VAV unit sensor option A - Johnson Controls - LIT-12011950 - Building automation software - Smart Equipment Controller - 5.0

Smart Equipment Controls Sequence of Operation Technical Bulletin

Product name
Smart Equipment Controller
Document type
Technical Bulletin
Document number
LIT-12011950
Version
5.0
Revision date
2024-06-06
Product status
Active

The operating VAV SAT setpoint is determined by the reset function not by the number of compressors operating.

When free cooling available and the SAT is above the operating VAV SAT setpoint, the dampers modulate to control the operating, upper or lower, SAT setpoint +/-0.5°F.

If the economizer output is at 100% for 5 consecutive minutes and the operating space temperature is 0.6°F or greater than the operating cooling setpoint, the control starts to energize compressors. See Table 1 for additional information.

As soon as the staged percent command begins to increase, the economizer remains at 100%. If the SAT drops to less than the operating VAV SAT setpoint +1.8F, the staged percent command holds the current value.

If the SAT drops to less than the operating VAV SAT setpoint -1.8°F, the staged percent command begins to decrease.

If the staged percent command remains at 0% for 5 consecutive minutes, the economizer modulates to control to the upper SAT setpoint +/-0.5°F.