Outside Air Single Duct Air Handling Unit

115 Pages·2008·2.28 MB·English

Application Note Outside Air Single Duct Air Handling Unit
Issue Date December 4, 2008

Outside Air Single Duct (OASD) Air Handling Unit (AHU)
Application Note

OASD AHU Application Note ....................................................................4
Introduction............................................................................................................4
Related Documentation.........................................................................................6
Key Concepts.........................................................................................................7
State Based Control.............................................................................................................7
Occupancy Determination....................................................................................................8
Temperature Control Strategies...........................................................................................9
Discharge Air Temperature (DAT) Control.....................................................................9
Discharge Air Temperature Reset by Zone Temperature Error.....................................9
Discharge Air Temperature Reset by Exhaust Air Temperature Error...........................9
Discharge Air Temperature Reset by Outside Air Temperature...................................10
Active Setpoint Determination............................................................................................10
Active Process Variable Determination..............................................................................11
Occupied Control Sequencer.............................................................................................12
Unoccupied Control Sequencers.......................................................................................14
Discharge Air Unoccupied Sequencer.........................................................................14
Sequencers........................................................................................................................17
Emergency Mode.........................................................................................................17
No Airflow.....................................................................................................................18
Unit Enable...................................................................................................................19
Start Stop Sequencer...................................................................................................20
Energy Recovery Low Limit.........................................................................................22
Control of Staged Devices.................................................................................................23
Discharge Air Control of Staged Devices.....................................................................23
Device Availability Determination.................................................................................24
Dehumidification...........................................................................................................25
Output Device Control........................................................................................................26
Energy Recovery..........................................................................................................26
Preheat.........................................................................................................................31
Heating.........................................................................................................................35
Cooling.........................................................................................................................39
Two Pipe Coil...............................................................................................................43
Supply Fan...................................................................................................................43
Exhaust Fan.................................................................................................................45
Humidification...............................................................................................................47
© 2008 Johnson Controls, Inc. www.johnsoncontrols.com
Code No. LIT-12011289
2 OASD AHU Application Note
PID Tuning.........................................................................................................................48
Integration Time...........................................................................................................48
Proportional Band........................................................................................................48
Saturation Time............................................................................................................48
FX Builder Application Wizard Concepts ..........................................................50
Installing the OASD AHU Application Package..................................................................50
Selecting the OASD AHU Application Template................................................................53
Configuring the OASD AHU Application............................................................................55
Configuring the Control Strategy..................................................................................55
Adjusting Setpoints......................................................................................................59
Adjusting Parameters...................................................................................................61
Adjusting Proportional Plus Integral plus Derivative (PID) Parameters........................64
Configuring the Internal Occupancy Schedule.............................................................66
Viewing the Configuration Summary............................................................................67
Viewing Required Inputs and Outputs..........................................................................68
Selecting the User Interface(s) and Supervisor Interface..................................................69
Selecting the Target Device...............................................................................................70
Configuring the Hardware I/Os...........................................................................................71
Generating the Application Files and Documentation........................................................73
Viewing Generated Application and Documentation Files...........................................74
Reviewing an Exported Application File.............................................................................74
FX CommPro Concepts.......................................................................................76
User Interface Concepts......................................................................................76
Medium User Interface.......................................................................................................76
Medium User Interface Capabilities.............................................................................77
Medium User Interface Navigation...............................................................................77
Status Folder................................................................................................................79
Modes Folder...............................................................................................................81
Configuration Folder.....................................................................................................83
Setpoints Folder...........................................................................................................86
Parameters Folder.......................................................................................................87
PID Parameters Folder................................................................................................90
Balancer Folder............................................................................................................91
Time Folder..................................................................................................................92
Schedulers Folder........................................................................................................93
Password Folder..........................................................................................................93
MUI Status LEDs..........................................................................................................93
Accessing a Folder in the MUI.....................................................................................94
Changing a Configuration Setting, Setpoint, or Parameter in the MUI.........................94
LCD2x4 User Interface.......................................................................................................95
LCD2x4 User Interface Capabilities.............................................................................96
LCD2x4 User Interface Navigation...............................................................................96
Config 1 Page..............................................................................................................98
OASD AHU Application Note 3
Config 2 Page............................................................................................................100
Analog Inputs Page....................................................................................................101
Digital Inputs Page.....................................................................................................101
Analog Outputs Page.................................................................................................102
Digital Outputs Page..................................................................................................102
Setpoints 1 Page........................................................................................................103
Setpoints 2 Page........................................................................................................104
Parameters 1 Page....................................................................................................104
Parameters 2 Page....................................................................................................106
PID Parameters Page................................................................................................107
Modes Page...............................................................................................................108
Time Page..................................................................................................................111
Balancer Page............................................................................................................112
FX Setup....................................................................................................................113
Password Page..........................................................................................................113
Events Page...............................................................................................................114
Schedulers Page........................................................................................................114
Graphical Status Icons...............................................................................................114
Accessing a Page in the LCD2x4 UI..........................................................................114
Changing a Configuration Setting, Setpoint, or Parameter in the LCD2x4 UI............114
Supervisor Interface..........................................................................................115
4 OASD AHU Application Note
OASD AHU Application Note
Introduction
This application note introduces the standard 100% Outside Air Single
Duct (OASD) Air Handling Unit (AHU) controller application template,
provides procedures to configure the application using FX Builder’s
Application Wizard, and provides the procedures to commission the
system using the Integral and Medium User Interface (MUI) and FX
CommPro.
The 100% OASD AHU application template consists of a single
application software file which includes multiple configuration options
and control strategies for controlling many different types of air handlers.
You use FX Builder’s Application Wizard to select the specific
configuration options and control strategies for your specific 100% OASD
AHU control requirements. The available control strategy configuration
options appear in Table 1.
Table 1: OASD AHU Configuration Options
Configuration Setting Allowable Options
Temperature Control Strategy Discharge Air Temperature Control
Discharge Air Temperature reset by Zone
Temperature Error
Discharge Air Temperature reset by Exhaust Air
Temperature Error
Discharge Air Temperature reset by Outside Air
Temperature
Type of Energy Recovery None
Glycol Loop (Proportional)
Glycol Loop (2-Position)
Energy Wheel (Proportional)
Energy Wheel (2-Position)
Type of Preheat None
Staged (up to four stages)
Face & Bypass Damper (with 2-position or
proportional valve)
Proportional valve
Staged Preheat Control Type Equal Runtime
First On/Last Off
Continued on next page . . .
OASD AHU Application Note 5
Configuration Setting (Cont.) Allowable Options
Type of Cooling None
2 Pipe (Common Heating/Cooling Coil)
Staged (up to 4 stages)
Face and Bypass Damper (with 2-position valve)
Proportional valve
Staged Cooling Control Type Equal Runtime
First On/Last Off
Type of Heating None
2 Pipe (Common Heating/Cooling Coil)
Staged (up to 4 stages)
Face & Bypass Damper (with 2-position valve)
Proportional valve
Staged Heating Control Type Equal Runtime
First On/Last Off
Supply Fan Type Constant Volume
Variable Volume
Exhaust Fan Type None
Constant Volume
Supply Fan Tracking
Building Pressure Control
Humidification Enable
Disable
Dehumidification Enable
Disable
Alarm Options High Static Pressure Alarm
Low Limit Alarm
Supply Fan Proof
Smoke Alarm
Reset After Loss of Airflow Manual
Automatic
Power Fail Restart Enable
Disable
6 OASD AHU Application Note

