Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive - Air-Cooled (A Frame) - Manual (Page 188)

4-34 Commissioning
7000A-RM001A-EN-P – January 2011 7000 “A” Frame
Snubber Capacitance (SGCT Device)
Turn the multimeter from the resistance to capacitance measurement
mode. Proceed to verify the snubber capacitor by measuring from the
test point to the heatsink adjacent to the right.
Measure capacitance
between heatsink
and test point.
Snubber test point
Figure 4.7 – Snubber Capacitor Test
Refer to Table 4.A to determine the appropriate snubber capacitance
value for the current rating of the SGCT used.
The capacitance measured is actually affected by the snubber
capacitor and other capacitance in the circuit, including capacitance
from the Gate Driver circuit. You are actually looking for a
consistent reading for all devices.
If the capacitor is found to be out of tolerance, refer to Chapter 5 –
Component Definition and Maintenance for detailed instructions on
how to replace the snubber capacitor.
Resistance Checks
(cont.)