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Rockwell Automation Publication 20P-TG002B-EN-P - February 2018
Chapter 2
Component Test Procedures
A malfunctioning thyristor is connected to the relative gate. For example, if the
tested signal is at XR25 and the positive bridge is active (MP high) from this
figure you can deduce that SCR connected to gate G6 is open.
Figure 5 - Open Thyristor Example
Troubleshoot a Field Current
Loss Fault
If the drive faults with a “Field Current Loss” fault (F6) and there is low or
incorrect field current present at the motor, as seen in parameter 351 [Field
Current], complete the steps in Low or Incorrect Field Current. If the drive
faults with a “Field Current Loss” fault (F6) and there is no field current
present at the motor, as seen in parameter 351 [Field Current], complete the
steps in No Field Current on page
Low or Incorrect Field Current
Note: For a flow chart version of these steps, see Low or Incorrect Field
Current on page
1. Read the General Safety Precautions on page
2. Verify the actual value of parameter 351 [Field Current] by measuring
the DC motor field current using a DC clamp.
3. Verify that the drive rated field bridge current is set correctly in
parameter 374 [Drv Fld Brdg Cur] and DIP switch S14 is configured to
correctly (according to the instructions in the PowerFlex Digital DC
Drive User Manual, publication
) and make any necessary
corrections. See Control Board on page
for DIP switch location.
5 V
0 V
XY19