Location (MASD) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 16.0

Controller Tool Help

Brand
Johnson Controls
Metasys
Product name
Controller Configuration Tool
Document type
User Guide
Document number
LIT-12011147
Version
16.0
Revision date
2023-10-02
Language
English

The preheat coil may be located in the outdoor air duct or the mixed air duct. When the preheat coil is located in the outdoor air stream, a preheat temperature sensor is added to provide the process variable for the control loop. The control loop provides a minimum of 55 °F air to the mixing box of the air handler. When the preheat coil is located in the mixed air stream, the user has the option of controlling the coil Sequenced with Main Control Strategy, or using a separate Control to Preheat Air Temperature. When the coil is to be sequenced with the main control strategy, it is treated as the first stage of heat. That is to say it is energized first when the process variable falls below setpoint. When the coil is set to control to preheat temperature, a preheat temperature sensor is added, and this becomes the process variable for the preheat coil control loop.