Mitsubishi Electric 800 Series Instruction Manual page 506

NOTE
• During the pre-charge operation, it is regarded as integrated value=estimated value. The motor speed may drop shortly from
the automatic switchover frequency depending on the parameter settings.
• Parameter changes and switchover to the second PID control are applied immediately. If PID control has not started when
the settings were changed, PID control starts with changed settings. (If PID control has already started, these settings do not
apply. If the changed settings already satisfies a condition to start PID control, the PID control starts as soon as these are
changed.)
• The pre-charge also ends when PID control is set to invalid, the start command has been turned OFF, and output has been
shut off.
Example of pre-charge operation
• When the measured amount reaches the pre-charge ending level (Pr.761 Pre-charge ending level  "9999")
The pre-charge operation ends when the measured value reaches the Pr.761 setting or higher, then the PID control is
performed.
Measured value[PSI]
Pr.761
Output frequency[Hz]
Pr.127
• When the elapsed time reaches the pre-charge ending time (Pr.762 Pre-charge ending time  "9999")
The pre-charge operation ends when the pre-charge time reaches the Pr.762 setting or higher, then the PID control is
performed.
Output frequency[Hz]
Pr.127
• When the signal is input to end the pre-charge operation
When the X77 signal turns ON, the pre-charge operation ends, and the PID control starts. (If a start command is given while
the X77 signal is ON, the pre-charge operation is not performed, and PID control starts.)
Ending level
0Hz
STF
Y49
Ending time
Pr.762
0Hz
STF
Y49
Output frequency[Hz]
Pr.127
0Hz
STF
X77
Y49
(A) Application parameters
PID control
PID control
PID control
Time
10ms or more
Time
Time
Time
505
PARAMETERS
5
GROUP
A