YASKAWA A1000 Technical Manual page 348

6.4 Fault Detection
Digital Operator Display
Cause
Motor has been damaged from overheat or the motor
insulation has been weakened.
The cable is damaged and is coming into contact with
something causing a short-circuit.
Hardware fault.
Digital Operator Display
Cause
Speed Search parameters are set to the wrong values.
The motor is coasting in the opposite direction of the
Run command.
Digital Operator Display
Cause
The wrong motor code is set (YASKAWA motors only).
Load is too heavy.
Load inertia is too heavy.
Acceleration and deceleration times are too short.
Speed response is too slow.
Digital Operator Display
Cause
Torque limit is set too low.
Excessive load torque.
Electrical signal interference along PG encoder wiring.
Digital Operator Display
<2>
Cause
The motor thermistor is not connected properly.
Digital Operator Display
Cause
Parameter settings are not appropriate for the load.
There is a fault on the machine side.
Digital Operator Display
Cause
Parameter settings are not appropriate for the load.
There is a fault on the machine side.
Digital Operator Display
Cause
Undertorque was detected and matched the conditions
for mechanical loss detection set to L6-08.
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Output Short-Circuit or IGBT Fault
SC
Short Circuit or Ground Fault is detected
Note: Fault reset will not be received to prevent a short-circuit of the internal circuitry caused by the IGBP fault.
Check the motor insulation resistance and replace the motor if continuity is detected.
Check the motor power cable. Repair any short-circuits.
A short-circuit or grounding fault on the drive output side has damaged the output transistors.
Too Many Speed Search Restarts
SEr
The number of Speed Search restarts exceeded the number set to b3-19.
• Reduce the detection compensation gain during Speed Search (b3-10).
• Increase the current level when attempting Speed Search (b3-17).
• Increase the detection time during Speed Search (b3-18).
• Repeat Auto-Tuning.
Enable Bi-Directional Speed Search (b3-14 = 1).
Motor Pull Out or Step Out Detection
STo
Motor pull out or step out has occurred. Motor has exceeded its pull-out torque.
• Enter the correct motor code for the PM being used into E5-01.
• For special-purpose motors, enter the correct data to all E5 parameters according to the test report provided for the motor.
• Increase the load inertia for PM motor (n8-55).
• Increase the pull-in current during accel/decel (n8-51).
• Reduce the load.
• Increase the motor or drive capacity.
Increase the load inertia for PM motor (n8-55).
• Increase the acceleration and deceleration times (C1-01 through C1-08).
• Increase the S-curve acceleration and deceleration times (C2-01).
Increase the load inertia for PM motor (n8-55).
Zero Servo Fault
SvE
Position deviation during zero servo.
Set the torque limit to an appropriate value using parameters L7-01 to L7-04.
Reduce the amount of load torque.
Check the PG signal for electrical signal interference.
Thermistor Disconnect
THo
The thermistor used to detect motor temperature has become disconnected.
Check the wiring for the thermistor.
Undertorque Detection 1
UL3
The current has fallen below the minimum 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 load for any problems.
Undertorque Detection 2
UL4
The current has fallen below the minimum value set for torque detection (L6-05) for longer than the allowable time (L6-06).
Check the settings of parameters L6-05 and L6-06.
Check the load for any problems.
Mechanical Weakening Detection 2
UL5
The operation conditions matched the conditions set to L6-08.
Check the load side for any problems.
Fault Name
Possible Solution
Make sure drive output is not shorted as follows:
B1  U, V, W
– (negative)  U, V, W
The above short-circuit will damage the output transistors.
Contact your YASKAWA representative or our sales offices for assistance.
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YASKAWA ELECTRIC SIEP C710616 27G YASKAWA AC Drive A1000 Technical Manual