CV option B thermostat sequence - Johnson Controls - LIT-12011950 - Building automation software - Smart Equipment Controller - 5.0

Smart Equipment Controls Sequence of Operation Technical Bulletin

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

Cooling stages set to one for single compressor unit

With a stage 1 cooling demand (Y1 input), the economizer modulates to get the SAT to the upper SAT setpoint +/-5°F.

If the stage 1 cooling demand (Y1 input) remains on for 20 minutes, the economizer remains at 100% for an additional 5 minutes, and the SAT is greater than the upper SAT setpoint + 5°F, the compressor output energizes.

With a stage 2 cooling demand (Y2 input), the economizer modulates to get the SAT to the lower SAT setpoint +/-5°F.

If the stage 2 cooling demand (Y2 input) remains on, the economizer remains at 100% for 5 minutes, and the SAT is greater than the lower SAT setpoint + 5°F, the compressor output energizes.

If the economizer remains at the minimum position for 5 consecutive minutes, the compressor output turns off.

Cooling stages set to two or more for multiple compressor units

With a stage 1 cooling demand (Y1 input) the economizer modulates to get the SAT to the upper SAT setpoint+/- 0.5°F.

With a stage 2 cooling demand (Y2 input), the economizer modulates to get the SAT to the lower SAT setpoint+/-.0.5°F.

If the stage 2 cooling demand (Y2 input) remains on, the economizer remains at 100% for 5 minutes and the SAT is greater than the lower SAT setpoint + 5°F, the compressor output energizes.

If the economizer position remains at 100% for another 5 minutes, the next available compressor turns on. This process repeats every 5 minutes until all the compressors energize.

If the economizer position drops below 100% and does not reach the minimum position then returns to 100% and remains at 100% for 5 minutes, the next available compressor energizes. If the economizer position remains at 100%, the process repeats every 5 minutes until all the compressors energize.

Any time the economizer remains at the minimum position for 5 consecutive minutes, the last energized compressor turns off. If it remains at the minimum position, the compressors de-energize every 5 minutes until all the compressor are off.

Y3 and Y4 inputs have no additional impact on economizer operation.