Allied A93UH1E - Performance and Checks; Proper Combustion Analysis; High Altitude Adjustments

508107-01Issue 2041Page 48 of 58
Proper Combustion
Furnace should operate minimum 15 minutes with correct
manifold pressure and gas ow rate before checking
combustion. Take combustion sample beyond the ue
outlet and compare to Table 16.
Capacity CO
2
% for Nat CO
2
% for L.P.
030 6.5 - 7.5 7.5 - 8.5
045, 070, 090, 110 7 - 9 8 - 10
The maximum carbon monoxide reading should not exceed
100 ppm.
Table 16.
High Altitude
NOTE: In Canada, certication for installations at
elevations over 4500 feet (1372 m) is the jurisdiction of
local authorities.
Some units installed at altitude of 4501 - 10,000 feet
(1373 to 3048 m) may require a pressure switch change
which can be ordered separately and a manifold de-rate.
See Table 17 or Table 18 for manifold pressures at all
altitudes. Table 19 lists conversion kit and pressure switch
requirements at varying altitudes.
The combustion air pressure switch is factory-set and
requires no adjustment.
Unit Fuel
Manifold
Pressure
Supply Line
All Nat 3.5 4.5 - 13.0
All LP/Propane 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 17. Supply Line and Manifold Pressure at All
Altitudes (inches w.c.) for -1 Through -3 Units
Capacity Gas
Manifold Pressure in. w.g.
Supply Line Pressure
in. w.g.
0-10,000 ft.
0-4500 ft. 4501-5500 ft. 5501-6500 ft. 6501-7500 ft. 7501-10000 ft.
All Sizes
Natural 3.5 3.3 3.2 3.1 3.5 4.5 13.0
LP /
Propane
10.0 9.4 9.1 8.9 10.0 11.0 13.0
NOTE: A natural to LP 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.
Capacity
0 - 7,500 ft
(0 - 2,286 m)
7,501 - 10,000 ft
(2,286 - 3,048 m)
Natural to LP/Propane LP/Propane to Natural
High Altitude
Natural Burner Orice Kit
High Altitude
LP/Propane Burner
Orice Kit
030 17H62+ N/A N/A 17H90
045
11K50+ 73W80* 51W01 11K45+
070
090
110
* Conversion requires installation of a gas valve regulator spring which is provided with the gas conversion Kit.
+ LP Kits include low line pressure switch.
Table 19. Burner Orice Conversion Kits at Varying Altitudes