Rockwell Automation 7000L PowerFlex Medium Voltage AC Drive (C Frame) - Classic Control - Manual (Page 342)

5-34 Functional Description
7000L-UM300I-EN-P – June 2013 7000 “C” Frame
Transfer to Drive
To transfer a motor running on the bypass back to the drive a
Transfer to Drive command is requested. Following sequence of
events take place:
1. The drive is given a Transfer to Drive command. After a normal
start command is given, the drive closes the output contactor.
After the do contactor close input indicates that the output
contactor has closed, there is a short delay (~1second) to allow
the output filter capacitors to charge to the bypass voltage.
Within this time, the drive synchronizes to the capacitor voltage
with the motor still running on bypass. The drive then deactivates
its bp contactor close output.
2. When the bp contactor status input indicates that the bypass
contactor has opened, the drive goes to run mode. As the drive
brings the motor torque up to the level required by the load, the
motor speed will drop slightly before returning to the commanded
speed.
3. The Transfer to Drive command is removed. The transfer is now
complete and the motor is running on the drive.
Synchronous Transfer
(cont.)