Sears 8MPL050B12B1 Furnace User Manual


 
MANIFOLDPRESSUREAND ORIFICESIZE FORHIGHALTITUDEAPPLICATIONS
NATURAL GAS MANIFOLD PRESSURE (" w.c.)
.............................................................. MEAN ELEVATION FEET ABOVE SEA LEVEL
HEATING 0 to 2001 to 3001 to 4001 to 5001 to 6001 to 7001 to
VALUE 2000 3000 4000 5000 6000 7000 8000
at ALTITUDE Orifice Manifold Orifice Manifold Orifice Manifold Orifice Manifold Orifice Manifold Orifice Manifold Orifice Manifold
BTU/CU. FT. No. Pressure No. Pressure No. Pressure No. Pressure No. Pressure No. Pressure No. Pressure
700 41 3.7
725 41 3.7 41 3.4
750 41 3.5 42 3.6
775 41 3.6 42 3,6 42 3.3
800 41 3.6 42 3.7 42 3.4 42 3.1
825 41 3.7 41 3.4 42 3,5 42 3,2 42 2.9
850 41 3.5 42 3.6 42 3.3 42 3.0 42 2.8
875 41 3.6 42 3,6 42 3.4 42 3,1 42 2,8 42 2.6
900 42 3,7 42 3,4 42 3.2 42 2,9 42 2,7 42 2.5
925 41 3.7 42 3.5 42 3.3 42 3.0 42 2,8 42 2.5 44 3.3
950 41 3.5 42 3,3 42 3,1 42 2.9 42 2,6 42 2,4 44 3.1
975 42 3.7 42 3.2 42 2.9 42 2.7 42 2.5 44 3.2 45 3.6
1000 42 3.5 42 3,0 42 2,8 42 2.6 42 2.4 45 3.7 45 3.4
1050 42 3.2 42 2.7 42 2.5 44 3.3 45 3.6
1100 43 3.6 42 2,5 44 3.2 45 3.6
NOTE: Natural gas data is based on 0.60 specific gravity.
Z223.1-2002/NFPA 54-2002 or National Standard of Canada, Natural Gas And Propane Installation Code CSA B149.1-05.
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HEATING VALUE
at ALTITUDE
BTU/CU. FT.
2500
Orifice Size
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For fuels with different specific gravity consult the National Fuel Gas Code ANSI
LPG or PROPANE GAS MANIFOLD PRESSURE (" w.c.)
MEAN ELEVATION FEET ABOVE SEA LEVEL
0 to 2001 to 3001 to 4001 to 5001 to
2000 3000 4000 5000 6000
10.0 10.0 9.0 10.0 9.4
#54 #54 #54 #55 #55
6001 to 7001 to
7000 8000
8.5 10.0
#55 #56
NOTE: Propane data isbased on 1.53 specific gravity. For fuels with different specific gravity consult the National Fuel Gas Code ANSI Z223.1-2002/N FPA
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 6 and Table 7.
The burner orifice part nos. are as follows:
Orifice #41 1096942 Orifice #42 1011351
Orifice #43 1011377 Orifice #44 1011352
Orifice #45 1011353 Orifice #54 1011376
Orifice #55 1011354 Orifice #56 1011355
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High Altitude Air Pressure Switch
The factory-installed pressure switch need NOT be changed for
any furnace installations from sea level up to and including 8,000'
altitude
Changing Orifices
1. After disconnecting power and gas supply to the furnace, re-
move the burner compartment door, exposing the burner
compartment.
2. Disconnect gas line from gas valve so manifold can be re-
moved.
3. Disconnect wiring at gas valve. Be sure to note the proper
location of all electrical wiring before being disconnected.
4. Remove the four (4) screws holding the manifold and gas
valve to the manifold supports. Do not discard any screws.
See Figure 35.
Some Models may vary
25-25-00
Manifold
5. Carefully remove the manifold assembly.
6. Remove the orifices from the manifold and replace them with
proper sized orifices. See Figure 36.
7. Tighten orifices so they are seated and gas-tight. See
Figure 36.
8. Reassemble all parts in reverse order as removed. Be sure to
engage the main burner orifices in the proper openings in the
burners.
441 01 261302 [_