Motor brake and stop operation
4.10.4 Stop-on contact control function (Pr. 6, Pr. 48, Pr. 270, Pr. 275, Pr. 276)
To ensure accurate positioning at the upper limit etc. of a
lift, stop-on-contact control causes a mechanical brake to
be closed while the motor is developing a holding torque
to keep the load in contact with a mechanical stopper etc.
This function suppresses vibration which is liable to occur
when the load is stopped upon contact in vertical motion
applications, ensuring steady precise positioning.
Multi-speed setting (low
Second stall prevention
Stop-on contact control
excitation current low-
speed multiplying factor
PWM carrier frequency at
* The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 179)
Connection and operation example
Forward rotation command
High-speed operation command
Middle-speed operation command
Stop-on contact selection 0
Stop-on contact selection 1
* The input signal terminal used differs according to the Pr. 180 to Pr. 184
Set stop-on-contact control
Make sure that the inverter is in External operation mode. (Refer to page 182)
Select Advanced magnetic flux vector control or General-purpose magnetic flux vector control.
Set "1" in Pr. 270 Stop-on contact 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 starts the stop-on-contact control, in which operation is
performed at the frequency set in Pr. 6 independently of the preceding speed.
For the terminal used for X18 signal input, set "3" in any of Pr. 178 to Pr. 184 (input terminal function selection) and "0" in Pr. 178
to Pr. 184 (input terminal function selection) to assign the function.
By increasing the Pr. 275 setting, the low-speed (stop-on-contact) torque increases, but overcurrent fault (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 change to a mechanical brake to hold the load.
Under the following operating conditions, the stop-on-contact functionis made invalid:
PU operation (Pr. 79), Jog operation (JOG signal), PU+External operation (Pr. 79), PID control function operation (Pr.
128), remote setting function operation (Pr. 59), automatic acceleration/deceleration operation (Pr. 292)
0 to 400Hz
0 to 200%
0 to 300%
0 to 9
<Without stop-on-contact control>
Sets the output frequency for stop-on-contact control.
Sets the stall prevention operation level for stall
prevention operation level.
Pr. 22 setting
Set the force (holding torque) for stop-on-contact control.
Normally set 130% to 180%.
Sets a PWM carrier frequency for stop-on-contact control.
As set in Pr. 72 PWM frequency selection.
Normal mode Stop-on-contact control mode
* Goes into stop-on-contact control when both RL and RT switch ON.
RL and RT may be switched on in any order with any time difference.
(a) Acceleration time (Pr. 7 )
(c) Second deceleration time (Pr. 44/Pr. 45 )
<With stop-on-contact control>
(b) Deceleration time (Pr. 8 )