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6.4 Fault Detection
364
YASKAWA ELECTRIC
SIEP C710636 02B YASKAWA U1000 Technical Manual
Digital Operator Display
Fault Name
SoH
Snubber Discharge Resistor Overheat
Cause
Possible Solution
• The input power supply voltage is too high.
• The capacity of the power supply is too small.
• The distortion in the power supply is too large.
• Reduce the voltage to within the range in the power supply specifications.
• Increase the capacity of the power supply.
• Lower the impedance of the input power supply wiring.
The load was too large during repetitious operation.
• Check the load conditions. (Reduce the load.)
• Increase the acceleration/deceleration time.
A phase loss occurred in the input power supply.
Check the input power supply for phase loss or an imbalance in the interphase voltages.
Digital Operator Display
Fault Name
SrC
Phase Order Detection Fault
The phase rotation direction for the input power supply changed.
Cause
Possible Solution
The power supply phase order changed during
operation.
Investigate and correct the cause and then reset the fault.
Refer to
Diagnosing and Resetting Faults on page 382
An input power supply wiring terminal is loose.
The fluctuation in the voltage of the input power supply
is too large.
Digital Operator Display
Fault Name
Srr
Internal Resistance Fault
An operation failure occurred in the snubber discharge resistor circuit.
Cause
Possible Solution
The snubber discharge resistor or peripheral circuits
failed.
• Cycle power to the drive.
• If the problem continues, replace either the control board or the entire drive. For instructions on replacing the control board,
contact Yaskawa or your nearest sales representative.
Digital Operator Display
Fault Name
STo
Pull-Out Detection
Motor pull out or step out has occurred. Motor has exceeded its pull-out torque.
Cause
Possible Solution
The wrong motor code is set (Yaskawa motors only).
• 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.
Load is too heavy.
• Increase the load inertia for PM motor (n8-55).
• Increase the pull-in current during accel/decel (n8-51).
• Reduce the load.
• Use a larger motor and drive.
Load inertia is too heavy.
Increase the load inertia for PM motor (n8-55).
Acceleration and deceleration times are too short.
• Increase the acceleration and deceleration times (C1-01 through C1-08).
• Increase the S-curve acceleration and deceleration times (C2-01).
Speed response is too slow.
Increase the load inertia for PM motor (n8-55).
Digital Operator Display
Fault Name
SvE
Zero Servo Fault
Position deviation during zero servo.
Cause
Possible Solution
Torque limit is set too low.
Set the torque limit to an appropriate value using parameters L7-01 to L7-04.
Excessive load torque.
Reduce the amount of load torque.
Electrical signal interference along PG encoder wiring.
Check the PG signal for electrical signal interference.
Digital Operator Display
Fault Name
UL3
Undertorque Detection 1
The current has fallen below the minimum value set for torque detection level 1 (L6-02) for longer than the allowable time
(L6-03).
Cause
Possible Solution
Parameter settings are not appropriate for the load.
Check the settings of parameters L6-02 and L6-03.
There is a fault on the machine side.
Check the load for any problems.
Digital Operator Display
Fault Name
UL4
Undertorque Detection 2
The current has fallen below the minimum value set for torque detection level 2 (L6-05) for longer than the allowable time
(L6-06).
Cause
Possible Solution
Parameter settings are not appropriate for the load.
Check the settings of parameters L6-05 and L6-06.
There is a fault on the machine side.
Check the load for any problems.
Digital Operator Display
Fault Name
UL5
Mechanical Weakening Detection 2
The operation conditions matched the conditions set to L6-08.
Cause
Possible Solution
Undertorque was detected and matched the conditions
for mechanical loss detection set to L6-08.
Check the load side for any problems.
SIEP_C710636_02B_1_0.book 364 ページ 2015年11月25日 水曜日 午後4時56分