84
PARAMETERS
4.2.12 Stall prevention (Pr. 22, Pr. 23, Pr. 66, Pr. 148, Pr. 149, Pr. 154)
Pr. 22 "stall prevention operation level"
Pr. 23 "stall prevention operation level
compensation factor at double speed"
Pr. 66 "stall prevention operation level
reduction starting frequency"
Pr. 148 "stall prevention operation level
at 0V input"
Pr. 149 "stall prevention operation level
at 10V input"
Pr. 154 "voltage reduction selection during stall
prevention operation"
z Set the output current level at which the output frequency will be adjusted to prevent the inverter from
stopping due to overcurrent etc.
z For high-speed operation at or over the more base frequency, acceleration may not be made because the
motor current does not increase. To improve the operation characteristics of the motor in such a case, the
stall prevention level in the high-frequency range can be reduced. This is effective for operation of a
centrifugal separator up to the high-speed range. Normally, set 60Hz in Pr. 66 and 100% in Pr. 23.
z For operation in the high-frequency range, the current in the locked motor state is smaller than the rated
output current of the inverter and the inverter does not result in an alarm (protective function is not
activated) if the motor is at a stop. To improve this and activate the alarm, the stall prevention level can be
reduced.
z In order to provide torque during stall prevention, Pr. 154 is factory-set not to reduce the output voltage.
The setting of reducing the output voltage further decreases the probability of overcurrent trip occurrence.
z The stall prevention operation level can be varied by entering the analog signal into terminal 1.
Parameter
Number
Factory
Setting
Setting Range Remarks
22 150% 0 to 200%, 9999 9999: Analog variable
23 9999 0 to 200%, 9999 9999: Constant according to Pr. 22
66 60Hz 0 to 400Hz
148 150% 0 to 200% (Bias)
149 200% 0 to 200% (Gain)
154 1 0, 1
0: Output voltage reduced
1: Output voltage not reduced
Pr.22
Pr.23
Pr.66
400Hz
Output frequency (Hz)
Stall prevention operation level (%)
Pr. 23 = 9999
Reduction ratio
compensation factor (%)
150
90
60
45
30
22.5
600 100 200 300 400
Output frequency (Hz)
Setting example (Pr.22=150%, Pr.23=100%, Pr.66=60Hz)
Stall prevention operation level (%)
(170%)
(130%)
0%
0V
Pr.148
Pr.149
10(5)V
Input voltage (V)
(across frequency setting terminals 1-5)
Stall prevention operation level (%)
Related parameters
Pr. 48 "second stall prevention
operation current"
Pr. 49 "second stall prevention operation
frequency"
Pr. 73 "0-5V/0-10V selection"
Pr. 114 "third stall prevention operation
current"
Pr. 115 "third stall prevention operation
frequency"
Pr. 156 "stall prevention operation
selection"
