Mitsubishi Electric FR-A800, Instruction Manual

Page: 724 / 1042

(A) Application parameters Parameters
5 - 544
●
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%.
●
There are three methods to adjust the PID display bias/gain.
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 ( ) to ( ), and make the necessary adjustments by considering
C7 (Pr. 905) as C45 (Pr. 935) and Pr. 126 as C44 (Pr. 935).
●
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.
I002699E
Fig. 5-268: PID bias and gain
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.
Pr. 934 < Pr. 935 (normal setting) Pr. 934
≥
Pr. 935
Reverse action
Reverse action setting to
Pr. 128
Reverse action
Forward action setting to
Pr. 128
Forward action
Forward action setting to
Pr. 128
Forward action
Reverse action setting to
Pr. 128
PID output shutoff release level Pr. 577 – 1000 PID output shutoff release level 1000 – Pr. 577
Tab. 5-230: Special conditions for parameter settings
100
0
0
0
0
100%
20
4
1
2
C
o
e
fficien
t
Initial value
Gain
C44 (Pr. 935)
Frequency setting signal
C43 (Pr. 934) C45 (Pr. 935)
20 mA
5 V
10 V
Bias
C42 (Pr. 934)