Mitsubishi Electric 800 Series Instruction Manual page 427

When Pr.1132 Pre-charge change increment amount  "9999" (vertical pumps), PID control is performed so that the
-
change increment amount of the set point equals the Pr.1132 setting after the automatic switchover frequency is
reached until the pre-charge ending condition is satisfied. (Although PID control is performed after the automatic
switchover frequency is reached until the pre-charge ends, the status is regarded as the one during pre-charge.)
• 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.
• 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.)
NOTE
• When the PID output suspension (SLEEP) function is in use, and the X77 signal is set to valid after this function is released,
set the X77 signal to OFF after checking that the during pre-charge operation signal (Y49) is OFF.
• When the PID output suspension (SLEEP) function is in use, and PID control is to be performed immediately after this
function is released, leave the X77 signal ON until PID control ends.
• When the pre-charge operation is valid, the pre-charge operation is performed at the output shutoff cancellation (MRS
signal, etc.). (The pre-charge operation is also performed in the case of instantaneous power failure when the automatic
restart after instantaneous power failure is valid.)
• When the control method is changed to PID control from a control with higher priority in frequency command (multi-speed
setting, Jog operation, etc.), the motor is accelerated/decelerated until its speed reaches the automatic switchover
frequency (Pr.127), and the pre-charge is performed.
426
5. PARAMETERS
5.11 (A) Application parameters
Ending level
Measured value[PSI]
Pr.761
Target
Output frequency[Hz]
Pr.127
0 Hz
STF
Y49
Output frequency [Hz]
Pr.127
Ending time
Pr.762
0 Hz
STF
Y49
Output frequency [Hz]
Pr.127
0 Hz
STF
X77
Y49
Measured value
PID control
PID control
PID control
10 ms or more
Time
Time
Time
Time