• Set the frequency around the motor rated slip frequency. Increase the setting value if the overvoltage protection function
(E.OV) is activated at the start of deceleration.
Rated motor slip frequency =
Adjusting the regeneration avoidance operation (Pr.665, Pr.886)
• If the frequency becomes unstable during regeneration avoidance operation, decrease the setting of Pr.886 Regeneration
avoidance voltage gain. On the other hand, if an overvoltage fault occurs due to a sudden regeneration, increase the
• If setting a smaller value in Pr.886 does not suppress the vibration, set a smaller value in Pr.665 Regeneration avoidance
• During the regeneration avoidance operation, the stall prevention (overvoltage) "oL" is displayed and the Overload warning
(OL) signal is output. Set the operation pattern at an OL signal output using Pr.156 Stall prevention operation selection.
Use Pr.157 OL signal output timer to set the OL signal output timing.
• The stall prevention is enabled even during regeneration avoidance operation.
• The regeneration avoidance function cannot decrease the actual deceleration time for the motor to stop. Since the actual
deceleration time is determined by the regenerative power consumption performance, consider using a regeneration unit (FR-
BU2, BU, FR-BU, FR-CV, or FR-HC2) to decrease the deceleration time.
• When using a regeneration unit (FR-BU2, BU, FR-BU, FR-CV, or FR-HC2) to consume the regenerative power at constant
speed, set Pr.882 = "0 (initial value)" to disable the regeneration avoidance function. When consuming the regenerative power
at the time of deceleration with the regeneration unit, etc., set Pr.882 = "2" (enables regeneration avoidance function only at
the constant speed).
Parameters referred to
Pr.22 Stall prevention operation
5.13.13 Increased magnetic excitation deceleration
Increase the loss in the motor by increasing the magnetic flux during deceleration. The deceleration time can be reduced by
suppressing the stall prevention (overvoltage) (oL).
The deceleration time can further be shortened without a brake resistor.
excitation current level
Setting of increased magnetic excitation rate (Pr.660, Pr.661)
• To enable the increased magnetic excitation deceleration, set Pr.660 Increased magnetic excitation deceleration
operation selection = "1".
Synchronized speed at the time of base frequency – rated rotation speed
Synchronized speed at the time of base frequency
Output frequency (Hz)
0 to 40%
0 to 300%
Without the increased magnetic excitation deceleration function
With the increased magnetic excitation deceleration function
Set the increase of excitation.
and Advanced magnetic flux vector control.
The increased magnetic excitation rate is automatically lowered
when the output current exceeds the setting value during increased
magnetic excitation deceleration.
× Rated motor frequency
5.13 (G) Control parameters