Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - Classic Control - Manual (Page 197)

4-38 Commissioning
7000-UM150I-EN-P – June 2013 7000 “B” Frame
Snubber Resistance (SCR Device)
Access to the snubber resistor is not required to test the resistance.
The snubber circuit test point is located within the PowerCage under
the heatsinks. For each device, there is one test point. To verify the
resistance, measure the resistance between the test point and the
heatsink above.
Resistance value between Test Point
and heatsink to its left is snubber resistance
Sharing Resistance
Snubber Resistance Snubber Capacitor
Testpoint
To Gate
Driver Board
Heatsink Heatsink
Sharing Resistance
Snubber Resistance Snubber Capacitor
Testpoint
To Gate
Driver Board
Heatsink Heatsink
Figure 4.11 – Snubber Resistance Test
Refer to Table 4.B to determine the appropriate snubber resistance
value for the current rating of the SCR used.
If the resistor is found to be out of tolerance, refer to Chapter 6 –
Component Definition and Maintenance for detailed instructions on
how to replace the snubber resistor assembly.