Gary sez:

" Because the motor won't actually try to spin up when fed only 1 ph, the
starting
surge isn't all that much over normal running current, impedance limited.
So the
breaker probably won't trip. But the converter motor will just sit there
humming,
no cooling air flow, and will rapidly overheat. The chance of electrical
fire is high.
That's why dropout protection is a must."

Since the rotor can't turn, I imagine the 1 ph current is more like locked
rotor current, considerably higher than normal inrush.

Bob Swinney