YASKAWA A1000 Series Technical Manual page 315

Digital Operator Display
Cause
Excessive load inertia.
Motor is driven by the load.
Something on the load side is restricting deceleration.
The overload time during High Slip Braking is too short.
Digital Operator Display
Cause
External operator is not properly connected to the drive.
Digital Operator Display
Cause
Overshoot is occurring.
Incorrect speed feedback scaling if terminal RP is used
as speed feedback input in V/f control.
Incorrect number of PG pulses has been set.
Inappropriate parameter settings.
Digital Operator Display
Cause
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 causing the DC bus
capacitor to overcharge.
Improper Setting of Speed Search related parameters.
(Includes Speed Search after a momentary power loss
and after a fault restart.)
Drive input power voltage is too high.
The braking transistor is 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 has been set incorrectly.
Braking function is being used in OLV/PM.
Motor hunting occurs.
YASKAWA ELECTRIC SIEP C710616 27C YASKAWA AC Drive A1000 Technical Manual
High Slip Braking oL
oL7
The output frequency stayed constant for longer than the time set in n3-04 during High Slip Braking.
• Reduce deceleration times in parameters C1-02, C1-04, C1-06, and C1-08 for applications that do not use High Slip Braking.
• Use a braking resistor to shorten deceleration time.
• Increase parameter n3-04 (High-slip Braking Overload Time).
• Install a thermal relay and increase the setting of n3-04 to the maximum value.
External Digital Operator Connection Fault
• The external operator has been disconnected from the drive.
oPr
Note: An oPr fault will occur when all of the following conditions are true:
• Output is interrupted when the operator is disconnected (o2-06 = 1).
• The Run command is assigned to the operator (b1-02 = 0 and LOCAL has been selected).
• Check the connection between the operator and the drive.
• Replace the cable if damaged.
• Turn off the drive input power and disconnect the operator. Next reconnect the operator and turn the drive input power back on.
Overspeed (for Control Mode with PG)
oS
The motor speed feedback exceeded the F1-08 setting.
• Increase the settings for C5-01 (Speed Control Proportional Gain 1) and reduce C5-02 (Speed Control Integral Time 1).
• If using a Closed Loop Vector mode, enable Feed Forward and perform Inertia Auto-Tuning.
• Set H6-02 to the value of the speed feedback signal frequency when the motor runs at the maximum speed.
• Adjust the input signal using parameters H6-03 through H6-05.
• Check and correct parameter F1-01.
Check the setting for the overspeed detection level and the overspeed detection time (F1-08 and F1-09).
Overvoltage
Voltage in the DC bus has exceeded the overvoltage detection level.
ov
• For 200 V class: approximately 410 V
• For 400 V class: approximately 820 V
• Increase the deceleration time (C1-02, C1-04, C1-06, C1-08).
• Install a dynamic braking option.
• Enable stall prevention during deceleration (L3-04 = 1).
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 reactor.
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 turn the power back on.
• 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 enable Speed Estimation Speed Search (b3-24 = 1).
• Check the voltage.
• Lower drive input power voltage within the limits listed in the specifications.
• Check braking transistor 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 the output lines from the drive).
• 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.
• 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.
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).
• Adjust the speed feedback detection suppression gain for PM motors (n8-45) and the time constant for pull-in current (n8-47).
6.4 Fault Detection
Fault Name
Possible Solution
Fault Name
Possible Solution
Fault Name
Possible Solution
Fault Name
Possible Solution
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