Machine Protection; Limiting Motor Torque (Torque Limit Function) - YASKAWA FSDrive-MV1S Instructions Manual

Machine Protection

This section explains functions for protecting the machine.

Limiting Motor Torque (Torque Limit Function)

The motor torque limit function is enabled with flux vector control and open-loop vector control.
In the open-loop vector control and flux vector control, the user-set value is applied to the torque limit by cal-
culating internally the torque output by the motor. Enable this function if you do not want a torque above a
specified amount to be applied to the load, or if you do not want a regeneration value above a specified
amount to occur.
Related Constants
Constant
Number
L7-01
L7-02
L7-03
L7-04
Note The forward torque limit is the limit value when the analog input signal generates forward torque. This torque limit setting is enabled even when the
analog input signal generates forward torque while the motor is operating (regeneration).
* The factory setting will change when the control method is changed.
Setting the Torque Limit in Constants
Using L7-01 to L7-04, you can set individually four torque limits in the following directions: Forward drive,
reverse drive, forward regeneration, and reverse regeneration.
Setting Precautions
When the torque limit function is operating, control and compensation of the motor speed is disabled
•
because torque control is given priority. Therefore, the acceleration and deceleration times may increase or
the number of motor rotations may decrease.
The torque limit accuracy is ±5% at the output frequency of 10 Hz or above. When output frequency is less
•
than 10 Hz, accuracy is lowered.
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6
Name
Display
Forward drive
torque limit
Sets the torque limit value as a percentage
Torq Limit Fwd
of the motor rated torque.
Reverse drive
Four individual regions can be set.
torque limit
Torq Limit Rev
Output frequency
Upper limit
Forward
Accelerates to
lower limit
regenerative
Lower limit
torque limit
Forward
Torq Lmt Fwd operation/stop
On
UP command
Rgn
DOWN
command
Reverse
On
Frequency
matching signal*
regenerative
Power supply
torque limit * The frequency matching signal turns on when the motor
is not accelerating/decelerating while the Run Command is on.
Torq Lmt Rev
Rgn
Setting
Description
Range
0 to
300
0 to
300
Same d4-01=1
frequency
d4-01=0
0.0 to
100.0
On
Reference
On
frequency reset
On On
0.0 to
100.0
Control
Change
Methods
during
Factory
Open-
Setting Opera-
Flux
loop
tion
Vector
Vector
100%
No A A
*
100%
No A A
*
0.5%
No A A
*
0.5%
No A A
*
MEMO-
BUS
Register
560H
561H
562H
563H