Protection parameter group 06
PARAMETER DESCRIPTION 185
5.7.2 Current stalling protection
In order to avoid the alarm and stop of the inverter due to over-current and over-voltage, the output current is
monitored to automatically change the output frequency. It can realize stall prevention during acceleration and
deceleration process or during electric regeneration, and make high response current limit valid.
Parameter
Name
Default Setting Range
Content
06-01
P.22
Stall prevention
operation level
150.0%
0～250.0%
---
06-02
P.23
Stall prevention
operation level
correction factor
99999
0～150.0%
---
99999
Stall prevention operation level is the setting value of
06-01(P.22).
06-03
P.66
Stall prevention
operation reduction
starting frequency
50.00Hz
0～650.00Hz
50Hz system(00-24(P.189)=1): 0～650.00Hz
60.00Hz
60Hz system(00-24(P.189)=0): 0～650.00Hz
06-04
P.220
Acceleration and
deceleration
time
when
current stall
3
0
According to the
current
Acc/Dec time
1
According to the first
Acc/Dec time
2
According to the second Acc/Dec time
3
Automatically calculate proper
Acc/Dec time
Current stalling protection
When load is heavy and motor starts or target frequency changes (increases), the rotating speed of motor often
cannot keep up with the speed of output frequency change. When the rotation speed of motor is lower than output
frequency, output current will increase to enhance output torque. However, if the difference between output
frequency and motor speed is too large, motor torque will be reduced, which is called “stall”.
06-01
（
P.22
）
Output frequency
Level decreasing
region
100%
Output current
percentage
06-03
(P.66)
(Full load
current)
Formula for stall prevention level:
Level percentage=A+B×
06-01(P.22)-A
06-01(P.22)-B
×
06-02(P.23)-100
B=
100
400
A=
Output frequency
(06-23(P.66))x(06-01(P.22))
(06-23(P.66))x(06-01(P.22))
When load is heavy, the output current of inverter will increase. Once the percentage of output current exceeds
curve shown in the diagram below, inverter will reduce output frequency according to deceleration time selected in
06-04(P.220). After rotation speed of motor keeps up (output current of inverter will decrease accordingly), inverter
will accelerate and recover to original output frequency (output frequency at stall) according to acceleration time
selected in 06-04(P.220), and then continue to increase output frequency.
Setting
