Carrier 58MVP Installation, Start-Up, And Operating Instructions Manual page 23

3. Use largest diameter pipe determined in 1. and 2. above for
both pipes.
NOTE: Do not count elbows or pipe sections in terminations or
within furnace. See shaded areas in Fig. 31, 32, 33, 34, and 35.
EXAMPLE:
An 080-14 size furnace located in Indianapolis, elevation 650 ft
above sea level, could be installed in an application requiring 3
elbows and 17 ft of vent pipe, along with 5 elbows and 16 ft of
combustion-air pipe. Table 5 indicates this application would
allow a 1-1/2-in. diameter vent pipe, but require a 2-in.
diameter combustion air pipe (1-1/2-in. pipe is good for 20 ft
with 3 elbows, but only 10 ft with 5 elbows). Therefore, 2-in.
diameter pipe must be used for both vent and combustion-air
pipes since larger required diameter must always be used for
both pipes. If same installation were in Albuquerque, elevation
5250 ft above sea level, installation would require 2-in. vent
pipe and combustion-air pipe. At 5001- to 6000-ft elevation,
1-1/2-in. pipe is not allowed with 5 elbows, and 2-in. pipe is
good for 68 ft with 5 elbows.
COMBUSTION-AIR AND VENT PIPE ATTACHMENT
NOTE: All pipe joints must be watertight except attachment of
combustion-air pipe to inlet housing connection since it may be
necessary to remove pipe for servicing.
1. Attach combustion-air pipe as follows:
a. Determine location of combustion-air intake pipe connec-
tion to combustion-air intake housing as shown in Fig. 28
for application.
b. Reposition combustion-air intake housing plug fitting in
appropriate unused intake housing connection.
c. Insert perforated disk assembly (factory supplied) in intake
housing where combustion-air intake pipe will be con-
nected.
d. Install pipe support (factory-supplied in loose parts bag)
into selected furnace casing combustion-air pipe hole. Pipe
support should be positioned to bottom of casing hole.
e. Insert 2-in. diameter pipe into intake housing.
NOTE: A 2-in. diameter pipe must be used within the furnace
casing. Make all pipe diameter transitions outside furnace casing.
f. Drill a 1/8-in. hole in 2-in. combustion-air pipe using hole
in intake housing as a guide.
g. Install a field-supplied No. 6 or No. 8 sheet metal screw
into combustion-air pipe.
NOTE: DO NOT OVERTIGHTEN SCREW. Breakage to intake
housing or fitting may cause air leakage to occur.
NOTE: Do not attach combustion-air intake pipe permanently to
combustion-air intake housing since it may be necessary to remove
pipe for service of ignitor or flame sensor.
COMBUSTION-AIR INTAKE HOUSING PLUG
FITTING
The combustion-air intake plug fitting must be installed in
unused combustion-air intake housing. This fitting must be
attached by using RTV sealant, or by drilling a 1/8-in. hole in
fitting, using hole in intake housing as a guide. Install a
field-supplied No. 6 or No. 8 sheet metal screw.
NOTE: DO NOT OVERTIGHTEN SCREW. Breakage to intake
housing or fitting may cause air leakage to occur.
A plugged drain connection has been provided on this fitting
for use when moisture is found in combustion-air intake pipe
and combustion box.
NOTE: Moisture in combustion-air intake may be result of
improper termination. Ensure combustion-air intake pipe is similar
to that shown in Fig. 31, 32, 33, 34, or 35 so it will not be
susceptible to areas where light snow or other sources of moisture
could be pulled in.
If use of this drain connection is desired, drill out fitting's tap
plug with a 3/16-in. drill and connect a field-supplied 3/8-in.
tube. This tube should be routed to open condensate drain for
furnace and A/C (if used), and should be trapped. (See Fig.
30.)
3/8" ID TUBE
3/16"
DRILL
4"
MIN
TRAP
TO OPEN
DRAIN
Fig. 30—Intake Housing Plug Fitting Drain
2. Attach vent pipe as follows:
a. Determine location of vent pipe connection to inducer
housing as shown in Fig. 28 for application.
b. Reposition neoprene inducer housing outlet cap and clamp
to appropriate unused inducer housing connection. Tighten
clamp.
Inducer housing outlet cap must be installed and fully seated
against inducer housing. Clamp must be tightened to prevent
any condensate leakage. Failure to follow this warning could
result in electrical shock, fire, personal injury, or death.
c. Install pipe support (factory-supplied in loose parts bag)
into selected furnace casing vent pipe hole. Pipe support
should be positioned to bottom of casing hole.
d. Insert 2-in. diameter pipe into inducer housing through
neoprene coupling and clamp in inducer housing. Tighten
clamp.
Vent pipe must be installed and fully seated against inducer
housing. Clamp must be tightened to prevent any condensate
leakage. Failure to follow this warning could result in
electrical shock, fire, personal injury, or death.
NOTE: A 2-in. diameter pipe must be used within the furnace
casing. Make all pipe diameter transitions outside furnace casing.
3. Working from furnace to outside, cut pipe to required
length(s).
4. Deburr inside and outside of pipe.
5. Chamfer outside edge of pipe for better distribution of primer
and cement.
6. Clean and dry all surfaces to be joined.
7. Check dry fit of pipe and mark insertion depth on pipe.
NOTE: It is recommended that all pipes be cut, prepared, and
preassembled before permanently cementing any joint.
23
COMBUSTION – AIR
INTAKE HOUSING
BURNER
BOX
COMBUSTION –
AIR PIPE
A93035