Mitsubishi Electric FR-A800 Series Instruction Manual page 618

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 a 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. In this case, the PID output shutoff release level is (1000 - Pr.577).
Reverse action
Forward action
PID output shutoff release level
(Example) Set the following: Pr.934 = "500" or 20% (4 mA is applied), Pr.935 = "100" or 100% (20 mA is applied).
When the set point = 400 and the measured value = 360, the deviation is +40 (>0), but the inverter recognizes the deviation
as -10% (<0). Because of this, operation amount does not increase in the reverse operation setting.
The operation amount increases when the forward operation is set.
To perform PID output shutoff release at deviation of +40 or higher, set Pr.577 = "960".
• The display of the following parameters is changed according to the C42 (Pr.934), C44 (Pr.935), Pr.1136, and Pr.1138
settings.
Pr.
131
132
133
553
577
761
763
 Changing the PID display coefficient of the LCD operation panel (FR-
LU08) or the parameter unit (FR-PU07) (Pr.759)
• Use Pr.759 PID unit selection to change the unit of the displayed value on the FR-LU08 or the FR-PU07. For the
coefficient set in C42 (Pr.934) to C44 (Pr.935), the units can be changed as follows.
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Pr.934 < Pr.935 (normal setting)
Reverse action setting to Pr.128
Forward action setting to Pr.128
Pr.577 - 1000
Deviation +40
* ( ) indicates the deviation value
which the inverter can recognize
Name
PID upper limit
PID lower limit
PID action set point
PID deviation limit
Output interruption cancel level
Pre-charge ending level
Pre-charge upper detection level
search engine
Reverse action
Forward action
PID output shutoff release level
500
Set point 400
Measured value
360
100
0
20%
(0%) (25%) (35%)
Pr.
1143
1144
755
1145
1149
766
768
Pr.934 ≥ Pr.935
Forward action setting to Pr.128
Reverse action setting to Pr.128
1000 - Pr.577
100%
(100%)
Deviation -10%
Name
Second PID upper limit
Second PID lower limit
Second PID action set point
Second PID deviation limit
Second output interruption cancel level
Second pre-charge ending level
Second pre-charge upper detection level
5.14 (A) Application parameters
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5. PARAMETERS