DC wire sizing

[orion7144]

I am getting ready to install a 3000 watt inverter/charger. The manual says minimum 4/0 gauge cable from the inverter/charger to the battery's if under 3 meters. My question is can I keep the same 2ga cable that runs to the current charger and move it to the breaker panel DC side? I currently have 2 shutoff switches (1 for inverter that runs to the fridge and the main to the rest of the RV). I will be removing the current inverter and charger.

 

[roundabout]

I think what you are saying is your replacing the factory “converter” with an inverter/charger

or do you already have an inverter/charger your replacing?

the 2ga wire sounds like it powers the rv and has shut off switches. And supplies charge current to the batteries

3000 watts of 12v dc current is about 250 amps and will need much larger wire size like the 4/0 specified. But the 2ga wire can still be used as intended as long as it’s the proper size specified

there should be included wiring diagrams for the system that will specified wire sizes and connections




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[orion7144]

I will be replacing a 1000W inverter that is for the residential refrigerator and the progressive dynamics 80a charger with an AIMS 3000W inverter charger. My plan is to run 4/0 to the AIMS and keep the 2awg to the rest of the coach. I will be removing the 14/2 and 12/2 romex and replacing it with 6/2 to and from the AIMS.

 

[roundabout]

It sounds like your following the recommended wire size specs. I haven’t checked your particular inverter specs. But it’s inportant if you don’t already know about wire size and length that produce voltage drop that’s what the specs are about.
If your wire is too small for the load which sounds like your tripling. Then the resistance in the undersize wire drops the voltage and the amps increase to continue to provide the wattage draw. Increasing the amps can cause wires to heat up. Fuses and breakers to open and failure of your inverter and appliances.
It sounds like you are following the specs
i installed a new 1000 w inverter myself. I used marine switch panels for two a/c curcuits. The entertainment center and the garage. I used oversized d/c tinned marine grade wires. Marine wire is a little bigger to begin with and one size up wire size and short wire length insures I get every watt out of the inverter I can. I crimped and soldered all connectors. Crimping makes the best mechanical connection and soldering makes the best electrical connection.
I visited an rv show and looked at one motorcoach model that ran off battery inverter power alone if needed. I can only imagine how many batteries it had to power the entire rv.
I figure do it right the first time and I have no worries years latter
i hope I helped though I can’t actually see what you’re doing