Carrier PY5G B Series Installation Instructions Manual

PY5G--B: Installation InstructionsManufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.18Check Gas InputCheck gas input and manifold pressure after unit start-up (See Table 7).If adjustment is required proceed as follows:• The rated gas inputs shown in Table 7 are for altitudes from sea levelto 2000 ft (610 m) above sea level. These inputs are based on naturalgas with a heating value of 1025 Btu/ft 3 at 0.60 specific gravity, orpropane gas with a heating value of 2500 Btu/ft 3 at 1.5 specificgravity.IN THE U.S.A.:The input rating for altitudes above 2,000 ft (610 m) must be reduced by4% for each 1,000 ft (305 m) above sea level.For installations below 2,000 ft (610 m), refer to the unit rating plate.For installations above 2,000 ft (610 m). multiply the input on the ratingplate by the derate multiplier in Table 5 for correct input rate.IN CANADA:The input rating for altitudes from 2,000 (610 m) to 4,500 ft (1372 m)above sea level must be derated 10% by an authorized Gas ConversionStation or Dealer.When the gas supply being used has a different heating value or specificgravity, refer to national and local codes, or contact your distributor todetermine the required orifice size.Adjust Gas InputThe gas input to the unit is determined by measuring the gas flow at themeter or by measuring the manifold pressure. Measuring the gas flow atthe meter is recommended for natural gas units. The manifold pressuremust be measured to determine the input of propane gas units.Measure Gas Flow (Natural Gas Units)Minor adjustment to the gas flow can be made by changing the manifoldpressure. The manifold pressure must be maintained between 3.2 and 3.8IN. W.C.A07751Fig. 16 – Single-Stage Gas ValveIf larger adjustments are required, change main burner orifices followingthe recommendations of national and local codes.NOTE: All other appliances that use the same meter must be turned offwhen gas flow is measured at the meter.Proceed as follows:1. Turn off gas supply to unit.2. Remove pipe plug on manifold (See Fig. 14) and connectmanometer. Turn on gas supply to unit.3. Record number of seconds for gas meter test dial to make onerevolution.4. Divide number of seconds in Step 3 into 3600 (number of secondsin one hr).5. Multiply result of Step 4 by the number of cubic feet (cu ft) shownfor one revolution of test dial to obtain cubic feet (cu ft) of gas flowper hour.6. Multiply result of Step 5 by Btu heating value of gas to obtain totalmeasured input in Btuh. Compare this value with heating inputshown in Table 7 (Consult the local gas supplier if the heating valueof gas is not known).Table 5 – Altitude Derate Multiplier for U.S.A. **. In Canada see Canadian Altitude Adjustment.Altitude ft (m) Percent of Derate Derate MultiplierFactor††. Derate multiplier factors are based on midpoint altitude for altitude range.0-2000(0-610) 0 1.002001-3000*(610-914) 8-12 0.903001-4000(915-1219) 12-16 0.864001-5000(1220-1524) 16-20 0.825001-6000(1524 -1829) 20-24 0.786001-7000(1829-2134) 24-28 0.747001-8000(2134-2438) 28-32 0.708001-9000(2439-2743) 32-36 0.669001-10,000(2744-3048) 36-40 0.62EXAMPLE:90,000 Btu/hr Input Furnace Installed at 4300 ft.Furnace Input Rate atSea Level X Derate MultiplierFactor = Furnace Input Rate atInstallation Altitude90,000 X 0.90 = 81,000CAUTION!UNIT DAMAGE HAZARDFailure to follow this caution may result in reduced unit and/orcomponent life.Do Not redrill an orifice. Improper drilling (burrs, out-of-round holes,etc.) can cause excessive burner noise and misdirection of burner flame.If orifice hole appears damaged or it is suspected to have been redrilled,check orifice hole with a numbered drill bit of correct size.REGULATORCOVER SCREWADJUSTMENTSCREWREGULATOR SPRING(PROPANE - WHITE)NATURAL - SILVER)GAS PRESSUREREGULATORADJUSTMENTMANIFOLDPRESSURE TAPINLETPRESSURE TAPON/OFF SWITCHPLASTIC(