Mitsubishi Electric FR-E740 SC EC Series User Manual

Adjust the output torque (current) of the motor Parameter
6 - 42
6.3.5 Stall prevention operation
(Pr. 22, Pr. 23, Pr. 48, Pr. 66, Pr. 156, Pr. 157, Pr. 277)
This function monitors the output current and automatically changes the output frequency to pre-
vent the inverter from coming to trip due to overcurrent, overvoltage, etc. In addition, simple torque
limit which limits the output torque to the predetermined value can be selected.
It can also limit stall prevention and fast-response current limit operation during acceleration/decel-
eration, driving or regeneration.
● Stall prevention
If the output current exceeds the stall prevention operation level, the output frequency of the
inverter is automatically varied to reduce the output current.
● Fast-response current limit
If the current exceeds the limit value, the output of the inverter is shut off to prevent an
overcurrent.
● Torque limit
The inverter output frequency is controlled so that the output torque (torque current) will not
exceed the stall prevention operation level (motor rated torque is referenced).
The above parameters can be set when Pr. 160 "User group read selection" = 0.

This parameter allows its setting to be changed during operation in any operation mode even if
"0" (initial value) is set in Pr. 77 "Parameter write selection".
Pr. No. Name Initial Value Setting Range Description Parameters referred to
Refer to
Section
22
Stall prevention operation level

150%
0 Stall prevention operation invalid
3
178–184
190–192
Base frequency
Input terminal function
selection
Output terminal
function selection
6.5.1
6.10.1
6.10.5
0.1–200%
Set the current value to start the stall pre-
vention operation.
23
Stall prevention operation level
compensation factor at double speed
9999
0–200%
The stall operation level can be reduced
when operating at a high speed above the
rated frequency.
9999 Constant according to Pr. 22.
48
Second stall prevention operation
current
9999
0 Stall prevention operation invalid
0.1–200% Second stall prevention operation level
9999 Same level as Pr. 22.
66
Stall prevention operation reduction
starting frequency
50Hz 0–400Hz
Set the frequency at which the stall opera-
tion level is started to reduce.
156
Stall prevention operation selection 0
0–31/
100/101
Select whether stall prevention operation
and fast-response current limit operation
will be performed or not.
157
OL signal output timer 0s
0–25s
Output start time of the OL signal output
when stall prevention is activated.
9999 Without the OL signal output
277
Stall prevention operation current
switchover
0
0 Output current is the limit level
1
Output torque (torque current) is the limit
level

Mitsubishi Electric FR-E740 SC EC Series Specifications

General

Brand	Mitsubishi Electric
Model	FR-E740 SC EC Series
Category	Inverter
Language	English