6. Control Functions and Parameter Settings
6-68
C24-0
Overspeed protection level
This parameter set the overspeed protection level, as a percentage in respect to the
maximum frequency (B00-4) or maximum speed (B01-4). The output frequency or motor
speed is the target for comparison.
C 2 4-0
O u tp ut fre q ue n cy
M o tor spe e d
M o tor coa stin g
FLT
(o ve rsp ee d)
Tim e
C24-1
Control mode changeover during speed detection error
This is valid when vector control with sensor (C30-0 = 4) is selected.
= 1: The speed detection error is disabled.
= 2: The speed detection function is enabled. Then if an error occurs, a fault (FLT) is output
and the motor coasts to a stop.
= 3: The speed detection error is enabled, and if an error occurs, a minor fault (ALM) is
output. The control changes from the vector control with sensor to the sensor-less
vector control, and the operation is continued. When the speed detection returns to the
normal state, the control changes again from the sensor-less vector control to the
vector control with sensor, and the minor fault output is cleared. The presence of a
minor fault due to a speed detection error can be confirmed through the minor fault
monitor (D05-0).
C24-2
Speed detection error level
C24-3
Speed detection error recovery level
This is valid when C24-1 = 3.
Set as a percentage in respect to the maximum speed (B01-4).
If the deflection of the speed detection value per 2ms increases above the value set with
C24-2, it is judged as a speed detection error, and the control changes from the vector
control with sensor to the sensor-less vector control. After changing, when the deflection of
the speed estimated value for sensor-less vector control and the speed detection value
drops to below the value set with C24-3, it will be judged that the speed detection has
returned to the normal state. The control changes again from the sensor-less vector control
to the vector control with sensor.
