Mitsubishi Electric FR-E800, Instruction Manual

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16. (G) Control Parameters
16.6 DC injection brake, zero speed control, servo lock, and magnetic flux decay output shutoff
NOTE
• Under a control other than Real sensorless vector control, the inverter will immediately shutoff the output when the X74 signal
is turned ON.
• Even under Real sensorless vector control, the inverter will immediately shutoff the output when the X74 signal is turned ON
during the automatic restart after instantaneous power failure and online auto tuning during the start up.
• If another output-shutoff trigger (inverter fault, turning ON the MRS signal, etc.) occurs during the magnetic flux decay
operation, the magnetic flux decay operation is terminated, and the output is shut off immediately.
• Unlike the MRS signal, voltage is output during the magnetic flux decay output shutoff operation, so take caution on electric
shocks.
• When the release timing of the mechanical brake is too fast, the motor shaft may be rotated by dropping or external force.
When the release timing is too late, the overcurrent prevention operation, stall prevention operation, or electronic thermal O/
L relay function may be activated. Perform release of the mechanical brake matching the equipment using the Output
frequency detection (FU) signal or Output current detection (Y12) signal.
• Changing the terminal assignment using Pr.178 to Pr.189 (Input terminal function selection) may affect the other functions.
Set parameters after confirming the function of each terminal.
 Braking operation selection under Vector control or PM sensorless
vector control (Pr.802)
• Use Pr.802 Pre-excitation selection to select the braking operation when the pre-excitation is performed from either zero
speed control or servo lock.
• The relation between the DC injection brake operation and pre-excitation operation is as follows.
 Pre-excitation signal (LX signal)
• When the Pre-excitation (LX) signal is turned ON while the motor stops under Real sensorless vector control or Vector
control, pre-excitation (zero speed control / servo lock) starts.
Pr.802 setting
Pre-
excitation
Description
0 (initial value)
Zero speed
control Even under a load, the inverter does not rotate the motor and holds 0 r/min. However, it will not return to
its original position when the shaft moves due to external force.
1 Servo lock
Even under a load, the inverter holds the position of the motor shaft. When the shaft moves due to external
force, it will return to its original position after the external force is removed.
The position loop gain can be adjusted using
Pr.422 Position control gain .
Control method
Control
mode
Pr.802 Pr.850 Deceleration stop LX-ON
X13-ON
(Pr.11 = "8888")
V/F control — — — DC injection brake — DC injection brake
Advanced magnetic flux vector
control
— — — DC injection brake — DC injection brake
Real sensorless vector control
Speed
— 0 DC injection braking
Zero speed Zero speed
— 1 Zero speed
— 2
Magnetic flux decay
output shutoff
Zero speed Zero speed
Torque
— 0 DC injection braking
Zero speed Zero speed
— 1 Zero speed
— 2
Magnetic flux decay
output shutoff
Zero speed Zero speed
Vector control
Speed
0 — Zero speed Zero speed Zero speed
1 — Servo lock Servo lock Servo lock
Torque — — Zero speed Zero speed Zero speed
PM sensorless vector control Speed — — DC injection brake — DC injection brake