YASKAWA LA500, Technical Manual

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12.7 L: Protection Functions
334 YASKAWA SIEPYEULA5001C LA500 Technical Manual
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L6: Torque Detection
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Overview
The overtorque/undertorque detection function prevents damage to machinery and loads.
Overtorque is when there is too much load on the machine. If the motor current or output torque is at the
overtorque detection level for the overtorque detection time, the drive will output an alarm and turn off the output.
Undertorque is when a load suddenly decreases. When the motor current or output torque is at the undertorque
detection level for the undertorque detection time, the drive will output an alarm and turn off the output.
You can use the undertorque detection function to detect these conditions, for example:
• Machine belt cuts
• Unusual operation of the electromagnetic contactor on the drive output side
• Clogged output side air filters in fans and blowers
• Damage to blade tips and broken string
Note:
If there is oC [Overcurrent] or oL1 [Motor Overload] , the drive can stop during overtorque conditions. Use torque detection to identify
overload conditions before the drive detects oC or oL1 and stops. Use this function to detect issues that occur in the application.
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Parameter Settings
You can individually set the two overtorque/undertorque detection functions with the drive. Use the information in
Table 12.10 to set the parameters.
Table 12.10 Overtorque/Undertorque Detection Parameters
Configuration Parameter Overtorque/Undertorque Detection 1 Overtorque/Undertorque Detection 2
MFDO Function Select
• Terminal MA-MC
• Terminal P1-C1
• Terminal P2-C2
H2-01, H2-02, and H2-03 = B
N.O.: Activated when detected
H2-01, H2-02, and H2-03 = 18
N.O.: Activated when detected
H2-01, H2-02, and H2-03 = 17
N.C.: Disactivated when detected
H2-01, H2-02, and H2-03 = 19
N.C.: Disactivated when detected
Detection conditions and selection of operation after
detection L6-01 L6-04
Detection Level L6-02 L6-05
Detection Time L6-03 L6-06
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Overtorque Detection Time Chart
When you use Overtorque/Undertorque Detection 1, the drive detects overtorque if the motor current or motor
torque is at the detection level set in
L6-02 [Torque Detection Level 1]
for the time set in
L6-03 [Torque Detection
Time 1] . Parameter L6-01 [Torque Detection Selection 1] sets the operation after detection.
When you use Overtorque/Undertorque Detection 2, set L6-04 [Torque Detection Selection 2] , L6-05 [Torque
Detection Level 2] , and L6-06 [Torque Detection Time 2] .
Set the terminal that outputs the alarm in H2-01 to H2-03 [MFDO Function Select] .
Figure 12.31 Overtorque Detection Time Chart
Note:
The drive applies a hysteresis of approximately 10% of the drive rated output current or the motor rated torque to the overtorque/
undertorque detection function.