L7: Torque Limit - YASKAWA U1000 Series Technical Manual

5.8 L: Protection Functions
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
L6-11: Mechanical Weakening Detection Start Time

Sets the drives cumulative operation time at which Mechanical Weakening Detection is activated. If U4-01 reaches the
L6-11 value, the function is activated.
No.
L6-11
 L7: Torque Limit
The torque limit function can be used to limit the torque in each of the four quadrants individually and thereby protect the
machinery. It can be used in OLV, CLV, AOLV/PM, and CLV/PM control modes. The limit can be either set by
parameters or by analog inputs. A digital output programmed for "During torque limit" (H2-01, H2-02, H2-03 = 30) can
be switched when the drive is operating at the torque limit.
Setting Torque Limits

The torque limits are defined by parameters L7-01 to L7-04 for each of the four operation quadrants. Analog inputs can
also be used to either define a general limit for all operation conditions (H3-02, H3-06, H3-10 = 15) or for setting
separate limits for each operation condition (H3-02, H3-06, H3-10 = 10, 11, or 12).
limit settings is applied in each quadrant.
If two limit values are defined for the same operation conditions, the drive will use the lower value.
Note: The maximum output torque is ultimately limited by the drive output current (max. 150% of drive rated current in HD, 120% in
ND). Output torque will not exceed the limit set for the drive rated current, even if the torque limits are set to higher values.
Example: If parameter L7-01 = 130%, L7-02 to L7-04 = 200%, and a general torque limit of 150% is set by an analog
input (H3-02, H3-06, H3-10 = 15), then the torque limit in quadrant 1 will be 130%, but 150% in all other quadrants.
Figure 5.100
REV motor rotation
L7-01 to L7-04: Torque Limits

These parameters set the torque limits in each quadrant.
No.
L7-01
274
Name
Mechanical Weakening Detection Speed Level
Name
Mechanical Weakening Detection Time
Name
Mechanical Weakening Detection Start Time
positive torque reference
REV run regenerative
10: Forward Torque Limit
12: Regenerative Torque Limit
15: General Torque Limit
Parameter L7-04
quadrant 2
quadrant 3
11: Reverse Torque Limit
15: General Torque Limit
Parameter L7-02
REV run motoring
negative torque reference
Figure 5.100 Torque Limit Parameters and Analog Input Settings
Name
Forward Torque Limit
FWD run motoring
10: Forward Torque Limit
15: General Torque Limit
Parameter L7-01
quadrant 1
quadrant 4
11: Reverse Torque Limit
12: Regenerative Torque Limit
15: General Torque Limit
Parameter L7-03
FWD run regenerative
YASKAWA ELECTRIC SIEP C710636 03A YASKAWA U1000 Technical Manual
Setting Range
-110.0 to 110.0%
Setting Range
0.0 to 10.0 s
Setting Range
0 to 65535 h
Figure 5.100 shows which of the
FWD motor rotation
common_TMonly
Setting Range
0 to 300%
Default
110.0%
Default
0.1 s
Default
0 h
Default
200%