Mitsubishi FR-A800

Speed control under Real sensorless vector control, vector control, PM sensorless vector
control
190
PARAMETERS
Changing the torque characteristic of the constant-output range (Pr.803)
• In torque limit operations under Real sensorless vector control or vector control, the torque characteristic in a
low-speed range and constant-output range can be changed.
 Valid only under Real sensorless vector control.
 Differs by the motor. (30 Hz for the SF-HR/SF-HRCA 3.7 kW to 7.5 kW, 18.5 kW, and 22 kW. 20 Hz for the 30 kW to 55 kW.)
Trip during torque limit operation (Pr.874)
• A trip can be set for when the torque limit is activated and the motor stalls.
• When a high load is applied and the torque limit is activated under speed control or position control, the motor stalls. At this
time, if a state where the rotation speed is lower than the value set in Pr.865 Low speed detection and the output torque
exceeds the level set in Pr.874 OLT level setting continues for 3 s, Stall prevention stop (E.OLT) is activated and the
inverter output is shut off.
NOTE
• Under V/F control or Advanced magnetic flux vector control, if the output frequency drops to 0.5 Hz due to the stall prevention
operation and this state continues for 3 s, a fault indication (E.OLT) appears, and the inverter output is shut off. This operation
is activated regardless of the Pr.874 setting.
• This fault does not occur under torque control.
Pr.803 setting Torque characteristic in low-speed range Torque characteristic in constant-output range
0 Torque rise  Constant motor output
1 Constant torque Constant torque
10 Constant torque Constant motor output
11 Torque rise
 Constant torque
10Hz ∗2
Pr.803=0
Torque
Low-speed
range
Constant torque
range
Constant power range
constant power limit
(torque reduction)
Torque rise limit
Base frequency
Output frequency
Pr.803=1
Torque rise limit
constant torque limit
10Hz ∗2
Base frequency
Output frequency
Torque
Low-speed
range
Constant torque
range
Constant power range
Pr.803=11
Torque rise limit
constant torque limit
10Hz ∗2
Base frequency
Output frequency
Torque
Low-speed
range
Constant torque
range
Constant power range
Pr.803=10
10Hz ∗2
Torque
Low-speed
range
Constant torque
range
Constant power range
constant power limit
(torque reduction)
Torque rise limit
Base frequency
Output frequency
Output torque
Output
frequency
Start signal
(STF)
Fault signal
(ALM)
Pr.874
Torque limit
Pr.865
3s
Torque
Time
Time
E.OLT occurrence