Simple/Dumb Question about shore power connections

[Pettigrewr]

First, some background on the boat wiring.
My 1965 Hat has original wiring with 3 shore power receptacles.
Receptacles 1 & 2 are 50 amp 125 volt.
Receptacle 1 supplies all 125 volt needs except the 3 air conditioners.
Receptacle 2 supplies the 3 air conditioners
Receptacle 3 is 250 volt and was used only for the stove/oven which has been removed long ago and there is nothing onboard that uses 250 volt.

Since I have owned the boat, I have been making do using 30 amp cables that came with the boat (minding loads on the one cable and using only one or two air conditioners on the other) plugged into 30 amp dockside receptacles (that is all that was available).

I am moving to a new marina and requested two 50 amp 125 volt receptacles.
I was informed that the marina has 50 amp 125/250 volt receptacles and I was advised I can use 125/250 volt cables and if I only need 125 volts, that's what it will pull/supply.

So, I ordered and am waiting on delivery of two 50 amp 125/250 volt shore power cords with a plug that will fit the boat's 125 volt receptacles and on the other end, a plug that will fit the shore power receptables 125/250 volt.

BEFORE I go plugging anything in, will this work or did I order the wrong cords.

Thanks for any and all assistance,advice and input.

 

[Boatsb]

1 125/250 50 amp cord can split to 2 125 volt 50 amp cords

There an adapter for that.

 

[Pascal]

You don’t need two 120/240-50 cords, a single one will be plenty with a splitter to feed each 125/50 inlets from the single cord.

125/50 is pretty much extinct. You would be better off getting rid of the all three inlets and install a single 120/240-50 inlet.

 

[Pettigrewr]

You are right again, the 125/50 is rare to find.
Until I find a qualified marine electrician to do the conversion, I will have to do with what I have.
Not sure if the panel amp meters are reading correctly but two refrigerators, a portable air conditioner and a 50 amp battery charger alone pulls 25 amps on the one cord.
The two marine air conditioners with two pumps shows 40 amps on the other cord so I only run one at a time, rotating them.
That's why I was thinking two 50 amp cords.
The circuit breakers do get very warm to the touch, not hot.
If you think I can use the one cord with the splitter, that's what I will purchase.
Thanks for the advice.

 

[rsmith]

When we got our 50 it was the same deal. 2 50a recepticals on the boat inlets one for ships service one for the AC’s and one 30 250v for the stove. Back in the day there were very few 50 amp twist locks on the docks. The typical was 2 30 250v and if you found a 50 it was a crows foot range plug. Hatteras was a great at fiberglass and wood but their electrical systems back then were horrible. We rewired the boat for 1 50a cable back in the late 70’s and found Hatteras used #8 gauge wire in the boat for the 50@125v service instead of #6 which is 50a. Hatteras had installed a cooling fan in the electrical panel. Wonder why? You might want to take a look at the complete electrical distribution system on the boat side also.

 

[Pascal]

Same here… the original 1970 panel was in the port ER and very crude. Worst was the wiring for the shore power system where they ran wires from the port and stbd and then spliced connections from these wires to the panel. The splices, hidden in the loom in the generator room, consisted of a split piece of copper pipe somewhat crimped over the wires and wrapped in electrical tape. It’s a miracle it never melted down

A 120/240-50 cord will give you a full 50 amps on each leg so your 25 amps on one leg and 40 on the other will be fine. Right now I m running all my house loads incl water heater and 120v shallow well pump on one leg, 5 air handler and one of the battery charger on the other legs. Plus the 2 36k chillers, pumps and cooktop on the 240 panel from both legs. The only time I need to juggle loads is if cooking but then I just turn off the water heater. My point is that you should have no problem running your loads on a 120/240-50

 

[Pettigrewr]

So if I am understanding this correct, a 125/250 cord rated at 50 amps can supply 50 amps on each leg of the 125 (100 amps total?).

 

[SeaEric]

You could use a splitter on the boat end that has 2 - 50a 125v females to a single 50a 250v male on the other end. Then use a typical 50a 250v cord to the dock. I owned a 42 Post with that set up and that's what I used. The only logistic is that the 2 - 125v inlets must be next to one another so the splitter will plug in to both inlets.

 

[Pettigrewr]

Until I get the boat rewired with up to date shore power connections and heavier wiring, I will go get a splitter and use it with a 125/250-50 cord as suggested.
And keep a carefuleye on everything (circuit breakers and cord temps)
Thank you all for the info.

 

[SeaEric]

I found a photo of the set up I'm talking about...

 

[Pettigrewr]

Pictures always helps.
Thanks.
I've got togo shopping (Bring On Another Thousand, LOL).

 

[krush]

So if I am understanding this correct, a 125/250 cord rated at 50 amps can supply 50 amps on each leg of the 125 (100 amps total?).

Sort of. To get 50amps on each leg of 120VAC, you need to be sure that each leg is on split phase and has 240VAC between them. If this is not the case, and the two hot wires are on the same hot leg (meaning, you measure 0volts between the two hots), you will overload the neutral wire.

The are two hots and one neutraul wiring in the 120/240 cord. The neutral only carries the difference in load between the two hots--specifically, if you are using 20 amps L1 and 20 amps on L2, the neutral will carry 0 amps. 10 on L1, 20 on L2, the neutral will carry 10.