Mitsubishi Electric FR-A760 Series Instruction Manual page 203

Motor brake and stop operation
(3) Operation voltage (torque) setting (Pr. 12)
⋅ Use Pr. 12 to set the percentage to the power supply voltage. (This parameter is not used during zero speed control
or servo lock.)
⋅ When Pr. 12 = "0%", the DC injection brake is not operated. (At a stop, the motor coasts.)
(4) Brake operation selection during real sensorless vector control (Pr. 850)
⋅ You can select DC injection brake (initial value) or zero speed control for brake operation during real sensorless
vector control.
When Pr. 850 = "1", zero speed control is exercised when the frequency reaches or decreases below the frequency
set in Pr. 10.
REMARKS
⋅ When the X13 signal is on with Pr. 11 = "8888", zero speed control is activated regardless of setting of Pr. 850 Brake operation
selection.
⋅ When restarting from brake operation during real sensorless vector control, set "1" (zero speed control) in Pr. 850. When the
setting value is "0" (DC injection brake), it may take approx. 2s until frequency is actually output from when the start command
is input.
(5) Brake operation selection under vector control (Pr. 802)
⋅ When pre-excitation is performed, select zero speed control or servo lock using Pr. 802.
Pr. 802 Setting Pre-excitation
0 (initial value) Zero speed control
1 Servo lock
⋅ The relationship between the DC injection brake operation and pre-excitation operation under each control
Control Method
V/F control
Advanced magnetic flux
vector control
Real sensorless vector
control
Vector control
192
Even under load, an attempt is made to maintain 0r/min to keep the motor shaft stopped. Note that
if the shaft is overcome and turned by external force, it does not return to the original position.
Position control is not exercised and only speed control is carried out to perform operation.
Even under load, an attempt is made to maintain the motor shaft position. Note that if the shaft is
turned by external force, it returns to the original position after the external force has gone away.
Since position control is exercised, you can adjust this position loop gain using Pr. 422 Position loop gain.
Control Mode
Pr. 802
⎯ ⎯
⎯ ⎯
⎯
Speed
⎯
⎯
Torque
⎯
0
Speed
1
⎯
Torque
⎯
Position
Description
Decelerates to Stop
Pr. 850
⎯
DC Injection brake
⎯
DC Injection brake
0 DC Injection brake
1 Zero speed
0 DC Injection brake
1 Zero speed
⎯
Zero speed
⎯
Servo lock
⎯
Zero speed
⎯ ⎯
X13-ON
LX-ON
(Pr. 11 = "8888")
⎯
DC Injection brake
⎯
DC Injection brake
Zero speed Zero speed
Zero speed Zero speed
Zero speed Zero speed
Servo lock Servo lock
Zero speed Zero speed
⎯
Servo lock