Mitsubishi Electric FR-A820-00046 Instruction Manual page 724

(A) Application parameters
● When both of C42 (Pr. 934) and C44 (Pr. 935) ≠ "9999" and Pr. 133 is set as the set point, the setting
of C42 (Pr. 934) is treated as 0%, and C44 (Pr. 935) as 100%.
Fig. 5-268:
● There are three methods to adjust the PID display bias/gain.
³ Method to adjust any point by application of a current (voltage) to the measured value input
terminal
· Method to adjust any point without application of a current (voltage) to the measured value
input terminal
» Method to adjust only the display coefficient without adjustment of current (voltage)
(Refer to page 5-401 for details on (³) to (»), and make the necessary adjustments by considering
C7 (Pr. 905) as C45 (Pr. 935) and Pr. 126 as C44 (Pr. 935).
NOTE Always calibrate the input after changing the voltage/current input specification with Pr. 73 and
Pr. 267, and the voltage/current input selection switch.
● Take caution when the following condition is satisfied because the inverter recognizes the
deviation value as negative (positive) value even though a positive (negative) deviation is given:
Pr. 934 (PID bias coefficient) > Pr. 935 (PID gain coefficient)
To perform a reverse action, set Pr. 128 "PID action selection" to forward action. Alternatively, to
perform a forward action, set Pr. 128 to reverse action.
Reverse action
Forward action
PID output shutoff release level Pr. 577 – 1000
Tab. 5-230: Special conditions for parameter settings
5 - 544
100
Bias
C42 (Pr. 934)
0
0
0
0
C43 (Pr. 934)
PID bias and gain
Pr. 934 < Pr. 935 (normal setting)
Reverse action setting to
Pr. 128
Forward action setting to
Pr. 128
Initial value
20 100%
20 mA
4
Frequency setting signal
5 V
1
10 V
2
C45 (Pr. 935)
Reverse action
Forward action
PID output shutoff release level 1000 – Pr. 577
Parameters
Gain
C44 (Pr. 935)
Pr. 934 ≥ Pr. 935
Forward action setting to
Pr. 128
Reverse action setting to
Pr. 128
I002699E