Primary States (Heat Recovery Wheel) - 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: Operate the energy recovery wheel at the maximum wheel speed.

  • Hold: Hold the outputs at their current position.

  • T Control: Modulate the energy wheel speed 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.

  • Limited Max: Operate the energy recovery wheel at the Limited Max Speed.

  • LL-T Control: Modulate the energy wheel speed to control the Low Limit Variable. The low limit variable is the air temperature leaving the energy wheel, and this mode would be used to prevent the leaving temperature from dropping below freezing. If the Limit Variable is reliable, the module controls the output in order to maintain the Limit Variable at the Limit Setpoint.

Table 1. Heat Recovery Wheel 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

Limited Max

*

Limited Max

T Control

*

T Control

LL-T Control

*

LL-T Control