Figure 1: Facility Explorer OASD AHU Application Architecture
Related Documentation
Table 2: Related Documentation
For Information On See Document LIT or Part Number
FX15 Overview Information FX15 Field Controller LIT-12011082
Product Bulletin
FX15 Technical Information FX15 Controller Technical LIT-12011107
Bulletin
FX16 Overview Information FX16 Master Controller LIT-12011084
Product Bulletin
FX16 Technical Information FX16 Master Controller LIT-12011108
Technical Bulletin
OASD AHU Application Note 7
Key Concepts
State Based Control
The OASD AHU application uses State Based Control to ensure proper
control of the air handling unit. State Based applications have the
following components.
• Inputs: Extract information from the system. Examples include
hardwired sensors (for example, discharge air temperature sensor),
switches (for example, proof of airflow switch), and network overrides
(for example, networked outside air temperature).
• Parameters: Refer to pieces of information stored inside the
application. Examples include configuration settings, setpoints, unit
parameters, and Proportional plus Integral plus Derivative (PID)
parameters. Many parameters are adjustable.
• Miscellaneous Logic: Defines all logic not defined via a State
Generator or Output Controller. Examples include occupancy
determination and active setpoint determination.
• State Generators: Defines the sequences of operation for a specific
control system. State generators need information from the appropriate
inputs or parameters or status information from the output controllers
to ensure proper sequencing.
• State Selector: Receives state information from all of the state
generators. The state selector then determines the current set of output
controller modes based on the current states of all the state generators.
• Output Controllers: Defines the operation of the output devices (for
example, valves, dampers, and fans) based on the modes determined
by the State Selector.
• Outputs: Converts the output controller information into action.
Examples include valve and damper outputs, fan commands, and
cooling and heating stage commands.

