Mitsubishi Electric Freqrol-A100 Instruction Manual page 160

4.8.7 Calibration
The following example shows the adjustment of a room temperature to 25°C under PI control using
a detector which detects 4mA at 0°C and 20mA at 50°C. The set value is provided to across inverter
terminals 2 and 5 (0 to 5V).
START
s
Determination of set value
Determine the set value of the object
to be adjusted.
[Specific example]
............
Abjust the room temperature to 25°C.
Set a value other than 0 and 1 in Pr. 128 and connect
terminals RT and SD to enable PI control.
............
Make calibration.
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When the set value setting input (0 to 5V) and
detector output (4 to 20mA) calibration are required,
perform the following calibration marked
*.
1
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Setting of set value
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Conversion of set value into %
Calculate the percentage of the set
value to the detector output.
Input a voltage to across terminals 2-
5 according to the percentage of the
............
Detector specifications
When the detector used detects 4mA at 0°C and
20mA at 50°C, 4mA corresponds to 0%, 20mA to
loo%, and the set value of 25°C to 50%.
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Operation
Set a slightly wider value to the pro-
portional band and a slightly longer
value to the integral time, and switch
............
To set the set value to 50%
As 0% corresponds to O V and 100% to 5V in the
specifications of terminal 2, input 2.5V to terminal 2
to set the set value to 50%.
............
When operation is performed from the parameter
unit, input the set value (0 to 100%) in Pr. 133.
At first, set slightly larger values to the proportional
band and integral time. Reduce the proportional
band and integral time values according to the
Parameter adjustment
To stabilize the process value,
change the proportional band to a throughout the operation, the propor-
slightly wider value and the integral
tional band and integral time may be
*time to a slightly longer value.
[on the start signal.
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ADJUSTMENT COMPLETE
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operation of the system.
*
When calibration is needed, use calibration parameters Pr. 902 to Pr
905 to calibrate the detector output and set value setting input.
Make calibration in the PU mode while the inverter is at a stop.
(1) Calibration of set value input
1) Apply a voltage for 0% set value setting input (e.g. OV) to across terminals 2 and 5.
2) Make calibration using Pr. 902 "frequency setting voltag'e bias". At this time, input the
frequency which the inverter should output at the deviation signal of 0% (e.g. OHz).
3) Apply a voltage for 100% set value setting input (e.g. 5V) to across terminals 2 and 5.
4) Make calibration using Pr. 903 "frequency setting voltage gain". At this time, input the
frequency which the inverter should output at the deviation signal of 100% (e.g. 60Hz).