4-53
The table below shows the conditions for zero speed control to be enabled or disabled.
Speed command
Run command
Data for d24
Operation
At startup
Below the starting and
stop frequencies
OFF
―
Stop (Gate OFF)
ON
0
Stop (Gate OFF)
1
Zero speed control
At stop
Below the stop
frequency
ON
―
Zero speed control
OFF
―
Stop (Gate OFF)
Stop Frequency (Detection mode) (F38) (Under vector control with speed sensor)
F38 specifies whether to use the detected or reference speed as criterion to shut down the inverter output. Usually
the inverter uses the detected speed. However, if the inverter undergoes a load exceeding its capability, e.g., an
external excessive load, the motor cannot stop so that the detected speed may not reach the stop frequency level.
When such a situation arises, select an appropriate speed that can reach the stop frequency level even if the
detected speed does not, in order to stop the inverter without fail for general fail-safe operation.
- Data setting range:
0 (Detected speed)
1 (Reference speed)