Allied A97UH2E - Page 53

508433-01 Issue 2345 Page 53 of 70
Proper Combustion
Furnace should operate minimum 15 minutes with correct
manifold pressure and gas ow rate before checking
combustion. See sections E- and F-. Take combustion
sample beyond the ue outlet. Table 17 shows acceptable
combustions. The maximum carbon monoxide reading
should not exceed 100 ppm.
Capacity
CO
2
% for Nat CO
2
% for L.P.
Low Fire High Fire Low Fire High Fire
030 5.4 - 6.4 7.5 - 8.5 6.4 - 7.4 8.8 - 9.8
045 5.4 - 6.4 7.5 - 8.5 6.4 - 7.4 8.8 - 9.8
070 5.3 - 6.3 7.4 - 8.4 6.3 - 7.3 8.7 - 9.7
090 6.1 - 7.1 8.0 - 9.0 7.1 - 8.1 9.3 - 10.3
110 6.1 - 7.1 7.8 - 8.8 7.1 - 8.2 9.1 - 10.1
The maximum carbon monoxide reading should not exceed
100 ppm.
Table 17.
High Altitude
The manifold pressure, gas orice and pressure switch
may require adjustment or replacement to ensure proper
operation at higher altitudes. See Table 18 for manifold
pressures and Table 19 for gas conversion and pressure
switch kits.
Unit Gas
Manifold Pressure in. w.g. Supply Line
Pressure in.
w.g. 0 - 10000 ft.
0 - 4500 ft. 4501 - 5500 ft. 5501 - 6500 ft. 6501 - 7500 ft. 7501 - 10000 ft.
Low
Fire
High
Fire
Low
Fire
High
Fire
Low
Fire
High
Fire
Low
Fire
High
Fire
Low
Fire
High
Fire
Min Max
All
Sizes
Natural 1.7 3.5 1.6 3.3 1.5 3.2 1.5 3.1 1.7 3.5 4.5 13.0
LP/
Propane
4.5 10.0 4.2 9.4 4.0 9.1 3.9 8.9 4.5 10.0 11.0 13.0
NOTE - A natural to L.P. propane gas changeover kit is necessary to convert this unit. Refer to the changeover kit installation
instruction for the conversion procedure.
Table 18. Manifold and Supply Line Pressure 0 - 10,000 ft.
Model
Natural to LP/
Propane
High Altitude
Natural Burner
Orice Kit
High Altitude
LP/Propane Burner
Orice Kit
High Altitude Pressure Switch
0 - 7500 ft
(0 - 2286m)
7501 - 10000 ft
(2286 - 3048m)
7501 - 10000 ft
(2286 - 3048m)
4501 - 7500 ft
(1371 - 2286m)
7501 - 10000 ft
(2286 - 3048m)
030 17H64 14C92 17H65 14A47 14A50
045
11K48 *51W01 11K47
14A51 14A53
070 14A48 14A54
090 14A54 14A53
110 25B93 14A45
*Conversion requires installation of a gas valve manifold spring which is provided with the gas conversion kit.
Pressure switch is factory set. No adjustment necessary. All models use the factory-installed pressure switch from 0-4500 feet (0-
1370 m).
Table 19. Conversion Kit Fan Pressure Switch Requirements at Varying Altitudes