Table of Contents
0 to 100% Horizontal Dry Bulb Economizer Precedent™ Packaged Rooftop Units 12.5 to 25 Tons
Used With
| Model Number: | Used With: |
| FIAECON303* | Precedent D cabinet (Digit 39 = D) |
Installation Instructions Manual
Click the e-library symbol for the latest version of the 0 to 100% Horizontal Dry Bulb Economizer Installation Instructions.
Notes
- A Fresh Air Options Module (FIAOPTN002*) must be installed in the unit for the accessory to operate.
- If the optional sensors for humidity and temperature monitoring are needed to install them using the instructions (FIAENTH001* - Reference Enthalpy Precedent™ Packaged Rooftop Units 3 to 25 Tons, Installation Instructions (ACC-SVN234*-EN)), (FIAENTH002* - Comparative Enthalpy Kit Precedent™ Packaged Rooftop Units 3 to 25 Tons, Installation Instructions (ACC-SVN235*-EN)) provided in those kits, and (FIADFDB001* - Dry Differential Bulb Kit Precedent™ Packaged Rooftop Units 3 to 25 Tons, Installation Instructions (ACC-SVN264*-EN)).
- For horizontal application, a smoke detector may need to be converted to a horizontal configuration. Please follow the instructions in the unit IOM document. Click below to find your IOM.
- 12.5 to 25 Ton (T/YS*180-300, T/YH*180-300, T/YZ*150-300, W/D/G**180-300) units being converted to horizontal application must use the horizontal duct conversion kit.
- To set the minimum positions, Click the link below.
Wiring
- Route the controls harness from the actuators to the fresh air options module located in the return enclosure using the factory-installed wire ties. Be sure the harness is away from all moving parts of the damper assemblies. Connect the harness P11 (Blue Connector) to the fresh air options module J11 (Blue Connector). Confirm the harness is securely connected.
- P9 (Red Plug) is for optional humidity and temperature sensors for Differential Dry Bulb, Reference Enthalphy, and Comparative Enthalphy.
- P5 (White Plug) powers the FAOM with the red and black wires; it requires 24VAC. The blue and orange wires are used for the module's communication with the unit controller, which requires 3.2-3.9 VDC via IMC protocol.
Economizer Type
| Type | Economizer Status | Calculation |
|---|---|---|
Fixed Dry Bulb |
Enable |
Outdoor Air Temperature < Economizer Outdoor Air Enable Setpoint - Economizer Dry Bulb Enable Offset |
Disable |
Outdoor Air Temperature Economizer Outdoor Air Enable Setpoint | |
Differential Dry Bulb |
Enable |
Outdoor Air Temperature < (Return Air Temperature - Economizer Dry Bulb Enable Offset - Economizer Dry Bulb Diable Return Air Offset) |
Disable |
Outdoor Air Temperature < (Return Air Temperature - Economizer Dry Bulb Diable Return Air Offset) | |
Reference Enthalpy |
Enable |
Outdoor Air Enthalpy < (Economizer Outdoor Air Enthalpy Enable Setpoint - Economizer Cooling Reference Enthalphy Offset) AND Outdoor Air Enthalpy < (Economizer Outdoor Air Enable Setpoint - Economizer Dry Bulb Enable Offset) |
Disable |
Outdoor Air Enthalpy > Economizer Outdoor Air Enthalpy Enable Setpoint OR Outdoor Air Temperature > Economizer Outdoor Air Enable Setpoint |
|
Comparative Enthalpy |
Enable |
Outdoor Air Enthalpy < (Return Air Enthalpy - Economizer Cooling Reference Enthalpy Hysteresis Offset) AND Outdoor Air Temperature < (Economizer Outdoor Air Enable Setpoint - Economizer Dry Bulb Enable Offset) |
Disable |
Outdoor Air Enthalpy > Return Air Enthalpy OR Outdoor Air Temperature > Economizer Outdoor Air Enable Setpoint |
Field-Installed Module Addressing
-
Change the rotary dials from 00 to 76.
If the FOAM was factory-installed, the module will have a factory-installed address plug on J11, and there is no need to use the rotary dials.
Configuration
For more information about Fresh Air Option Module Configuration, click the link below:
Relief Fan (Power Exhaust)
For more information about Relief Fan (Power Exhaust), click the link below:
Possible Alarms
- Symbio™ 700 provides Economizer fault detection and diagnostics, which can affect the controller’s ability to provide economizer cooling.
| Diagnostic/Alarm | Target |
Severity |
Persistence |
Alarm Indicator |
Condition/Response |
| FDD: Excessive Outdoor Air | Economizer cooling |
Warning |
Non-Latching |
YES |
Economizer cooling disabled (Economizer Airside Status = Inactive), and outdoor air damper command is less than the outdoor air damper position feedback – 10% for five minutes. Economizer operation is disabled. |
| FDD: Outdoor Air Damper Not Modulating | Economizer cooling |
Warning |
Non-Latching |
YES |
Economizer cooling disabled (Economizer Airside Status = Inactive), and outdoor air damper command is less than the outdoor air damper position feedback + 10% for five minutes. Economizer operation is disabled |
| FDD: Unit Economizing When It Should Not | Economizer cooling |
Warning |
Non-Latching |
YES |
Economizer cooling enabled (Economizer Airside Status = Active), and outdoor air damper command is less than the outdoor air damper position feedback – 10% for five minutes. Economizer operation is disabled. |
| FDD: Unit Not Economizing When It Should | Economizer cooling |
Warning |
Non-Latching |
YES |
Economizer cooling enabled (Economizer Airside Status = Active), and outdoor air damper command is less than the outdoor air damper position feedback + 10% for five minutes. Economizer operation is disabled. |
| Fresh Air Options Module | Partial |
Warning |
Non-Latching |
YES |
All economizer outdoor air damper and power exhaust operation are disabled. |
| Diagnostic: Unit Communications Failure | Unit |
Warning |
Non-Latching |
YES |
Active if any diagnostic listed in this table have a “not communicating” status. |
- Verify the PPM87/PPF87 or PPM201/PPF201 plug if you have any of the FDD economizer alarms.
- If P11-3 Blue wire is sending 10VDC on OA DAMPER OUT, then P11-2 Red wire should have 10VDC on OA DAMPER FEEDBACK.
- For Fresh Air Options Module Communication Diagnostic/Alarm, use the link below under (Not Communicating Troubleshooting).
Not Communicating Troubleshooting
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.