Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - ForGe Control (PanelView 550) - Manual (Page 278)

278 Rockwell Automation Publication 7000-UM151E-EN-P - January 2013
Appendix C Snubber Testing
Snubber Capacitance (SCR Device)
Turn the multimeter from the resistance to capacitance measurement mode.
Proceed to verify the snubber capacitor by measuring from the test point and the
white wire at the 2-pole device snubber plug (labeled snubber).
Figure 261 - Snubber capacitance test
To test the snubber capacitance, disconnect the plug of the self-powered gate
driver board labeled SHARING and SNUBBER. The resistance between the
white wire of the plug and the Test Point to its left is the snubber capacitance.
Refer to Figure 15 on page 272 to determine the appropriate snubber capacitance
value for the current rating of the SCR used. Read the actual snubber capacitor
value shown in the table.
If the capacitor is out of tolerance, refer to Component Definition and
Maintenance on page 23 for the snubber capacitor replacement procedure.
Resistance between Test Point and white wire
at 2-pole plug is snubber capacitance
Heatsink Heatsink
Sharing Resistance
Snubber Resistance Snubber Capacitor
Testpoint
To Gate
Driver Board
Heatsink Heatsink