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Controls |
Trane set the standard for unit microprocessor controls in 1985 with the first
generation UCP. Associated with this standard have
been:
- Proportional Integral Derivative (PID) control strategies which provide stable operation and higher accuracy for better
performance;
- 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.
Key to designing non-traditional systems is the ability to evaluate the cost and reliability issues of these systems
in comparison to the more traditional systems. Trane
recommends the use of C.D.S. Network Equipment Economics, the Trane Applications Manuals,
and consultation with a Trane sales engineer for help
in this analysis.
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?
- The modular structure of 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 his 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 the 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 CenTraVac
® 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.
- Equipment room refrigerant ppm monitoring can be integrated into the control
panel by employing a chiller mounted monitor or a wall
mounted monitor. 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.
- With Enhanced Adaptive Control ™ the controller does everything it can to avoid taking the chiller off line:
— senses potential overload, freeze and condenser overpressure conditions
— displays a warning message about the potential condition/safety trip
— takes the following corrective action sequentially as the condition worsens:
- limits loading
- prevents further loading
- unloads until condition improves
- takes chiller off line
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