If the second drive did not "power up", it could also mean that its output transistors were burned up the moment power was applied. In the case that I mentioned previously, 3 drives were installed in sequence, power was turned on each, then there was instant destruction (also black-out of the drive HMIs) due to the phase-to-phase short at the motor.
Not thoroughly checking the wiring from drive-to-motor can lead to sequential, expensive, destruction of multiple drives. Reading 240 volts to ground with a voltmeter does not exclude a partial short-circuit. That only shows up when some amount of current is applied to break down the damaged insulation on the cables.
The problem is solved - for now! But probably there is at least one damaged leg in use for the new 1-phase drive. That means trouble is coming down the road in a year or so.
Some parameters that would have helped:
1. Does the power feed from drive to motor run underground in a conduit?
2. If in a conduit, during construction, were steps taken to seal the ends to prevent water from getting into the conduit.
3. Who was present when the cable or wire was pulled in? Was there a problem or incident that could have damaged the insulation?