YASKAWA L1000A Technical Manual page 265

Accel/decel ramp is too short.
The output voltage is too high.
Drive capacity is too small.
Overload occurred when operating at low speeds.
Excessive torque compensation.
Output current fluctuation due to input phase loss
Digital Operator Display
Cause
Parameter settings are not appropriate for the load.
Fault on the machine side (e.g., machine is locked up).
Digital Operator Display
Cause
Parameter settings are not appropriate for the load.
Digital Operator Display
Cause
External operator is not properly connected to the drive.
Digital Operator Display
Cause
Overshoot is occurring.
Inappropriate parameter settings.
Digital Operator Display
Cause
Deceleration ramp is too short and regenerative energy
is flowing from the motor into the drive.
Fast acceleration ramp causes the motor to overshoot the
speed reference.
Surge voltage entering from the drive input power.
Ground fault in the output circuit causes the DC bus
capacitor to overcharge.
Drive input power voltage is too high.
The braking transistor is wired incorrectly.
Encoder cable is disconnected.
Encoder cable wiring is wrong.
Noise interference along the encoder wiring.
Drive fails to operate properly due to noise interference.
Motor hunting occurs.
YASKAWA ELECTRIC SIEP C710616 38A YASKAWA AC Drive L1000A Technical Manual
Increase the settings for the acceleration and deceleration times (C1-01 through C1-08).
• Adjust the preset V/f pattern (E1-04 through E1-10) by reducing E1-08 and E1-10.
• Do not lower E1-08 and E1-10 excessively. This reduces load tolerance at low speeds.
Replace the drive with a larger model.
• Reduce the load when operating at low speeds.
• Replace the drive with a model that is one frame size larger.
• Lower the carrier frequency (C6-03).
Reduce the torque compensation gain (C4-01) until there is no speed loss but less current.
Check the power supply for phase loss.
Overtorque Detection 1
oL3
The current has exceeded the value set for torque detection (L6-02) for longer than the allowable time (L6-03).
Check the settings of parameters L6-02 and L6-03.
Check the status of the load. Remove the cause of the fault.
Overtorque Detection 2
oL4
The current has exceeded the value set for Overtorque Detection 2 (L6-05) for longer than the allowable time (L6-06).
Check the settings of parameters L6-05 and L6-06.
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 Up/Down 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. Then reconnect the operator and turn the drive input power back on.
Overspeed (for Control Mode with Encoder)
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 Inertia Compensation.
Check the setting for the overspeed detection level and the overspeed detection time (F1-08 and F1-09).
DC Bus 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 ramp (C1-02, C1-04, C1-06, C1-08).
• Make sure the braking resistor rating/external braking transistor rating fits the application.
• If an external braking transistor is used, make sure it is connected properly and working as expected.
• Check if sudden drive acceleration triggers an overvoltage alarm.
• Increase the acceleration ramp (C1-01, C1-03, C1-05, C1-07).
• Increase the jerk setting in C2-02 (decrease if o1-03 > 3)
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 turn the power back on.
• 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.
• Adjust the parameters that control hunting.
• Adjust the AFR time constant (n2-02 and n2-03).
6.3 Fault Detection
Fault Name
Possible Solution
Fault Name
Possible Solution
Fault Name
Possible Solution
Fault Name
Possible Solution
Fault Name
Possible Solution
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