Primary States (Heat Recovery Low Limit Sequencing) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 13.1

Controller Tool Help
Product
Controls > Control Tools > Controller Configuration Tool
Document type
User Guide
Document number
LIT-12011147
Version
13.1
Revision date
2019-12-04

  • T Control: This is the temperature control and starting state. The sequencer transitions to this state from either the LL-T Wait or LL-T Control if the Heat Recovery device is not responding to the sequencer and the Low Limit Process Variable is greater than the Low Limit Setpoint. The Sequencer transitions to T Control from LL-T Control if the Low Limit Process Variable is greater than the Low Limit Setpoint and the heat recovery device Control Status is High. Finally, the sequencer transitions to T Control from LL-T Wait if it has been in this state for more than the Delay.

  • LL-T Control: The sequencer transitions to LL-T Control from T Control or LL-T Wait states if the Low Limit Process Variable is less than the Low Limit Setpoint.

  • LL-T Wait: This state is achieved only when sequencing on/off heat recovery devices. The sequencer transitions to LL-T Wait from LL-T Control if the Low Limit Process Variable is greater than the Low Limit Setpoint.