Rockwell Automation 7763 Medium Voltage OneGear SMC Flex Motor Controller (10-15 kV) - Manual (Page 112)

112 Rockwell Automation Publication 7760-UM001D-EN-P - October 2014
Chapter 8 Troubleshooting
Voltage Sensing Board
Testing 1. Check the resistance of the voltage sensing module (refer to Figure 49 ).
Remove the ribbon connector from J1 by pressing down on the locking
tabs then gently pulling the connector out. Measure the resistance between
each tap and the ground connection, and compare to the values in
Figure 49 . If the equipment includes an earthing switch, the board will be
effectively short-circuited to ground. In this case, remove the ground wires
before taking measurements.
Figure 49 - Voltage Sensing Board
Measure across R2, R4, R6, R10, R12, R14, R18, R20 and R22 located at the
bottom of each leg of the module. The resistance should be 11.3 kohm. (The two
ground connections must be connected to ground, or to each other if the module
has been removed.)
L1 T1 L2 T2 T3 L3
To Interface Board Ground Connections
Rated
Voltage
12 kV
14.4 kV
Tap 1, 3, 5
to GND1
17.1 MΩ
22.2 MΩ
Tap 2, 4, 6
to GND1
25 MΩ
33.8 MΩ