Carrier 59MN7B Installation, Start-Up, Operating And Service And Maintenance Instructions page 47

NOTE: Pipe length (ft. / M) specified for maximum pipe lengths
located in unconditioned spaces cannot exceed total allowable pipe
length as calculated from Table 14.
Configure the Furnace
WARNING
!
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal
injury or death.
To route the vent pipe and combustion air pipe through the
furnace, the manufacturer supplied kit must be used. Failure
to properly seal the blower compartment from the furnace
vestibule could result in the circulation of carbon monoxide
throughout the structure. The vent pipe and combustion air
pipe must be a continuous pipe while passing through the
blower compartment. Seals supplied in this kit must be
installed per the instructions provided. Follow all
procedures outlined in these instructions.
Near Furnace Vent Connections
Offsets in the vertical portion of the vent pipe should be made with
45 deg. elbows instead of 90 deg. elbows. Short horizontal runs of
Avoid short horizontal offsets with 90
deg. Elbows. Short offsets can be
difficult to slope and may trap con-
densate.
Use 45 deg. Elbows where
possible, to ensure conden-
sate drainage.
Fig. 42 - - Near Furnace Vent Connections
TABS ON THE INDUCER OUTLET RESTRICTOR SNAP
INTO THE SLOTS AT THE OUTLET OF THE INDUCER
SEE MAXIMUM EQUIVALENT VENT LENGTH TABLE
(10FT. (3.1 M) OF VENT OR LESS ONLY)
Fig. 43 - - Inducer Vent Elbow
(Appearance May Vary)
47
vent pipe are difficult to pitch correctly and may trap water in the
vent pipe. See Fig. 42.
Trapped water in the vent pipe may result in nuisance pressure
switch tripping.
Install the Vent and Combustion Air Pipes
With the furnace installed in the required position, remove the
desired knockouts from the casing. It will be necessary to remove
one knockout for the vent pipe and the other knockout for the
combustion air connection. See Fig. 15.
Use a flat blade screwdriver and tap on the knockout on opposite
sides, where the knockout meets the casing. Fold the knockout
down with duct pliers and work the knockout back and forth until
it is removed. Trim any excess metal from the knockout with tin
snips.
The vent elbow can be rotated to the required location on the
casing if necessary. See Fig. 43. To rotate the vent elbow:
1. Loosen the clamp on the inlet of the vent elbow attached to
the inducer.
2. Rotate the vent elbow to the required position. There are
rounded notches in the vent elbow to align it with the
inducer housing for each orientation.
3. Tighten the clamp around the vent elbow. Torque the clamp
to 15 lb- -in. See Fig. 47- -50.
Slope vent pipe back to the
furnace at least ¼" per foot
FOR USAGE:
A14546
A170006