Limit Switch ............................................................29
Heating Cycle .........................................................29
Cooling Cycle .........................................................30
Fan Mode ................................................................30
MAINTENANCE .........................................................30
Air Filters ................................................................31
Lubrication ..............................................................31
Vent System ...........................................................31
Figure 28 - Furnace Dimensions ........................33
Airfl ow Data ...........................................................34
Table 8 - Heating / Cooling Airfl ows &
Temperature Rises - Fixed Speed .......34
Table 9 - Nominal CFM & Temperature Rises -
Variable Speed .....................................35
Table 10 - Nominal Cooling / Heat Pump CFM -
Variable Speed .....................................36
Table 11 - Gas Flow Rates .................................37
Table 12 - Gas Pipe Capacities ..........................37
Table 13 - High Altitude Deration Chart for
Propane Gas .....................................38
Table 14 - Natural Gas Heating Values ..............38
Table 15 - High Altitude Deration Chart for
Nat. Gas - High Heating Value ...........39
Table 16 - High Altitude Deration Chart for
Nat. Gas - Low Heating Value ...........39
Figure 29 - Two-Stage Fixed Speed Motor
Control Board ....................................40
Figure 30 - Two-Stage Variable Speed
Figure 31 - Two-Stage Furnace Control Board ....40
Figure 32 - Wiring Diagram - Two Stage Fixed
Speed Upfl ow / Horiz. Furnaces .......41
Figure 33 - Wiring Diagram - Two Stage Fixed
Speed Downfl ow Furnaces ...............42
Figure 34 - Wiring Diagram - Two Stage Variable
Speed Upfl ow / Horiz. Furnaces .......43
Figure 35 - Wiring Diagram - Two Stage Variable
Speed Downfl ow Furnaces ...............44
Table 17 - Vent Termination Clearances .............45
Figure 36 - Horizontal & Vertical Venting ............46
Figure 37 - Upfl ow Options .................................47
Figure 38 - Horizontal Options ..........................48
Figure 39 - Downfl ow Options ............................49
Figure 40 - Furnace Components ....................50
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