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162
Operation selection at power failure and
instantaneous power failure
4.13 Operation selection at power failure and instantaneous
power failure
4.13.1 Automatic restart after instantaneous power failure/flying start under general-
purpose motor control (Pr. 57, Pr. 58, Pr. 162 to Pr. 165, Pr. 299, Pr. 611)
<V/F><S MFVC>
Purpose Parameter that must be Set Refer to Page
At instantaneous power failure
occurrence, restart inverter without
stopping motor (general-purpose
motor control)
Automatic restart operation
after instantaneous power
failure / flying start
Pr. 57, Pr. 58, Pr. 162 to Pr. 165,
Pr. 299, Pr. 611
162
At instantaneous power failure
occurrence, restart inverter without
stopping motor (IPM motor control)
Automatic restart operation
after instantaneous power
failure / flying start
Pr. 57, Pr. 162, Pr. 611 166
When undervoltage or a power
failure occurs, the inverter can be
decelerated to a stop.
Power failure-time
deceleration-to-stop
function
Pr. 261 to Pr. 266 169
You can restart the inverter without stopping the motor in the following cases.
⋅ when bypass operation is switched to inverter operation
⋅ when power comes back ON after an instantaneous power failure
⋅ when motor is coasting at start
Parameter
Number
Name Initial Value Setting Range Description
57
Restart coasting
time
9999
0
1.5K or
lower ......................................... 0.5s
2.2K to 7.5K............................................ 1s
11K to 55K ............................................. 3.0s
75K or higher.......................................... 5.0s
The above times are coasting time.
55K or lower
0.1 to
5s
Set the waiting time for inverter-triggered restart
after an instantaneous power failure.
75K or
higher
0.1 to
30s
9999 No restart
58
Restart cushion
time
1s 0 to 60s Set a voltage starting time at restart.
162
Automatic
restart after
instantaneous
power failure
selection
0
0 With frequency search
1
Without frequency search (Reduced voltage
system)
10 Frequency search at every start
11 Reduced voltage system at every start
163
First cushion
time for restart
0s 0 to 20s
Set a voltage starting time at restart.
Consider using these parameters according to the
load (moment of inertia, torque) magnitude.
164
First cushion
voltage for
restart
0% 0 to 100%
165
Stall prevention
operation level
for restart
120% 0 to 150%
Considers the rated inverter current as 100% and
set the stall prevention operation level during
restart operation.
299
Rotation
direction
detection
selection at
restarting
9999
0 Without rotation direction detection
1 With rotation direction detection
9999
When Pr. 78 = "0", the rotation direction is detected.
When Pr. 78 = "1","2", the rotation direction is not
detected.
611
Acceleration
time at a restart
55K or lower 5s
0 to 3600s, 9999
Set the acceleration time to reach
Pr. 20
Acceleration/deceleration reference frequency at a
restart.
Acceleration time for restart is the normal acceleration
time (e.g. Pr. 7) when "9999" is set.
75K or
higher
15s
The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 201)
V/F
V/F
V/F
S
MFVC
S
MFVC
S
MFVC