YASKAWA Varispeed L7 Instruction Manual page 166

Limiting Motor Torque (Torque Limit Function)
This function allows limitation of motor shaft torque independendly for each of the four quadrants. The torque
limit can be set as fixed value using parameters or as variable value using an analog input. The torque limit
function can be used with Open Loop Vector and Closed Loop Vector control only.
Related Parameters
Parameter
No.
L7-01 Forward drive torque limit
L7-02 Reverse drive torque limit
L7-03 Forward regenerative torque limit
L7-04 Reverse regenerative torque limit
L7-06 Torque limit time constant
L7-07 Torque limit operation during accel./decel.
* A setting value of 100% is equal to the motor rated torque.
Multi-function Output (H2-01 to H2-03)
Set
Value
30 During torque limit
Setting the Torque Limit Using Parameters
Using L7-01 to L7-04, four torque limits in the following directions can be set individually: Forward drive,
reverse drive, forward regenerative and reverse regenerative (see
Using a Digital Output to Signalize Operation at the Torque Limit
If a multifunction output is set for this function (H2-01 to H2-03 is set to "30"), the output is switched ON
when the motor output torque reaches one of the torque limits.
Factory Set-
Name
200%*
200%*
200%*
200%*
200 ms
Function
Output Torque
L7-01
L7-04
Forward
Reverse
Drive
Regenerative
Forward
Reverse
Regenerative
Drive
L7-03
L7-02
Fig 5.17 Torque Limit Paremeters
http://nicontrols.com
Protective Functions
Control Methods
Change dur-
ing Opera-
ting
V/f
tion
No No
No No
No No
No No
No No
0 No No
Control Methods
Open
V/f Loop
Vector
No Yes
Fig 5.17)
Output Speed
Open Closed
Loop Loop
Vector Vector
A A
A A
A A
A A
A No
A No
5
Closed
Loop
Vector
Yes
37
5-