APC ACRD101, ACRD100 manual Tune the PID loop, Control Method Proportional Integral Derivative

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Tune the PID loop

Tune the PID loop to optimize the performance of the cooling group.

Caution: This procedure must be performed by APC authorized personnel only. The PID loop must be tuned after the equipment in the room is installed and running. The loop should be tuned periodically to account for changes in the room load.

1.Adjust the integral and derivative constants to zero and the proportional constant to 1.0.

2.Set the temperature setpoint value and start the cooling group.

3.When the temperature reaches a stable value, increase the proportional constant by 0.5. If the temperature does not respond to this change, adjust the setpoint.

4.Repeat step 3 until the temperature value starts to oscillate and the peak amplitude of the oscillations is constant.

5.Note the time, in minutes, between the peaks of the oscillations. This is the Ultimate Period, PU.

6.Note the value of the proportional constant. This is the Ultimate Gain, GU.

7.Compute the PID constants using the table below. Use the equations for that control method in the row to compute the values for each constant.

Control Method

Proportional

Integral

Derivative

 

 

 

 

P

0.5*GU

P + I

0.45*GU

0.54*GU/PU

P + I + D

0.6*GU

1.2*GU/PU

0.075*GU*PU

8. Set each constant according to these calculations.

You may need to further tune the PID loop in the following ways to account for changes in the room load:

Loop Behavior

PID Tuning Correction

 

 

Slow response to temperature changes

Increase the proportional multiplier or increase the

 

derivative multiplier.

 

 

Overcooling/undercooling after changes in the

Increase the derivative or the proportional multiplier.

room load or changes in setpoint

 

 

 

Environmental temperature never reaches the

Increase the integral multiplier.

setpoint

 

 

 

Overcooling/undercooling on constant room

Decrease the integral multiplier.

load

 

 

 

InRow RD 10 kW Air Cooled Operation and Maintenance

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Contents Operation and Maintenance 동봉된 CD 안에 한국어 매뉴얼이 있습니다 American Power Conversion Legal Disclaimer Page Contents Cooling Group Configuration Network Management Card Page Overview Symbols used in this manualCross-reference symbol used in this manual Safety Ensure that Inspection ChecklistsInitial inspection checklist Electrical inspection checklist Ensure that Mechanical inspection checklistStart-up inspection checklist User interface inspection checklistFinal inspection checklist While the cooling unit is operating, ensure thatCalculating R410A charge Charging With RefrigerantInRow RD 10 kW Air Cooled Operation and Maintenance Charging the equipment Compressor Oil Charge Oil charging procedureInRow RD 10 kW Air Cooled Operation and Maintenance Display Interface OperationScrolling status screens Using the Display InterfaceStatus Screen Name Status Information Displayed Main menu screensNavigating the sub-menus Navigating the main menuStart the cooling unit Using the Path statementPassword entry Stop the cooling unit General ConfigurationCooling unit configuration Configure the cooling group Cooling Group ConfigurationContacts View the state of input and output contactsIdentify the cooling unit Configure ModbusSetpoints Control the EnvironmentPID settings Control Method Proportional Integral Derivative Loop Behavior PID Tuning CorrectionTune the PID loop Thresholds Service intervalsRun hours Date and time Password and time-outDisplay units Adjust display settingsConfigure network Network ConfigurationCooling unit status View Status ReadingsAbout the cooling unit Cooling group statusClear the event log Event LogView the event log View active alarms Respond to AlarmsClear active alarms Alarm messages and suggested actionsThreshlds screen Configure Unit Discrete I/O screen. See page 17 for more Overview Quick ConfigurationTCP/IP configuration methods Ini file utility APC Device IP Configuration WizardBootp & Dhcp configuration NetworkTCP/IPBoot ModeDHCP onlyAdvancedDHCP Cookie Is Remote access to the control console Local access to the control consoleChoose Network from the Control Console menu Control consoleWeb interface Access a Configured Network Management CardTelnet and SSH Modbus Simple Network Management Protocol SnmpRecover From a Lost Password Environment Monthly Preventive MaintenanceCleanliness Electrical MechanicalFunctional tests Semi-Annual Preventive MaintenanceProblem Possible Cause Corrective Action TroubleshootingCorrective Action Problem Possible CausePage Page 990-3212A-001 11/2009 APC Worldwide Customer Support