74
Adjustment of the output torque (current) of the motor
4.4 Adjustment of the output torque (current) of the motor
4.4.1 Stall prevention operation (Pr. 22, Pr. 48, Pr. 156, Pr. 157)
(1) Block diagram
(2) Setting of stall prevention operation level (Pr. 22)
Purpose Parameter that should be Set Refer to Page
Limit output current to prevent drive
unit trip
Stall prevention operation Pr. 22, Pr. 48, Pr. 156, Pr. 157
74
Improve the torque in the
low-speed range
PM control torque boost
Pr. 785
77
This function monitors the output current and automatically changes the rotation speed to prevent the drive unit from
tripping due to overcurrent, overvoltage, etc.
If the output current exceeds the stall prevention operation level, the rotation speed of the drive unit is automatically
changed to reduce the output current.
Use the following parameters to limit the stall prevention operation during acceleration/deceleration and power driving/
regenerative driving.
Parameter
Number
Name Initial Value Setting Range Description
22
Stall prevention operation
level
150%
0 Stall prevention operation invalid
0.1 to 200%
Set the current value to start the stall
prevention operation.
48
Second stall prevention
operation current
9999
0 Stall prevention operation invalid
0.1 to 200% Second stall prevention operation level
9999 Same level as Pr. 22.
156
Stall prevention operation
selection
0 0 to 31, 100, 101
Enables/disables the stall prevention
operation
157 OL signal output timer
0s
0 to 25s
Output start time of the OL signal output
when stall prevention is activated.
9999 Without the OL signal output
The above parameters can be set when Pr. 160 Extended function display selection = "0". (Refer to page 144)
Set in Pr. 22 the percentage of the output current to the rated
drive unit current at which stall prevention operation will be
performed. Normally set this parameter to 150% (initial value).
Stall prevention operation stops acceleration (makes
deceleration) during acceleration, makes deceleration during
constant speed, and stops deceleration (makes acceleration)
during deceleration.
When stall prevention operation is performed, the OL signal is
output.
The stall prevention does not operate in the low-speed range
of 300r/min or less.
NOTE
If an overload status lasts long, a drive unit trip (e.g. electronic thermal O/L relay (E.THM)) may occur.
RT ON
0
0
RT OFF
Stall prevention operation level
Stall prevention operation invalid
r. 48
r. 22
Stall prevention operation example
r. 22
OL
Output current
Acceleration
Time
Constant
speed
Deceleration
Rotation speed
