Download Medium Voltage OneGear SMC Flex Motor Controller

Chapter 8
Troubleshooting
Display
Possible Causes
Possible Solutions
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
• Duty cycle
• Allow motor to cool and reduce load.
• Remove blockage and ensure motor is being
adequately cooled.
• 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
Motor coasts when option stop is programmed
• Option not programmed
• Current loop power supply not active
• Incorrect control logic
• Verify the option parameter settings and correct if
necessary
• Verify current loop power supply (see Resistance
Checks and Power Supply Tests)
• Verify connections to module terminals 16 and 17 (see
Functional Description on page 44)
Note: For Pump Stop issues, please refer to Pump Application Considerations on
page 39.
Control Module Removal
The control module is not intended for field repair. The entire module must be
replaced in the event of failure. The following procedure must be followed before
unplugging the control module.
1. Remove all power from the equipment.
SHOCK HAZARD: To avoid shock hazard, ensure the main power has been
disconnected before working on the controller, motor or control devices. Verify
that all circuits are voltage free using a hot stick or appropriate voltage
measuring device. Failure to do so may result in burns, injury or death.
2. Make sure that the wires are properly marked and that the program
parameters are recorded.
3. Disconnect all control wires to control module.
4. Loosen the four control module screws.
5. Carefully rotate the module to the left, and unplug the five ribbon cables
from the interface board.
102
Rockwell Automation Publication 7760-UM001E-EN-P - December 2014