Low limit tempering - Johnson Controls - LIT-12011950 - Building automation software - Smart Equipment Controller - 5.0

Smart Equipment Controls Sequence of Operation Technical Bulletin

Johnson Controls
Product name
Smart Equipment Controller
Document type
Technical Bulletin
Document number
Revision date
Product status

Use low limit tempering in applications that use the HVAC unit as additional ventilation. For example, in a restaurant kitchen. Low limit tempering engages the first stage heat when there are low ambient outside air requirements to keep the supply air at a set minimum temperature. This maintains customer comfort when there is not a call for heat from the thermostat.

To enable low limit tempering, complete the following step.

  • Select Details > Control > Htg > Setup. Select LL_Enable and press ENTER.
  • Select Details >Fan > Setup > FanCtl-Type must be set to Single Speed or Fixed Variable

The low limit upper SAT setpoint (LL_UPSAT_SP) default is 80. The low limit lower setpoint (LL_LOWSAT_SP) default is 65°F. Both setpoints are adjustable.