Primary States (Heating Proportional Valve with Low Limit) - 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
  • Off: Turn everything off. The Heating Percent Cmd is set to 0%.

  • Max: Open the heating valve. The Heating Percent Cmd is set to 100%.

  • Hold: Hold the outputs at their current position.

  • Water Flush: The valve is opened to the Water Flush Position.

  • Limited Max: The valve is opened to the Limited Max Value. This state may be used for unoccupied heating.

  • T Control: Open the heating valve and adjust the output to control the Process Variable. If the Process Variable is reliable, the module controls the output to maintain the Process Variable at the Setpoint. The Heating Percent Cmd is adjusted between 0% and 100%.

  • LL-T Control: Open the heating valve and adjust the output to control the Limit Variable. If the Limit Variable is reliable, the module controls the output to maintain the Limit Variable at the Limit Setpoint. The Heating Percent Cmd is adjusted between 0% and 100%.

  • Low OA Temperature: The valve is opened to the Low OA Temperature Position when the Protect-T is less than the Protect-Tsp.

  • Failsoft: The valve is opened to the Failsoft Value. This state may be used when the control temperature is unreliable.

  • Low OA Temperature Startup: This mode activates the T Control state section, but limits the rate at which the valve can close so that the unit can safely come into control (typically used for 100% OA units with low OA temperatures at startup).

  • Remain In Control: Modulate the valve to control the Limit Variable to the Limit Setpoint. If the Limit Variable is reliable, the module controls the output to maintain the Limit Variable at the Limit Setpoint. This mode should only be used as a shutdown strategy to add energy to the duct when the fan is off. It should not be used for general temperature control.

Table 1. Heating Proportional Valve with Low Limit Command Hierarchy

OA Temperature isReliable

Low Limit Process Variable isReliable

PID Tuning Reset

Mode

State

*

*

*

Off

Off

Max

Max

T Control

T Control

LL-T Control

LL-T Control

Reset 1st PID

Hold

T Control

Reset 2nd PID

Hold

LL-T Control

*

Hold

Hold

True

*

*

Low OA Temperature

Low OA Temperature

False

*

*

Low OA Temperature

Failsoft

*

*

*

Water Flush

Water Flush

Limited Max

Limited Max

Failsoft

Failsoft

Low OA Temperature Startup

T Control

True

*

Remain In Control

Remain In Control

False

*

Remain In Control

Failsoft