High Altitude - Lennox SL280DFV Installation Instructions Manual

High Altitude

The manifold pressure, gas orifice and pressure switch
may require adjustment or replacement to ensure proper
operation at higher altitudes. Tables 24 through 27 shows
manifold pressure, pressures switch and gas conversion
kits at all altitudes.
Unit Orifice Size
Gas
Input 0 − 7500 ft.
Natural
070
3
LP/propane
Natural
090
LP/propane 3
Natural
110
3
LP/propane
1
This is the only permissible derate for these units.
2
Natural gas high altitude orifice kit required.
3
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.
NOTE − Units may be installed at altitudes up to 4500 ft. above sea level without modifications.
TABLE 25
High Altitude Pressure Switch Kits
Unit
Input
0 − 4500 ft.
070 No Change
090 No Change
110 No Change
TABLE 26
Honeywell Gas Valve Conversion Kits
High Altitude
Natural Gas
Unit Orifice Kit
Input
7501 −
0 − 7500 ft.
10,000 ft.
070 73W37 51W02
090 73W37 51W02
110 73W37 51W02
Manifold Pressure Settings
Orifice Size
Pressure in.wg.
7501 −
1
10,000 ft.
.063 .055
.039 .037
.063 .055
.039 .037
.063 .055
.039 .037
High Altitude
Pressure Switch Kit
4501 − 7500 ft. 7501 − 10,000 ft.
No Change 73W36
69W56 73W36
69W56 73W35
LP/Propane
Natural Gas to to
LP/ Propane Kit Natural Gas
Kit
7501 −
0 − 7500 ft.
10,000 ft.
73W38 69W79
73W38 69W79
73W38 69W79
For safety, shut unit off and remove manometer as
soon as an accurate reading has been obtained.
Take care to replace pressure tap plug.
TABLE 24
Manifold Manifold
Pressure in.wg.
0−4500 ft. 4501−7500 ft.
Low High Low
Fire Fire Fire
1.7 3.5 1.6
4.9 10.0 4.9
1.7 3.5 1.5
4.9 10.0 4.9
1.7 3.5 1.5
4.9 10.0 4.9
White Rodgers Gas Valve Conversion Kits
High Altitude
Natural Gas
Unit Orifice Kit
Input
7501 −
10,000 ft.
070 77W05
090 77W05
110 77W05
Page 41
IMPORTANT
Manifold
Pressure in.wg.
2
7501 − 10,000 ft.
High Low High
Fire Fire Fire
3.4 1.7 3.5
10.0 4.9 10.0
3.0 1.7 3.5
10.0 4.9 10.0
3.2 1.7 3.5
10.0 4.9 10.0
TABLE 27
Natural Gas to
LP/ Propane Kit
7501 −
0 − 7500 ft.
10,000 ft.
77W07 77W11
77W07 77W11
77W07 77W11
Supply Line
Pressure
in. w.g.
Min Max
4.5 13.0
11.0 13.0
4.5 13.0
11.0 13.0
4.5 13.0
11.0 13.0
LP/Propane
to
Natural Gas
Kit
0 − 7500 ft.
77W09
77W09
77W09