5.14.15 Automatic restart after instantaneous power
failure/flying start with an IPM motor
When using the IPM motor MM-CF, the inverter operation can be restarted without stopping the motor operation.
When the automatic restart after instantaneous power failure function is selected, the motor driving is resumed in the following
• When power comes back ON during inverter driving after an instantaneous power failure
• When the motor is coasting at start
Acceleration time at
Automatic restart after instantaneous power failure function
10 to 100 ms for IP55 compatible models
• The inverter output is shut off at the activation of the Instantaneous power failure (E.IPF) or Undervoltage (E.UVT). (Refer
for E.IPF or E.UVT.)
• When E.IPF or E.UVT is activated, the Instantaneous power failure/undervoltage (IPF) signal is output.
• The IPF signal is assigned to terminal IPF in the initial status. By setting "2 (positive logic) or 102 (negative logic)" in any
of Pr.190 to Pr.196 (Output terminal function selection), the IPF signal can be assigned to another terminal.
• When the automatic restart after instantaneous power failure function is selected, motor driving is resumed at the power
restoration after an instantaneous power failure or undervoltage. (E.IPF and E.UVT are not activated.)
Connection (CS signal)
• When the Selection of automatic restart after instantaneous power failure / flying start (CS) signal is assigned to an input
terminal (initial setting), a restart operation is enabled at turn-ON of the CS signal.
• The inverter operation is disabled at turn-OFF of the CS signal while Pr.57 Restart coasting time ≠ "9999" (with restart).
• The CS signal is assigned to terminal CS in the initial setting. By setting "6" to any of Pr.178 to Pr.189 (Input terminal function
selection), the CS signal can be assigned to other terminals. 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 enables the restart operation at all times.
• If the restart operation is selected, instantaneous power failure (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 function occurs.
• The automatic restart after instantaneous power failure function is invalid when the load torque high-speed frequency control
(Pr.270 = "2, 3, 13") is set.
5.14 (A) Application parameters
0.1 to 30 s
0, 1, 2, 3
10, 11, 12, 13
0 to 3600 s
15 to 100 ms
No waiting time
Set the waiting time for the inverter to perform a restart after restoring
power due to an instantaneous power failure.
Frequency search only performed at the first start
Frequency search at every start
Set the acceleration time to reach Pr.20 Acceleration/deceleration
reference frequency at restart.
Standard acceleration time (for example, Pr.7) is applied as the
acceleration time at restart.