warning - Nordyne

TIME FORONE REVOLUTION(SECONDS)GAS FLOW RATE (CUBIC FEET PER HOUR)CUBIC FEET PER REVOLUTION OFMETERTIME FORONE REVOLUTION(SECONDS)Table 13. Gas Flow RateCUBIC FEET PER REVOLUTION OFMETER1 5 10 1 5 1024 150 750 1500 80 45 225 45026 138 692 1385 82 44 220 43928 129 643 1286 84 43 214 42930 120 600 1200 86 42 209 41932 113 563 1125 88 41 205 40934 106 529 1059 90 40 200 40036 100 500 1000 92 39 196 39138 95 474 947 94 38 191 38340 90 450 900 96 38 188 37542 86 429 857 98 37 184 36744 82 409 818 100 36 180 36046 78 391 783 102 35 176 35348 75 375 750 104 35 173 34650 72 360 720 106 34 170 34052 69 346 692 108 33 167 33354 67 333 667 110 33 164 32756 64 321 643 112 32 161 32158 62 310 621 114 32 158 31660 60 300 600 116 31 155 31062 58 290 581 118 31 153 30564 56 281 563 120 30 150 300control board. Reconnect the desired blower tapto the piggyback quick connect.The blower control is designed to start thecirculating air blower 30 seconds after the gasvalve is opened. The blower control is factorywired to turn the blower motor off 120 secondsafter the gas valve is closed. This timing can bechanged using the BLOWER OFF timing switchopposite the terminal block on the control board.(See Figure 28.)Verifying Burner OperationTo verify operation of the burners, make surethat the blower compartment door is in placeand that there is power to the furnace. Set thethermostat above room temperature and observethe ignition sequence. The flame can beobserved through the small clear window on theburner box. The burner flame should carry overbetween all burners. The flames should be blue,without yellow tips. Flames should extend fromeach burner without lifting, curling, or fl oating.After verifying ignition, set the thermostat belowroom temperature and verify that the burner flameextinguishes completely.Verifying Operation of the SupplyAir Limit SwitchTo verify operation of the supply air limit switch,make sure that the blower door is in place andthat there is power to the furnace. Completelyblock the return airflow to the furnace by installinga close-off plate in place of or upstream of thefilter(s). Set the thermostat above room temperatureand verify that the Sequence of Operationis as described in these instructions. The supplyair limit switch should function to turn off thegas valve within approximately fi ve minutes. Thecirculating air and combustion blowers shouldcontinue to run when the supply air limit switchopens. Remove the close-off plate immediatelyafter the supply air limit switch opens. If thefurnace operates for more than fi ve minuteswith no return air, set the thermostat below roomtemperature, shut off the power to the furnace,and replace the supply air limit switch.DESCRIPTION OF COMPONENTSFigure 28 shows the location of each of thefunctional components described below. If anycomponent of the furnace must be replaced,use only factory authorized replacement parts.See the Replacement Parts List for each component.Flame Sensor – The fl ame sensor acts to provethat fl ame has carried over from the igniter to theopposite end burner. If no fl ame is sensed, thefurnace will be shut down automatically.Gas Valve – The gas valve controls the fl owof gas to the burners. When the gas valve isenergized it automatically opens and regulatesthe gas pressure in the manifold.Pressure Switch – The pressure switch verifiesthat the inducer is drawing the combustion gases34