Filter capacitor cabinet, Filter capacitors – Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - ForGe Control User Manual
Page 46
46
Rockwell Automation Publication 7000-UM202B-EN-P - June 2014
Chapter 3
Component Definition and Maintenance
Replacing the Current Transformer (CT)
1.
Isolate and lock out all power to the drive.
2.
Note the location of all wires and the orientation of the CT. For quick
reference when checking the orientation of the CT, look for the white dot.
3.
Disconnect the wires.
4.
Disassemble the bus bar to remove the CT. Remove the M10 hardware to
slide out the bus bar.
5.
Remove the four screws located in the base of the CT and remove the CT.
6.
Replace the CT, ensuring the proper orientation. Fasten the CT securely
with the four screws in the base
7.
Reconnect the ring lugs. Do not overtighten or you will break the threaded
stud. For torque specifications, refer to
Threaded Fasteners on page 183
. Replace the bus bar and tighten into
place.
Filter Capacitor Cabinet
Filter Capacitors
All “B” Frame drives use filter capacitors on the motor side. The AFE rectifier
options also include filter capacitors on the line side. Refer to
(Cabling Cabinet for AFE Rectifier) and
(Cabling
Cabinet for 18 Pulse Rectifier).
The filter capacitors are three-phase, oil-filled, four-bushing units. The three-
phase capacitors are internal single-phase units connected in a Y configuration.
The neutral point of the Y connects to the fourth bushing, which is available to
use as a neutral point voltage measurement or other protection/diagnostics
purposes. The metal cases of the capacitors are grounded through a stud on the
capacitor housing.
The capacitors have internal “bleeding resistors” to discharge the capacitor and
reduce its voltage below 50V in five minutes when disconnected.
shows
a typical three-phase capacitor.
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.
IMPORTANT
The CT and wires must be in the proper orientation. Note the position before
disassembly.