Split-System Heat Pump Outdoor Unit HVAC Guide Specifications — Section 15678 Size Range: 83,000 Nominal Btuh Heating 7 1 /2 Nominal Tons Cooling Carrier Model Number: 38AQS008 Part 1 — General 1.01 SYSTEM DESCRIPTION A. TOutdoor-mounted, electrically controlled, air-cooled split system heat pump unit utilizing a reciprocating-type semi-hermetic compressor for refrigerant compression. Unit shall function as the outdoor component of an air-to-air electric heat pump system. B. Unit shall be used in a refrigerant circuit to match Packaged Air-Handling Unit, Section 15859, for matched system approved by manufacturer. 1.02 QUALITY ASSURANCE A. Unit performance shall be certified in accordance with ARI Standards 210/240 and 270, latest versions. B. The refrigerant coil shall be designed and tested in accordance with ASHRAE 15 Safety Code for Mechanical Refrigeration. C. Unit shall be constructed in accordance with UL and UL, Canada regulations and shall carry the UL and UL, Canada labels of approval. Units shall be manufactured in a facility registered to the ISO 9001 manufacturing quality standard. D. Coil leak testing shall be at 300 psig air pressure with the coil submerged in water. After testing, the coil shall be dehydrated and charged with dry air. E. Unit casing shall be capable of withstanding 500-hour salt spray exposure per ASTM B117 (scribed specimen). 1.03 DELIVERY, STORAGE, AND HANDLING Unit shall be stored and handled in accordance with unit manufacturer’s instructions. Part 2 — Products 2.01 EQUIPMENT A. General: Outdoor-mounted, air-cooled split system heat pump unit shall be suitable for on-theground or rooftop installation on a full level pad or on raised pads at each support point. The unit shall consist of a semi-hermetic reciprocating compressor, a fin-tube coil, propeller-type fan, fan motor, refrigeration control devices, and a control box. All components shall be factory assembled as a single unit. A holding charge of R-22 shall be included. Units shall be used in a refrigeration circuit matched with a 40RMQ008 packaged air-handling unit. B. Unit Cabinet: 1. Cabinet shall be constructed of galvanized steel, bonderized, and finished with baked enamel. 2. Fan venturi housings and guards shall be assembled on the unit. 3. A removable panel shall be provided for access to compressor and control compartments. 4. A refrigerant accumulator with a fusible plug relief shall be installed in the cabinet. 5. Lifting holes shall be provided to facilitate rigging. C. Fan: 1. Propeller fan shall be directly driven by weather-proof motors. Fan motor bearings shall be permanently lubricated. 2. Fan shall be arranged for vertical discharge. D. Compressor/Motor Assembly: 1. Semi-hermetic, reciprocating-type 06D compressor shall be complete with a motor and oil pump all on a single polished crankshaft. 2. Motor stator winding shall be NEMA Class F rated, suitable for operation in a refrigerant atmosphere. 3. Oil pump shall be automatically reversible. 4. Casing shall include discharge shutoff valves, oil level control orifice, oil-pressure regulating valve, and a crankcase oil heater. E. F. G. H. 5. Suction and discharge manifold valves shall be Swedish steel, reed-type flapper valves. 6. Pistons and connecting rods shall be high-density aluminum alloy castings. Pistons shall be equipped with automotive-type compression and oil scraper rings. 7. Pump-end bearing shall be cast aluminum. Motor-end bearing shall be steel-backed, tin-base babbit type. 8. Compressor assembly shall be installed on spring vibration isolators. Coil: Coil shall have copper tubes, aluminum plate fins (copper fins optional), and galvanized steel tube sheets. The fins shall be bonded to tubes by mechanical expansion. Coil shall be circuited for subcooling in cooling mode operation. For refrigerant control, the unit shall be equipped with a liquid line, suction line, and compressor discharge service valves. The unit shall include an accumulator with a fusible plug relief and a reversing valve for effective heat pump operation. Each unit system shall have 3 service ports: one on the suction line, one on the liquid line, and one on the compressor discharge line. Each port shall be capped for leak tightness. Controls and Safeties: Operating controls and safeties shall be factory selected, assembled, and tested. Minimum control functions shall be as listed below: 1. Controls: a. Time-delay restart control to prevent compressor short-cycling. b. Defrost control to consist of a time and temperature activated system that initiates defrost mode at selectable intervals of 30, 50, or 90 minutes in response to a temperature signal. 2. Safeties: a. High discharge pressure cutout switch. b. Loss-of-charge cutout switch. c. Compressor motor current and temperature overload cutouts. d. Five-minute recycle protection to prevent compressor short cycling. e. Device to hold the compressor off-line until manual reset at the thermostat when any of the following are tripped: High discharge pressure, high compressor motor temperature, or loss of charge. Electrical Requirements: 1. Factory supplied and installed transformer shall provide 24 v control voltage. 2. All power and control circuit wiring shall comply with local and national codes. Special Features: 1. Head Pressure Control: Control shall vary the fan motor speed in response to the saturated condensing temperature of the unit. The control shall be capable of maintaining a condensing temperature of 100 F ± 10 F with outdoor temperature at –20 F. 2. Outdoor Thermostat: Adjustable control shall activate electric heaters in stages to provide supplemental heat. Range: –30 F to 90 F. 3. Gage Panel: Panel shall provide one suction pressure and one discharge pressure gage mounted on a common panel. A shut-off valve shall be provided for each gage. 4. Coil Guard: Grille shall protect outdoor coil from damage by large objects or vandalism. 5. Hail Guard: Guard shall protect unit against damage from damage by hail or flying debris. 6. Optional Outdoor Coil Materials: a. Pre-coated aluminum-fin coils: Shall have a durable epoxy-phenolic coating to provide protection in mildly corrosive coastal environments. Coating shall be applied to the aluminum fin stock prior to the fin stamping process to create an inert barrier between the aluminum fin and copper tube. Epoxy-phenolic barrier shall minimize galvanic action between dissimilar metals. b. Copper-Fin Coils: Shall be constructed of copper fins mechanically bonded to copper tubes and copper tube sheets. Galvanized steel tube sheets shall not be acceptable. A polymer strip shall prevent coil assembly from contacting sheet metal coil pan to minimize potential for galvanic corrosion between the coil and pan. All copper construction shall provide protection in moderate coastal applications. c. Post-Coated Aluminum-Fin Coils: Shall have a durable organic coating uniformly applied over all coil surfaces. Coating shall be deep brown color applied by a dip and bake process to ensure complete encapsulation of all coil surfaces. Coated coil shall withstand 1,000hour salt spray test in accordance with ASTM B117. Coil construction shall be aluminum fins mechanically bonded to copper tubes. d. Post-Coated Copper-Fin Coils: Shall have a durable organic coating uniformly applied over all coil surfaces. Coating shall be deep brown color applied by a dip and bake process to ensure complete encapsulation of all coil surfaces. Coated coil shall withstand 1,000 hour-salt spray test in accordance with ASTM B117. Coil construction shall be copper fins mechanically bonded to copper tubes. 7. Thermostat Controls: a. Programmable multi-stage thermostat with 7-day clock, holiday scheduling, large backlit display, remote sensor capability, and Title 24 compliance. b. TEMP System programmable communicating multi-stage thermostat with fan switch, timeclock, LCD display, °F/°C capability, and CCN (Carrier Comfort Network) compatibility. c. Commercial Electronic Thermostat with 7-day timeclock, auto-changeover, multistage capability, and large LCD temperature display. d. Non-programmable thermostat with fan switch subbase.