Rockwell Automation SMC Dialog Plus User Manual page 154

Table 10.E Miscellaneous Situations
Situation Possible Cause
Motor current and •
voltage fluctuates
with steady load •
•
Erratic operation •
Accelerates too fast •
•
•
•
Accelerates too •
slow •
•
•
Fan does not •
operate
(97–1000A) •
Motor stops too •
quickly with
Soft Stop option
Motor stops too •
slowly with
Soft Stop option •
Fluid surges with •
pumps still occur
with the Soft Stop
option
Motor overheats •
Motor short circuit •
Troubleshooting
Motor • Verify type of motor as a standard
squirrel cage induction motor
Energy Saver • Set Energy Saver Off, then restart.
–
–
Erratic Load • Check load conditions
Loose • Shut off all power to controller and
connections check for loose connections
Starting time • Increase starting time
Initial torque • Lower initial torque setting
Current limit • Decrease current limit setting
setting
Kickstart • Lower kickstart time or turn off
Starting time • Decrease starting time
Initial torque • Increase initial torque setting
Current limit • Increase current limit setting
setting
Kickstart • Increase kickstart time or turn off
Wiring • Check wiring and correct if
necessary
Failed fan(s) • Replace fan(s)
Time setting • Verify the programmed stopping
time and correct if or increase
Stopping time • Verify the programmed stopping
setting time and correct if necessary
Misapplication • The Soft Stop option is intended to
extend the stopping time for loads
that stop suddenly when power is
removed from the motor.
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
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.
Winding fault • Identify fault and correct.
• Check for shorted SCR; replace if
necessary.
• Ensure power terminals are secure.
10-5
Possible Solutions
If problem stops, replace
control module
If problem persists, shut off
all power to controller and
check connections