6. Description of Parameters    
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6.5.2  Torque Boost 
The torque compensation function compensates for insufficient torque production at low 
frequency.
Function Code Parameter Name Setting Range Default
F3-01
Torque boost 0.0%: No torque boost
0.1% to 30%
Model 
dependent
F3-02
Cut-off frequency of 
torque boost
0.00 Hz to max. frequency 50.00 Hz
F3-01 compensates for insufcient torque production by boosting output voltage of the AC drive. 
But very large setting will result in motor overheat and AC drive overcurrent.
 ● On starting a heavy load and insufcient torque is experienced, increase the torque boost in 
F3-01.
 ● Decrease this parameter on light loads to avoid overheating the motor.
F3-02 sets the cutoff frequency. The torque boost function is disengaged when the output 
frequency exceeds the cutoff point.
6.5.3  Current Limit Control
When output current exceeds the value set in F3-18 during acceleration, constant running or 
deceleration, current limit is enabled and output frequency starts to drop. Until output current 
recovers below the current limit level, output frequency starts to rise to target frequency again.
Figure 6-40 Current limit
Current limit level
150%
Current limit during 
acceleration
t
t
Output current
Current limit 
during RUN
Current limit during 
deceleration
Output frequency