YASKAWA U1000 Series Technical Manual page 362

6.4 Fault Detection
Digital Operator Display
Cause
Load is too heavy.
Cycle times are too short during acceleration and
deceleration.
A general purpose motor is driven below the rated speed
with too high load.
V/f characteristics (voltage and frequency) are not
suitable.
The wrong motor rated current is set to E2-01.
Multiple motors are running off the same drive.
The electrical thermal protection characteristics and
motor overload characteristics do not match.
The electrical thermal relay is operating at the wrong
level.
Motor overheated by overexcitation operation.
Speed Search related parameters are set incorrectly.
Output current fluctuation due to power supply loss
Digital Operator Display
Cause
Load is too heavy.
Acceleration or deceleration times are too short.
A V/f characteristic (voltage) is not suitable.
Drive capacity is too small.
Overload occurred when operating at low speeds.
Excessive torque compensation.
Speed Search related parameters are set incorrectly.
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
Overtorque triggered mechanical weakening detection
level set to L6-08.
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Motor Overload
oL1
The electronic motor overload protection tripped.
Reduce the load.
Note: After the value of U4-16 has decreased to one less than 100, reset oL1. The value of U4-16 must be less than 100 before
oL1 can be reset.
Increase the acceleration and deceleration times (C1-01 through C1-08).
• Reduce the load.
• Increase the speed.
• If the motor is supposed to operate at low speeds, either increase the motor capacity or use a motor specifically designed to
operate in the desired speed range.
Set the V/f pattern setting parameters E1-04 through E1-10 so that they match the motor characteristics.
• Check the motor-rated current.
• Enter the value written on the motor nameplate to parameter E2-01.
Disable the motor protection function (L1-01 = 0) and install a thermal relay to each motor.
• Check the motor characteristics.
• Correct the type of motor protection that has been selected (L1-01).
• Install an external thermal relay.
• Check the current rating listed on the motor nameplate.
• Check the value set for the motor rated current (E2-01).
• Overexcitation increases the motor losses and the motor temperature. If applied too long, motor damage can occur. Prevent
excessive overexcitation operation or apply proper cooling to the motor.
• Reduce the excitation deceleration gain (n3-13).
• Set L3-04 (Stall Prevention during Deceleration) to a value other than 4.
• Check values set to Speed Search related parameters.
• Reduce the Speed Search Operation Current Level 1 (Current Detection Type 3, Current Detection Type 3, Speed Estimation
Type 2) (b3-31).
• After Auto-Tuning, enable Speed Estimation Speed Search (b3-24 = 1).
Check the power supply for phase loss.
Drive Overload
oL2
The thermal sensor of the drive triggered overload protection.
Reduce the load.
Increase the settings for the acceleration and deceleration times (C1-01 through C1-08).
Set the V/f pattern setting parameters E1-04 through E1-10 so that they match the motor characteristics.
Use a larger drive.
• Reduce the load when operating at low speeds.
• Use a larger drive.
• Lower the carrier frequency (C6-02).
Reduce the torque compensation gain (C4-01) until there is no speed loss but less current.
• Check the settings for all Speed Search related parameters.
• Adjust the current used during the Speed Search deceleration time (b3-03).
• Reduce the Speed Search Operation Current Level 1 (Current Detection Type 3, Current Detection Type 3, Speed Estimation
Type 2) (b3-31).
• After Auto-Tuning the drive, enable the Speed Estimation Speed Search (b3-24 = 1).
Check the power supply for phase loss.
Overtorque Detection 1
oL3
The current has exceeded the value set for torque detection level 1 (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 torque detection level 2 (L6-05) for longer than the allowable time (L6-06).
Check the settings of parameters L6-05 and L6-06.
Mechanical Weakening Detection 1
oL5
Overtorque occurred, matching the conditions specified in L6-08.
Check for the cause of mechanical weakening.
Fault Name
Possible Solution
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Possible Solution
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Possible Solution
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Possible Solution
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Possible Solution
YASKAWA ELECTRIC SIEP C710636 02B YASKAWA U1000 Technical Manual