Stall Prevention (Pr. 22, Pr. 23, Pr. 66, Pr. 148, Pr. 149, Pr. 154) - Mitsubishi Electric FR-A500 Instruction Manual

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"
Set the output current level (% to the inverter rated current) at which the output frequency is adjusted so
that the inverter will not come to an alarm stop due to overcurrent etc.
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 <50Hz> in Pr. 66 and 100% in Pr. 23.
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.
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.
The stall prevention operation level can be varied by entering the analog signal into terminal 1.
Parameter Factory
Number Setting
22
23
66 60Hz<50Hz>
148
149
154
Pr.22
Pr. 23
Pr.66
( 170% )
( 130% )
0%
0V
Input voltage (V)
(across frequency setting terminals 1-5)
Setting Range
150% 0 to 200%, 9999
9999 0 to 200%, 9999
0 to 400Hz
150% 0 to 200%
200% 0 to 200%
1 0, 1
= 9999
Pr.23
Reduction ratio
compensation factor (%)
400Hz Output frequency (Hz)
Pr.149
Pr.148
10(5)V
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"
Remarks
9999: Analog variable
9999: Constant according to Pr. 22
(Bias)
(Gain)
0: Output voltage reduced
1: Output voltage not reduced
Setting example (Pr.22=150%, Pr.23=100%, Pr.66=60Hz)
150
90
60
45
30
22.5
0 60 100
82
PARAMETERS
200 300 400
Output frequency (Hz)