Inverter setup

You are looking for AC inverters that supply 120/240 VAC 60 Hz power for North America (you are in the Dominican Republic?)?

Yes, they are available--But mostly (nearly all?) are relatively large units (3,000 Watts or more). Your present battery bank of 420 AH @ 48 volts would power upwards of 4,200 Watts of AC inverter pretty well (as a first guess--Detail matter here).

For example, here is a smaller 120/240 VAC 60 Hz unit (3,800 Watts total)

https://www.solar-electric.com/hoymiles-power-hys-3-8lv-usg1-hys-dc-hybrid-inverter.html

Note that when you use 120/240 VAC split phase power, the inverter can output only 50% of rated power into L1 or L2 @ 120 Volt outputs. The total 3,800 Watts (in this case) can only be supplied if you have two 1,900 Watt loads (one on L1/N and the second on L2/N), or if you have a (maximum of) 3,800 Watt @ 240 VAC load...

Other brands/models may supply slightly better than 50% into a single 120 VAC load.

-Bill

I did not want to start with the "full price" inverter in the discussion... The cost for that 70lbs of copper and iron (plus electrics, engineering, mfg., etc.) is not cheap ($1,000 vs $4,000 roughly):

https://www.solar-electric.com/schneider-electric-xw-pro-6848-21-inverter.html

All depends on the power needs of the poster... Lots of small/distributed 120 VAC loads, or one large 120 or 240 VAC load(s), etc...

Comes back to my "starting suggestions"... Review you power needs and loads. Conservation & high efficiency loads are almost always cheaper than just throwing a big solar power system (batteries, inverters, solar panels, etc.) at the problem.

-Bill

Don't disagree... 

-Bill

Reviewing the manual--There is not a lot of detail about operating 120/240 VAC split phase mode (L1/N/L2):

https://m.media-amazon.com/images/I/D1nHVHvAcPL.pdf

Strangly, it mostly talks about 120 or 240 VAC mode and the 120 VAC mode shows only(?) connecting L1/N or N/L2...

I am not sure I understand your question... The typical method would be to find out from the manual/mfg's specifications what the maximum current/VA per L1+N or L2+N... I.e., are the Lx+N just 1/2 of the rated unit Watts/VA or are they rated for some number between 50% to 100% of inverter Watts/VA rating?

Once you "know" what the ratings are, then you would move your loads across L1+N and L2+N such that they do not exceed the inverter's maximum output current per leg...

For example, the main breaker for the Lx outputs are 40 amps for the 6kW unit... 40 amps * 120 VAC = 4,800 Watts--Certainly less than 6,000 Watts... But that does not tell us what the actual factory rating(s) are.

The AC wiring diagram seems to indicated that the units are 120 OR 240 VAC and there is no 120/240 VAC split phase function (notice the 120 VAC wiring says HOT1+N OR HOT2+N and no "N" connection for 240 VAC operation.

There is just not enough information to figure out 120/240 VAC split phase operation, and what those limits (if split phase) may be...

I may have the wrong spec's/manuals... But this is all I could find with a couple quick searches.

-Bill