Trane RT-PRC005 - Manual (Page 73)

73 RT-PRC005-EN
Mechanical
Specifications
General
The units shall be convertible airflow.
The operating range shall be between
115°F and 0°F in cooling as standard
from the factory for units with
microprocessor controls. Operating
range for units with electromechanical
controls shall be between 115°F and
40°F. Cooling performance shall be
rated in accordance with ARI testing
procedures. All units shall be factory
assembled, internally wired, fully
charged with R-22, and 100 percent run
tested to check cooling operation, fan
and blower rotation, and control
sequence before leaving the factory.
Wiring internal to the unit shall be
colored and numbered for simplified
identification. Units shall be UL listed
and labeled, classified in accordance to
UL 1995/CAN/CSA No. 236-M90 for
Central Cooling Air Conditioners.
Canadian units shall be CSA Certified.
Casing
Unit casing shall be constructed of zinc
coated, heavy gauge, galvanized steel.
Exterior surfaces shall be cleaned,
phosphatized, and finished with a
weather-resistant baked enamel finish.
Unit’s surface shall be tested 1000
hours in a salt spray test in compliance
with ASTM B117. Cabinet construction
shall allow for all maintenance on one
side of the unit. Service panels shall
have lifting handles and be removed
and reinstalled by removing only a
single fastener while providing a water
and air tight seal. All exposed vertical
panels and top covers in the indoor air
section shall be insulated with a
cleanable foil-faced, fire-retardent
permanent, odorless glass fiber
material. The base of the unit shall be
insulated with 1/2 inch, 1 pound density
foil-faced, closed-cell material. All
insulation edges shall be either
captured or sealed.The unit’s base pan
shall have no penetrations within the
perimeter of the curb other than the
raised 1
1 /
8
inch high downflow supply/
return openings to provide an added
water integrity precaution, if the
condensate drain backs up. The base of
the unit shall have provisions for forklift
and crane lifting, with forklift
capabilities on three sides of the unit.
Unit Top
The top cover shall be one piece
construction or where seams exist, it
shall be double-hemmed and gasket-
sealed. The ribbed top adds extra
strength and prevents water from
pooling on unit top.
Filters
One inch, throwaway filters shall be
standard on all 3-5 ton units. The filter
rack can be converted to two inch
capability. Two inch filters shall be factory
supplied on all 6-10 ton units. Optional 2-
inch pleated filters shall be available.
Compressors
All 3 ton standard units shall have direct-
drive, hermetic, reciprocating type
compressors. The reciprocating type
compressors have a centrifugal oil pump
providing positive lubrication to moving
parts. Motor shall be suction gas-cooled
and shall have a voltage utilization range
of plus or minus 10 percent of unit
nameplate voltage. Crankcase heater,
internal temperature, and current-
sensitive motor overloads shall be
included for maximum protection.
Compressors shall have internal spring
isolation and sound muffling to minimize
vibration transmission and noise. Low
pressure switches shall be standard.
3 ton high efficiency and 4-10 ton
standard and high efficiency units shall
have direct-drive, hermetic, scroll type
compressors with centrifugal type oil
pumps. Motor shall be suction gas-
cooled and shall have a voltage
utilization range of plus or minus 10
percent of unit nameplate voltage.
Internal overloads shall be provided with
the scroll compressors.
Refrigerant Circuits
Each refrigerant circuit offers a choice of
independent fixed orifice expansion
devices or thermal expansion valve.
Service pressure ports, and refrigerant
line filter driers are factory-installed as
standard. An area shall be provided for
replacement suction line driers.
Evaporator and Condenser Coils
Internally finned, 5/16” copper tubes
mechanically bonded to a configured
aluminum plate fin shall be standard.
Coils shall be leak tested at the factory to
ensure the pressure integrity. The
evaporator coil and condenser coil shall
be leak tested to 200 psig and pressure
tested to 450 psig. The condensor coil
shall have a patent pending 1 + 1 + 1
hybrid coil designed with slight gaps for
ease of cleaning. A removeable,
reversible, double-sloped condensate
drain pan with provision for through the
base condensate drain is standard.
Outdoor Fans
The outdoor fan shall be direct-drive,
statically and dynamically balanced,
draw-through in the vertical discharge
position. The fan motor shall be
permanently lubricated and shall have
built-in thermal overload protection.
Indoor Fan
All 3-5 ton 3-phase units offer a choice of
direct-drive, FC, centrifugal fans or belt
driven, FC centrifugal fans with
adjustable motor sheaves. 3-5 ton direct
drive oversized motors shall be available
for high static operations. All 6-10 ton
units shall have belt drive motors with
an adjustable idler-arm assembly for
quick-adjustment to fan belts and motor
sheaves. All motors shall be thermally
protected. All indoor fan motors meet
the U.S. Energy Policy Act of 1992
(EPACT).
Controls
Unit shall be completely factory-wired
with necessary controls and contactor
pressure lugs or terminal block for
power wiring. Unit shall provide an
external location for mounting a fused
disconnect device.
A choice of microprocessor or
electromechanical controls shall be
available.
Microprocessor controls provide for all
24 volt control functions. The resident
control algorithms shall make all
heating, cooling, and/or ventilating
decisions in response to electronic
signals from sensors measuring indoor
and outdoor temperatures. The control
algorithm maintains accurate
temperature control, minimizes drift
from set point, and provides better
building comfort. A centralized
Microprocessor shall provide anti-short
cycle timing and time delay between
compressors to provide a higher level of
machine protection.