Mitsubishi Electric FR-A720-0.4K Instruction Manual page 112

Speed control by real sensorless vector
control, vector control
(9) Alarm stop when torque limit is activated (Pr. 874 )
Torque
Pr. 874
Output torque
Output
frequency
Pr. 865
Start
signal
(STF)
Alarm
contact
REMARKS
⋅ If the frequency has fallen to 0.5Hz by stall prevention operation and remains for 3s under V/F control and advanced magnetic
flux vector control, an alarm (E.OLT) appears to shutoff the inverter output. In this case, this function is activated regardless of
Pr. 874 .
This alarm is not provided under torque control.
♦Parameters referred to♦
⋅ Pr. 22 Stall prevention operation level
⋅ Pr. 178 to Pr. 189 (input terminal function selection)
⋅ Pr. 840 Torque bias selection
⋅ Pr. 865 Low speed detection
102
Torque limit
Time
Time
3s
E.OLT occurrence
Refer to page 148
Refer to page 222
Refer to page 112
Refer to page 237
⋅ This function can make an alarm stop if the torque limit is
activated to stall the motor.
⋅ The motor stalls if the torque limit is activated under a high
load applied during speed control or position control. At this
time, if the motor speed is lower than the speed set in Pr.
865 Low speed detection and also the output torque exceeds
the level set in Pr. 874 OLT level setting for 3s, it is regarded
as a stop effected by stall prevention and E. OLT is output,
resulting in an alarm stop.