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TABLE 19
ML193
Unit
CO
2
%
For Nat
CO
2
%
For L.P.
-045
7.2 - 7.9
8.6 - 9.3
-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
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.
TABLE 20
Supply Line and Manifold Pressure (inches w.c.) At
All Altitudes For -1 Through -6 Units
Unit
Fuel
Manifold
Pressure
Line
Pressure
All
Nat. Gas
3.5
4.5 - 13.0
All
L.P. Gas
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 21
Manifold and Supply Line Pressure 0-10,000ft. For -7 Units and Later
ML193
Unit
Gas
Manifold Pressure in. wg.
Supply Line Pressure
in. w.g.
0 - 10000 ft.
0-4500 ft.
4501-5500 ft.
5501-6500 ft.
6501 - 7500ft.
7501 - 10000ft.
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 L.P. propane gas changeover kit is necessary to convert this unit. Refer to the changeover kit installation instruction for the conversion
procedure.
TABLE 22
Conversion Kit and Pressure Switch Requirements at Varying Altitudes
ML193
Unit
Natural to
LP/Propane
High Altitude
Natural Burner
Orifice Kit
LP/Propane to
Natural
High Altitude Pressure Switch
0 - 7500 ft
(0 - 2286m)
7501 - 10,000 ft
(2286 - 3038m)
0 - 7500 ft
(0 - 2286m)
4501 - 7500 ft
(1373 - 2286m)
7501 -10,000 ft
(2286 - 3048m)
-045
*69W73
73W37
*73W81
93W87
93W88
-070
-090
-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).