Yaskawa P7 Drive User Manual - Manual (Page 160)

Diagnostic & Troubleshooting 6 - 16
The motor stops during acceleration or when a load is connected.
The load may be too high. The Drive has a stall prevention function and an automatic torque boost function, but the motor
responsiveness limit may be exceeded if acceleration is too rapid or if the load is too great. Lengthen the acceleration time
(CI-01) or reduce the load. Also consider increasing the motor size.
The motor only rotates in one direction.
“Reverse run prohibited” may be selected. If b1-04 (Prohibition of Reverse Operation) is set to 1 (reverse run prohibited), the
Drive will not receive reverse run commands. This is the default to use both forward and reverse operation, set b1-04 to 0, and
operate in Auto mode.
The Direction of the Motor Rotation is Reversed
If the motor rotates in the wrong direction, the motor output wiring is incorrect. When the Drive U/T1, V/T2, and W/T3
terminals are properly connected to the motor, the motor operates in a forward direction when a forward run command is
received. The forward direction depends on the manufacturer and the motor type, so be sure to check the specifications.
The direction of rotation can be reversed by switching any two wires among U/TI, V/T2, and W/T3.
If the Motor Does Not Put Out Torque or If Acceleration is Slow
Use the following information if the motor does not output torque or if acceleration is too slow.
The stall prevention level during acceleration is too low.
If the value set for L3-02 (Stall Prevention Acceleration Level) is too low, the acceleration time will be too long. Check to be
sure that the set value is suitable.
The stall prevention level during running is too low.
If the value set for L3-06 (Stall Prevention Level during Running) is too low, the motor speed and torque will be limited.
Check to be sure that the set value is suitable.
If the Motor Operates at a Higher Speed Than the Speed Command
Use the following information if the motor operates at a higher speed than the Speed Command.
A signal is being input to the Speed Command (current) terminal A2.
If a preset frequency reference is selected, the preset reference takes priority over the normal reference.
If the PI mode of operation is enabled, the drive output frequency will change to regulate the process variable to the desired
setpoint. Then, the Drive speed may go to maximum.