Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - ForGe Control - Manual (Page 122)

122 Rockwell Automation Publication 7000-UM202B-EN-P - June 2014
Chapter 3 Component Definition and Maintenance
6. Tighten the cap screws progressively with a wrench. Do this evenly as
though mounting an automobile wheel. Turn one a quarter turn, then the
next a quarter turn, then go back and turn the other a quarter turn and so
on. Torque to 10.2 N•m (7.5 lb•ft).
7. Peen the end of the motor shaft at the keyway with a chisel or center punch
to prevent the key from falling out of position.
Fan Balance
Fan impellers are statically and dynamically balanced within acceptable
tolerances at the factory. Damage in shipping or from poor handling or
installation may upset the unit’s balance. An impeller that is not properly
balanced can lead to excessive vibration causing undue wear on the entire unit.
If vibration is excessive, shut down the fan and determine the cause.
Some common causes of excessive vibration include:
• support structure not sufficiently rigid or level. Vibration amplified by
resonance in duct work or support structure.
• bearing locking collar or mounting bolts loose. Impeller or bushing loose.
• material accumulation on impeller.
• wheel rubbing on inlet ring.
The inlet ring is the large circular part located on the underside of a horizontal
barrier beneath the fan impeller. The position enables the impeller to sit inside
without touching the ring. The ring sits inside the impeller 10 mm (0.40 inches).
Safety Notes
This procedure requires contact with the internal electrical connectors and
devices. Disconnect all power to the drive before beginning the work. Failing to
do so may result in serious injury or death.
Ensure you can prevent the inlet ring from falling after you have removed all of
the bolts.
If rear panel access is possible, remove rear middle panel of the DC link/fan
portion of the cabinet and remove the inlet ring from the back.
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.