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Job Name:WA A • <br /> 4 Prepared By En State Sheet Metal <br /> Unit Tag:Y4V-1 <br /> • <br /> Quantity:1 <br /> General - Downflow <br /> The units shall be dedicated downflow airflow. The operating range shall be between 115°F and 0°F in <br /> cooling as standard from the factory for all units. Cooling performance shall be rated in accordance <br /> with ARI testing procedures. All units shall be factory assembled, internally wired, fully charged with R- <br /> 410A, and 100 percent run tested to check cooling operation, fan and blower rotation and control <br /> sequence, before leaving the factory. Wiring internal to the unit shall be colored and numbered for <br /> simplified identification. Units shall be UL listed and labeled, classified in accordance to UL 1995/C <br /> 22.2, 236-05 3rd Edition. <br /> Packaged Rooftop units cooling, heating capacities, and efficiencies are AHRI certified within scope of <br /> AHRI Standard 340/360 (I-P) and ANSIZ21.47 and 10 CFR Part 431 pertaining to Commercial Warm <br /> Air Furnaces (gas heating units). <br /> Casing - Downflow <br /> Unit casing shall be constructed of zinc coated, heavy gauge, galvanized steel. Exterior surfaces shall <br /> be cleaned, phosphatized, and finished with a weather-resistant baked enamel finish. Unit's surface <br /> shall be tested 672 hours in a salt spray test in compliance with ASTM B117. Cabinet construction <br /> shall allow for all maintenance on one side of the unit. In order to ensure a water and air tight seal, <br /> service panels shall have lifting handles and no more than three screws to remove. All exposed <br /> vertical panels and top covers in the indoor air section shall be insulated with a 1/2 inch, 1 pound <br /> density foil-faced, fire-resistant, permanent, odorless, glass fiber material. The base of the downflow <br /> unit shall be insulated with 1/2 inch, 1 pound density foil-faced, closed-cell material. The downflow <br /> unit's base pan shall have no penetrations within the perimeter of the curb other than the raised 11/8 <br /> inch high supply/return openings to provide an added water integrity precaution, if the condensate <br /> drain backs up. The base of the unit shall have provisions for forklift and crane lifting. <br /> Unit Top <br /> The top cover shall be one piece, or where seams exist, double hemmed and gasket sealed to prevent <br /> water leakage. <br /> Filters <br /> Two inch standard filters shall be factory supplied on all units <br /> Compressors <br /> All units shall have direct-drive, hermetic, scroll type compressors with centrifugal type oil pumps. <br /> Motor shall be suction gas-cooled and shall have a voltage utilization range of plus or minus 10 <br /> percent of nameplate voltage. Internal overloads shall be provided with the scroll compressors. All <br /> models shall have crankcase heaters, phase monitors and low and high pressure control as standard. <br /> Dual compressors are available on all standard efficiency models and 12.5 to 20 tons high efficiency <br /> models and allow for efficient cooling utilizing 3 stages of compressor operation (high efficiency <br /> models only). 25 tons high efficiency units have 3 compressors for up to 4 stages of compressor <br /> operation. <br /> Crankcase Heaters <br /> These band heaters provide improved compressor reliability by warming the oil to prevent migration <br /> during off-cycles or low ambient conditions. <br /> Refrigerant Circuits <br /> Each refrigerant circuit shall have service pressure ports, and refrigerant line filter driers factory <br /> installed as standard. An area shall be provided for replacement suction line driers. <br />