Packaged Rooftop Air Conditioners Manual

7RT-PRC010-EN
Features and
Benefits
The modular control design of the UCM
allows for greater application flexibility.
Customers can order exactly the options
required for the job, instead of one large
control package. Unit features are
distributed among multiple field
replaceable printed circuit boards. The
Trane UCM can be set up to operate
under one of three control applications:
1) stand-alone
2) interface with Trane’s Tracer® building
management system
3) interface with a generic (non-Trane)
building management system. All set-up
parameters are preset from the factory,
requiring less start-up time during
installation.
The unit mounted Human Interface and
the Remote Human Interface Panels’
functions are identical, except for the
Service mode is not available on the
Remote Human Interface Panel. This
common interface feature requires less
time for building maintenance personnel
to learn to interact with the unit. All of the
rooftop’s control parameters are
adjustable and can be set up through the
Remote Human Interface Panel such as,
but not limited to: system on/off,
demand limiting type, night setback
setpoints, and many other setpoints. No
potentiometers are required for setpoint
adjustment, all adjustments are done
through the Remote Human Interface
key-pad. Also up to 48 different rooftop
diagnostic points can be monitored
through the human interfaces such as:
sensor failures, loss of supply airflow,
and compressor trip. No special tools are
required for servicing of the unit. All
diagnostic displays are available in clear
English at the Remote Human Interface
and will be held in memory, so that the
operator/servicer can diagnose the root
cause of failures.
Statitrac™ Direct Space
Building Pressurization Control
Trane’s Statitrac™ control is a highly
accurate and efficient method of
maintaining building pressure control
with a large rooftop air conditioner.
The efficiency is achieved with a 100
percent modulating exhaust system with
two forward-curved fans with
modulating discharge dampers that
operate only when needed, compared to
some systems that operate continually.
And most of the operating hours of the
100 percent modulating exhaust system
are at part load, saving more energy.
Trane’s Statitrac, with the 100 percent
modulating exhaust system, provides
comfort and economy for buildings with
large rooftop air conditioning systems.
Statitrac control is simple! The space
pressure control turns the exhaust fans
on and off as required and modulates
exhaust dampers to maintain space
pressure within the space pressure dead
band. Using the unit mounted Human
Interface Panel you can
1) adjust space pressure setpoint
2) adjust space pressure dead band
3) measure and read building space
pressure. The modulating exhaust
system maintains the desired building
pressure, saving energy while keeping
the building at the right pressure. Proper
building pressurization eliminates
annoying door whistling, doors standing
open, and odors from other zones.
The Statitrac™ direct space building
control sequence will be maintained
when a variable frequency drive is used.
Fans With Inlet Guide Vanes
Trane’s forward curved fans (20 through
75 tons) and air foil fans (90 through 130
tons) with inlet guide vanes pre-rotate
the air in the direction of the fan wheel,
decreasing static pressure and
horsepower, essentially unloading the
fan wheel. The unloading characteristics
of a Trane FC fan with inlet guide vanes
result in superior part load performance.
Variable Frequency Drives
(VFD)
Variable Frequency Drives are factory
installed and tested to provide supply/
exhaust fan motor speed modulation.
VFD’s, as compared to inlet guide vanes
or discharge dampers, are quieter, more
efficient, and are eligible for utility
rebates. The VFD’s are available with or
without a bypass option. Bypass control
will simply provide full nominal airflow
in the event of drive failure.
Optimum
Building
Comfort Control