Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - ForGe Control User Manual
Page 49
Rockwell Automation Publication 7000-UM202B-EN-P - June 2014
49
Component Definition and Maintenance
Chapter 3
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. If the difference between the
highest and the lowest readings is off by 15% or more, then you might have
a bad capacitor. If more than one capacitor is used in the circuit, then you
would need to isolate each of them and check them separately to identify
which one is defective.
6.
Before disconnecting the capacitors, note the location of all the cables and
mark them accordingly.
7.
Disconnect power cables from the capacitor terminals on all four bushings
and isolate them from the capacitor (see
Replacing Filter Capacitors on
8.
Repeat step 5 to check each capacitor separately to confirm which is
defective.
Second Method
1.
Ensure there is no power to the equipment.
2.
Perform visual inspection to ensure there is no oil leak or bulge in any of
the capacitors.
3.
Note the location of all the cables and mark them accordingly.
4.
Disconnect power cables from the capacitor terminals on all four bushings
and isolate them from the capacitor (see
Replacing Filter Capacitors on
ATTENTION: Capacitors that appear bulged or are leaking oil indicate potential
problems with the internal elements. DO NOT USE. These units must be
replaced. Failure to do so may lead to personal injury or death, property
damage, or economic loss.
ATTENTION: To prevent electrical shock, disconnect the main power before
working on the drive. 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.
ATTENTION: Verify the load is not running due to process. A freewheeling
motor can generate voltage that feeds back to the equipment.
ATTENTION: Capacitors that appear bulged or are leaking oil indicate potential
problems with the internal elements. DO NOT USE. These units must be
replaced. Failure to do so may lead to personal injury or death, property
damage, or economic loss.