International comfort products N9MP1 Service Manual page 10

Service Manual
NATURAL GAS MANIFOLD PRESSURE (, w.c.) FOR THE90% 80,000 BTUH MODEL AND
Table 4
ALTERNATE INPUT MODELS
HEATING
0 to
VALUE
2000
at ALTITUDE
Orifice Manifold
BTU/CU. FT.
No. Pressure
700 −− −−
725 −− −−
750 −− −−
775 −− −−
800 −− −−
825 −− −−
850 −− −−
875 −− −−
900 −− −−
925 44 3.7
950
44 3.5
975
44 3.3
1000 44 3.2
1050 46 3.6
1100 46 3.3
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 #44.
LPG or PROPANE GAS MANIFOLD PRESSURE (, w.c.)
Table 5
FOR THE 80,000 BTUH MODEL AND ALTERNATE INPUT MODELS
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.
General Derating Rules
1. These furnaces may be used at full input rating when
installed at altitudes up to 2,000'. When installed
above 2,000', the input must be decreased 2% (natu-
ral) or 4% (LP) for each 1000' above sea level in the
USA. In Canada, the input rating must be derated 5%
(natural) or 10% (LP) for each 1000' above sea level.
See Table 4 or Table 5 for required high altitude in-
put rate.
2. For operation with natural gas at altitudes above
2,000', orifice change and/or manifold pressure ad-
justments may be required for the gas supplied. First
consult your local gas supplier, then refer to Table 2
for required pressure change and/or orifice change
for high altitudes.
3. For operation with LP gas, gas orifices MUST be
changed and manifold pressure MUST be maintained
10
MEAN ELEVATION FEET ABOVE SEA LEVEL
2001 to 3001 to
3000 4000
Orifice Manifold Orifice Manifold
No. Pressure No. Pressure
−− −− −− −−
−− −− −− −−
−− −− −− −−
−− −− −− −−
−− −− −− −−
−− −− 42 3.3
−− −− 42 3.1
43 3.5 43 3.6
43 3.3 43 3.4
44 3.7 44 3.7
44 3.5 44 3.5
44 3.3 44 3.3
44 3.2 44 3.2
46 3.6 46 3.6
46 3.3 46 3.3
MEAN ELEVATION FEET ABOVE SEA LEVEL
0 to 2001 to
2000 3000
10.0 10.0
#54 #54
Single Stage Multi Position Furnace
4001 to 5001 to
5000 6000
Orifice Manifold Orifice
No. Pressure No.
−− −− −−
−− −− −−
−− −− −−
−− −− 41
42 3.5 42
42 3.3 42
42 3.1 42
43 3.6 43
43 3.4 43
44 3.7 44
44 3.5 44
44 3.3 44
44 3.2 44
46 3.6 46
46 3.3 −−
3001 to 4001 to
4000 5000
9.0 10.0
#54 #55
as per Table 3. Orifices can be ordered through your
distributor. (See Figure 6)
High Altitude Input Rate =
*
Nameplate Sea Level Input Rate x (Multiplier)
High Altitude
Multiplier
Elevation
LP Gas*
Standard Input
0' - 2000'
2001' - 3000'
3001' - 4000'
4001' - 5000'
5001' - 6000'
6001' - 7000'
7001' - 8000'
* Based on mid−range of elevation.
6001 to
7000
Manifold Orifice Manifold Orifice
Pressure No. Pressure No.
−− −− −− −−
−− −− −− −−
−− 41 3.6 41
3.4 41 3.4 41
3.5 42 3.5 42
3.3 42 3.3 42
3.1 42 3.1 42
3.6 43 3.6 43
3.4 43 3.4 43
3.7 44 3.7 44
3.5 44 3.5 44
3.3 44 3.3 44
3.2 44 3.2 44
3.6 −− −− −−
−− −− −− −−
5001 to 6001 to
6000 7000
9.4 8.5
#55 #55
High Altitude
Multiplier
LP Gas*
80,000 BTUH Input
Model
1.00 1.00
0.90 1.00
0.86 1.00
0.82 1.00
0.78 0.96
0.74 0.92
0.70 0.88
440 08 2011 00
7001 to
8000
Manifold
Pressure
−−
−−
3.6
3.4
3.5
3.3
3.1
3.6
3.4
3.7
3.5
3.3
3.2
−−
−−
7001 to
8000
10.0
#56
High Altitude
Multiplier
LP Gas*
Alternate Input
0.80
0.80
0.80
0.80
0.76
0.72
0.68