YASKAWA A1000 Technical Manual page 293


Mechanical Weakening Detection
This function can be used to detect mechanical weakening of a machine that leads to overtorque or undertorque situations
after a certain machine operation time has elapsed.
The function is activated in the drive when the cumulative operation counter U4-01 exceeds the time set in parameter
L6-11. Mechanical Weakening Detection uses the torque detection 1 settings (L6-01, L6-02, L6-03) and triggers an oL5
or UL5 fault when overtorque or undertorque occurs in the speed range determined by parameter L6-08 and L6-09. The
oL5 or UL5 operation is set by parameter L6-08.
To output a signal for Mechanical Weakening Detection, set H2- to 22.
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L6-08: Mechanical Weakening Detection Operation
Sets the speed range to detect mechanical weakening and the action to take when mechanical weakening is detected.
No.
L6-08
Setting 0: Disabled
Setting 1: Continue running if the speed is greater than L6-09 (signed) (Alarm)
Detection when the speed is above L6-09 (signed). Upon detection operation continues, but an oL5 alarm is output.
Setting 2: Continue running if the speed is greater than L6-09 (Alarm)
Detection when the speed is above L6-09 (unsigned). Upon detection operation continues, but an oL5 alarm is output.
Setting 3: Stop when motor speed is greater than L6-09 (signed) (Fault)
Detection when the speed is above L6-09 (signed). Upon detection operation is stopped and an oL5 fault is output.
Setting 4: Stop when Motor Speed is Greater than L6-09 (Fault)
Detection when the speed is above L6-09 (unsigned). Upon detection operation is stopped and an oL5 fault is output.
Setting 5: Continue running if the speed is less than L6-09 (signed) (Alarm)
Detection when the speed is below L6-09 (signed). Upon detection operation continues, but a UL5 alarm is output.
Setting 6: Continue running if the speed is less than L6-09 (Alarm)
Detection when the speed is below L6-09 (unsigned). Upon detection operation continues, but a UL5 alarm is output.
Setting 7: Stop when Motor Speed is less than L6-09 (signed) (Fault)
Detection when the speed is below L6-09 (signed). Upon detection operation is stopped and a UL5 fault is output.
Setting 8: Stop when motor speed is less than L6-09 (Fault)
Detection when the speed is below L6-09 (unsigned). Upon detection the operation is stopped and a UL5 fault is output.

L6-09: Mechanical Weakening Detection Speed Level
Sets the speed level for Mechanical Weakening Detection.
No.
L6-09
The value is set as a percentage of the maximum frequency. If L6-08 is set for unsigned speed detection (L6-08 = 2, 4, 6,
8) then the absolute value of L6-09 is used (negative settings are treated as positive values).

L6-10: Mechanical Weakening Detection Time
Sets the time permitted for the situation selected in parameter L6-08 to arise before mechanical weakening is detected.
No.
L6-10
YASKAWA ELECTRIC SIEP C710616 27G YASKAWA AC Drive A1000 Technical Manual
Name
Mechanical Weakening Detection Operation
Name
Mechanical Weakening Detection Speed Level
Name
Mechanical Weakening Detection Time
5.8 L: Protection Functions
Setting Range Default
0 to 8
Setting Range Default
-110.0 to 110.0%
Setting Range Default
0.0 to 10.0 s
0
5
110.0%
0.1 s
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