6.4 Fault Detection
YASKAWA ELECTRIC
SIEP C710606 44B YASKAWA AC Drive T1000V Technical Manual
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LED Operator Display
Fault Name
oL2
Drive Overload
The thermal sensor of the drive triggered overload protection.
Cause
Possible Solution
Load is too heavy.
Reduce the load.
Cycle times are too short during
acceleration and deceleration.
Increase the settings for the acceleration and deceleration times (C1-01 through C1-08).
Voltage is too high for the V/f
characteristics.
• Adjust the V/f pattern (E1-04 through E1-10). This will mainly involve reducing E1-08 and E1-10.
• Be careful not to lower E1-08 and E1-10 excessively because this reduces load tolerance at low
speeds.
Drive capacity is too small.
Replace the drive with a larger model.
Overload occurred when operating at low
speeds.
• Reduce the load when operating at low speeds.
• Replace the drive with a model that is one frame size larger.
• Lower the carrier frequency (C6-02).
Excessive torque compensation.
Reduce the torque compensation gain (C4-01) until there is no speed loss but less current.
Speed Search related parameters are not set
correctly.
• Check the settings for all Speed Search related parameters.
• Adjust the current used during Speed Search and the Speed Search deceleration time (b3-03 and
b3-02 respectively).
• After Auto-Tuning the drive, enable the Speed Search Estimation Type (b3-24 = “1”).
Output current fluctuation due to input
phase loss
Check the power supply for phase loss.
LED Operator Display
Fault Name
oL3
Overtorque Detection 1
The current has exceeded the value set for torque detection (L6-02) for longer than the allowable
time (L6-03).
Cause
Possible Solution
Parameter settings are not appropriate for
the type of load.
Check the settings of parameters L6-02 and L6-03.
There is a fault on the machine side (e.g.,
the machine is locked up).
Check the status of the load. Remove the cause of the fault.
LED Operator Display
Fault Name
oL4
Overtorque Detection 2
The current has exceeded the value set for Overtorque Detection 2 (L6-05) for longer than the
allowable time (L6-06).
Cause
Possible Solution
Parameter settings are not appropriate for
the type of load.
Check the settings of parameters L6-05 and L6-06.
LED Operator Display
Fault Name
oPr
External Digital Operator Connection Fault
• The external operator has been disconnected from the drive.
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).
Cause
Possible Solution
External operator is not properly connected
to the drive.
• 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.
LED Operator Display
Fault Name
oS
Overspeed (Simple V/f with PG)
Pulse input (RP) indicates that motor speed feedback exceeded F1-08 setting.
Cause
Possible Solution
Overshoot or undershoot is occurring.
• Adjust the gain by using the pulse train input parameters (H6-02 through H6-05).
• Increase the settings for C5-01 (Speed Control Proportional Gain 1) and reduce C5-02 (Speed
Control Integral Time 1).
Incorrect PG pulse settings.
Set the H6-02 (Pulse Train Input Scaling) = 100%, the number of pulses during maximum motor
revolutions.
Inappropriate parameter settings.
Check the setting for the overspeed detection level and the overspeed detection time (F1-08 and F1-
09).
