Optional Features (SZAHU) - 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

These selections provide the logic for controlling the operation of the application. The Unit Enable logic includes the option to delay startup after controller restart (Power Fail Restart).

The selection options for Optional Features are:
  • Unit Enable: This option determines whether the application operates based on the Network Input (BV). If you select the Unit Enable Switch, then when the Network Input is considered unreliable when it does not have a valid command from the network. If you select both BI and BV, the state of both must be Enable for the unit to operate .
  • Unit Enable Switch (BI): This option determines whether the application operates based on the Hardware Input (BI). If you select Unit Enable, then the Network Input is considered unreliable when it does not have a valid command from the network. If you select both BI and BV, the state of both must be Enable for the unit to operate.
  • Power Fail Restart: This feature is available as part of the State Generator module. When you select this option after a restart (power cycle, transfer to the controller, or manual restart command), the application is held in the shutdown state for the Power Fail Restart Time. The deafult is 60 seconds.
  • AHU Alarms: This option adds alarms for fan maintenance, fan status, large filter pressure drops, and high and low building static pressures. You can temoporarily disable alarms by setting the network BI (ALM-MS) to true.
  • Generic Thermal Zone Alarms: This option adds alarms for CO2, low zone temperature, high zone temperature, and open windows while unoccupied. You can temoporarily disable alarms by setting the network BI (ALM-MS) to true.
  • Automatic Fault Detection and Diagnostics: This option adds logic which assesses AHU performance by comparing network BAS inputs and outputs to a subset of potential fault conditions. The subset of potential fault conditions that is assessed at any point depends on the operating state (OS) of the AHU, as determined by the position of cooling and heating valves and the economizer damper (OAD-O). Time delays are applied to the evaluation and reporting of fault conditions to suppress false alarms. Fault condition which pass these filters are reported to the engine along with a series of possible causes.
  • Request Generation: Adds AO network outputs which you send to chillers and boilers. They include CLG-PLANT-REQ and HTG-PLANT-REQ which request to enable the chiller or boiler, and they include CLG-RESET-REQ and HTG-RESET-REQ which request the chiller or boiler to reset their supply pressure or temperature.
  • Request Accumulation: Adds logic to help identify whether the VAV is sending so many requests that it is driving trim and respond for the chillers or boilers.
  • Request Accumulation: Adds logic to help identify whether the VAV is sending so many requests that it is driving trim-and-respond setpoint reset logic.
  • Return Time Calculation (Optimal Start): Adds logic to calculate a RETURN-TIME AO to be used at the engine level. This is an estimate of the time required to reach the occupied setpoint and is used to determine when to enter warmup or cooldown.
  • System OK: Adds logic which sets a BO output (AHU-OK) that is true whenever the system in proven on, has been achieving its temperature or pressure setpoints for at least five minutes, and is ready and able to serve its load. The value is also set to false whenever there are Level 1 through 3 alarms.