Mitsubishi Electric 700 Series, Instruction Manual

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276
PID control
(1) Operation selection for the pre-charge function
The pre-charge function ends when any of the following conditions is satisfied. It also ends when the start signal turns
OFF or the output is shutoff (except for the PID output suspension function (SLEEP)).
Using parameters, set the pre-charge ending conditions and the pre-charge function to be valid or invalid.
* When two or more conditions are satisfied, the pre-charge operation ends by the first-satisfied condition.
⋅
Starting the pre-charge operation
Pre-charge operation starts when a start command is given (after the PID output suspension (SLEEP) or the MRS
(output shutoff) signal cancellation) while the pre-charge operation is set active by parameters.
⋅
Ending the pre-charge operation
The pre-charge operation ends and PID control starts when any of the ending conditions in the above table is satisfied.
Pre-charge ending condition Related parameter
Measured
amount
The measured amount reaches Pr. 766 Pre-charge ending level or higher. Pr. 761
Time The pre-charge operation lasts Pr. 767 Pre-charge ending time or longer. Pr. 762
Signal The pre-charge end command (X78) is input.
Pr. 178 to Pr. 189
Pr. 127
PID control
automatic
switchover
frequency
Pre-charge ending condition *
Pre-charge
function
Valid pre-charge ending condition
Pr. 761
Pre-charge
ending level
Pr. 762
Pre-charge
ending time
Pre-charge
end
command
(X77)
9999 - - -
Invalid -
Other than
9999
9999
9999
Not assigned
Assigned
Valid
- - X77
Other than
9999
Not assigned - Time -
Assigned - Time X77
Other than
9999
9999
Not assigned
Measured
amount
- -
Assigned
Measured
amount
- X77
Other than
9999
Not assigned
Measured
amount
Time -
Assigned
Measured
amount
Time X77
REMARKS
⋅
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 settings already satisfy a condition to start PID control, the PID control starts as soon as these are changed. )