Yaskawa YASNAC PC NC Maintenance Manual - Manual (Page 96)

Chapter 4: Troubleshooting PC NC Maintenance Manual
4-75
The motor reverses
Cause and measures
The motor does not rotate at the command speed.
Cause and measures
The acceleration/declaration time is long.
Cause and measures
Cause Measures
Main circuit and motor encoder signal conduc-
tor improper connection Check wiring according to the interconnecting wir-
ing chart.
Cause Measures
Speed command signal error Check the speed command by the drive state display function
(U1-02).
Readjust the host speed command function.
Motor rated speed improper setting Confirm the control parameter (C1-26) setting and refer to the
setting list.
Motor speed adjustment is defective. Check the motor speed by the drive state display function
(U1-01).
Adjust the motor speed by the control parameter (C1-12)
(Refer to P157).
Speed control is P control Check whether the PPI signal is not inputted by the drive
state display function (U1-09).
Torque control drive Check whether neither external torque limit signal TLL nor
TLH are inputted.
Control card fault Exchange unit (exchange control card)
Cause Measures
Software starting time setting is
defective. (Setting time is long) Confirm the control parameter (C1-10) setting and refer to the
setting list.
Motor code improper selection Confirm the control parameter (C1-25) setting and refer to the
setting list.
Torque control drive Check whether neither external limiting torque signal TLL nor
TLH are input.
Load machine overload Check the load state for the load factor meter state to examine
the load machine loss and inertia moment, etc.
Raise the drive capacity of the inverter and the motor.
Control card fault Exchange unit (exchange control card)