Rockwell Automation Publication 7000-UM202D-EN-P - May 2018 89
Power Component Definition and Maintenance Chapter 2
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 79 - 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.
See Table 4 on page 83
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, see page 80
for the snubber capacitor
replacement procedure.
To Gate Driver Board
Heatsink
Heatsink
Snubber
Resistor
Snubber
Capacitor
Sharing Resistor
Test Point
Resistance value between test point and white
wire at 2-hole plug is snubber capacitance
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