I have a customer that has two Quattros in split phase. I have unselected 'switch as group' and they are 2 phase floating (return). Twice now they have had a fault condition, once with an input interrupt, and once with low batt shutdown, where they would not recover when only one unit was powered on ac in. As soon as the second unit was powered on ac in at the same time, they recovered and went back to normal operation. But as long as power was put to only one unit they would not restart.
Once we had recovered them by applying power to both units at the same time, They will start and operate normally with only one unit powered on AC input.
Has anyone seen this or have a theory on the condition? When remote, he has only a single phase generator, so it would be difficult to restart them in this condition.