User Manual
Preventive Maintenance and
Troubleshooting Common Drive Problems
Appendix B
B-10
2. The motor will not run continuously -- OC
is displayed.
Does a short circuit exist in the output leads or motor windings?
Remove the cause of the short circuit.
Yes
Does
a ground fault
exist between the drive output leads and the motor or in
the
motor windings?
No
Remove the cause of the ground fault.
Is the application a fan or pump system?
Does the drive trip when the speed reference is below 5.0Hz?
Is the acceleration time too short? Is Parameter 17, Accel Frequency Hold
off?
Is
the load within the rated current of the drive?
No
No
No
Yes
Yes
Yes
No
Reduce
the boost
setting
in
Parameter 5.
Yes
Change
the V/Hz ramp to
variable by setting
Parameter 4 to 1, then
reduce the boost level
setting in Parameter 5 if
required.
Increase
the value of Accel T
ime 1 Parameter 1,
or set Parameter 17 Accel
Frequency
Hold on.
No
Program Parameter 46 Current Limit to eliminate nuisance tripping, lighten
the
load, or resize the drive and motor to meet your application.
Is OC displayed even if the drive output leads are disconnected?
No
Verify
motor operation by line operating the motor or repeating the above.
Is
the
motor now operating correctly?
No
Contact your nearest AB representative for application assistance.
Yes
Yes
Yes