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Testing sharing resistors, Sgct powercages, Scr powercages – Rockwell Automation 7000L PowerFlex Medium Voltage AC Drive (C-Frame) - ForGe Control User Manual

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308

Rockwell Automation Publication 7000L-UM301D-EN-P - June 2014

Chapter 5

Component Definition and Maintenance

Testing Sharing Resistors

SGCT PowerCages

To determine the sharing resistor value, simply measure the resistance between
the anode and cathode chill blocks. A value between 60 kΩ and 75 kΩ indicates
a good sharing resistor.

Figure 256 - SGCT Power Cage

SCR PowerCages

To obtain the sharing resistor value, disconnect the 2-pole plug of the self-
powered gate driver board labeled SHARING and SNUBBER on the circuit
board. The red wire of the plug is the sharing resistor. Measure the resistance
between the red wire of the plug and the chill block to the left (the anode chill
block). A value of approximately 80 kΩ indicates a healthy sharing resistor.

SGCT

Cathode Chill Block

Anode Chill Block

SGCT

Sharing Resistor

Snubber Resistors

Anode Chill block

Cathode Chill block

Test Point

Snubber Capacitor