Continuing Operation
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Continuing Operation
This section explains functions for continuing or automatically restarting Inverter operation after a
momentary power loss.
Restarting Automatically After Power Is Restored
After a momentary power loss, the Inverter can be restarted automatically to continue motor operation.
To restart the Inverter after power is recovered, set L2-01 to 1 or 2.
If L2-01 is set to 1, when power is recovered within the time set in L2-02, the Inverter will restart. If the power
loss time exceeds the time set in L2-02, an alarm UV1 (main circuit undervoltage) will be detected.
If L2-01 is set to 2, when the main power supply is recovered while the control power supply (i.e., power sup-
ply to the control circuit) is backed up, the Inverter will restart. Consequently, alarm UV1 (main circuit under-
voltage) will not be detected.
Related Parameters
* 1. Factory settings depend on Inverter capacity. (The values shown are for a 200 V Class Inverter for 0.4 kW.)
* 2. These values are for a 200 V Class Inverter. For a 400 V Class Inverter, double the values.
Setting Precautions
•
Error output signals are not output during momentary power loss recovery.
•
To continue Inverter operation after power has been restored, make settings so that run commands from
the control main circuit terminal are stored even while power is suspended.
•
If the momentary power loss operation selection is set to 0 (Disabled), when the momentary power loss
exceeds 15 ms during operation, alarm UV1 (main circuit undervoltage) will be detected.
Param-
eter-
Number
Name
Description
Setting
Range
Factory
Setting
Change
during
Opera-
tion
Access
Level
LCD Display
L2-01
Momentary power loss detec-
tion
0: Disabled (main circuit undervoltage (UV) detection)
1: Enabled (Restarted when the power returns within the
time for L2-02. When L2-02 is exceeded, main circuit
undervoltage detection.)
2: Enabled while CPU is operating. (Restarts when power
returns during control operations. Does not detect
main circuit undervoltage.)
0 to 2
0
No
A
PwrL Selection
L2-02
Momentary power loss ride-
thru time
Ridethrough time, when momentary power loss selection
(L2-01) is set to 1.
0 to 2.0
0.1 s
*1
No
A
PwrL Ridethru t
L2-03
Min. baseblock (BB) time
Set the Inverter’s minimum baseblock time; when the
Inverter is restarted after power loss ridethrough.
Sets the time to approximately 0.7 times of the motor sec-
ondary circuit time parameter.
When an overcurrent or overvoltage occurs during a speed
search or DC injection braking, increase the set values.
0.1 to 5.0
0.1 s
No
A
PwrL Baseblock t
L2-04
Voltage recovery time
Set the time required to return the Inverter output voltage
to normal voltage at the completion of a speed search.
Set the time required to recover from 0 V to the maximum
voltage.
0.0 to
5.0
0.3 s
*1
No
A
PwrL V/f Ramp t
L2-05
Undervoltage (UV) detection
level
Sets the main circuit undervoltage (UV) detection level
(main circuit DC voltage).
Usually changing this setting is not necessary.
Insert an AC reactor in the Inverter input side to lower the
main circuit undervoltage detection level.
150 to
210
*2
190 V
*2
No
A
PUV Det Level