45
RT-PRC016-EN
Mechanical
Specifications
General
The units shall be convertible airflow. The
operating range shall be between 46°C
and -18°C (115°F and 0°F) in cooling as
standard from the factory for all units. 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.
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.
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 13 mm, 16 kg (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 29 mm (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 5 ton units. The filter rack
can be converted to two inch capability.
50 mm (2 inch) filters shall be factory
supplied on all 6-10 ton units. Optional 50
mm (2 inch) pleated filters shall be
available.
Compressors
All 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. Low and high
pressure switches shall be standard.
Refrigerant Circuits
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, 8 mm (
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 1375 kPa (200 psig)
and pressure tested to 3100 kPa (450
psig). The condenser 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 units shall have belt drive motors.
Units with belt drive motors shall have
an adjustable idler-arm assembly for
quick-adjustment to fan belts and motor
sheaves. All motors shall be thermally
protected. Oversized motors shall be
available for high static operations.
Controls
Unit shall be completely factory-wired
with necessary controls and contactor
pressure lugs or terminal block for
power wiring. Units shall have single
point power connection as standard.
Unit shall provide an external location
for mounting a fused disconnect device.
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.
