Lennox ML193UH045P36B Unit Information page 42

TABLE 19
ML193
Unit
-045
-070
-090
-110
-135
The maximum carbon monoxide reading should not exceed 50 ppm.
F-High Altitude
NOTE - In Canada, certification for installations at eleva­
tions over 4500 feet (1372 m) is the jurisdiction of local au­
thorities.
ML193UH -1 through -6 units require no manifold pressure
adjustments for operation at altitudes up to 10,000 feet
(3048 m) above sea level. However, -7 units and later in­
stalled at altitude of 4501 - 10,000 feet (1373 to 3048m) re­
quire a pressure switch change which can be ordered sep­
Manifold and Supply Line Pressure 0-10,000ft. For -7 Units and Later
ML193
Gas
Unit
Natural
All Sizes
LP/propane
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.
Conversion Kit and Pressure Switch Requirements at Varying Altitudes
Natural to
LP/Propane
ML193
Unit
0 - 7500 ft
(0 - 2286m)
-045
-070
-090
*69W73
-110
-135
* 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).
CO % CO %
2 For Nat 2 For L.P.
7.2 - 7.9 8.6 - 9.3
Manifold Pressure in. wg.
0-4500 ft. 4501-5500 ft.
3.5 3.3
10.0 9.4
High Altitude
Natural Burner
Orifice Kit
7501 - 10,000 ft
(2286 - 3038m)
73W37
arately and manifold pressure de-rate. See table 20 or
table 21 for manifold pressures at varying altitudes. Table
22 lists conversion kit and pressure switch requirements at
varying altitudes.
The combustion air pressure switch is factory-set and re­
quires no adjustment.
Supply Line and Manifold Pressure (inches w.c.) At
All Altitudes For -1 Through -6 Units
Unit
All
All
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 21
5501-6500 ft. 6501 - 7500ft.
3.2 3.1
9.1 8.9
TABLE 22
LP/Propane to
Natural
0 - 7500 ft
(0 - 2286m)
*73W81
Page 42
TABLE 20
Manifold
Fuel
Pressure
Nat. Gas 3.5
L.P. Gas 10.0
Supply Line Pressure
0 - 10000 ft.
7501 - 10000ft.
3.5 4.5
10.0 11.0
High Altitude Pressure Switch
4501 - 7500 ft 7501 -10,000 ft
(1373 - 2286m) (2286 - 3048m)
93W87
Line
Pressure
4.5 - 13.0
11.0 - 13.0
in. w.g.
13.0
13.0
93W88