Dual 50amp to dual 30amp

[rob37w]

Hello everyone. Just closed on my first Carver this week and will take delivery in about a week.

1996 Carver 370 Aft Cabin

Question: The boat has dual 120v 50amp plugs. My dockside hookup is dual 120v 30amp plugs. Am I correct to use two 30amp cables and put a male 30amp to female 50amp adapter on the boat side?

Or is there a better way to do this?

[buster53]

I used to have a 3807 that came from the factory with the same 50 amp, 120 volt service. Previous owner had 30 amp cords with 30 amp male and 50 amp female ends made up. Worked just fine.
Or you could replace the 50 amp boat side connections with 30 amp. Either way will work. I suggest going with the improvised cord. I’m surprised the boat doesn’t already have these cords (or some kind of adaptor) as I’ve never seen a marina with 120-50 amp dockside service. It has to be rare.

[Midnightsun]

Problem is you are missing 40 amps somewhere as the dual 50a gives a total of 100amp whereas dual 30's gives you 60a. This is probably not an issue but one has to wonder why Carver designed the input with so much juice available. Midnight Sun came from the factory with a single 50a 125/250 inlet which does give 100a although through a single cable which is really practical. I do plug into dual 30's (splitter at the pedestal) and am also missing 40a however this has never been an issue no matter what I am using on board. 50a 125/250 sounds like 50a however it has 2 live 120 volt 50a wires in the cable for a total of 100a to the boat and therefor does supply 100a

That being said, another option is converting 1 of your existing inlets to 125/250 50 which is a common shore power receptacle albeit far from the 30a service which is pretty much standard everywhere. This option gets expensive fast because to hook into dual 30a shore power you will require a rather special "reverse Y" adapter which does not come cheap, the cords and connectors are much more. Just another option to consider which will now require a single cord as opposed to 2 not to mention if you plug into a 50a receptacle, you will get the full 100a Carver intended the boat to have.

To do this you do need to have a good electrical back ground or hire an electrician, not recommended if you need to watch you tubes to accomplish this.

[buster53]

That’s why I suggest an improvised power cord. Keep it simple and easy.
We managed our 3807 for 7 years with the reduced power of twin 30 amp cords. We ran 3 AC units on one cord and the house on the other. Anytime we knew we would be pulling a lot of amps, we would just switch off the water heater and 90% of the time, that was enough.
Biggest amp eaters...stove, microwave, water heater and hair dryer. You quickly learn what you can and cannot run at the same time.

[Viper]

Ya my 3807 is the same with dual 50s. The older AC units back then drew more power than the newer ones do now so a 50 amp service was needed to run 3 units. They'll run on a 30 but you have to be careful because that starts burning up cord plugs after a while. I rarely run all three at the same time so a 30 service x 2 works fine for me with power management on the other house leg as buster mentioned. I use 30A cords with 30-50 adapters that were already on board. I also carry 50A cords on board in case I end up at a port that has 50A service available. I wouldn't bring out the 50s unless it's absolutely necessary though, way too heavy to manage.

I wouldn't replace the inlets on the boat, that might trigger an electrical safety red flag by a savvy surveyor. Use adaptors or retrofit your existing cord. Having said that, a reverse Y adapter with 2x30 to a 50 is technically what you should be using as it's safer. They are pricey and I haven't met one yet that doesn't fail after a while but such is boating.

[ColRon]

My 89 Santego has two 125v/50 amp connectors at the boat and I have a 125/250 volt supply at the pedestal. in my case I use a single 125/250 volt shore power cable that connects to a 125/250v adapter/splitter to 2-125v 50 amp outlets which connects to the boat inlet. now that 125/250 volt to 2-125v splitter/adapter isn't cheap, as it can cost as much as a shore power cord, but I only have one cord to mess with at the pedestal and I still get my full 50 amp service.

[g36]

My 97 405 is also like yours. At my dock I have dual 30 and just watch any heavy loads never had a problem