International comfort products N9MP1 Installation Instructions Manual page 35

Alternate BTUH Input Ratings (USA Only) *
The input rating of these furnaces can be changed from the
standard input rating to the alternate input rating shown in Table 8,
by changing the main burner orifices. Changing of burner orifices
MUST be done by a qualified service technician. See section on
changing orifices or following page.
* In the USA, 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 (609.6
to1371.6m) above sea level. Use the 2001 to 3000 (609.9 to
914.4m) column in Table 9, Table 10, Table 11 and Table 12.
Table 8 Alternate Input Ratings, USA ONLY.
BTUH BTUH
Standard Alternate
Rating Rating
MANIFOLD PRESSURE AND ORIFICE SIZE FOR HIGH ALTITUDE APPLICATIONS
NATURAL GAS MANIFOLD PRESSURE (in wc)
Table 9
HEATING 0 to 2000
VALUE
(0 to 609.6)
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
Conversion: 1 in wc = .25 kPa
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/NFPA
54−2009 or National Standard of Canada, Natural Gas And Propane Installation Code CSA B149.1−05.
* In the USA, 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 (609.6 to
1371.6m) above sea level. Use the 2001 to 3000 (609.9 to 914.4m) column in Table 9, Table 10, Table 11 and Table 12.
Table 10
HEATING VALUE
at ALTITUDE
BTU/CU. FT.
2500
Orifice Size
Conversion: 1 in wc = .25 kPa
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/NFPA
54−2009 or National Standard Of Canada, Natural Gas And Propane Installation Code CSA B149.1−05.
* In the USA, 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 (609.6 to
1371.6m) above sea level. Use the 2001 to 3000 (609.9 to 914.4m) column in Table 9, Table 10, Table 11 and Table 12.
440 01 1024 04
Natural Propane
Gas Gas
Orifice* Orifice**
MEAN ELEVATION ABOVE SEA LEVEL − ft(m)
2001 to 3000* 3001 to 4000
(609.9 to 914.4)* (914.7 to 1219.2)
Orifice Manifold Orifice
No. Pressure No.
−− −− −−
−− −− −−
−− −− −−
−− −− −−
−− −− −−
−− −− 41
−− −− 41
41 3.6 42
42 3.7 42
42 3.5 42
42 3.3 42
42 3.2 42
42 3.0 42
42 2.7 42
42 2.5 44
PROPANE GAS MANIFOLD PRESSURE (in wc)
0 to 2000 2001 to 3000*
(0 to 609.6) (609.9 to 914.4)*
10.0 10.0
#54 #54
Specifications are subject to change without notice
50,000
75,000
100,000
125,000
* See Table 11 for High Altitude
** See Table 12 for High Altitude
Manifold Gas Pressure Adjustment
SEE CHECKS AND ADJUSTMENTS, Manifold Gas Pressure
Adjustment in this manual.
25,000 BTU per burner
4001 to 5000 5001 to 6000
(1219.5 to 1524) (1524.3 to 1828.8)
Manifold Orifice Manifold Orifice
Pressure No. Pressure No.
−− −− −− −−
−− −− −− −−
−− −− −− −−
−− −− −− 41
−− 41 3.6 42
3.7 41 3.4 42
3.5 42 3.6 42
3.6 42 3.4 42
3.4 42 3.2 42
3.3 42 3.0 42
3.1 42 2.9 42
2.9 42 2.7 42
2.8 42 2.6 42
2.5 44 3.3 45
3.2 45 3.6 −−
MEAN ELEVATION ABOVE SEA LEVEL − ft(m)
3001 to 4000 4001 to 5000
(914.7 to 1219.2) (1219.5 to 1524)
9.0 10.0
#54 #55
40,000 #44
60,000 #44
80,000 #44
100,000 #44
6001 to 7000
(1829.1 to 2133.6)
Manifold Orifice Manifold
Pressure No. Pressure
−− −− −−
−− 41 3.7
−− 41 3.5
3.6 42 3.6
3.7 42 3.4
3.5 42 3.2
3.3 42 3.0
3.1 42 2.8
2.9 42 2.7
2.8 42 2.5
2.6 42 2.4
2.5 44 3.2
2.4 45 3.7
3.6 −− −−
−− −− −−
25,000 BTU per burner
5001 to 6000 6001 to 7000
(1524.3 to 1828.8) (1829.1 to 2133.6)
9.4 8.5
#55 #55
#55
#55
#55
#55
7001 to 8000
(2133.9 to 2438.4)
Orifice Manifold
No. Pressure
41 3.7
41 3.4
42 3.6
42 3.3
42 3.1
42 2.9
42 2.8
42 2.6
42 2.5
44 3.3
44 3.1
45 3.6
45 3.4
−− −−
−− −−
7001 to 8000
(2133.9 to 2438.4)
10.0
#56
35