Mitsubishi Electric FR-A820-00046 Instruction Manual page 540

(H) Protective function parameter
Setting example
● The load characteristics are calculated from the parameter setting and the output frequency.
● A setting example is shown below. The reference value is linearly interpolated from the parameter
settings. For example, the reference when the output frequency is 30 Hz is 26%, which is linearly
interpolated from values of the reference 2 and the reference 3.
Reference
Load characteristics reference 1
Load characteristics reference 2
Load characteristics reference 3
Load characteristics reference 4
Load characteristics reference 5
Tab. 5-128: Setting example for load reference
Fig. 5-148:
NOTE When the load reference is not set for five points, the load characteristics value is determined by
linear interpolation of the set load reference values only. If there is only one load reference setting,
the set load reference is used as the load reference all through the range.
Parameters referred to
Pr. 41
Pr. 190 to Pr. 196
5 - 338
Load [%]
120
100
80
60
40
26
20
0
0 10 20
Reference value when the output frequency is 30 Hz
Up-to-frequency sensitivity
(Output terminal function selection)
Frequency
f1: load characteristics minimum frequency
(Pr. 1487) = 10 Hz
f2 = (f5 - f1)/4 + f1 = 22.5 Hz
f3 = (f5 - f1)/2 + f1 = 35 Hz
f4 = (f5 - f1) × 3/4 + f1 = 47.5 Hz
f5: load characteristics maximum frequency
(Pr. 1486) = 60 Hz
30 40 50 60
Parameters
Load reference
Pr. 1481 = 15%
Pr. 1482 = 20%
Pr. 1483 = 30%
Pr. 1484 = 60%
Pr. 1485 = 100%
Frequency [Hz]
70
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I003029E