6
-30
Machine Protection
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.
If the Inverter output current continues to exceed the setting in parameter L3-06 for 100 ms or longer, the
motor speed is reduced. Set the enable or disable deceleration time using parameter L3-05. Set the decelera-
tion time using C1-02 (Deceleration time 1) or C1-04 (Deceleration Time 2).
If the Inverter output current reaches the set value in L3-06 – 2%, the motor will accelerate again to the set fre-
quency.
Related Parameters
Detecting Motor Torque
If an excessive load is placed on the machinery (overtorque) or the load is suddenly lightened (undertorque),
you can output an alarm signal to multi-function output terminal M1-M2 or M3-M4.
To use the overtorque/undertorque detection function, set B or 17 (overtorque/undertorque detection NO/NC)
in one of the following parameters: H2-01 and H2-02 (multi-function output terminals M1-M2 and M3-M4
function selection).
The overtorque/undertorque detection level is the current level (Inverter rated output current 100%).
Param-
eter-
Number
Name
Description
Setting
Range
Factory
Setting
Change
during
Opera-
tion
Access
Level
LCD Display
L3-05
Stall prevention selec-
tion during running func-
tion selection
0: Disabled (Operates according to the setting. Motor
may stall when the load is large.)
1: Enabled--Deceleration time 1 (Stall prevention func-
tion during operation deceleration time is set in C1-
02.)
2: Enabled--Deceleration time 2 (Stall prevention func-
tion during operation deceleration time is set in C1-
04.)
0 to 2
1
No
A
StallP Run Sel
L3-06
Stall prevention level
during running
Enabled when L3-05 is set to 1 or 2. Set as a percentage,
taking Inverter rated current to be 100%.
Normally, there is no need to make this setting.
Lower the set value if the motor stalls at the factory set-
ting.
30 to 200
120%
No
A
StallP Run Level
