Economizer Suitability (MASD) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 15.0

Controller Tool Help

Brand
Johnson Controls
Metasys
Product name
Controller Configuration Tool
Document type
User Guide
Document number
LIT-12011147
Version
15.0
Revision date
2022-11-18
Language
English

Use this section to select the method of determining when free cooling is available.

Network Command adds a network input to indicate free cooling is available for the unit. The value of this input should be calculated elsewhere using the prescribed logic for your project.

Enthalpy Switch (BI) adds a binary input designed to be connected to a commercially available enthalpy switch. This type of sensor is typically supplied with package equipment or packaged economizer sections.

Outdoor Air allows the user to select the desired logic to determine when free cooling is available.
Note: Any economizer strategy that requires the outdoor air temperature or humidity uses a network input by default for these values unless the application included analog inputs for these values. If there are analog inputs for outdoor air temperature or humidity, the network inputs are removed, and the module inputs receive data from the analog inputs.
  • Dry Bulb Temp Economizer enables free cooling when the outdoor air temperature drops below the economizer switchover setpoint (ECONSWO-SP).
  • Temperature & Enthalpy Economizer uses the outdoor temperature and humidity and the return temperature and humidity to calculate the enthalpy difference of the two airstreams. It uses free cooling if there is less enthalpy in that air stream as long as the dry bulb temperature is below the economizer switchover setpoint (ECONSWO-SP).
  • Outdoor Air versus Return Air compares the dry bulb temperature for the outdoor and return air to determine when free cooling is available.