Carrier 58UVB series Installation, Start-Up, And Operating Instructions Manual page 21

Attachment of 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 of
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.
If use of this drain connection is desired, drill out fitting's tap
plug with 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, as shown in Fig. 26.
Fig. 27 --- Attic Termination
UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit component
damage.
Inducer housing outlet cap must be installed and fully
seated against inducer housing. Clamp must be tightened to
prevent any condensate leakage.
NOTE:
combustion air intake may be a result of improper termination.
Ensure combustion air pipe termination is similar to those as
shown in Fig. 31 so that it will not be susceptible to area where
light snow or others sources of moisture could be pulled in.
21
CAUTION
!
(Direct Vent/2- -Pipe System ONLY). Moisture in
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