YORK ® AIR-CONDITIONING PRODUCTS
Creating a complex program without programming
The System Selection Tool (SST) is a control program generator that relies on defining
the characteristics of the chiller plant and its control strategies. The tool supports
selection and sequencing of
• up to eight chillers of different sizes, compressor types and fixed or variable speed
• up to eight (each) primary and secondary chilled water pumps of varying pumping
capacities
• up to eight condenser water pump
• of cooling towers and bypass valve, including single speed, multi-speed, and vernier
control (one variable speed fan with all other tower fans at constant speed)
• up to four heat exchangers (Waterside Economizers)
• both water-cooled and air-cooled chillers
Furthermore, control definition for the chiller plant in a single Field Equipment Controller
(FEC)/Network Controller Engine (NCE), if supported by available memory and point Input/
Output (I/O), or split across multiple FECs/NCEs, is offered.
Flexibility, ready for use
A variety of primary control strategies are also available, including
• measuring building chilled-water flow and differential temperature
• chiller load (kW)
• flow through a decoupler pipe in a primary/secondary system
• differential temperature only, in a constant speed chilled water pump system
It is also possible to select dozens of secondary strategies, such as
• open loop control of the cooling towers (as defined by the American Society of Heating,
Refrigerating and Air-Conditioning Engineers)
• closed loop control of condenser-water setpoint
After making the selections, SST generates a complete program by linking together
appropriate software modules. This process removes the variability commonly found
in totally custom-generated programs using a traditional software program editor.
Once the software modules are linked, the tool allows the entry of all equipment
parameters. The resulting program can also be run in a simulator mode to verify
proper operation before downloading it into Metasys ® .
Manufacturer reserves the rights to change specifications without prior notice.
75