Rockwell Automation 7000L PowerFlex Medium Voltage AC Drive (C Frame) - Classic Control - Manual (Page 388)

6-44 Component Definition and Maintenance
7000L-UM300I-EN-P – June 2013 7000 “C” Frame
Sharing Resistors (cont.)
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 k
Ω indicates a healthy sharing resistor.
Anode
Chillblock
Cathode
Chilblock
Disconnect Points
Rsh-1
Rsn -1
Cs-1
Cs-2
Rsn -2
To Gate Driver Board
TP
Rsh-2
Figure 6.35 – SCR PowerCage Snubber Circuit Connections
In the liquid cooled drive the sharing and snubber resistors can be
replaced independently. The sharing resistor is located in the same
spot on every chill block assembly, and the number of snubber
resistors can vary with the drive rating. The snubber and sharing
resistors are part of the chill block assembly. Servicing of resistors
requires that the chill block be removed from the PowerCage. See
“Chill block Removal and Replacement”.
1. Remove the chill block outlined in “Chill Block Removal and
Replacement”
2. Note all connections for correct replacement.
Snubber and Sharing
Resistor Replacement