Yaskawa G7 Drive - Manual (Page 403)

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‹ If the Motor Operates Higher Than the Reference
Use the following information if the motor operates higher than the reference.
„ The analog frequency reference bias setting is wrong (the gain setting is wrong).
The frequency reference bias set in parameter H3-03 is added to the frequency reference. Check to be sure that
the set value is suitable.
„ A signal is being input to the frequency reference (current) terminal A1.
When 1F (frequency reference) is set for parameter H3-09 (Multi-function Analog Input Terminal A2 Func-
tion Selection), a frequency corresponding to the terminal A2 input voltage (current) is added to the frequency
reference. Check to be sure that the set value and analog input value are suitable.
‹ If the Slip Compensation Function Has Low Speed Precision
If speed control accuracy is low for the slip compensation function, the slip compensation limit has been
reached. With the slip compensation function, compensation cannot be carried out beyond the slip compensa-
tion limit set in parameter C3-03. Check to be sure that the set value is suitable.
‹ If There is Low Speed Control Accuracy at High-speed Rotation in Open-
loop Vector Control Mode
The motor's rated voltage is high.
The Drive's maximum output voltage is determined by its input voltage. (For example, if 200 Vac is input,
then the maximum output voltage will be 200 Vac.) If, as a result of vector control, the output voltage refer-
ence value exceeds the Drive output voltage maximum value, the speed control accuracy will decrease. Use a
motor with a low rated voltage (i.e., a special motor for use with vector control), or change to flux vector con-
trol.