Mitsubishi Electric FR-A700 Instruction Manual page 426

Motor brake and stop operation
Pre-excitation signal (LX signal)
When the LX signal is turned on under real sensorless vector control or vector control, pre-exci-
tation (zero speed control or servo lock) is exercised during a stop.
For the terminal used for LX signal input, set "23" in any of Pr. 178 to Pr. 186 to assign the func-
tion.
Abb. 6-98: Selection of pre-excitation using an external signal
NOTE
Changing the terminal assignment using Pr. 178 to Pr. 189 (input terminal function selection)
may affect the other functions. Make setting after confirming the function of each terminal.
b
CAUTION:
● Performing pre-excitation (LX signal and X13 signal) under torque control (real
sensorless vector control) may start the motor running at a low speed even when
the start command (STF or STR) is not input.The motor may run also at a low speed
when the speed limit value=0 with a start command input. Perform pre-excitation
after making sure that there will be no problem in safety if the motor runs.
● Although FWD/REV of the operation panel is not lit during pre-excitation, note that
voltage is applied to the motor.
● Note that when offline auto tuning (Pr. 96 "Auto tuning setting/status" = "1 or 101")
is performed during pre-excitation, offline auto tuning is not executed but the motor
starts.
● Do not set Pr. 11 to "0, 8888" and Pr. 12 to "0" under orientation operation.
Otherwise, the motor will not stop properly.
● As stop holding torque is not produced, install a mechanical brake. After the
machine stops fully and the mechanical brake is applied, switch the LX signal (pre-
excitation) off.
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Zero speed control
Normal Operation
Signal LX
Pr. 10
Operation
frequency
Pr. 11 Normal Operation
Time
ON
Parameter
Time
I001560E