Isolation Valve (CPO) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 13.1

Controller Tool Help

Brand
Johnson Controls
Metasys
Product name
Controller Configuration Tool
Document type
User Guide
Document number
LIT-12011147
Version
13.1
Revision date
2019-12-04
Language
English
  • CHW Isolation Valve: This option controls a CHW isolation valve for each chiller.
    • Valve Open Status: This option monitors the CHW isolation valve status.
    • Loss of Status Strategy
      • Automatic Restart
      • Manual Restart
        • Unit Reset Switch (BI)
    • Isolation Valve Analog Output: This option provides an analog output for the isolation valve rather than binary output.

Headered systems use isolation valves and the pumps are commanded on or off by a dP control module. Dedicated systems, on the other hand, do not use isolation valves and the pumps are directly commanded by the chiller selector primitive. Therefore, since the primitive knows (CW Headered/Dedicated property) whether the CW loop is headered or dedicated, the CW Iso Valve/Pump command behaves accordingly, that is, if it is dedicated, it is a Pump command and if it is headered it is an Isolation Valve command.

Likewise, since the primitive knows (CHW Headered/Dedicated property) whether the CHW loop is headered or dedicated, the CHW Iso Valve/Pump command behaves accordingly. That is, if the CHW loop is dedicated, the CHW loop is a pump command; and if the CHW Iso Valve/Pump command is headered, the CHW Iso Valve/Pump command is an isolation valve command.