6
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Preventing Motor Stalling During Operation
Stall prevention during operation prevents the motor from stalling by automatically lowering the Inverter's
output frequency when a transient overload occurs while the motor is operating at a constant speed.
Stall prevention during operation is enabled only during V/f control. If the Inverter output current continues to
exceed the setting in constant L3-06 for 100 ms or longer, the motor speed is reduced. Set whether to enable or
disable deceleration time using constant L3-05. Set the deceleration time using C1-02 (Acceleration time 1) or
C1-04 (Acceleration Time 2).
If the Inverter output current reaches the set value in L3-06 - 2% (Inverter Rated Output Current), the motor
will accelerate again at the frequency set or the acceleration time set.
Related Constants
* C6-01= 1: 120 %, C6-01= 0: 150 %
Con-
stant
Number
Name
Description
Setting
Range
Factory
Setting
Change
during
Opera-
tion
Control Methods
MEMO
BUS
Regis-
ter
V/f
V/f
with
PG
Open
Loop
Vec-
tor
Flux
Vec-
tor
L3-05
Stall preven-
tion selection
during run-
ning
0: Disabled (Runs as set. With
a heavy load, the motor may
stall.)
1: Deceleration time 1 (the
deceleration time for the stall
prevention function is C1-
02.)
2: Deceleration time 2 (the
deceleration time for the stall
prevention function is C1-
04.)
0 to 2
1
No
A
A
No
No
493H
L3-06
Stall preven-
tion level dur-
ing running
Effective when L3-05 is 1 or 2.
Set as a percentage of the
Inverter rated output current.
Usually setting is not necessary.
The factory setting reduces the
set values when the motor stalls.
30 to
200
120%
*
No
A
A
No
No
494H
150%
*