Natural Gas Manifold Pressure; Propane Gas Manifold Pressure; General Derating Rules; High Altitude Air Pressure Switch - Arcoaire N9MP1 Installation Instruction

NATURAL GAS MANIFOLD PRESSURE (in wc)
Table 11
FOR THE 40k, 60k & 80k BTUH MODEL AND 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
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--2006/NFPA 54--2006 or National Standard of Canada, Natural Gas And Propane Installation Code CSA B149.1--05.
PROPANE GAS MANIFOLD PRESSURE (in wc)
Table 12
FOR THE 40k, 60k & 80k BTUH MODEL AND ALTERNATE INPUT MODELS
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.
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 9, Table 10, Table 11 and Table 12.
The burner orifice part nos. are as follows:
Orifice #41 1096942
Orifice #43 1011377
Orifice #45 1011353
Orifice #47 1011378
Orifice #49 1113202
Orifice #55 1011354

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% (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 11 or Table 12 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 9 for required pressure 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 10. Orifices can be ordered through our
distributor. (See Figure 39)
36
MEAN ELEVATION FEET ABOVE SEA LEVEL
2001 to 3001 to
3000 4000
Orifice Manifold Orifice
No. Pressure No.
---- ---- ----
---- ---- ----
---- ---- ----
---- ---- ----
---- ---- ----
---- ---- 43
---- ---- 43
43 3.4 43
44 3.7 44
44 3.5 44
44 3.3 44
44 3.1 45
45 3.6 45
45 3.3 45
45 3.0 46
MEAN ELEVATION FEET ABOVE SEA LEVEL
0 to 2001 to
2000 3000
10.0 8.9
#55 #55
For fuels with different specific gravity consult the National Fuel Gas Code ANSI
Orifice #42 1011351
Orifice #44 1011352
Orifice #46 1011744
Orifice #48 1113201
Orifice #54 1011376
Orifice #56 1011355
Specifications are subject to change without notice
4001 to
5000
Manifold Orifice Manifold Orifice
Pressure No. Pressure No.
---- ---- ---- ----
---- ---- ---- ----
---- ---- ---- ----
---- ---- ---- 41
---- 42 3.1 43
3.7 43 3.6 43
3.5 43 3.4 44
3.3 44 3.6 44
3.6 44 3.4 44
3.4 44 3.2 44
45
3.2 44 3.1
3.7 45 3.5 45
3.5 45 3.4 45
3.2 45 3.1 46
3.0 46 2.9 ----
3001 to 4001 to
4000 5000
8.4 10.0
#55 #56
Nameplate Sea Level Input Rate x (Multiplier) [USA]
Elevation
2001' - 3000'
3001' - 4000'
4001' - 5000'
5001' - 6000'
6001' - 7000'
7001' - 8000'
* Based on mid--range of elevation.
4. In cases where Table 9 or Table 10 is not applicable, eg.
alternate input rate application, refer to
Table 12 for required high altitude input rate.

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.
20,000 BTU per burner
5001 to 6001 to
6000 7000
Manifold Orifice Manifold
Pressure No. Pressure
---- ---- ----
---- 42 3.5
---- 42 3.3
2.9 43 3.7
3.6 43 3.5
3.4 43 3.3
3.7 44 3.6
3.5 44 3.4
3.3 44 3.2
3.1 45 3.6
3.6 45 3.5
3.4 45 3.3
3.2 45 3.1
3.1 ---- ----
---- ---- ----
20,000 BTU per burner
5001 to 6001 to
6000 7000
10.0 10.0
#56 #56
High Altitude Input Rate =
High Altitude Multiplier
Natural Gas
0.95
0.93
0.91
0.89
0.87
0.85
7001 to
8000
Orifice Manifold
No. Pressure
42 3.6
42 3.4
42 3.2
43 3.6
43 3.4
44 3.6
44 3.4
44 3.2
44 3.1
45 3.5
45 3.3
45 3.2
46 3.1
---- ----
---- ----
7001 to
8000
10.0
#56
Propane Gas
0.90
0.86
0.82
0.78
0.74
0.70
Table 11 or
440 01 1024 01