353
Special operation and frequency control
4
PARAMETERS
(5) PID control automatic switchover control (Pr. 127)
⋅
For a fast system startup at an operation start, the system can be started up in normal operation mode only at a start.
⋅ When the frequency is set to Pr. 127 PID control automatic switchover frequency within the range 0 to 400Hz, the
system starts up in normal operation mode from a start until Pr. 127 is reached, 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.
(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.
(7) PID monitor function
⋅ The PID control set value, measured value and deviation value can be output to the operation panel monitor
display and terminal CA, AM.
⋅ The deviation monitor can display a negative value on the assumption that 1000 is 0%. (The deviation monitor
cannot be output from the terminal CA, AM.)
⋅ For the monitors, set the following values in Pr. 52 DU/PU main display data selection, Pr. 54 CA terminal function
selection, and Pr. 158 AM terminal function selection.
Setting Monitor Description
Minimum
Increments
Terminal CA,
AM Full Scale
Remarks
52 PID set point 0.1% 100%
For deviation input (Pr. 128 = 10, 11), the monitor
value is always displayed as 0.
53 PID measurement value 0.1% 100%
54 PID deviation value 0.1% ⎯
Value cannot be set to Pr. 54 or Pr. 158.
The PID deviation value of 0% is displayed as 1000.
Output frequency
r.127
STF
Time
PID
PID control
Normal
operation
Output frequency
Deviation
Reverse action (Pr.128 10)
Pr.576
Pr.577 - 1000%
RUN
Time
ON
OFF
SLEEP
Less than Pr. 575
Pr. 575 or more SLEEP period
PID
Cancel
level