Assessments - 2, GPA: 4 ( )

Fabricante : Carrier Arquivo Tamanho: 2.05 mb Arquivo Nome : Língua de Ensino:

See Fig. 7. Then, connect capped nipple into lower end of tee. Extend capped nipple below level of gas controls. Table 2 — Maximum Gas Glow Capacity* NOMINAL IRON PIPE, SIZE (in.) INTERNAL DIAMETER (In.) LENGTH OF PIPE, FTf 10 20 30 40 50 60 70 80 90 100 125 150 175 200 Vi .622 175 120 97 82 73 66 61 57 53 50 44 40 — — % .824 360 250 200 170 151 138 125 118 110 103 93 84 77 72 1 1.049 680 465 375 320 285 260 240 220 205 195 175 160 145 135 VA 1.380 1400 950 770 600 580 530 490 460 430 400 360 325 300 280 IV2 1.610 2100 1460 1180 990 900 810 750 690 650 620 550 500 460 430 ‘Capacity of pipe in cu ft of gas per hr for gas pressure of 0 5 psig or less. Pressure drop of 0.5 in. wg (based on a 0.60 specific gravity gas) Refer to Table C-4, NFPA 54-1984 tThis length includes an ordinary number of fittings our Fig. 7 — Sediment Trap testing of the piping systems when test pressure in excess of 0.5 psig. Pressure test the gas supply piping system at pressures equal to or less than 0.5 psig. The unit heating section must be isolated from the gas piping system by closing the external main manual shutoff valve and slightly opening the ground-joint union. A CAUTION Unstable operation may occur when the gas valve and manifold assembly are forced out of position while connecting improperly-routed rigid gas piping to the gas valve. Use a backup wrench when making connection to avoid strain on, or distortion of, the gas control piping. A CAUTION If a flexible conductor is required or allowed by the authority having jurisdiction, black iron pipe shall be installed at the gas valve and shall extend a minimum of 2 in. outside the unit casing. CAUTION: DO NOT DRILL OR SCREW IN SHADED AREA 5 0" INLET/OUTLET PANEL Size "A" Small Cabinet NLT018—NET042 2OV2 in. Large Cabinet NHT036—NVT060 251/2 in. Fig. 8 — Location of Coil Area Not to be Drilled 5. Install an accessible, external, manual main shutoff valve in gas supply pipe within 6 ft of heating section. 6. Install ground-joint union close to heating section between unit manual shutoff and external manual main shutoff valve. 7. Pressure-test all gas piping in accordance with local and national plumbing and gas codes before connecting piping to unit. NOTE: Pressure test the gas supply system after the gas supply piping is connected to the gas valve. The supply piping must be disconnected from the gas valve during the A WARNING Never use a match or other open flame when checking for gas leaks. Never purge gas line into combustion chamber. Failure to follow this warning could result in an explosion causing personal injury or death. 8. Check for gas leaks at the field-installed and factory-installed gas lines after all piping connections have been completed. Use soap-and-water solution (or method specified by local codes and/or regulations). Step 8 — Install Duct Connections — The unit has duct flanges on the supply- and return-air openings on the side and bottom of the unit. See Fig. 2 and 3 for connection sizes and locations. NOTE: The design and installation of the duct system must be in accordance with the standards of the NFPA for installation of nonresidence-type air conditioning and ventilating systems, NFPA No. 90A orresidence-type, NFPA No. 90B; and/or local codes and residence-type, NFPA No. 90B; and/ or local codes and ordinances. Adhere to the following criteria when selecting, sizing and installing the duct system: 1. The unit is shipped in vertical configuration. To convert unit to horizontal application, remove side duct covers, save screws and install the covers on bottom duct openings. 2. Select and size ductwork, supply-air registers and return-air grilles according to ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers) recommendations. A CAUTION When drilling the duct-system fastening holes into the side of the unit instead of the unit duct flanges, use extreme care to avoid puncturing the coil or coil tubes. See Fig. 8. 7 3. Use flexible transition between rigid ductwork and unit to prevent transmission of vibration. The transition may be screwed or bolted to duct flanges. Use suitable gaskets to ensure weather- and airtight seal. 4. Install external, field-supplied air filter(s) in return-air ductwork where it is easily accessible for service. Recommended filter sizes are shown in Table 1. 5. Size all ductwork for maximum required airflow (either heating or cooling) for unit being installed. Avoid abrupt duct size increases or decreases. 6. Adequately insulate and weatherproof all ductwork located outdoors. Insulate ducts passing through unconditioned space, and use vapor barrier in accordance with latest issue of SMACNA (Sheet Metal and Air Conditioning Contractors National Association) and ACCA (Air Conditioning Contractors of America) minimum installation standards for heating and air conditioning systems. Secure all ducts to building structure. 7. Flash, weatherproof...

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