Assembling hard wired A/C off my backup solar system

Once this second solar system is hard wired, my next project is to design and construct an ABT(auto bus transfer)..Strictly voltage driven and designed with a 5 second delay relay to allow all residual voltages to expire before being re-energized....The ABT will be in service only when in inverter mode, to allow automatically continuous power from the other inverter should one inverter fail or overload.

The primary inverter will be my 1000 watt PSW, with my 2000 watt as secondary....Because.....Because My 2000 watt inverter will seldom be used except for the microwave and large power tools.....The 1000 watt will be my bread and butter inverter for usual nightly use....Yaknow TV, sat dome, computer, led lighting and device charging duties.

And yeah each inverter is powered by it's own battery bank, where each bank has it's own solar cells and charge controllers, but those banks will remain split and not cross connectable....So, that means each inverter draws from ONLY it's battery bank and cannot draw from the other....That way both battery banks remain totally isolated from each other and can store a full charge as a back up for my back up other system....No loops, no system chasing the tail of the other....A sorta split-yet auto cross connect typa system, maybe?...Yep, exactly that.

Maybe you get the idea?...Let me explain it like this; WHEN on inverter power, IF I was to lose A/C power due to equipment failure or overload, then the secondary inverter would automatically kick in after my timed 5 second delay....So Ok, the 120V stuff will fade out for a few seconds, then be re-energized, but that way none will suffer, even tho I'll have to restart perhaps several things, they will not suffer damage.

BUT, how about stuff like my frig?...Well the fridge control energy will remain on my house bank that powers my 1000 watt inverter, but the fridge is fused D/C to that inverter bank and will remain there.... when boondocking I always run the fridge on propane, and I tote 134 lbs of propane, so the fridge will last several months...I also always heat my water from propane when boondocking...and from experience both the fridge and water heater require no more than 30lbs per month in my normal usage.....Cooking I usually do over a wood or charcoal fire, but sometimes on my propane range top....My onboard propane tank has a neat little 3 way connection that allows me to connect external propane tanks and also fire a gas grill, but I always cook with charcoal or wood....The external tank connection feature tho is handy.