YASKAWA Varispeed G7 Series User Manual

7 -36
• 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 only)
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.
TOE-S616-60.1.book 36 ページ ２０１７年８月４日 金曜日 午後３時４１分

YASKAWA Varispeed G7 Series Specifications

General

Brand	YASKAWA
Model	Varispeed G7 Series
Category	Inverter
Language	English