Allen-Bradley SMC-50, User Manual

Page: 163 / 292

Rockwell Automation Publication 1560F-UM001A-EN-P - June 2019 163
Troubleshooting Chapter 9
Table 61 - Motor Stops While Running
Display Possible Cause Possible Solutions
Fault displayed • See fault description • See addressing fault conditions
HIM display is blank
• Failed HIM
• Control voltage is absent
• Failed control module
• HIM connection is loose
• Replace HIM
• Check control wiring and correct if necessary
• Replace control module
• Check HIM connection
Stopped
0.0 Amps
• Pilot devices
• Failed control module
• Check control wiring and correct if necessary
• Replace control module
Starting
• One or more power phases are missing
• Failed control module
• Check power system
• Replace control module
Table 62 - Miscellaneous Situations
Display Possible Causes Possible Solutions
Motor current and voltage fluctuates with
steady load
• Motor
• Erratic Load
• Verity type of motor as a standard
squirrel cage induction motor
• 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
Motor stops too quickly with Soft Stop
option
• Time setting • Verify the programmed stopping time
and correct if necessary
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.
Motor overheats • Overload
• Blocked ventilation
• Allow motor to cool and reduce load.
• Remove blockage and ensure motor is
being adequately cooled.
Motor short circuit • Winding fault • Identify fault and correct
• Check for shorted SCR; replace if
necessary
• Ensure power terminals are secure
Motor coasts when option stop is
programmed
• Option not programmed
• Current loop power supply not active
• Incorrect control logic
• Bypass contactor set for delayed drop-
out
• Verify the option parameter settings
and correct if necessary
• Verify current loop power supply
• Verify connections to module terminals
16 and 17
• Verify that the Bypass Contactor is
configured for <100ms drop-out time.
For relay control, the FDO version
contactor is required; for IntelliVAC
control, set Drop-out time to 50 ms (no
PFCC) or 75 ms (if PFCC contactor in
same controller). For IntelliVAC settings,
refer to Chapter 4 of 1503-UM053 .