Hi everyone,
I know this is a slightly older topic/thread, and id guess you already have rectified this issue, but thought id throw my 2 cents in to see what you thought since it sounds like we are trying to achieve the same goal of NOT selling or back feeding to the grid.. I do have a slightly older Xantrex XW6048, but I believe it is nearly the same as your XW pros, (but I could be wrong).
So as stated, I do NOT want to sell any power to the grid, but DO want to use grid power in case my batteries fall below say 20%, at that point all I want it to do is AC passthrough, no charging, no selling, no nothing other than passing straight through to my loads, until the sun comes back out to charge my batteries with external mppt. My seemingly simple idea is to use the AC2 (Generator) as my AC input, with a large relay to connect and disconnect it. This way "as far as I know" it would be impossible for the inverter to back feed or SELL anything at all since again "as far as I know" it should never do this to a generator input... I would use the auxiliary control to "activate" the relay when the voltage falls below a threshold, at which point the relay would allow grid AC to power the AC2 Generator input, which after the inverter qualifies it, would then passthrough to my loads. As long as my charger is set to disabled it shouldn't do anything other than just power loads. load imbalance shouldn't matter at this point, which to my understanding was your biggest issue in getting this to work on the AC1 side.
so in essence I am tricking the inverter into thinking I have a generator, so it should still act as if I am totally off grid.
Any thoughts?