2 breaker panels on one inverter?

[Salty_colada]

Hello, i am trying to set up an off grid system for my liveaboard. I have 2 120 volt input panels, one for the boat AC, and the other for the 120 volt systems on board. I am planning on getting a 3000 watt inverter for my house batteries. Is it possible to wire 1 inverter to 2 breaker panels? Both systems together don't pull more than 25 amps or so at one time.

Thank you! I am very new to off grid electric

[leecea]

I imagine you'd want something similar to how my boat is setup.

My main 120v feed (called Line 1) can be from shore power or from a generator/inverter.

My AirCon 120v feed (Line 2) can be from a second shore power cable or connected to Line 1.

The switches are setup to prevent bad combinations. See the attached image which shows Line 1 on shore power and Line 2 connected to Line 1.

[Adelie]

The only reason to have 2 AC panels is if there is a very high load use you will only run when on shore power like A/C or water heating or a space heater.

An inverter converts battery 12v DC (or 24,36,48) to 120v AC. It will not put energy back in the batteries.

If it’s an inverter/charger that will put energy back in the batteries. If it is an inverter charger it should connect to the shore power, the batteries and the house AC panel but not the high load AC panel. It should automatically decide where to get the energy and where to send it depending on AC loads and whether you are plugged in.

[ranger58sb]

Originally Posted by Salty_colada

Hello, i am trying to set up an off grid system for my liveaboard. I have 2 120 volt input panels, one for the boat AC, and the other for the 120 volt systems on board. I am planning on getting a 3000 watt inverter for my house batteries. Is it possible to wire 1 inverter to 2 breaker panels? Both systems together don't pull more than 25 amps or so at one time.

Thank you! I am very new to off grid electric

Not sure I understand, but...

The inverter won't usually run aircon, at least for very long, unless you've got a ji-normous! battery bank. Water heater and electric cooktop, same category.

Sounds to me like you should only need to connect the inverter to the panel that services general 120VAC outlets and appliances. Don't have to service the whole panel; you can connect to specific breakers if necessary.

Ours is an inverter/charger, so automatically senses shorepower/genset power, automatically kicks in when neither of those are present.

-Chris

[CharlieJ]

If the inverter or inverter/charger is 12VDC than drawing 25A AC will require supplying about 270A DC from the battery bank, assuming an inverter efficiency of 95%. Inverters and inverter/chargers are generally rated at 77F and derate themselves based on the actual temperature of their environment and the internal temperature of the inverter or I/C.
In other words, at first blush your idea looks ok but it will not work in the real marine world.

[FlyingScot]

1. If you are planning a Victron Multiplus 3000VA inverter keep in mind it is 3000VA not 3000W. The max Volt Amps also decreases as temperature goes up. Read the manual for details. Also learn Power Factor (PF) and how it affects AC circuits.

2. Many inverters have two AC outputs. One for strictly inverter loads and another that is simply a pass through when you have shore power/generator.

As far as the Multiplus is concerned it doesn't care if you use one or both outputs.

Most boats are wired where water heaters and air conditioners only work when on shore power (or generator) as most don't have a robust enough battery bank to power large loads. This requires a seperate neutral bus.
On our boat we do not split shore or inverter loads but we have a large house bank.

3. As far as AC outputs it doesn't matter how many breaker panels you wire up to the it. There is no functional difference between 10 single breakers, 2 panels of 5 breakersor or 1 panel of 10 breakers. This assumes all the same voltage.