Troubleshooting
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The motor only rotates in one direction.
“Reverse run prohibited” is selected. If b1-04 (Prohibition of Reverse Operation) is set to 1 (reverse run pro-
hibited), the Inverter will not receive Reverse Run Commands. To use both forward and reverse operation, set
b1-04 to 0.
If the Direction of the Motor Rotation is Reversed
If the motor operates in the wrong direction, the motor output wiring is faulty. When the Inverter T1 (U), T2
(V), and T3 (W) are properly connected to the motor T1 (U), T2 (V), and T3 (W), the motor operates in a for-
ward direction when a Forward Run Command is executed. The forward direction depends on the manufac-
turer and the motor type, so be sure to check the specifications.
The direction of rotation can be reversed by switching two wires among T1 (U), T2 (V), and T3 (W).
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 torque limit has been reached.
When a torque limit has been set in constants L7-01 to L7-04, no torque will be output beyond that limit. This
can cause the torque to be insufficient, or the acceleration time to be too long. Check to be sure that the value
set for the torque limit is suitable.
If torque limits have been set for the multi-function analog input (H3-05 or H3-09 = 10 to 12 or 15), check to
be sure that the analog input value is suitable.
The stall prevention level during acceleration is too low.
If the value set for L3-02 (Stall Prevention Level during Acceleration) 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 speed will drop before out-
putting torque. Check to be sure that the set value is suitable.
Autotuning has not been performed for vector control
Vector control will not perform if autotuning has not been performed. Perform autotuning separately for the
motor, or set the motor constants through calculations. Alternatively, change the Control Method Selection
(A1-02) to V/f control (0 or 1).
If the Motor Operates Higher Than the Reference
Use the following information if the motor operates higher than the reference.
