Mitsubishi Electric FR-A720-0.4K Instruction Manual page 216

Motor brake and stop operation
(1) Set stop-on-contact control
⋅ Make sure that the inverter is in external operation mode. (Refer to page 298 )
⋅ Select either real sensorless vector control or advanced magnetic flux vector control.
⋅ Set"1 or 3" in Pr. 270 Stop-on contact/load torque high-speed frequency control selection .
⋅ Set output frequency during stop-on-contact control in Pr. 6 Multi-speed setting (low speed).
The frequency should be as low as possible (about 2Hz). If it is set to more than 30Hz, the operating frequency will
be 30Hz.
⋅ When both the RT and RL signals are switched on, the inverter enters the stop-on-contact mode, in which operation
is performed at the frequency set in Pr. 6 independently of the preceding speed.
CAUTION
⋅ By increasing the Pr. 275 setting, the low-speed (stop-on-contact) torque increases, but overcurrent alarm (E.OCT) may occur or
the machine may oscillate in a stop-on-contact state.
⋅ The stop-on-contact function is diferent from servo-lock function, and if used to stop or hold a load for an extended period, this
function can cause the motor to overheat.
After a stop, immediately reset this function and use a mechanical brake to hold the load.
⋅ Under the following operating conditions, the stop-on-contact function is made invalid:
·
PU operation (Pr. 79)
·
Remote setting function operation (Pr. 59)
⋅ When performing stop-on-contact control during encoder feedback control, encoder feedback control is made invalid due to a
mode shift to the stop-on-contact control mode.
(2) Function switching of stop-on-contact control selection
Useful Functions
Output frequency
Stall prevention operation level
Torque limit level
Excitation current low speed
scaling factor
Carrier frequency
Fast response current limit
* When RL and RT are on, Pr. 49 Second stall prevention operation frequency is invalid.
206
JOG operation (JOG signal)
·
Start time tuning
Normal Operation
(either RL or RT is off or both are off)
Real sensorless
vector control
Multi-speed
0 to 5V, 0 to 10V
4 to 20mA etc.
⎯
Pr. 22 setting
Pr. 72 setting
⎯
·
PU+external operation (Pr. 79)
·
Orientation control function operation
Advanced
magnetic flux vector
control
Pr. 22 setting
⎯
⎯
Valid
·
PID control function operation (Pr. 128)
With Stop-on-Contact Control
(both RL and RT are on)
Real sensorless
magnetic flux vector
vector control
Pr. 6 setting
The smaller value set
⎯
in either Pr. 22 or Pr. 48.
Pr. 22 setting
The current is
compensated for by Pr.
⎯
275 (0 to 1000%)
settings before RL and
RT are switched on.
Pr. 276 setting when output frequency is 3Hz or
less (Pr. 72 when Pr. 276 = "9999")
⎯
Advanced
control
*
⎯
Invalid