Operation selection at power failure and
instantaneous power failure
When Pr. 162 = 1, 11 (without frequency search)
Instantaneous (power failure) time
Motor speed N
Pr. 57 setting
* The output shut off timing differs according
to the load condition.
(4) Restart coasting time (Pr. 57)
Coasting time is the time from when the motor speed is detected until automatic restart control is started.
Set Pr. 57 to "0" to perform automatic restart operation. The coasting time is automatically set to the value below.
Generally this setting will pose no problems.
Operation may not be performed well depending on the magnitude of the moment of inertia(J) of the load or
operation frequency. Adjust the coasting time between 0.1s and 5s according to the load specifications.
(5) Restart cushion time (Pr. 58)
Cushion time is the length of time taken to raise the voltage appropriate to the detected motor speed (output
frequency prior to instantaneous power failure when Pr. 162 = "1" or "11).
Normally the initial value need not be changed for operation, but adjust it according to the magnitude of the
moment of inertia(J) of the load or torque magnitude.
Changing the terminal assignment using Pr. 178 to Pr. 196 (I/O terminal function selection) may affect the other functions. Make
setting after confirming the function of each terminal.
When automatic restart operation is selected, undervoltage protection (E.UVT) and instantaneous power failure protection
(E.IPF) among the fault output signals will not be provided at occurrence of an instantaneous power failure.
The SU and FU signals are not output during a restart. They are output after the restart cushion time has elapsed.
Automatic restart operation will also be performed after a reset when a retry is made by the retry function.
Pr. 58 setting
00038 or less
(6) Automatic restart operation adjustment (Pr. 163 to
Without frequency search
When Pr. 162 = "1, 11", automatic restart operation is performed
in a reduced voltage system, where the voltage is gradually
risen with the output frequency unchanged from prior to an
instantaneous power failure independently of the coasting
speed of the motor.
This system stores the output frequency prior to an instantaneous
power failure and increases the voltage. Therefore, if the
instantaneous power failure time exceeds 0.2s, the inverter starts
at Pr. 13 Starting frequency (initial value = 0.5Hz) since the stored
output frequency cannot be retained.
Restart operation at every start
When Pr. 162 = "10" or "11", automatic restart operation is also
performed every start, in addition to the automatic restart after
instantaneous power failure. When Pr. 162 = "0", automatic
restart operation is performed at the first start after power
supply-on, but not performed at the second time or later.
00052 to 00170
00250 to 01160
Pr. 165, Pr. 611)
Using Pr. 163 and Pr. 164, you can adjust the voltage rise time at
a restart as shown on the left.
Using Pr. 165, you can set the stall prevention operation level at
Using Pr. 611, you can set the acceleration time until Pr. 20
Acceleration/deceleration reference frequency is reached after
automatic restart operation is performed besides the normal
If the setting of Pr. 21 Acceleration/deceleration time increments is
changed, the setting increments of Pr. 611 do not change.
01800 or more