YASKAWA T1000V Technical Manual page 279

■ Motor Operates at a Higher Speed than the Speed Command
Cause
PID is enabled. If the PID mode is enabled (b5-01 =
1 to 4), the drive output frequency will change to
regulate the process variable to the target setpoint.
The PID can command a speed up to maximum
output frequency (E1-04).
Poor Speed Control Accuracy Above Base Speed in Open Loop Vector Motor Control
■
Method
Cause
The maximum output voltage of the drive is
determined by its input voltage. Vector control uses
voltage to control the currents within the motor. If
the vector control voltage reference value exceeds
the drive output voltage capability, the speed
control accuracy will decrease because the motor
currents cannot be properly controlled.
■ Peripheral Devices Affected by Drive Operation
Cause
Radio frequency interference may be generated by
drive output PWM waveform.
■ Ground Fault Interrupter Activates When Drive is Running
Cause
The output of the drive is a series of high frequency
pulses (PWM), so there is a certain amount of
leakage current. This may cause the ground fault
interrupter to operate and cut off the drive input
power.
YASKAWA ELECTRIC SIEP C710606 44B YASKAWA AC Drive T1000V Technical Manual
If PID operation is not target, disable PID by setting b5-01 = "0".
Use a motor with a lower rated voltage compared to the input voltage.
• Change the Carrier Frequency Selection (C6-02) to lower the carrier frequency. This will
help to reduce the amount of transistor switching noise.
• Install an Input Noise Filter at the input power terminals.
• Install an Output Noise Filter at the motor terminals.
• Use conduit. Metal can shield electrical noise.
• Ground the drive and motor.
• Separate main circuit wiring from control wiring.
• Change to a ground fault interrupter with a higher leakage current detection level (such as,
a sensitivity current of 200 mA or greater per Unit, with an operating time of 0.1 s or more),
or one that incorporates high-frequency corrective actions.
• Change the Carrier Frequency Selection (C6-02) to lower the carrier frequency.
Note: Leakage current increases in proportion to cable length.
6.9 Troubleshooting without Fault Display
Possible Solution
Possible Solution
Possible Solutions
Possible Solutions
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