Adjustment Of The Output Torque (Current) Of The Motor; Stall Prevention Operation (Pr. 22, Pr. 48, Pr. 156, Pr. 157) - Mitsubishi Electric FR-D720-0.2K-G Instruction Manual

4.5

Adjustment of the output torque (current) of the motor

Purpose
Limit output current to prevent drive
unit trip
Improve the torque in the
low-speed range
4.5.1

Stall prevention operation (Pr. 22, Pr. 48, Pr. 156, Pr. 157)

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
Name
Number
Stall prevention operation
22
level
Second stall prevention
48
operation current
Stall prevention operation
156
selection
157 OL signal output timer
The above parameters can be set when Pr. 160 Extended function display selection = "0". (Refer to page 161.)
(1) Block diagram
Pr. 22
Pr. 48
(2) Setting of stall prevention operation level (Pr. 22)
Pr. 22
Constant
speed
OL
Stall prevention operation example
NOTE
 If an overload status lasts long, a drive unit trip (e.g. electronic thermal O/L relay (E.THM)) may occur.

Adjustment of the output torque (current) of the motor

Parameter that should be Set
Stall prevention operation
PM control torque boost
Initial Value
150%
9999
0
0s
RT OFF
0
RT ON
0
Set in Pr. 22 the percentage of the output current to the rated
drive unit current at which stall prevention operation will be
Output current
performed. Normally set this parameter to 150% (initial value).
Stall prevention operation stops acceleration (makes
deceleration) during acceleration, makes deceleration during
Rotation speed
constant speed, and stops deceleration (makes acceleration)
during deceleration.
Time 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.
Pr. 22, Pr. 48, Pr. 156, Pr. 157
Pr. 785
Setting Range
0 Stall prevention operation invalid
Set the current value to start the stall
0.1 to 200%
prevention operation.
0 Stall prevention operation invalid
0.1 to 200% Second stall prevention operation level
9999 Same level as Pr. 22.
Enables/disables the stall prevention
0 to 31, 100, 101
operation
Output start time of the OL signal output
0 to 25s
when stall prevention is activated.
9999 Without the OL signal output
Stall prevention operation invalid
Stall prevention operation level
Refer to Page
83
86
Description
83
4