords you will have two breakers...it is possible that one tripped. It's a square looking box thing typically with a plastic panel over it. Lift the cover up and you will see the breaker switch.
Switching you cables around does not identify this problem as you are still using the one breaker which may be operable.
Also check the " connectors"...these are the little metal teeth that stick out from the power cord...should be 3 of them....check for burn marks or melted rubber.....sometimes water gets in there and can short this out...check the connection at the splitter and also at the boat.
An a/c, when starting up, can suck a lot of amps.....maybe more than the dock power can provide....and trip the system.
Hope this provides some guidance.

[DeepFrz]

Time to get your DVM out and troubleshoot instead of hoping for magical answers from people who don't read the description of your problem.

[Ferrari]

50 Amp and 30 Amp plugs and connectors are not compatible! But can be jury rigged.
50 amp is usually associated with 240V in the US, Canada and Mexico.
You may be connecting to one of the two hot 120v in the usual 50amp 240v shore connections. Be careful.

[MicHughV]

one is assuming, off course, that the OP
1) has stated the problem correctly.
2) there is the stated voltage and amperage available at the dock pedestal, not always the case.
3) the OP has a meter
4) the OP knows how to read one...
5) the OP has checked the boat's breaker system
6) a 50 amp supply thru' two cords means means if once cord is sucking 30 amps, there is only 20 amps left for the other cord..which could trip a breaker if there is an a/c on it.
7) the LED lights may suggest that there is power in the cord, but without a functioning breaker, no power at the boat...
did I miss something

You could also check this..

https://www.westmarine.com/WestAdvis...Powersomething ?

[Squanderbucks]

Ok. Here is what I think is the short answer to this question. Likely one leg of the 240 v from the dock is missing.
Unplug the two 30 amp cords from the Y splitter.
With Multimeter:
Check the Volts across the 30 AMP at the ends of the Y splitter.
Ok then Plug cords back In to Y.
Check for current on each cord separably across the Hot and Neutral sockets at the boat end of the cords.
If Ok
Check Breaker Panel on Boat.

Does your shore panel have built in lights that show power to each line?
My boat has three LEDs -One for each 30 AMP line and a Third for showing power from the Generator. Also if Reverse Polarity the Normally Green LEDs turn Red. A Blue Seas Rotary Selector Switch.

[Compactorguy]

Question
Does your boat require both 30amp plugs to be used to charge batteries and provide shore power?
Your resent issue probably has more to do with a combination of the marina power and the wiring of you boat.
We had an issue with tripping the gfci at a new Marina but no issues at my Marina.
We had our electrician come out and rewire our grounding and install a galvanic isolator (zinc issue) and our next visit to the other marina we had no issues. Have your electrician deal with it if you have one or ask around your Marina for a good recommendation. Especially since your insurance company can now find this thread.

[smac999]

the LED only needs 2v to light up. who knows what the issue was. if its working again at your dock I wouldn't worry about it.

[MicHughV]

one more thought....
when I got my Beneteau, it also came with the double 30 amp cords and a 50 amp splitter....
the previous owner had the boat bow in at the dock and the power connecting terminals are on the transom, so he had purchased 2 extra lengths of 25' long power cord to reach the power pedestal on the dock. This meant each power cord was now 75' long vs. the standard 50' length in addition to the 50 amp cord, which was also quite long.
He had told me, that he was using only 1 of his a/c's at a time, as using both a/c's would trip the breaker. The boat had 2 a/c's.....one on each 30 amp circuit.
When I moved the boat to my new slip (bow in), this setup caused me no end of problems just as the previous owner and one breaker was constantly tripping, due I believe, to the voltage drop caused by the extra 25' of cord..
I finally pulled the boat out and backed it in and ended up being able to use only the two 25' long power cords and the 50 amp splitter and the problem went away.

[Disailor]

sometimes corrosion will show voltage but not pass enough current to operate the device