Preventing Motor Stalling During Operation - Omron VARISPEED G7 Instruction Manual

Setting Precautions
When the torque limit function is operating, control and compensation of the motor speed is disabled
•
because torque control is given priority.
When using the torque limit to raise and lower loads, do not carelessly lower the torque limit value, as this
•
may result in the motor falling or slipping.
Torque limits using an analog input are the upper limit value (during 10 V or 20 mA input) of 100% of the
•
motor rated torque. To make the torque limit value during 10 V or 20 mA input 150% of the rated torque,
set the input terminal gain to 150.0 (%). Adjust the gain for multi-function analog input terminal A2 using
H3-10 and for multi-function analog input terminal A3 using H3-06.
The torque limit accuracy is ±5% at the output frequency of 10 Hz or above. When output frequency is less
•
than 10 Hz, accuracy is lowered.

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
Name
Con-
stant
Display
Number
Stall preven- 0: Disabled (Runs as set. With a
tion selection heavy load, the motor may stall.)
during run- 1: Deceleration time 1 (the
ning deceleration time for the stall
L3-05
prevention function is C1-02.)
2: Deceleration time 2 (the
StallP Run
deceleration time for the stall
Sel
prevention function is C1-04.)
Stall preven- Effective when L3-05 is 1 or 2.
tion level dur- Set as a percentage of the Inverter
ing running rated current.
L3-06
Usually setting is not necessary.
StallP Run
The factory setting reduces the set
Level
values when the motor stalls.
Setting
Description
Range
0 to 2
30 to
200
Machine Protection
Control Methods
Change
Factory during
V/f
Setting Opera-
V/f with
tion
PG
1 No A A
160% No A A
Open Open
Flux
Loop Loop
Vec-
Vector Vector
tor
1 2
No No No
No No No
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