Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive - Air-Cooled (A Frame) - Manual (Page 285)

Component Definition and Maintenance 5-43
7000 “A” Frame 7000A-RM001A-EN-P – January 2011
5. Using a DMM measure the capacitance across each phase-to-neutral
of capacitors without removing any connections. If the difference
between the highest and the lowest readings is below 15% then all
capacitors are in good condition.
6. If the difference between the highest and the lowest readings is off by
15% or more, then you might have a bad capacitor.
7. Before disconnecting the capacitors, note the location of all the cables
and mark them accordingly.
8. Disconnect power cables/bus bars from the capacitor terminals on all
four bushings and isolate them from the capacitor. (Refer to “Filter
Capacitor Replacement” guidelines in the Classic User Manual -
Component Definition and Maintenance chapter (Chapter 6) for using
proper torque when reconnecting the capacitors)
Second Method
1. Ensure there is no power to the equipment before testing the
capacitor.
A T T E N T I O N A T T E N T I O N To prevent electrical shock ensure the main power
has been disconnected before working on the
capacitor. Verify that all circuits are voltage free
using a hot stick or appropriate voltage-measuring
device. Failure to do so may result in injury or
death.
A T T E N T I O N A T T E N T I O N Verify the load is not running due to process. A
freewheeling motor can generate voltage that will
be back-fed to the equipment being worked on.
2. Follow appropriate safety steps to isolate the equipment from medium
voltage.
3. Verify that there is no voltage present on the capacitor by using a hot
stick or any other appropriate voltage-measuring device.
4. Perform visual inspection to ensure there is no oil leak or bulge in any
of the capacitors.