Fuji Electric FRENIC-AQUA series, User Manual

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Auto search for idling motor speed
Starting the inverter (with a run command ON,
BX OFF, auto-reset, etc.) with STM being ON
searches for the idling motor speed for a maximum of 1.2 seconds to run the idling motor
without stopping it. After completion of the auto search, the inverter accelerates the motor up
to the reference frequency according to the frequency command and the preset acceleration
time.
Auto search for idling motor speed to follow
„
Starting Mode (Auto search delay time 1) (H49)
- Data setting range: 0.0 to 10.0 (s)
Auto search for the idling motor speed will become unsuccessful if it is done while the motor
retains residual voltage. It is, therefore, necessary to leave the motor for an enough time for
residual voltage to disappear. H49 specifies that time (0.0 to 10.0 sec.).
At the startup triggered by a run command ON, auto search starts with the delay specified by
H49. Using H49, therefore, eliminates the need of the run command timing control when two
inverters drive a single motor alternately, allow the motor to coast to a stop, and restart it
under auto search control at each time of inverter switching.
„
Starting Mode (Auto search delay time 2) (H46)
- Data setting range: 0.0 to 10.0 (s) (ROM version earlier than 2000)
0.0 to 20.0 (s) (ROM version 2000 or later)
At the restart after a momentary power failure, at the start by turning the terminal command
BX ("Coast to a stop") OFF and ON, or at the restart by auto-reset, the inverter applies the
delay time specified by H46. The inverter will not start unless the time specified by H46 has
elapsed, even if the starting conditions are satisfied.
Under auto search control, the inverter searches the motor speed with the voltage applied at
the motor start and the current flowing in the motor, based on the model built with the motor
parameters. Therefore, the search is greatly influenced by the residual voltage in the motor.
H46 is available for motor 1 only.
At factory shipment, H46 data is preset to a correct value according to the motor capacity for
the general-purpose motor, and basically there is no need to modify the data.