Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive (A Frame) - ForGe Control (PanelView 550) - Manual (Page 149)

Component Definition and Maintenance 4-23
7000 “A” Frame 7000A-UM151D-EN-P – March 2013
8. Install the new capacitor, sliding it back until it fits into the slot.
Fasten the top bracket and grounding network.
9. Reconnect all the power cables and the ground connection. These use
M14 hardware, but should only be tightened to 30 Nm (22 ft-lbs.) due
to capacitor mechanical constraints.
10. Remove any shorting/grounding conductors.
11. Reinstall the sheet metal that was removed, and complete one final
check to ensure connections are secure and correct.
Testing Filter Capacitors
Two methods of testing/checking the capacitors are explained below. The
first method is simple, easy, and takes least amount of time to check the
capacitors. In this method, you would need a digital multimeter (DMM)
to measure the capacitance in micro-Farad (
µF) across each phase-to-
neutral of the capacitors. It is recommended that you should use this
method since it avoids the chance of creating re-torque issues because you
don’t have to disconnect the capacitors unless the readings are off by 15%
or more. For accurate measurements, Rockwell recommends that you
should use one of the DMMs given in Figure 4.19.
The second method involves disconnecting all capacitors from the circuit,
and testing each capacitor individually by applying 120V across each
phase-to-neutral and measuring the current in each phase. This method is
most accurate and can be used to confirm the integrity of the capacitor
when the readings from the first method appear to be unsatisfactory.
First 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.