L7: Torque Limit - YASKAWA GA800 Series Technical Reference

When the total operation time of the drive is more than the value set in L6-11, the drive will detect mechanical
weakening. Use U4-01 [Cumulative Ope Time] to monitor the drive total operation time.
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L7: Torque Limit

The torque limit function limits the internal torque reference for the drive to limit the quantity of torque generated by
the motor to a constant quantity. This function keeps the torque applied to loads and regenerative torque less than a set
quantity. This function also prevents damage to machinery and increases the reliability of continuous operation. You
can set torque limits individually for the four quadrants, which include torque direction (motoring/regeneration) and
direction of motor rotation (forward/reverse). When the torque reference value is at the set torque limit, the MFDO
terminal set for During Torque Limit [H2-xx = 30] activates.
Note:
• The drive output current limits maximum output torque. The drive limits torque to 150% of the rated output current for Heavy Duty Rating
(HD) and to 110% of the rated output current for Normal Duty Rating (ND). The actual output torque is not more than the limits of the
drive rated output current when you set the torque limit to a high value.
• When you use torque limits for lifting applications, do not lower the torque limit value too much. When the torque limit function is
triggered, falls and rollbacks can occur because of sudden acceleration stops and stalls of the motor.
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Configuring Settings
Use one of these methods to set torque limits:
• Individually set the four torque limit quadrants using L7-01 to L7-04 [Torque Limit].
• Use MFAI to individually set the four torque limit quadrants. Set H3-02, H3-06, H3-10 = 10, 11, 12 [MFAI
Function Select = Forward/Reverse/Regenerative Torque Limit].
• Use MFAI to set all four torque limit quadrants together. Set H3-02, H3-06, H3-10 = 15 [General Torque Limit].
• Use a communication option to set all four torque limit quadrants together.
Figure 12.141 shows the configuration method for each quadrant.
Note:
• When L7-01 to L7-04 and analog inputs or communication option torque limits set torque limits for the same quadrant, he drive enables the
lower value.
In this example of parameter settings, the torque limit for quadrant 1 is 130% and the torque limit for quadrants 2, 3, and 4 is 150%.
Settings: L7-01 = 130%, L7-02 to L7-04 = 200%, and MFAI torque limit = 150%
• The drive output current limits maximum output torque. The torque limit is 150% of the rated output current for HD and to 120% of the
rated output current for ND. The actual output torque is not more than the limits of the drive rated output current when you set the torque
limit to a high value.
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L7-01: Forward Torque Limit
No.
Name
(Hex.)
L7-01 Forward Torque Limit
(04A7)
RUN
YASKAWA SIEPC71061737B GA800 Drive Technical Reference
Figure 12.141 Torque Limits and Analog Input Setting Parameters
V/f CL-V/f OLV CLV
Sets the torque limit value for forward motoring as a percentage, where motor rated torque is the
100% value.
Description
AOLV OLV/PM AOLV/PM CLV/PM EZOLV OLV/PM
12.9 L: Protection Functions
Default
(Range)
200%
(0 - 300%)
12
937