Figure 2: State Based Control Diagram
8 OASD AHU Application Note
Occupancy Determination
The OASD AHU application:
• supports a local and network occupancy schedule with the network
schedule having priority
• supports a local and network occupancy sensor with the network
occupancy sensor having priority
• has a temporary occupancy input and a network occupancy manual
command with the network occupancy manual command having
priority
Table 3 displays the occupancy determination for the OASD application.
Table 3: Occupancy Determination
Inputs Result
Occupancy Manual Occupancy Occupancy Effective
Command Schedule Sensor Occupancy
Occupied − − Occupied
Unoccupied Unoccupied
Bypass Occupied Occupied
Unoccupied Bypass
Bypass Bypass
Standby Bypass
Invalid Occupied Occupied
Unoccupied Bypass
Standby − − Standby
Invalid Occupied Occupied Occupied
Unoccupied Standby
Invalid Occupied
Unoccupied − Unoccupied
Bypass Bypass
Standby Standby
Invalid Occupied Occupied
Unoccupied Unoccupied
OASD AHU Application Note 9
Temperature Control Strategies
The OASD AHU application supports the following selectable
temperature control strategies.
Discharge Air Temperature (DAT) Control
The OASD AHU sequences the controlled devices to control the discharge
air temperature to a constant setpoint.
Discharge Air Temperature Reset by Zone Temperature Error
The OASD AHU uses the zone temperature error to calculate a discharge
air temperature setpoint. The zone temperature error is the difference
between the actual zone temperature and the active zone setpoint. When
the zone is warm, the discharge air temperature setpoint resets down.
When the zone is cold, the discharge air temperature setpoint resets up.
The OASD AHU sequences the controlled devices to control the discharge
air temperature to this calculated setpoint. See Figure 3.

Figure 3: Discharge Air Temperature Reset by Zone Temperature Error
Discharge Air Temperature Reset by Exhaust Air Temperature
Error
The OASD AHU uses the exhaust air temperature error to calculate a
discharge air temperature setpoint. The exhaust air temperature error is the
difference between the actual exhaust air temperature and the active
exhaust air setpoint. When the exhaust air is warm, the discharge air
temperature setpoint resets down. When the exhaust air is cold, the
discharge air temperature setpoint resets up. The OASD AHU sequences
the controlled devices to control the discharge air temperature to this
calculated setpoint.
10 OASD AHU Application Note
Discharge Air Temperature Reset by Outside Air Temperature
The OASD AHU uses the outside air temperature to calculate a discharge
air temperature setpoint. When the outside air is warm, the discharge air
temperature setpoint resets down. When the outside air is cold, the
discharge air temperature setpoint resets up. The OASD AHU sequences
the controlled devices to control the discharge air temperature to this
calculated setpoint. See Figure 4.

Figure 4: Discharge Air Temperature Reset by Outside Air Temperature
Active Setpoint Determination
The active setpoint that the OASD AHU application uses depends on the
selected temperature control strategy and the current occupancy mode.
Use Table 4 and Table 5 to understand how the active setpoint is
determined.
Table 4: Active Setpoint Determination–Occupied Mode
Control Strategy Active Setpoint
Discharge Air Temperature Control Discharge Air Temperature Setpoint
Discharge Air Reset by Zone Temperature Calculated--based on zone
Error temperature error reset schedule
Discharge Air Reset by Exhaust Air Calculated--based on return air
Temperature Error temperature error reset schedule
Discharge Air Reset by Outside Air Calculated--based on outside air
Temperature temperature reset schedule