• Set the waiting time when the sine wave filter is used (Pr.72 PWM frequency selection = "25") to 3 seconds or more.
Restart cushion time (Pr.58)
• The cushion time is the time taken to raise the voltage to the level required for the specified speed after the motor speed
detection (output frequency before the instantaneous power failure when Pr.162= "1 or 11").
• Normally, the motor runs at the initial value as it is. However, adjust to suit the moment of inertia (J) of the load or the size
of the torque.
Adjustment of restart operation (Pr.163 to Pr.165, Pr.611)
• The voltage cushion time at a restart can be adjusted by Pr.163 and Pr.164 as shown in the figure on the left.
• The stall prevention operation level at a restart operation can be set in Pr.165.
• Using Pr.611, the acceleration time to reach Pr.20 Acceleration/deceleration reference frequency after a restart
operation can be set. This can be set individually from the normal acceleration time.
• Changing the Pr.21 setting does not affect the Pr.611 setting increment.
• Changing the terminal assignment using Pr.178 to Pr.189 (Input terminal function selection) may affect the other functions.
Set parameters after confirming the function of each terminal.
• When the restart operation is selected, Undervoltage (E.UVT) and Instantaneous power failure (E.IPF) of the fault output
signals become invalid.
• 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.
• Provide a mechanical interlock for MC1 and MC2. The inverter will be damaged if power supply is input to the
inverter output section.
• When the automatic restart after instantaneous power failure function is selected, the motor suddenly starts
(after reset time passes) when an instantaneous power failure occurs. Stay away from the motor and machinery.
Apply the supplied CAUTION stickers to easily visible places when automatic restart after instantaneous power
failure has been selected.
Parameters referred to
Pr.7 Acceleration time, Pr.21 Acceleration/deceleration time
Pr.65, Pr.67 to Pr.69 Retry
Pr.78 Reverse rotation prevention
Pr.178 to Pr.189 (Input terminal function
5.11.13 Automatic restart after instantaneous power
failure/flying start with a PM motor
When using the IPM motor MM-EFS or MM-THE4, 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
5.11 (A) Application parameters