Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - ForGe Control - Manual (Page 67)

Rockwell Automation Publication 7000-UM202B-EN-P - June 2014 67
Component Definition and Maintenance Chapter 3
Refer to Table 1 on page 63 to determine the appropriate snubber resistance value
for the current rating of the SGCT used.
If the resistor is found to be out of tolerance, refer to page page 72 for detailed
instructions on replacing the snubber resistor assembly.
Snubber Capacitance (SGCT Device)
Turn the multimeter from the resistance to capacitance measurement mode.
Verify the snubber capacitor by measuring from the test point to the heat sink
adjacent to the right for standard rectifiers, or from heat sink to heat sink. For
SPS rectifiers, measure from the test point to pin 1 of the Phoenix connector that
plugs into J1 of the SPS board (disconnect the J1 connector from the SPS board
first).
Figure 57 - Snubber Capacitor Test
Heatsink Heatsink
Snubber
Resistor Snubber
Capacitor
Sharing Resistor
SGCT
Test Point
Measure capacitance
between heat sink
and test point (or
from heat sink to
heat sink)
Snubber test point