Rockwell Automation 7763 Medium Voltage OneGear SMC Flex Motor Controller (10-15 kV) - Manual (Page 101)

Rockwell Automation Publication 7760-UM001D-EN-P - October 2014 101
Troubleshooting Chapter 8
Table 38 - Motor Stops While Running
Table 39 - Irregular Starts
Note: Although the default settings accommodate the vast majority of
applications, these tuning parameters may require more than one adjustment to
achieve optimal results. Some parameters are affected by motor loading and
power system conditions, so one setting may not be optimal for all conditions.
Table 40 - Miscellaneous Situations
(1)
Display Possible Causes Possible Solutions
Fault displayed • See fault description • See Table 35 addressing fault conditions
Display is blank • Control voltage is absent
• Failed control module • Check control wiring and correct if necessary
• Replace control module
Stopped 0.0 A • Pilot devices
• Failed control module • Check control wiring and correct if necessary
• Replace control module
Starting • Two or three power phases are missing
• Failed control module • Check power system
• Check voltage sensing module and connections
• Replace control module
Symptom Possible Causes Possible Solutions
Bypass contactor closes before motor is up to speed • Ramp time too short
• Motor characteristics cause Up-to-Speed sensing too
early
• Increase ramp time (parameter 18)
• Adjust parameter 114 higher (no more than 5% at a
time)
Motor is up to speed but bypass contactor is delayed in
closing or does not close at all • Ramp time too long
• Motor characteristics cause Up-to-Speed sensing too
late or not at all
• Decrease ramp time
• Adjust parameter 114 lower (no more than 5% at a
time)
Rough start, erratic current, growling from the motor
(may see Line Faults) • Poor grounding of the power system or controller
• Poor power quality, electrical noise, harmonics, VFD
line notching
• Resolve ground issues
• Adjust parameter 117 higher. Typical settings are 35 or
40. Not recommended to exceed 75 or go below 25.
During a Pump Stop, the motor takes more than 5 seconds
to begin to decelerate or takes longer than the
programmed stop time • Motor or pump characteristics do not match the
default setting
• Adjust parameter 34 to between 20 and 30 (not
recommended to go above 40).
(1) Various faults may occur if Parameter #15 is set to "Delta". It must be set to "Line" for all MV applications.
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
Fan does not operate • Wiring
• Failed fans(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
necessary