Controls Data and Connections

Trane set the standard for unit microprocessor controls in 1985 with the first generation of UCP. Associated with this standard have been:

• Proportional Integral Derivative (PID) control strategies which provide stable operation and high accuracy for better performance along with feed forward plus.

• Adaptive Control™ to keep the chiller "on line" and at the same time keep the chiller away from a major failure;

• Software based safeties that do not depend on electromechanical hardware — hardware that means questionable reliability and added cost;

• Operator interface that accesses chiller information and control adjustments at the front of the panel.

Now — in addition to all of the capability that our customers have come to expect — Trane offers UCP2.

Beyond the ‘traditional’ controls; beyond ‘traditional’ safeties; beyond ‘traditional’ chiller data availability; and beyond the ability of the ‘standard’ chiller and its associated controls to operate in ‘traditional’ systems, UCP2 adds more flexibility, more reliability and better system performance than even our most demanding customers expect.

Flexibility

Trane offers the ability to adapt to changes easily and effectively without adding prohibitive cost. To provide flexibility, the controller responds to a wide variety of needs for:

System Designs including equipment, operating conditions, and controls variations that are either existing or being considered for new installations.

System Upgrades including the ability to accommodate changes in the chilled water system design or equipment room requirements or to accommodate new technologies that become available.

How does Trane demonstrate this flexibility:

• Modular structure or the UCP2 makes it possible for the designer to select the system controls and associated interfaces to Tracer^® (or other building automation systems) that are required for the chiller plant design. With this modular concept, capability can be added or upgraded at any time — with only temporary interruption of chilled water production.

• The operator can quickly program a Custom Report — so that only what is considered to be the most frequently accessed/important reports are available — at any time, right at the front of the panel.

• With easy front panel programmability of Daily, Service Start-up and Machine Configuration settings and setpoints, the operator, serviceman, and system designer can customize the use of the micro controller to unique conditions of the chiller plant — whether the purpose of chilled water is for comfort cooling or for process cooling.

• All data that is necessary for the safe operation and easy serviceability of the chiller is provided as standard on all Horizon™ absorption chillers. Options are available that provide additional controls/data that are required for: an industrial/process system design, applications outside of the typical chilled water system design, the need for redundant machine protection, or the desire for more system information.

Reliability

What does this mean and how do we do it?

To most people, reliability means "dependable — giving the same result on successive trials." However, to our customers it has come to mean "keep chilled water flowing." In other words, "when I turn the switch on — cold water comes out." In order to do this, the micro controller must be aware of what is happening in the system. But more importantly, it must be able to make decisions and adjustments to keep the chiller running as long as possible even when non-standard conditions exist. Conditions such as bad power or bad water (flow, temperature, fouling) or system component failure. Also the Trane UCP2 panel continuously monitors for noncondensables and purges automatically.

• With Enhanced Adaptive Control™ the controller does everything it can toavoid taking the chiller off line.

— Senses potential overload, freeze and condenser overpressure conditions

— Displays a warning message about the potential condition/safety trip

— Take the following corrective action sequentially as the condition worsens:

- limits loading

- prevents further loading

- unloads until condition improves

- takes chiller off line

• With more diagnostics and diagnostic history that are time/date stamped and with help messages, the operator or serviceman can take faster and more effective corrective action.

System Performance

"Chilled Water System" encompasses many levels of control: Standalone Chiller, Chiller Plant, Applied System, Central Building Automation System. However, regardless of the system level being design, the unit controls become critical not just in making every level operate reliably but in facilitating optimal performance. UCP2  provides more capability and more intelligence to make this operation/optimization possible.

Panel Features:

The absorption chiller Unit Control Panel (UCP2) incorporates the following features and components:

Control Functions

• Smart dilution cycle duration based on system requirements

• Adaptive evaporator leaving fluid temperature control

• Low evaporator temperature limit

• High solution temperature limit

• Solution flow control via AFD

• Softloading

• Nuisance trip prevention via Adaptive Control

• Chilled water reset

• Optimum concentration control

• Crystallization recovery via SDR

• High temperature generator pressure limit