Yaskawa YASNAC PC NC Maintenance Manual - Manual (Page 95)

PC NC Maintenance Manual Chapter 4: Troubleshooting
4-74
The motor does not rotate
Cause and measures
The motor rotates slowly or not rotate because of vibration.
Cause and measures
Cause Measures
Security function drive Check the occurring fault by digital operator's security func-
tion drive display mode.
Main circuit disconnection /
improper connection Check wiring between the inverter and the motor.
The control signal is passive. Confirm the sequence input signal by the drive state display
(U1-09).
Drive preparation RDY,
Emergency stop EMG,
Drive FWD or REV
Check (U1-02) whether speed command SCOM is inputted.
Torque limit drive Check whether neither external limiting torque signal TLL
nor TLH are inputted.
Motor winding disconnection Check resistant value between motor terminals [circuit
tester is required)]
Exchange the motor with a non-defective one.
Motor fault
A fixed stator and rotor come in
contact.
Damage of bearing Confirm that motor shaft is turning by hand.
Exchange the motor with a non-defective one.
Control card fault Exchange unit (exchange control card)
Cause Measures
Main circuit disconnection /
improper connection Check wiring between the inverter and the motor.
Encoder signal conductor discon-
nection / improper connection / the
connector omission. Check encoder signal conductor wiring.
Motor encoder fault Confirm that there is no abnormal motor speed changes
by the speedometer indication or the drive state display
(U1-01). Exchange encoder or motor.
Speed command signal conductor
disconnection / improper connection Check speed command signal conductor wiring.
Torque limit drive Check whether neither external torque limit signal TLL
nor TLH are inputted.
Control card fault Exchange unit (exchange control card)