YASKAWA A1000 HHP Programming Manual page 197

Deceleration time is too short and regenerative
energy is flowing from the motor into the drive
Fast acceleration time causes the motor to
overshoot the speed reference
Excessive braking load
Surge voltage entering from the drive input
power
Ground fault in the output circuit causes the
DC bus capacitor to overcharge
Improper parameters related to Speed Search
(including Speed Search after a momentary
power loss and after a fault restart)
Drive input power voltage is too high
The braking transistor or braking resistor are
wired incorrectly
PG cable is disconnected
PG cable wiring is wrong
Noise interference along the PG encoder
wiring
Drive fails to operate properly due to noise
interference
Load inertia is set incorrectly
Braking function is being used in OLV/PM
Motor hunting occurs
Digital Operator Display
Cause
There is phase loss in the drive input power
There is loose wiring in the drive input power
terminals
There is excessive fluctuation in the drive
input power voltage
There is poor balance between voltage phases Stabilize drive input power or disable phase loss detection.
YASKAWA ELECTRIC SIEP YEAHHP 01B YASKAWA AC Drive – A1000 HHP Programming Manual
• Increase the deceleration time (C1-02, C1-04, C1-06, C1-08).
• Install a dynamic braking resistor or a dynamic braking resistor unit.
• Set L3-04 to 1 to enable stall prevention during deceleration. Stall Prevention is enabled as the default
setting.
• 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.
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.
Install a DC link choke.
Note: Voltage surge can result from a thyristor convertor and phase advancing capacitor using
the same input power supply.
• Check the motor wiring for ground faults.
• Correct grounding shorts and reapply power.
• 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.
• Check the voltage.
• Lower drive input power voltage within the limits listed in the specifications.
• Check braking transistor and braking resistor wiring for errors.
• Properly rewire the braking resistor device.
Reconnect the cable.
Correct the wiring.
Separate the wiring from the source of the noise. Often, this is the output lines from the drive.
• Review the list of possible solutions provided for controlling noise.
• Review the section on handling noise interference on page
main circuit lines, and ground wiring.
• Check the load inertia settings when using KEB, overvoltage suppression, or Stall Prevention during
deceleration.
Connect a braking resistor.
• Adjust the parameters that control hunting.
• Set the gain for Hunting Prevention (n1-02).
• Adjust the AFR time constant (n2-02 and n2-03).
Input Phase Loss
PF
Drive input power has an open phase or has a large imbalance of voltage between phases. Detected when
L8-05 is set 1 (enabled).
• Check for wiring errors in the main circuit drive input power.
• Correct the wiring.
• Ensure the terminals are tightened properly.
• Check for loose terminals.
• Check the voltage from the drive input power.
• Review the possible solutions for stabilizing the drive input power.
231 and check the control circuit lines,
Fault Name
Possible Solution
2.4 Fault Detection
2
197