Mitsubishi Electric FR-A720-0.4K Instruction Manual page 377

Special operation and frequency control
(5) PID control automatic switchover control (Pr. 127)
⋅ The inverter can be started up without PID control only at a start.
⋅ When the frequency is set to Pr. 127 PID control automatic switchover frequency within the range of 0 to 400Hz, the
system starts up without PID control from a start until Pr. 127 reaches, and then it shifts to PID control operation
mode. Once the system has entered PID control operation, it continues PID control if the output frequency falls to
or below Pr. 127.
Output frequency
Pr.127
STF
PID
(6) PID output suspension function (SLEEP function) (SLEEP signal, Pr. 575 to Pr. 577 )
⋅ The inverter stops operation if the output frequency after PID operation remains at less than the Pr. 576 Output
interruption detection level setting for longer than the time set in Pr. 575 Output interruption detection time. This function
can reduce energy consumption in the low-efficiency, low-speed range.
⋅ When the deviation (= set value - measured value) reaches the PID output shutoff cancel level (Pr. 577 setting -
1000%) while the PID output interruption function is ON, the PID output interruption function is canceled and PID
control operation is resumed automatically.
⋅ While the PID output interruption function is ON, the PID output interruption signal (SLEEP) is output. At this time,
the inverter running signal (RUN) is OFF and the PID control operating signal (PID) is ON.
Reverse action (Pr.128
Deviation
Pr.577 - 1000%
Output frequency
Pr.576
RUN
PID
SLEEP
(7) PID monitor function
⋅ The PID control set value, measured value and deviation value can be displayed on the operation panel and output
from terminal FM, AM.
⋅ Integral value indicating a negative % can be displayed on the deviation monitor. 0% is displayed as 1000. (The
deviation monitor cannot be output from the terminal FM, AM.)
⋅ For the monitors, set the following values in Pr. 52 DU/PU main display data selection, Pr. 54 FM terminal function
selection, and Pr. 158 AM terminal function selection.
Setting Monitor Description
52 PID set point
53 PID measurement value
54 PID deviation value
366
Without PID
control PID control
10)
Less than Pr. 575
Pr. 575 or more SLEEP period
Minimum Terminal FM,
Increments AM Full Scale
0.1%
0.1%
0.1%
OFF
ON
100% For deviation input (Pr. 128 = 10, 11), the monitor
value is always displayed as 0.
100%
Value cannot be set to Pr. 54 or Pr. 158.
⎯
The PID deviation value of 0% is displayed as 1000.
Time
Cancel
level
Time
Remarks