Mitsubishi Electric FR-D720-0.4K Instruction Manual page 83

(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, an inverter trip (e.g. electronic thermal O/L relay (E.THM)) may occur.
(3) Stall prevention operation signal output and output timing adjustment (OL signal, Pr. 157)
When the output current exceeds the stall prevention operation level and stall prevention is activated, the stall prevention
operation signal (OL signal) turns ON for longer than 100ms. When the output current falls to or below the stall prevention
operation level, the output signal turns OFF.
Use Pr. 157 OL signal output timer to set whether the OL signal is output immediately or after a preset period of time.
This operation is also performed when the regeneration avoidance function or
For the OL signal, set "3 (positive logic) or 103 (negative logic)" in Pr. 190, Pr. 192 or Pr. 197 (output terminal function
selection) and assign functions to the output terminal.
Pr. 157 Setting
0
Output immediately.
(initial value)
0.1 to 25 Output after the set time (s) has elapsed.
9999 Not output.
NOTE
If the frequency has fallen to 1Hz by stall prevention operation and remains for 3s, a fault (E.OLT) appears to trip the
inverter output.
Changing the terminal assignment using Pr. 190, Pr. 192, and Pr. 197 (output terminal function selection) may affect the other
functions. Set parameters after confirming the function of each terminal.
Adjustment of the output torque (current) of the motor
Output current
Output frequency
Time
Description
Pr. 22
Set in the percentage of the output current to the rated
inverter 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.
(overvoltage stall) is executed.
Overload state (OL operation)
OL output signal
Pr. 157 set time(s)
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