Help on 50A vs 30A Y-Adapter

[chicagoboaterrob123]

My boat needs (2), 30A 125V, lines plugged in for all systems to work. Dockside power is 30A 125V. Rather than running 2 lines to dock, I bought a Y-Adapter that I plug in on the boat side. West Marine said they knew our dock and boat power requirments and recommended the Marinco 152AY:

http://www.marinco.com/scpt/ProdPage.php?loadItem=152AY_Marinco Shore Power

I noticed the adapter itself is meant for splitting a 50A 125V source to (2) 30A 125V. Is this still OK to use or should I return for Marinco 157AY that is meant for 30A coming from the power source:

http://www.marinco.com/scpt/ProdPage.php?loadItem=157AY_Marinco Shore Power

So right now I have 30A 125V dockside power, going to 50ft 30A cable, to 152AY (50A to (2) 30A) adapter, to boat. Again, is this OK?

Thanks

 

[Reel Poor]

Re: Help on 50A vs 30A Y-Adapter

If your boat requires 2 30amp ckts you will not be able to run all of your ammenities off of a 30amp outlet from the dock. Your boat is requiring 60amps to function properly. You need 2 30amp cables running from 2 different 30amp ckts/outlets off the dock.

Your boat is probably set up to run the heat and A/C on 1 of the 30amp ckts and the rest of the house accessories on the other 30amp ckt.

It wouldn't work properly if you had a 100amp Y at the boat. You require 60amps from the dock.

 

[Texasmark]

Re: Help on 50A vs 30A Y-Adapter

Reel is dead on. Asking for trouble if you try to run everything from one, unless you only run half your boat and babysit what's on and what's not. Doubt you want to do that.

Mark

 

[msd58]

Re: Help on 50A vs 30A Y-Adapter

What kind boat do you have? How big is your A/C?

 

[jlinder]

Re: Help on 50A vs 30A Y-Adapter

Big warning. You cannot have a 50A fused circuit feeding connectors and wiring rated for 30amps

Consider this - one of your circuits is not drawing any power. The other develops a short in the supply line somewhere - connector develops problems or some high draw. You could be running 50 amps through wiring and connections rated for only 30 amps.

Big problems.

 

[--GQ--]

Re: Help on 50A vs 30A Y-Adapter

My boat needs (2), 30A 125V, lines plugged in for all systems to work. Dockside power is 30A 125V. Rather than running 2 lines to dock, I bought a Y-Adapter that I plug in on the boat side. West Marine said they knew our dock and boat power requirments and recommended the Marinco 152AY:

http://www.marinco.com/scpt/ProdPage.php?loadItem=152AY_Marinco Shore Power

I noticed the adapter itself is meant for splitting a 50A 125V source to (2) 30A 125V. Is this still OK to use or should I return for Marinco 157AY that is meant for 30A coming from the power source:

http://www.marinco.com/scpt/ProdPage.php?loadItem=157AY_Marinco Shore Power

So right now I have 30A 125V dockside power, going to 50ft 30A cable, to 152AY (50A to (2) 30A) adapter, to boat. Again, is this OK?

Thanks

Electrical language; a load (your boat) requiring two 30 amps circuits at 120 volts implies the load is a 240 volts system. In this case the 50 amps shore power exceeds the 30 amps rating of your y adapter. If an over load should occur, it may not be enough to trip the 50 amps breaker but sufficient to a point your 30 amps adapter will over heat starting a fire.

However, I don't think this is your situation. If I am correct, you have two separate systems requiring 30 amps each. In this case, splitting a 50 amps cord will work but highly not recommended for the same reason stated above. Explanation below.

Let us assume one of the load over heats and draws excessive current in the near 45 amps. At this current, the shore power breaker will not trip because it is rated at 50 amps. Your 30 amps Y adapter on the other hand is the weakest link. It will heat up to above acceptable temp. rating. At some point, the insulation on the wire will break down thus causing fire to your boat.

Electrical wiring should be of the same gauge from the power source to the load. In addition, the breaker/fuse should match the wire ampacity.

 

[Boatin Bob]

Re: Help on 50A vs 30A Y-Adapter

Guys...I think you are missing the point as he said in the first post " Dockside power is 30A 125V." so as previously stated it wouldn't matter if he put 100amp cable in the middle the dock power is still only 30 amp!
I have a similar set up in my boat, 2 separate 30 amp feeds, marina only supplies single 30 amp outlet. I use a 30 amp splitter to feed both at once, difference is I don't have AC so the loads are fairly well split between the 2 inputs, have never had a problem.

 

[seven up]

Re: Help on 50A vs 30A Y-Adapter

So pay for two 30 amp services and return the plug

 

[jlinder]

Re: Help on 50A vs 30A Y-Adapter

Guys...I think you are missing the point as he said in the first post " Dockside power is 30A 125V." so as previously stated it wouldn't matter if he put 100amp cable in the middle the dock power is still only 30 amp!

Boatin Bob - good point. We got so wrapped up in the description of the 50 amp plug we missed the 30A supply.

You can use any size wire or connector, as long as the fuse is rated at or below the rating of the weakest link. In this case if the supply is only 30a then a 50a cord is great.