Rockwell Automation 150 USE MN/SMC DIALOG + CONTROLLER - Manual (Page 154)

Troubleshooting 10-5
Table 10.E Miscellaneous Situations
Situation Possible Cause Possible Solutions
Motor current and
voltage fluctuates
with steady load • Motor
• Energy Saver
• Erratic Load
• Verify type of motor as a standard
squirrel cage induction motor
• Set Energy Saver Off, then restart.
–
If problem stops, replace
control module
– If problem persists, shut off
all power to controller and
check connections
• Check load conditions
Erratic operation • Loose
connections • Shut off all power to controller and
check for loose connections
Accelerates too fast • Starting time
• Initial torque
• Current limit
setting
• Kickstart
• Increase starting time
• Lower initial torque setting
• Decrease current limit setting
• Lower kickstart time or turn off
Accelerates too
slow • Starting time
• Initial torque
• Current limit
setting
• Kickstart
• Decrease starting time
• Increase initial torque setting
• Increase current limit setting
• Increase kickstart time or turn off
Fan does not
operate
(97–1000A) • Wiring
• Failed fan(s)
• Check wiring and correct if
necessary
• Replace fan(s)
Motor stops too
quickly with
Soft Stop option • Time setting • Verify the programmed stopping
time and correct if or increase
Motor stops too
slowly with
Soft Stop option • Stopping time
setting
• Misapplication
• Verify the programmed stopping
time and correct if necessary
• The Soft Stop option is intended to
extend the stopping time for loads
that stop suddenly when power is
removed from the motor.
Fluid surges with
pumps still occur
with the Soft Stop
option • Misapplication • Soft Stop ramps voltage down over
a set period of time. In the case of
pumps, the voltage may drop too
rapidly to prevent surges. A closed
loop system such as Pump Control
would be more appropriately
suited.
• Refer to Publication 150-911
Motor overheats • Duty cycle • Preset Slow Speed and Accu-Stop
options: Extended operation at
slow speeds reduces motor cooling
efficiency. Consult motor
manufacturer for motor limitations.
• Smart Motor Braking option:
Check duty cycle. Consult motor
manufacturer for motor limitations.
Motor short circuit • Winding fault • Identify fault and correct.
• Check for shorted SCR; replace if
necessary.
• Ensure power terminals are secure.