34
NATURAL GAS MANIFOLD PRESSURE (in wc)
HEATING
VALUE
at ALTITUDE
BTU/CU. FT.
MEAN ELEVATION FEET ABOVE SEA LEVEL
0to
2000
2001 to
3000
3001 to
4000
4001 to
5000
5001 to
6000
6001 to
7000
7001 to
8000
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
700 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 42 3.6
725 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 42 3.5 42 3.4
750 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 42 3.3 42 3.2
775 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 41 2.9 43 3.7 43 3.6
800 -- -- -- -- -- -- -- -- -- -- -- -- 42 3.1 43 3.6 43 3.5 43 3.4
825 -- -- -- -- -- -- -- -- 43 3.7 43 3.6 43 3.4 43 3.3 44 3.6
850 -- -- -- -- -- -- -- -- 43 3.5 43 3.4 44 3.7 44 3.6 44 3.4
875 -- -- -- -- 43 3.4 43 3.3 44 3.6 44 3.5 44 3.4 44 3.2
900 -- -- -- -- 44 3.7 44 3.6 44 3.4 44 3.3 44 3.2 44 3.1
925 44 3.7 44 3.5 44 3.4 44 3.2 44 3.1 45 3.6 45 3.5
950 44 3.5 44 3.3 44 3.2 44 3.1 45 3.6 45 3.5 45 3.3
975 44 3.3 44 3.1 45 3.7 45 3.5 45 3.4 45 3.3 45 3.2
1000 44 3.2 45 3.6 45 3.5 45 3.4 45 3.2 45 3.1 46 3.1
1050 46 3.6 45 3.3 45 3.2 45 3.1 46 3.1 -- -- -- -- -- -- -- --
1100 46 3.3 45 3.0 46 3.0 46 2.9 -- -- -- -- -- -- -- -- -- -- -- --
Conversion: 1 in wc = .25 kP a
NOTE:
Natural gas data is based on 0.60 specific gravity. For fuels with different specific gravity consult the National Fuel Gas Code ANSI
Z223.1---2006/NFPA 54---2006 or National Standard of Canada, Natural Gas And Propane Installation Code CSA B149.1---05.
Table 6 – Natural Gas Manifold Pressure
PROPANE GAS MANIFOLD PRESSURE (in wc)
HEATING VALUE
at ALTITUDE
BTU/CU. FT.
MEAN ELEVATION FEET ABOVE SEA LEVEL
0to
2000
2001 to
3000
3001 to
4000
4001 to
5000
5001 to
6000
6001 to
7000
7001 to
8000
2500 10.0 8.9 8.4 10.0 10.0 10.0 10.0
Orifice Size #55 #55 #55 #56 #56 #56 #56
Conversion: 1 in wc = .25 kP a
NOTE:
Propane data is based on 1.53 specific gravity. For fuels with different specific gravity consult the National Fuel Gas Code ANSI
Z223.1---2006/NFPA 54---2006 or National Standard Of Canada, Natural Gas And Propane Installation Code CSA B149.1---05.
NOTE: The derating of these furnaces at 2% (Natural Gas) and 4% (Propane Gas) has been tested and design---certified by CSA.
In Canada, the input rating must be derated 5% (Natural Gas) and 10% (Propane Gas) for altitudes of 2,000 to 4,500 above sea level. Use the 2001 to
3000 column in Table 6 and Table 7.
Table 7 – Propane Gas Manifold Pressure
The burner orifice part nos. are as follows:
Orifice #41 333730 --701
Orifice #42 333730 --702
Orifice #43 333730 --703
Orifice #44 333730 --704
Orifice #45 333730 --705
Orifice #46 333730 --709
Orifice #54 333730 --706
Orifice #55 333730 --707
Orifice #56 333730 --708
General Derating Rules
1. These furnaces may be used at full input rating when in-
stalled at altitudes up to 2,000′. When installed above
2,000′, the input must be decreased 2% (natural) or 4%
(Propane) for each 1000′ above sea level in the USA. In
Canada, the input rating must be derated 5% (natural) or
10% (Propane) for each 1000′ above sea level. See Table 6
or Table 7 for required high altitude input rate.
2. For operation with natural gas at altitudes above 2,000′,
orifice change and/or manifold pressure adjustments may
be required for the gas supplied. First consult your local
gas supplier, then refer to Table 6 for required pressu re
change and/or orifice change for high altitudes.
3. For operation with Propane gas, gas orifices MUST be
changed and manifold pressure MUST be maintained as
per Table 7. Orifices can be ordered through our distribut-
or. (See Fig. 35).
High Altitude Input Rate =
Nameplate Sea Level Input Rate x (Multiplier)
[USA]
Elevation
High Altitude Multiplier
Natural Gas Propane Gas
2001′ - 3000′ 0.95 0.90
3001′ - 4000′ 0.93 0.86
4001′ - 5000′ 0.91 0.82
5001′ - 6000′ 0.89 0.78
6001′ - 7000′ 0.87 0.74
7001′ - 8000′ 0.85 0.70
* Based on mid---range of elevation.
High Altitude Air Pressure Switch
Altitudes over 4,000′ may require a different air pressure switch
than the one installed at the factory. Check parts list for pressure
switch and consult your distributor for part number and
availability. In Canada, provincial codes may govern installation
of switch. Check with governing authorities.
PG9YAA
To Next Page
Loading...
