Yaskawa CIMR-PUxA User Manual
Page 142
Fast acceleration time causes the motor to
overshoot the speed reference
• Check if sudden drive acceleration triggers an overvoltage alarm.
• Increase the acceleration time.
• Use longer S-curve acceleration and deceleration times.
• Enable the Overvoltage Suppression function (L3-11 = 1).
• Lengthen the S-curve at acceleration end.
Excessive braking load
The braking torque was too high, causing regenerative energy to charge the DC bus. Reduce the braking
torque, use a dynamic braking option, or lengthen decel time.
Surge voltage entering from the drive input
power
Install a DC link choke.
Note:
Voltage surge can result from a thyristor convertor and phase advancing capacitor using
the same input power supply.
Ground fault in the output circuit causes the
DC bus capacitor to overcharge
• Check the motor wiring for ground faults.
• Correct grounding shorts and reapply power.
Improper parameters related to Speed Search
(including Speed Search after a momentary
power loss and after a fault restart)
• Check the settings for Speed Search-related parameters.
• Enable Speed Search restart function (b3-19 greater than or equal to 1 to 10).
• Adjust the current level during Speed Search and the deceleration time (b3-02 and b3-03 respectively).
• Perform Stationary Auto-Tuning for line-to-line resistance and then set b3-14 to 1 to enable Speed
Estimation Speed Search.
Drive input power voltage is too high
• Check the voltage.
• Lower drive input power voltage within the limits listed in the specifications.
The braking transistor or braking resistor are
wired incorrectly
• Check braking transistor and braking resistor wiring for errors.
• Properly rewire the braking resistor device.
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 is set incorrectly
• Check the load inertia settings when using KEB, overvoltage suppression, or Stall Prevention during
deceleration.
• Adjust the load inertia ratio in L3-25 to better match the load.
Motor hunting occurs
• Adjust the parameters that control hunting.
• Set the gain for Hunting Prevention (n1-02).
• Adjust the AFR time constant (n2-02 and n2-03).
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 is set 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 as specified in this manual.
Refer to Main Circuit Wire Gauges and
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.
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 main capacitor(s) if U4-05 is greater than 90%. For instructions on replacing the
capacitor(s), contact Yaskawa or a Yaskawa representative.
Check for problems with the drive input power. If drive input power appears normal but the alarm
continues to occur, replace either the control board or the entire drive. For instructions on replacing the
control board, contact Yaskawa or a Yaskawa representative.
rF
Braking Resistor Fault
The resistance of the braking resistor is too low.
rH
Braking Resistor Overheat
Braking resistor protection was triggered.
Fault detection is enabled when L8-01 = 1 (disabled as a default).
Cause
Possible Solution
5.2 Fault Detection
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YASKAWA ELECTRIC TOEP YAIP1U 01B YASKAWA AC Drive - P1000 Quick Start Guide