Mitsubishi Electric FR-F740 EC Instruction Manual page 502

PID control
NOTES
If the X77 or X78 signal is ON at start after the PID output suspension (SLEEP) or the output
shutoff cancellation, PID control starts without performing the pre-charge operation.
PID output suspension (SLEEP) is not performed until the pre-charge operation ends.
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 set-
tings already satisfy a condition to start PID control, the PID control starts as soon as these
are changed. )
Pre-charge operation
● When the measured amount reaches the pre-charge ending level
When the measured amount reaches the Pr. 761 setting or higher, the pre-charge operation
ends, and PID control starts.
Fig. 6-188: Pre-charge ending level (Pr. 761 ≠ 9999)
6 - 352
Measured value [PSI]
Pr. 761
Ending level
Output frequency [Hz]
Pr. 127
0Hz
STF
Output signal
Y49
PID control
Pre-charge
Parameter
Time
Time
I002310E