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Digital Operator Display
Fault Name
Drive fails to operate properly due to noise
interference.
• Review the list of possible solutions provided for controlling noise.
• Review the section on handling noise interference and check the control circuit lines, main circuit lines
and ground wiring.
Load inertia has been set incorrectly.
• Check the load inertia settings when using KEB, overvoltage suppression or Stall Prevention during
deceleration.
• Adjust L3-25 (Load Inertia Ratio) in accordance with the load.
Braking function is being used in PM Open
Loop Vector Control.
Connect a braking resistor.
Motor hunting occurs.
• Adjust the parameters that control hunting.
• Set the hunting prevention gain (n1-02).
• Adjust the AFR time constant 1 (n2-02) and the AFR time constant 2 (n2-03) when in OLV Control.
• Use parameters n8-45 (PM Speed Feedback Detection Suppression Gain)
and n8-47 (Pull-In Current Compensation Time Constant).
Digital Operator Display
Fault Name
PF
Input Phase Loss
Drive input power has an open phase or has a large imbalance of voltage between phases. Detected when
L8-05 = 1 (enabled).
Cause
Possible Solution
There is phase loss in the drive input power.
• Check for wiring errors in the main circuit drive input power.
• Correct the wiring.
There is loose wiring in the drive input power
terminals.
• Ensure the terminals are tightened properly.
• Apply the tightening torque specified in this manual to fasten the terminals.
and Tightening Torques on page 58
for details.
There is excessive fluctuation in the drive
input power voltage.
• Check the voltage from the drive input power.
• Review the possible solutions for stabilizing the drive input power.
• Disable Input Phase Loss Detection (L8-05 = “0”). PF is detected if DC bus ripple is too high. If it is
disabled, there is no fault but the ripple is still too high, thereby the capacitors are stressed more and
lose lifetime.
There is poor balance between voltage phases. • Stabilize drive input power or disable phase loss detection.
The main circuit capacitors are worn.
• Check the maintenance time for the capacitors (U4-05).
• Replace the drive if U4-05 is greater than 90%.
• Check for anything wrong with the drive input power.
• If nothing is wrong with the drive input power, try the following solutions if the alarm continues:
• Disable Input Phase Loss Protection selection (L8-05 = “0”). PF is detected if DC bus ripple is too high.
If it is disabled, there is no fault but the ripple is still too high, thereby the capacitors are stressed more
and lose lifetime.
• Replace the drive.
Digital Operator Display
Fault Name
PGo
PG Disconnect (for Simple V/f with PG)
No PG pulses are received for longer than the time set to F1-14.
Cause
Possible Solution
Pulse input (RP) is disconnected.
Reconnect the pulse input (RP).
Pulse input (RP) wiring is wrong.
Correct the wiring.
Motor brake engaged.
Ensure the motor brake releases properly.
Digital Operator Display
Fault Name
rH
Braking Resistor Overheat
Braking resistor protection was triggered.
Fault detection is enabled when L8-01 = 1 (disabled as a default).
Cause
Possible Solution
Deceleration time is too short and excessive
regenerative energy is flowing back into the
drive.
• Check the load, deceleration time and speed.
• Reduce the load.
• Increase the acceleration and deceleration times (C1-01 through C1-08).
• Replace the braking option with a larger device that can handle the power that is discharged.
6.4 Fault Detection
278
YASKAWA ELECTRIC SIEP C710606 18F YASKAWA AC Drive – V1000 Technical Manual