Rockwell Automation 7000L PowerFlex Medium Voltage AC Drive (C Frame) - Classic Control - Manual (Page 238)

Commissioning 4-33
7000 “C” Frame 7000L-UM300I-EN-P – Juen 2013
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 6 –
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 chill blocks. For each device, there is one test point. To verify
the resistance, measure the resistance between the test point and the
chill block directly above the test point.
Measure resistance
between chill block
and test point.
Snubber Test Point
Measure resistance
between chill block
and test point.
Snubber Test Point
Figure 4.5 – Snubber Resistor Test
Refer to Table 4.A to determine the appropriate snubber resistance
value for the SGCT used in either the PWM Rectifier or the inverter.
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.