Figure 31-1 — Human Interface Display  

The CGAF chiller is controlled by an IntelliPak^® microcomputer-based controller. IntelliPak provides better control, as well as several other important benefits.

Customized Control With IntelliPak controls, Trane can customize controls around the chiller application and the specific components used in the CGAF. For instance, the compressor protection system is specifically designed for the Trane 3-D^® Scroll compressor. A leaving chilled solution temperature control algorithm maintains accurate temperature control, for both comfort and process applications, minimizing the drift from setpoint. The IntelliPak controls incorporate improved chiller start-up, load limiting, compressor anti-recycle timing and lead/lag functions into standard chiller operation. Interface with outside systems such as building automation controls is flexible and easy.

Simple Interface with All Control Systems

The IntelliPak controls afford simple interface with Trane Tracer^® systems, providing broad control capabilities for Building Automation systems. For control systems other than Trane, two generic building automation system interfaces are available and offer simplicity and flexibility in accessing unit functions.

Safety Controls

A centralized microcomputer offers a higher level of machine protection. Since the safety controls are smarter, they limit compressor operation to avoid compressor or evaporator failures, thereby minimizing nuisance shutdown. For instance, the Unit Control Module (UCM) will provide condenser low pressure control by staging condenser fans on or off in an effort to maintain the saturated condensing temperature within a fixed range. Overall, the safety controls help keep the cooling system on-line and operating safely.

Monitoring and Diagnostics

Since the microcomputer provides all control functions, it can easily indicate such parameters as leaving chilled solution temperature and capacity staging. If a failure does occur, the diagnostic alarm will be displayed giving specific information about the failure. All of the monitoring and diagnostic information can be easily accessed at the Human Interface display, standard on every unit.