If The Motor Rotates Even When Inverter Output Is Stopped; If Output Frequency Does Not Rise To Frequency Reference; If Ov Is Detected When The Fan Is Started, Or Fan Stalls - YASKAWA Varispeed CIMR-G7A Instruction Manual

Reduce the setting for N4-11 to a value less than the factory setting. Reduce the setting in intervals of
•
approximately 5 Hz.
If shock occurs during deceleration:
•
Increase the deceleration time within the allowable range. Alternatively, reduce the torque limit.
•
Reduce the setting for N4-28 to a value less than the factory setting. Reduce the setting in intervals of
•
approximately 5 Hz.
The factory settings for N4-11 (speed estimator switching frequency) and N4-28 (speed estimator switching
frequency 2) are 70 Hz and 50 Hz respectively. If the problem still occurs after making the above adjustments,
use open-loop vector 1 control (A1-02 = 2).
If Torque Ripple Occurs at Very Low Speeds in Open-loop Vector 2 Con-
trol (PRG: 102
Either increase the operating frequency or use open-loop vector 1 control (A1-02 = 2).

If the Motor Rotates Even When Inverter Output is Stopped

If the motor rotates even when the Inverter output is stopped, the DC injection braking is insufficient. If the
motor continues operating at low speed, without completely stopping, and after a deceleration stop has been
executed, it means that the DC injection braking is not decelerating enough. Adjust the DC injection braking
as follows:
Increase the constant b2-02 (DC Injection Braking Current) setting.
•
Increase the constant b2-04 (DC Injection Braking (initial excitation) Time at Stop) setting.
•

If OV is Detected When the Fan is Started, or Fan Stalls

Generation of OV (main circuit voltage) and stalling can occur if the fan is turning when it is started. The DC
injection braking is insufficient when starting.
This can be prevented by slowing fan rotation by DC injection braking before starting the fan. Increase the
constant b2-03 (DC injection braking time (initial excitation) at start) setting.

If Output Frequency Does Not Rise to Frequency Reference

Use the following information if the output frequency does not rise to the frequency reference.
The frequency reference is within the jump frequency range.
When the jump frequency function is used, the output frequency does not change within the jump frequency
range. Check to be sure that the Jump Frequency (constants d3-01 to d3-03) and Jump Frequency Width (con-
stant d3-04) settings are suitable.
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