2x Growatt 5000 W/ Auto Transfer Switch

[kiteoregon]

First, this is 100% off grid. I currently have 2x Growatt 5000es Inverters each of them connected to a 5kW split phase transformer. I have a EG4 Chargeverter connected to my small generator, if the batteries get low, I fire the generator for about an hour and it brings the batteries to about 75%. This process is working fine, however, if I am not there, the system is dead until the sun comes out.

I am thinking about a 14kW diesel generator, and per the inverter vendor, they are saying not to connect the generator to the input of the inverters, but to continue to leverage the battery charger. So I was thinking that if I introduced an auto transfer switch with the generator being the "utility" the inverters would be the backup, anytime the generator was started, either manually or via the contact from the inverter the generator would take over charge the batteries and be a pass-through to the house.

The question is, how do I combine 2 or 3 growatt AC (post transformer) as a source to the transfer switch? I think the conventional thinking would be to introduce a small breaker panel with 50 amp dual pole breakers for each growatt, then 100 amp output to the transfer switch. Then from the transfer switch to the larger distribution sub panel. Is there a more sexy way to do this w/o another small breaker panel?

I am looking at the McPherson Controls TCS2PC125-22M 2 pole auto transfer switch, better option for this configuration?

 

[timselectric]

How are they currently combined?

 

[kiteoregon]

Today both of the outputs from the transformer land in the breaker panel. I suspect this is how it really should be done, just trying to avoid another breaker panel, but maybe it's the easiest path.

 

[timselectric]

A distribution block or Polaris type Splice will work. But you should still have individual OCP. (Breaker or fuse)