2.2
15780-3
PACKAGED ROOFTOP AIR HANDLING UNITS
provide anti-short cycle timing and time delay between compressors.
Phase monitor: Phase monitor shall provide 100% protection for motors and
compressors against problems caused by phase loss, phase imbalance, and phase
reversal. The module shall automatically reset from a fault condition.
Accessories: Factory-mounted disconnect switch and GFCI duplex electrical service
outlet.
Roof Mounting Curb: May be supplied factory assembled or disassembled. Once the
mounting curb is set in position, it shall be secured together with 1/4-20 x 1/2" long
sheet metal screw. The mounting curb shall have duct flanges shipped with it and no
separate duct flanges need be purchased.
PACKAGED VAV COOLING AIR HANDLING UNIT
A.
B.
Qn
General: Manufacturer and model numbers are indicated to establish type and quality.
Acceptable Manufacturers:
1. Trane.
2. Carrier.
3. York.
4. Or approved equal.
General: The units shall be dedicated downflow or horizontal airflow. The operating
range shall be between 115F and OF in cooling as standard from the factory for all
units Cooling performance shall be rated in accordance with AHRI testing
procedures. All units shall be factory assembled, internally wired, fully charged with
R-410A, 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.
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 672 hours in a salt spray ted in
compliance with ASTM B117. Cabinet construction shall allow for all maintenance
on one side of the unit. In order to ensure a water and airtight seal, service panels shall
have lifting handles and no more than three screws to remove. All exposed vertical
panels and top covers in the indoor air section shall be insulated with a 0.5 inch, 1
pound density foil-faced, fire-resistant, permanent, odorless, glass fiber material. The
base of the downflow unit shall be insulated with 0.5 inch, 1 pound density foil-faced,
closed-cell material. The downflow unit's base pan shall have no penetrations within
the perimeter of the curb other than the raised 1.125 inch high supply/return openings
to provide an added water integrity precaution, if the condensate drain back up. The
base of the unit shall have provisions for forklift and crane lifting.
Unit Top: The top cover shall be one piece, or where seams exist, double hemmed
and gasket sealed to prevent water leakage.
Filters: 2-inch pleated media filters.
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 nameplate voltage. Internal overloads
shall be provided with the scroll compressors. Unit shall have crankcase heaters,
phase monitors and low and high pressure control.
13089K
