Product 48TF004-014 Data Single-Package …

1 Copyright 2000 Carrier CorporationForm 48TF-1 PDStandard-Efficiency Rooftop Units with: Exclusive integrated gas control board with diagnostics Alumagard heat exchanger coating Induced-draft fan for gas combustion Tubular, dimpled heat exchangers Pre-painted galvanized steel cabinet for long life and quality appearance Commercial strength base rails with built-in rigging capability Convertible design for vertical or horizontal supply/return Non-corrosive, sloped condensate drain pan, meets ASHRAE 62 (IAQ) Two-inch return-air filters A wide assortment of factory-installed options available, including high static drives that provide additional performance rangeFeatures/BenefitsEvery compact one-piece unit arrives fully assembled, charged, tested, and ready to gas controller (IGC)All ignition components are contained in the compact IGC which is easily ac-cessible for servicing.

2 The IGC control board, designed and manufactured ex-clusively for Carrier rooftop units, pro-vides built-in diagnostic capability. An LED (light-emitting diode) simplifies troubleshooting by providing visual fault notification and system status IGC also contains an exclusive anti-cycle protection for gas heat oper-ation. After 4 continuous cycles on the unit high-temperature limit switch, the gas heat operation is disabled, and an 48TF004-014 Single-Package Rooftop UnitsGas Heating/Electric Cooling3 to Nominal TonsProductData48TF004-00748TF008-0142er ror code is issued. This feature great-ly improves reliability of the rooftop IGC also contains burner con-trol logic for accurate and dependable gas ignition.

3 The LED is visible without removing the unit control box access panel. This LED fault-notification sys-tem reduces service person trouble-shooting time and minimizes service costs. The IGC also maximizes heating efficiency by controlling evaporator-fan on and off , efficient operation and dependable performanceCompressors have vibration isolators for quiet operation. Efficient fan and motor design permits operation at low sound levels and all 48TF004-014 units are mounted either on mounting plate (004-007) or on an exclusive polycore plate (008-014).The 48TF008-014 units offer lower utility costs through part-load opera-tion using 2 stages of and efficient operation is pro-vided by belt-driven evaporator fans (standard on all units over 5 tons).

4 The belt-driven evaporator-fan is equipped with variable-pitch pulleys which allow adjustment within the rpm ranges of the factory-supplied pulleys. Increased operating efficiency is achieved through computer-designed coils featuring staggered internally enhanced copper tubes. Fins are ripple-edged for strength, lanced, and double waved for higher heat , dimpled gas heat exchang-ers optimize heat transfer for improved efficiency. The tubular design permits hot gases to make multiple passes across the path of the supply air. The dimpled design creates a turbulent gas flow to maximize heating California Air Quality Manage-ment Districts NOx requirement of 40 nanograms/joule or less is met on 004-006 size Low NOx extra thick Alumagard heat exchanger coating provides corrosion resistance and ensures long unsightly appearance of flue stacks is eliminated and the effects of wind on heating operations are dimin-ished by the induced draft combustion system.

5 The inducer fan draws hot combustion gas through the heat ex-changer at the optimum rate for the most effective heat transfer. The heat exchanger operates under negative pressure, preventing flue gas leakage into the indoor supply the Heating mode, the evaporator-fan relay automatically starts the evaporator fan after the heat exchanger warms up to a suitable temperature. The 30-second fan delay prevents cold air from entering the supply duct system when the condi-tioned space is calling for heat to maximize direct-spark ignition system saves operating expense when com-pared to pilot ignition systems.

6 No crossover tube is required, therefore no sooting or pilot fouling problems can 48TF standard units are designed for natural gas, but an accessory LP (liquid propane) conversion kit is is built inAll 48TF units have a flame rectifica-tion sensor to quickly sense the burner flame and ignite burners almost imme-diately. Fast shutdown is a certainty since the sensor reacts quickly to any flame outage or system failure. In the event of a shutdown, an error code is issued at the IGC is also assured due to the heating safety controls which will shut down the unit if there is a problem. If excessive temperatures develop, limit switches shut off the gas valve.

7 After 4 continuous short cycles of the high-temperature limit switch, the IGC board locks out the gas heat cycle to prevent any further short cycles. This safety feature is provided exclusively on Carrier rooftop units. The rollout switch also deenergizes the gas valve in the event of a flame , dependable constructionDesigned for durability in any climate, the weather-resistant cabinets are con-structed of galvanized steel and bond-erized, and all exterior panels are coat-ed with a prepainted baked enamel fin-ish. The paint finish is non-chalking, and is capable of withstanding ASTM B117 500-hour Salt Spray Test.

8 All internal cabinet panels are primed, permitting longer life and a more attractive appearance for the entire addition, all 48TF units are de-signed with a single , continuous top piece to eliminate any possible leaks. Totally enclosed condenser-fan motors and permanently lubricated bearings provide additional unit installation and conversionAll units are shipped in the vertical duct configuration for fit-up to standard roof curbs. (Two different curb sizes fit unit sizes 004-007 and 008-014, re-spectively.) The contractor can order and install the roof curb early in the construction stage, before decisions on size requirements are units feature roll-formed base rail design with forklift slots and rigging holes for easier maneuvering.

9 (Forklift slots are found on 3 sides for 48TF004-014 units.) The standard 48tf004 -006 units have operating weights under 500 lb and durable packaging protects all units during shipment and of contentsPageFeatures/Benefits..1-4 Model Number Nomenclature .. 5 ARI Capacity Ratings ..5,6 Physical data ..7-10 Options and Accessories..11-13 Base Unit Dimensions ..14,15 Accessory Dimensions ..16,17 Selection Procedure ..18,19 Performance data ..20-53 Electrical data ..54,55 Typical Piping and Wiring.. 56 Controls ..57-61 Application data .. 62 Typical Wiring Schematic ..63,64 Guide Specifications ..65-683 The units can be easily converted from a vertical to a horizontal duct con-figuration by relocating the panels sup-plied with the non-corrosive sloped conden-sate pan permits either an external horizontal side condensate drain (out-side the roof curb) or an internal verti-cal bottom drain (inside the roof curb).

10 Both options require an external, field- supplied 48TF units were designed with service technicians in mind. The single -row condenser coils on the 48tf004 and 008 units simplify the cleaning process. The efficient in-shot burners and all ignition components are contained in an easily removable, compact 48TF004-014 units also have a standard filter access panel, which per-mits tool-less filter changes, even on units with horizontal electrical connectionsTerminal boards, located in the base unit control box, facilitate connections to room thermostat, outdoor thermo-stat(s), and economizer. Service panels are quickly removed, permitting easy utility connection capability allow power, control wiring, and gas to be routed through unit base pan, minimizing roof penetrations.