Mitsubishi Electric FR-A800 Series Instruction Manual page 620

 Operation selection for the pre-charge function
• To enable the pre-charge function when PID control is enabled, set the pre-charge end conditions at Pr.761 Pre-charge
ending level and at Pr.762 Pre-charge ending time, or set "77" to Pr.178 to Pr.189 (Input terminal function selection).
When operation is started, the inverter runs at the frequency set to Pr.127 PID control automatic switchover frequency
to enter the pre-charge state.
• Pre-charge ends and PID control starts after a pre-charge ending condition is satisfied.
• The pre-charge function is also activated at a start after release of a PID output suspension (sleep) state or MRS (output
shutoff). The PID output suspension (sleep) function is not activated until the started pre-charge operation ends.
• During pre-charge operation, the During pre-charge operation (Y49) signal is output. For the terminal used for the Y49
signal output, set "49 (positive logic)" or "149 (negative logic)" in any of Pr.190 to Pr.196 (Output terminal function
selection) to assign the function.
• The pre-charge function valid/invalid settings and pre-charge ending conditions are as follows:
Pr.127 setting
9999
Other than
9999
*1 When two or more ends conditions are satisfied, the pre-charge operation ends by the first-satisfied condition.
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 the 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.
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Pre-charge ending condition setting
Pr.761 setting Pr.762 setting
— —
9999
9999
Other than 9999
9999
Other than 9999
Other than 9999
Measured value[PSI]
Pr.761
Ending level
Output frequency[Hz]
Pr.127
0Hz
STF
Y49
search engine
Pre-charge
function
X77 signal
—
Disabled
Not assigned
Assigned
Not assigned
Assigned
Not assigned Enabled
Assigned
Not assigned
Assigned
PID control
Valid pre-charge ending condition
—
— —
— Time
— Time
Result —
Result —
Result Time
Result Time
Time
Time
5. PARAMETERS
5.14 (A) Application parameters
1
2
3
4
*1
5
X77
6
—
X77
—
7
X77
—
X77
8
9
10
619