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Snubber resistance (scr device) – Rockwell Automation 7000A PowerFlex Medium Voltage Drive (A-Frame) - Classic Control User Manual

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4-38

Commissioning

7000A-UM150F-EN-P – June 2013

7000 “A” Frame

Snubber Resistance (SCR 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.

Resistance value between Test Point
and heatsink to its left is snubber resistance



Figure 4.11 – Snubber Resistance Test

Refer to Table 4.B to determine the appropriate snubber resistance
value for the current rating of the SCR used.


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.

Sharing Resistance

Snubber Resistance

Snubber Capacitor

Testpoint

To Gate
Driver Board

Heatsink

Heatsink

Sharing Resistance

Snubber Resistance

Snubber Capacitor

Testpoint

To Gate
Driver Board

Heatsink

Heatsink

Sharing Resistance

Snubber Resistance

Snubber Capacitor

Testpoint

To Gate
Driver Board

Heatsink

Heatsink

Sharing Resistance

Snubber Resistance

Snubber Capacitor

Testpoint

To Gate
Driver Board

Heatsink

Heatsink