Primary States (Heat Recovery Glycol Loop) - 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: Turn everything off. The Heat Recovery percent Cmd is set to 0%.

  • Max: The glycol valve is opened 100%.

  • Hold: Hold the outputs at their current position.

  • T Control: Modulate the glycol valve to control the Process Variable at the setpoint. This mode is used for heating only since the heat recovery device can provide more heat than what is required to condition the space. On the other hand, during cooling, the heat recovery device cannot produce enough cold air to condition the space.

  • LL-T Control: Modulate the glycol valve to control the Low Limit Variable. Normally the low limit variable is the glycol temperature, and this mode would be used to prevent the glycol temperature from dropping below freezing. If the Limit Variable is reliable, the module controls the output to maintain the Limit Variable at the Limit setpoint.

Table 1. Heat Recovery Glycol Loop Command Hierarchy

Heat Recovery Suitability

Cooling Mode

Heating Mode

PID Tuning Reset

State

*

Hold

*

Reset 1st PID

T Control

Hold

 

Reset 2nd PID

LL-T Control

*

Hold

Reset 1st PID

T Control

*

Hold

Reset 2nd PID

LL-T Control

None

*

*

*

Off

Cool

Off

*

*

Off

Max

*

*

Max

Hold

*

*

Hold

Heat

*

Off

*

Off

Max

*

Max

Hold

*

Hold

T Control

*

T Control

LL-T Control

*

LL-T Control