GENERAL
Units shall be manufactured by York International Unitary Products Group in an ISO 9001 certified facility. YORK® Predator™/Magnum units are convertible single packages with a common footprint cabinet and common roof curb for all 12-1/2 ton models. All units have two compressors
with independent refrigeration circuits to provide 2 stages of cooling. The units were designed for light commercial appli- cations and can be easily installed on a roof curb, slab, or frame. All Predator™ units are self-contained and assembled on rigid full perimeter base rails allowing for 3-way forklift access and overhead rigging. Every unit is completely charged, wired, piped, and tested at the factory to provide a quick and easy field installation. All units are convertible between side and down airflow. Independent Predator™/ Magnum Economizer designs are used on side and down discharge applications, as well as all tonnage sizes. Preda- tor™/Magnum units are available in the following configurations: cooling only, cooling with electric heat, and cooling with gas heat. Electric heaters are available as field- installed accessories.
DESCRIPTION
Units shall be factory assembled, single package, (Elec/Elec, Gas/Elec), designed for outdoor installation. Units shall have a minimum EER of 10.8. They shall have built in field convert- ible duct connections for down discharge supply/return or horizontal discharge supply/return and be available with fac- tory installed options or field installed accessories. The units shall be factory wired, piped and charged with R-22 refriger- ant and factory tested prior to shipment. All unit wiring shall be both numbered and color coded. The cooling performance shall be rated in accordance with DOE and ARI test proce- dures. Units shall be CSA certified to ANSI Z21.47 and UL 1995/CAN/CSA No. 236-M90 standards.
UNIT CABINET
Unit cabinet shall be constructed of G90 galvanized steel with exterior surfaces coated with a non-chalking, powder paint finish, certified at 750 hours salt spray test per ASTM-B117 standards. Indoor blower sections shall be insulated with 1/2” thick insulation coated on the airside. Aluminum foil faced insulation shall be used in the unit’s compartments and be fastened to prevent insulation from entering the air stream. Cabinet doors shall be hinged with tool-less access for easy servicing and maintenance. Full perimeter base rails shall be provided to assure reliable transit of equipment, overhead rigging, fork truck access and proper sealing on roof curb applications. Disposable 2” filters shall be fur- nished and be accessible through hinged access door. Fan
performance measuring ports shall be provided on the out- side of the cabinet to allow accurate air measurements of evaporator fan performance without removing panels or cre- ating bypass of the coils. Condensate pan shall be slide out design, constructed of a non corrosive material, internally sloped and conforming to ASHRAE 62-B9 standards. Con- densate connection shall be a minimum of ¾” I.D. female and be rigid mount connection.
INDOOR (EVAPORATOR) FAN ASSEMBLY
Fan shall be a belt drive assembly and include an adjustable pitch motor pulley. Job site selected brake horsepower shall not exceed the motors nameplate horsepower rating plus the service factor. Units shall be designed to operate within the service factor. Fan wheel shall be double inlet type with for- ward curve blades, dynamically balanced to operate smoothly throughout the entire range of operation. Airflow design shall be constant volume. Bearings shall be sealed and permanently lubricated for longer life and no maintenance. Entire blower assembly and motor shall be slide out design.
OUTDOOR (CONDENSER ) FAN ASSEMBLY
The outdoor fans shall be of the direct drive type, discharge air vertically, have aluminum blades riveted to corrosion resistant steel spider brackets and shall be dynamically bal- anced for smooth operation. The outdoor fan motors shall have permanently lubricated bearings internally protected against overload conditions and staged independently. A cleaning window shall be provided on two sides of the units for coil cleaning.
REFRIGERANT COMPONENTS
Compressors: A. shall be scroll type, direct drive, internally protected with internal high-pressure relief and over tempera- ture protection. The hermetic motor shall be suction gas cooled and have a voltage range of + or – 10% of the unit nameplate voltage. B. Shall have internal spring isolation and sound muffling to minimize vibration and noise, and be exter- nally isolated on a dedicated, independent mounting.
Coils: A. evaporator and condenser coils shall have alumi- num plate fins mechanically bonded to seamless internally enhanced copper tubes with all joints brazed. Special Phe- nolic coating shall be available as a factory option. B. Evapo- rator and condenser coils shall be of the direct expansion, draw-thru design.
Refrigerant Circuit and Refrigerant Safety Components shall include: A. Independent fixed-orifice or thermally operated expansion devices. B. Solid core filter drier/strainer to elimi-