The Cooling Tower Selector provides logic and sequencing for controlling a bank of cooling towers and cooling tower isolation valves. The Cooling Tower Selector provides individual outputs for each device. In general, when enabled, the Cooling Tower Selector determines the combination that best meets the requirements and turns on/off the appropriate towers in an orderly manner to arrive at the desired combination.
This selector works with the Chiller Selector and the Pump Selector to provide timing and sequencing for the condenser water system in a chilled water plant. The Cooling Tower Selector uses the core algorithm of the Chiller Selector.
When enabled, the Cooling Tower Selector receives condenser water requirements from both the Chiller Selector and the Condenser Water Pump Selector, using the larger of the two, and decides which towers to turn on. This module immediately opens the corresponding isolation valve, and after the Iso Valve Stroke Time timer expires, the module enables the tower fan (Device nn Cmd = True).
To shut off a tower, the module first disables the tower fan (Device nn Cmd = False), and after the Iso Valve Stroke Time, the module closes the isolation valve.
You cannot view and modify the modules in this group’s logic.
Once system selection is complete, the Cooling Tower Selector module requires further configuration. Refer to the Johnson Controls Central Plant Optimization™ 10 Application Note (LIT-12011575) for information on configuring this module and for more application level information.