International comfort products N9MP1 Service Manual page 9

Single Stage Multi Position Furnace
MANIFOLD PRESSURE AND ORIFICE SIZE FOR HIGH ALTITUDE APPLICATIONS
NATURAL GAS MANIFOLD PRESSURE (, w.c.)
Table 2
HEATING 0 to
VALUE 2000
at ALTITUDE
Orifice Manifold
BTU/CU. FT.
No. Pressure
700 −− −−
725 −− −−
750 −− −−
775 −− −−
800 −− −−
825 −− −−
850 −− −−
875 −− −−
900 −− −−
925 41 3.7
950 41 3.5
975 42 3.7
1000 42 3.5
1050
42 3.2
1100 43 3.6
NOTE: Natural gas data is based on 0.60 specific gravity. For fuels with different specific gravity consult the National Fuel Gas Code ANSI
Z223.1−2002/NFPA 54−2002 or National Standard of Canada, Natural Gas And Propane Installation Code CSA B149.1−05.
Bold indicated the factory shipped orifice size #42.
LPG or PROPANE GAS MANIFOLD PRESSURE (, w.c.)
Table 3
FOR THE 90% 80,000 BTUH MODEL AND ALTERNATE INPUT RATINGS
HEATING VALUE
at ALTITUDE
BTU/CU. FT.
2500
Orifice Size
NOTE: Propane data is based on 1.53 specific gravity. For fuels with different specific gravity consult the National Fuel Gas Code ANSI Z223.1−2002/NFPA
54−2002 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 2, Table 3, Table 4 and Table 5.
The burner orifice part nos. are as follows:
Orifice #41 1096942
Orifice #43 1011377
Orifice #45 1011353
440 08 2011 00
MEAN ELEVATION FEET ABOVE SEA LEVEL
2001 to 3001 to
3000 4000
Orifice Manifold Orifice Manifold
No. Pressure No. Pressure
−− −− −− −−
−− −− −− −−
−− −− −− −−
−− −− −− −−
−− −− −− −−
−− −− 41 3.7
−− −− 41 3.5
41 3.6 42 3.6
42 3.7 42 3.4
42 3.5 42 3.3
42 3.3 42 3.1
42 3.2 42 2.9
42 3.0 42 2.8
42 2.7 42 2.5
42 2.5 44 3.2
MEAN ELEVATION FEET ABOVE SEA LEVEL
0 to 2001 to
2000 3000
10.0 10.0
#55 #55
Orifice #42 1011351
Orifice #44 1011352
Orifice #46 1011744
4001 to 5001 to
5000 6000
Orifice Manifold Orifice
No. Pressure No.
−− −− −−
−− −− −−
−− −− −−
−− −− 41
41 3.6 42
41 3.4 42
42 3.6 42
42 3.4 42
42 3.2 42
42 3.0 42
42 2.9 42
42 2.7 42
42 2.6 42
45
44 3.3
45 3.6 −−
3001 to 4001 to
4000 5000
10.0 10.0
#55 #55
Orifice #47 1011378
Orifice #49 1113202
Orifice #55 1011354
Service Manual
6001 to
7000
Manifold Orifice Manifold Orifice
Pressure No. Pressure No.
−− −− −− 41
−− 41 3.7 41
−− 41 3.5 42
3.6 42 3.6 42
3.7 42 3.4 42
3.5 42 3.2 42
3.3 42 3.0 42
3.1 42 2.8 42
2.9 42 2.7 42
2.8 42 2.5 44
2.6 42 2.4 44
2.5 44 3.2 45
2.4 45 3.7 45
3.6 −− −− −−
−− −− −− −−
5001 to 6001 to
6000 7000
9.4 8.5
#55 #55
Orifice #48
Orifice #54
Orifice #56
7001 to
8000
Manifold
Pressure
3.7
3.4
3.6
3.3
3.1
2.9
2.8
2.6
2.5
3.3
3.1
3.6
3.4
−−
−−
7001 to
8000
10.0
#56
1113201
1011376
1011355
9