Rockwell Automation 20P PowerFlex Digital DC Drive - Manual (Page 261)

Rockwell Automation Publication 20P-UM001I-EN-P - February 2013 261
Application Notes Appendix C
6. Open the Enable input on the drive.
7. Set Par 166 [Alpha Test] to the desired value (1 = “Arm Fwd”, 2 = “Arm
Rev” or 3 = “Fld Fwd”).
8. Close the Enable input.
9. Slowly decrease the appropriate angle parameter (Par 167 [Arm Test
Angle] or Par 168 [Fld Test Angle]) until a steady pattern of voltage pulses
display on the oscilloscope.
If all thyristors in the selected bridge are operating, there will be six pulses
per AC line cycle. If not all thyristors in the selected bridge are operating,
one or more pulses will be missing. Note that conduction (or output
voltage) will not typically begin until the angle is below about 120 degrees.
10. Open the Enable input and set Par 166 [Alpha Test] to 0 "Off ".
11. Remove power from the drive.
12. Remove the oscilloscope from the leads of the drive and unlock the rotor.
13. If necessary, replace the defective firing board in the drive.
14. Reconnect the motor armature and field leads to the drive.
15. Reapply power to the motor and drive.