International comfort products N9MP1 Service Manual page 11

Single Stage Multi Position Furnace
High Altitude Input Rate =
*
Nameplate Sea Level Input Rate x (Multiplier)
High Altitude
Multiplier
Elevation
Natural Gas*
Standard Input
0' - 2000' 1.00
2001' - 3000' 0.95
3001' - 4000' 0.93
4001' - 5000' 0.91
5001' - 6000' 0.89
6001' - 7000' 0.87
7001' - 8000' 0.85
* Based on mid−range of elevation.
4. In cases where Table 2 or Table 3 is not applicable,
eg. alternate input rate application, refer to Table 4 or
Table 5 for required high altitude input rate.
Main Burner Flame Check
Allow the furnace to run approximately 10 minutes. Then inspect
the main burner flames. See Figure 5.
Check for the following:
• Stable and blue flames. Dust may cause orange tips
or wisps of yellow, but flames MUST NOT have solid,
yellow tips.
• Flames extending directly from burner into heat ex-
changer.
• Flames do NOT touch sides of heat exchanger
If any problems with main burner flames are noted, it may
be necessary to adjust gas pressures or check for drafts.
Figure 5
Main Burner
Changing Orifices for High Altitude
WARNING
!
ELECTRICAL SHOCK, FIRE OR EXPLOSION
HAZARD
Failure to properly install orifices could result in
death, personal injury and/or property damage.
Turn OFF electric power (at disconnect) and gas
supply (at manual valve in gas line) when installing
orifices. Installation of orifices requires a qualified
service technician.
440 08 2011 00
High Altitude
High Altitude
Multiplier
Multiplier
Natural Gas*
Natural Gas*
80,000 BTUH Input
Alternate Input
Model
1.00 0.80
1.00 0.80
1.00 0.80
1.00 0.80
1.00 0.80
1.00 0.80
1.00 0.80
Burner Face
10−10−78
NOTE: Main burner orifices can be changed for high alti-
tudes.
1. Disconnect gas line from gas valve.
2. Remove manifold from furnace.
3. Remove the orifices from the manifold and replace
them with properly sized orifices.
4. Tighten the orifices so they are seated and gas tight
1
approximately 1 / from the face of the orifice to the
8"
back of the manifold pipe. (See Figure 6) Make sure
orifice is installed straight so that it forms a right angle
(90°) to the manifold.
5. Reinstall manifold. Ensure burners do NOT bind on
new orifices.
Changing Orifices
Figure 6
1 3
1 / " to 1 / "
8 16
NOTE: For Ignitor location see Figure 7.
Figure 7
Ignitor Location
1/
2
16
5
/
16
NOTE: Flame sensor has a different orientation for all
050 models and alternate 040 input.
High Altitude Installation
Gas input rate on the furnace rating plate is for installation at up to
2000'. The #54 burner orifices supplied in this kit are sized for Pro-
pane Gas at full rate ONLY, for use between 0−2000' elevation. Do
not use them above 2000'(except when noted by Table 3 or
Table 5). Orifices for conversion at high altitude and alternate input
must be ordered from Service Parts.
Standard Input:
Units may be installed at full input rating (25,000 BTUH per heat
exchanger) when installed at altitudes up to 2000'.
80,000 BTUH model and Alternate Input (Conversions): See unit
instructions to determine if model may be converted to alternate in-
put.
Units may be installed at full input rating (20,000 BTUH per heat
exchanger) when installed at altitudes up to 5000'.
Service Manual
Measure from face of orifice
to the back side of the
manifold.
all dimensions are in inches.
1
/
4
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