(A) Application parameters
Connection (CS signal)
● Restart is enabled at turn-ON of the automatic restart after instantaneous power failure/flying
start (CS) signal.
● The inverter operation is disabled at turn-OFF of the CS signal while Pr. 57 "Restart coasting time"
≠"9999" (with restart).
Changing the terminal assignment may affect other functions. Set parameters after confirming
the function of each terminal.
If the CS signal is not assigned to any input terminal, solely setting Pr. 57 will enable the restart
operation at all times.
If the restart operation is selected, instantaneous power failure protection (E.IPF) is disabled while
the fault output signal is output at an instantaneous power failure.
The SU and FU signals are not output during the restart. These signals are output after the restart
cushion time passes.
Restart operation is also performed after the inverter reset is released or after the retry by the retry
Selection of restart operation (Pr. 162)
● At a power restoration, the encoder detects the motor speed by a frequency search so that the
inverter can re-start smoothly.
● The encoder also detects the rotation direction so that the inverter can re-start smoothly even
during the reverse rotation.
● When "10 (11, 12, 13)" is set in Pr. 162, a restart operation is performed at each start and automatic
restart after instantaneous power failure. When "0 (1, 2)" is set to Pr. 162, a restart operation is
performed at the first start after a power-ON, and from the second power-ON onwards, a start
from the starting frequency is performed.
Because a DC injection brake is applied instantaneously at speed detection during a restart, the
speed might drop if the moment of inertia (J) of the load is small.
Restart operation with reduced voltage is not available for PM motor control.
5 - 424
speed N (r/min)
frequency f (Hz)
voltage E (V)
time (Pr. 57)
* The output shut off timing differs
according to the load condition
Instantaneous (power failure) time
at a restart
(Pr. 611 setting)