Primary States (Humidification Scrubber Output) - 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
  • Off: Set Humidity Percent Cmd to 0% and turn off all the stages, but observe the minimum on and off timers. If this state is active longer than the Basin Delay Time and Basin Drain Enable is True, the drain valve opens and the fill valve closes.

  • Instant Shutdown: Turn everything off and do not observe minimum on and off timers. Close the fill valve and open the basin drain valve.

  • Hold: Holds the outputs at their current position. If the Output Overridden is true, then the Output Position input is passed to the Valve Percent Command.

  • H Control: When operating in the H Control mode, the module controls the process variable (either return humidity or zone humidity) to the setpoint. As the humidity drops below the setpoint, the analog percent output Humidity Percent Cmd increases, which with the intervention of the MSC module causes the controlled devices to remain on longer and/or turn on more devices. The fill valve opens and the drain valve closes. The pump stays off for an adjustable amount of time (Basin Fill Time) to allow the basin to fill if the drain valve was open when this state first occurred.

  • Limited H Control: When operating in the Limited H Control mode, the module controls the discharge humidity to the setpoint. As the humidity rises above the setpoint, the analog percent output Humidity Percent Cmd decreases, which with the intervention of the MSC module causes the controlled devices to remain on less time and/or turn off more devices. This mode is the humidity high limit mode and is intended to prevent the discharge air from becoming too humid. The fill valve opens and the drain valve closes.

Table 1. Humidification Scrubber Output Command Hierarchy

Mode

PID Tuning Reset

State

Off

*

Off

Instant Shutdown

*

Instant Shutdown

H Control

*

H Control

Limited H Control

*

Limited H Control

Hold

Reset 1st PID

Limited H Control

Hold

*

Hold

Table 2. Staged H Control Command Hierarchy

Drain Basin

Mode

State

True

*

Instant Shutdown

False

Off

Off

False

Instant Shutdown

Instant Shutdown

False

H Control

H Control

False

Limited H Control

H Control

False

Hold

Hold

Table 3. Staged Limited H Control Command Hierarchy

Drain Basin

Mode

State

True

*

No Limit Control

False

Off

No Limit Control

False

Instant Shutdown

No Limit Control

False

H Control

No Limit Control

False

Limited H Control

Limited H Control

False

Hold

Hold