YASKAWA VS-626M5 Instruction Manual page 198

Troubleshooting
Fault
Motor does not rotate at Motor does not rotate at
commanded speed.
12
Extended acceleration/de-
celeration time
Heavy motor noise, vibration
Motor does not stop. Motor does not stop.
Table 12.3 Motor Faults and Corrective Actions (continued)
Cause
Speed reference signal error
Incorrect setting of motor rated speed
Incorrect adjustment of motor speed *
Speed is controlled by P control.
Torque limiting
Control PCB fault
Soft starter time setting error
(Set time is too long.)
Motor code selection error
Torque limiting
Excess load on load machine
Control PCB fault
Inverter output disconnection
Grounding error of motor or Inverter
Malfunction due to noise
(Poor encoder characteristics)
Control constant setting error
(especially speed control proportional gain)
Motor installation error
Unbalanced motor
Motor fault
(Motor bearing fault, rotor fault)
Defective load machine coupling or centering
Insufficient strength of load machine
Loose foundation bolts
Control PCB fault
Control signal does not operate.
Control PCB fault
* Enabled for stand-alone drives (M5A) only.
S Check speed reference on operating status display (U1-02).
S Readjust master speed reference function.
Check the setting of control constant C1-26.
Check the operating status display of the motor speed
(U1-01), and adjust the control constant (C1-12).
Check if PPI signal is input or not on operating status display
(U1-09).
Check whether external torque limit signals TLL or TLH is
input on operating status display (U1-09).
Replace the control PCB.
Check the setting of control constant C1-10.
Check the setting of control constant C1-25 on the setting
list.
Check whether external torque limit signals TLL or TLH is
input on operating status display (U1-09).
S Check load status on the load factor meter for loss and inertia
moment of the load machine.
S Increase the capacity of Inverter and motor.
Replace the control PCB.
Check wiring between Inverter and motor.
Check continuity of motor and Inverter to see if they are
securely grounded.
S Confirm that encoder signal lines are separated from Inverter
output wiring or other power lines.
S Check encoder cable specifications (whether the cable is a
shielded twisted-pair cable).
Check control constants on the setting list.
Check for loose mounting bolts.
S Check if rotor is balanced.
S Replace the motor.
S Run a motor alone to check if noise and vibration are within
specifications.
S Replace the motor.
Confirm that coupling and centering are appropriate accord-
ing to the connection with load machine.
Check the load machine for deformations or resonance.
Check for loose foundation bolts on load machine.
Replace the control PCB.
Confirm that operation signal (FWD or REV) is open on
operating status display (U1-09).
Replace the control PCB.
12 -14
Corrective Action