Omron VARISPEED G7 -, Instruction Manual

Page: 238 / 417

Machine Protection
6-
43
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
Con-
stant
Number
Name
Description
Setting
Range
Factory
Setting
Change
during
Opera-
tion
Control Methods
Display
V/f
V/f
with
PG
Open
Loop
Vector
1
Flux
Vec-
tor
Open
Loop
Vector
2
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 No
StallP Run
Sel
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 current.
Usually setting is not necessary.
The factory setting reduces the set
values when the motor stalls.
30 to
200
160% No A A No No No
StallP Run
Level