Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive - Air-Cooled (A Frame) - Manual (Page 187)

Commissioning 4-33
7000 “A” Frame 7000A-RM001A-EN-P – January 2011
Damage to a sharing resistor is easily detected if the SGCT is
replaced and the anode-to-cathode resistance remains abnormal. If
the resistor is found to be out of tolerance, refer to Chapter 5 –
Component Definition and Maintenance for detailed instructions on
how to replace the snubber/sharing resistor assembly.
Snubber Resistance (SGCT 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.
Measure resistance
between heatsink
and test point.
Snubber test point
Figure 4.6 – Snubber Resistor Test
Refer to Table 4.A 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 Chapter 5 –
Component Definition and Maintenance for detailed instructions on
how to replace the snubber resistor assembly.