Table of Contents
4.3.4
Stall prevention operation
(Pr. 22, Pr. 23, Pr. 48, Pr. 49, Pr. 66, Pr. 148, Pr. 149, Pr. 154, Pr. 156, Pr. 157)
This function monitors the output current and automatically changes the output frequency to prevent the inverter
from coming to trip due to overcurrent, overvoltage, etc. It can also limit stall prevention and fast-response
current limit operation during acceleration/deceleration, driving or regeneration.
Stall prevention
If the output current exceeds the stall prevention operation level, the output frequency of the inverter is
automatically varied to reduce the output current.
Also the second stall prevention function can restrict the output frequency range in which the stall prevention
function is valid.
Fast-response current limit
If the current exceeds the limit value, the output of the inverter is shut off to prevent an overcurrent.
Parameter
Name
Number
Stall prevention operation
22
level
Stall prevention operation
23
level compensation factor
at double speed
Second stall prevention
48
operation current
Second stall prevention
49
operation frequency
Stall prevention operation
66
reduction starting frequency
Stall prevention level at 0V
148
input
Stall prevention level at
149
10V input
Voltage reduction
154
selection during stall
prevention operation
Stall prevention operation
156
selection
157
OL signal output timer
The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 175)
Pr.22
Constant
speed
OL
Stall prevention operation example
CAUTION
⋅ If an overload status lasts long, an inverter trip (e.g. electronic thermal relay function (E.THM)) may occur.
⋅ When Pr. 156 has been set to activate the fast-response current limit (initial setting), the Pr. 22 setting should not be higher than
140%. The torque will not be developed by doing so.
Initial Value
120%
9999
120%
0Hz
0.01 to 400Hz
60Hz
120%
150%
1
0
0s
(1) Setting of stall prevention operation level (Pr. 22)
Output current
⋅ Set in Pr. 22 the ratio of the output current to the rated inverter current at
which stall prevention operation will be performed. Normally set 120%
(initial value).
Output frequency
⋅ Stall prevention operation stops acceleration (makes deceleration) during
acceleration, makes deceleration during constant speed, and stops
deceleration during deceleration.
Time
⋅ When stall prevention operation is performed, the OL signal is output.
Adjustment of the output torque (current) of the motor
Setting
Range
0
Stall prevention operation selection becomes invalid.
Set the current value at which stall prevention
0.1 to 150%
operation will be started.
9999
Analog variable
The stall operation level can be reduced when
0 to 200%
operating at a high speed above the rated frequency.
9999
Constant according to Pr. 22
0
Second stall prevention operation invalid
0.1 to 150%
The second stall prevention operation level can be set.
0
Second stall prevention operation invalid
Set the frequency at which stall prevention operation
of Pr. 48 is started.
9999
Pr. 48 is valid when the RT signal is on.
Set the frequency at which the stall operation level is
0 to 400Hz
started to reduce.
0 to 150%
Stall prevention operation level can be changed by
the analog signal input to terminal 1.
0 to 150%
0
With voltage reduction
1
Without voltage reduction
0 to 31,
You can select whether stall prevention operation and fast-
100, 101
response current limit operation will be performed or not.
Set the output start time of the OL signal output when
0 to 25s
stall prevention is activated.
9999
Without the OL signal output
Description
You can select whether to use
output voltage reduction during
stall prevention operation or not.
4
77
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