50amp concerns

[Out on a limb]

I have a 2003 carver 410ss. It has a 50amp shore power cord. I am in the process of adding 4 lifepo4 300ah batteries and a victrom multiplus ii 12v 3000w 120v inverter charger. My question is, how do I hook the 4 wires that are in the 50amp service to the 3 wires connectors in the mpii? I understand the 50amp is 240 split phase. I’m pretty sure that I can just put the two hot legs together and hook that to ac in, but what do I do to hook up ac out when I’ll only have 3 wires and the wire I tie into will have 4?

 

[rodrick]

Don’t hook the L1and L2 from your shore power together it won’t end well

 

[Out on a limb]

Don’t hook the L1and L2 from your shore power together it won’t end well

So how does this work

 

[Danke]

So how does this work

Is the source 120V or 240V?

 

[Out on a limb]

Is the source 120V or 240V?

I saw it wrong. You are correct. It’s a 120 source. I just keep thinking there has to be a way. Just because I can go to other docks, and with an adapter, hook my boat to 2 30amp outlets and people with boats with 2 30amp cords can use an adapter to plug into a 50 amp service. I’m sure I’m missing something, but it just seems like there has to be a way.

 

[yabert]

people with boats with 2 30amp cords can use an adapter to plug into a 50 amp service. I’m sure I’m missing something, but it just seems like there has to be a way.

Like you share in picture post #3, Nema 14-50 plug (240V oven supply) is build with neutral + two 120V leg.
So, yes, it's possible to plug two 120V 30A plugs to a single 14-50 outlet with an adaptor (splitter) by using same neutral and separate 120v leg for each plug.

 

[OTRwSolar]

. . . . victrom multiplus ii 12v 3000w 120v inverter charger. My question is, how do I hook the 4 wires that are in the 50amp service to the 3 wires connectors in the mpii? . . . .

Sounds like you may have the Victron Multiplus II 3000 120v model which only has ground, common/neutral, and hot, on the AC input/output connectors. You'll need the Victron Multiplus II 3000 2x120 to support a 50a RV-type shore power connection. The 2x120 has a ground, common/neutral, L1 hot, and L2 hot, on the AC input/output connectors.

 

[RaySE]

When you are "pretty sure that I can just put the two hot legs together and hook that to ac"; The only serious advice I can give to you is: get a professional to do it for you. He can also check if the rest of the connections are in shape and up for the new job. Yes is does cost money, but you dont want to create expensive errors or worse, Fire....
Connecting 2 phases together can give serious weird voltages and with that expensive mistakes.

 

[ricardocello]

Connecting 2 phases together can give serious weird voltages and with that expensive mistakes.

240V at 50A, where you would combine them (PLEASE DON’T) would be 12000 W, and even much more instantaneously, before a breaker trips.
Enough to melt pretty much anything including steel.

 

[ricardocello]

So how does this work

If you start with 120V 30A, you can use the same 120V across both L1 and L2 safely because there is no 240V.
This also means that any 240V appliances you may have will see 0V (meaning they won’t do anything). But that is safe.
If you don’t have any 240V appliances, then happy day.

If you start with 240V and try to combine the L1 and L2 (which have 240V between them), then doomsday occurs.

 

[RaySE]

While living in France I had a technician from the EDF ( the electricity company from France) who came to change the old analoge meter for a new digitall meter. We had 3 phases and 0. While connecting the meter he had put together wire nr 8 and 9 in the same connector. After switching the power back on, a lot of appliances blew up....
After a quick check I had something around 700 volts on my wall sockets in phase 2 and 3.!!

Lesson learned; When your are working on your main supply cable: besides cutting the main switch, switch off all groups in your fuse box, and fire them up one by one after turning the main switch.
I am pretty sure I already knew, but didn't do it by the book.

 

[RaySE]

So how does this work

Looking at your picture: RED is 120V , BLACK is 120V, WHITE is neutral. For a short cut you should be able to take 1 phase either red OR black and connect that to the phase pin in your 3 pin plug which is a 1phase connector.

Result is a 1 phase 120V connection, not sure though if you will get the max of 50Amps. I can imagine the 50amps is over 2 phases. Not very familiar with the 120V system. In europe you are able to use only 1 of the 3 phases. But you need to keep in mind the other 2 wires of the other 2 phases are live wires!!

 

[Tadsher]

Looking at your picture: RED is 120V , BLACK is 120V, WHITE is neutral. For a short cut you should be able to take 1 phase either red OR black and connect that to the phase pin in your 3 pin plug which is a 1phase connector.

Result is a 1 phase 120V connection, not sure though if you will get the max of 50Amps. I can imagine the 50amps is over 2 phases. Not very familiar with the 120V system. In europe you are able to use only 1 of the 3 phases. But you need to keep in mind the other 2 wires of the other 2 phases are live wires!!

Ray, RVs in the US use 2 120 volt hots for the 50 amp wiring. All the appliances including the ACs are 120 volts. It is wire L1 Hot 120 volts L2 Hot 120 volts

neutral

ground

Even though between L1 and L2 is 240 volts the RVs are not using 240 volts. There is a pigtail that will combine L1 and L2 but is limited to 30 amps. RV wiring is oddball compared to residential or commercial wiring.

The 12 volt system is also different than Solar and automotive wiring. We are used to red is positive and black is negative but RVs use white for negative and black for positive, but sometimes they use green for positive in older (20teens) RVs. In the much newer RVs they sometimes use the Red positive/Black negative colors for the 12/24 volt systems but not in all cases.

So how does this work

The wiring in that picture shows how a 30 amp to 50 amp dog bone adapter is wired.

Amazon.com

www.amazon.com

 

[RaySE]

So the positive wire can either be Red, Black or Green and,
the negative wire can Black or White.

Very universal approach... Americans...
(not to mention most countries in Europe have an old and new color system and,... not all countries are the same...)

 

[dktool]

Do you have any 240v appliances / equipment on board ?