Bryant GAS-FIRED INDUCED-COMBUSTION FURNACES 373LAV - Manual (Page 4)

9. If a greasy residue is present on blower wheel, remove
wheel from the blower housing and wash it with an
appropriate degreaser. To remove wheel:
a. Mark blower wheel location on shaft before disassembly
to ensure proper reassembly.
b. Loosen setscrew holding blower wheel on motor shaft.
NOTE: Mark blower mounting arms, motor, and blower housing
so motor and each arm is positioned at the same location during
reassembly.
c. Mark blower wheel orientation and cutoff plate location
to ensure proper reassembly.
d. Remove screws securing cutoff plate and remove cutoff
plate from housing.
e. Remove bolts holding motor and motor mounts to
blower housing and slide motor and mounts out of
housing. Disconnect capacitor and ground wire attached
to blower housing before removing motor. Motor mount
belly band need not be removed unless motor is to be
replaced.
f. Remove blower wheel from housing.
CAUTION: The blower wheel should not be dropped or
bent as balance will be affected.
10. Reassemble motor and blower by reversing items 9a
through 9f. Be sure to reattach ground wire.
11. Reinstall blower assembly in furnace.
12. Reinstall control and transformer support assembly in
furnace.
13. Reconnect blower leads to furnace control and auxiliary
limit switch leads (downflow only).
Refer to furnace wiring diagram, and connect thermostat
leads if previously disconnected. (see Fig. 12.)
NOTE: Refer to Table 3 for motor speed lead relocation if leads
were not identified before disconnection.
CAUTION: Heating air speed selection MUST be ad-
justed to provide proper air temperature rise as specified
on the rating plate. Failure to adjust the heating speed
may shorten heat exchanger life.
14. Downflow furnaces only: Reinstall internal vent pipe and
enclosure by reversing items 3a through 3d.
NOTE: A releasing agent such as PAM cooking spray or equiva-
lent (must not contain corn or canola oil, aromatic or halogenated
hydrocarbons or inadequate seal may occur) and RTV sealant
(G.E. 162, 6702, or Dow-Corning 738) are needed before starting
installation. DO NOT substitute any other type of RTV sealant.
G.E. 162 (P771-9003) is available through RCD in 3-oz. tubes.
15. Reinstall vent connector to furnace flue collar. After fully
assembling vent connector to furnace flue collar, securely
fasten vent connector to flue collar with 2 field-supplied,
corrosion-resistant, sheet metal screws located 180° apart
and midway up the collar.
16. Turn on electrical supply. Manually close blower access
door switch. Use a piece of tape to hold switch closed.
Check for proper rotation and speed changes between
heating and cooling by jumpering R to W and then R to Y
on furnace control thermostat terminals.
→ Fig. 6—Model 383KAV Upflow
A00261
BLOCKED
VENT
SAFEGUARD
FLUE
COLLECTOR
BOX
MOUNTING
SCREWS
RELIEF
BOX
CONTROL
FILTER
RETAINER
WASHABLE
FILTER
FLUE
COLLAR
PRESSURE
SWITCH
GAS
VALVE
C OM 24V HUM
G R Y W
Fig. 7—Model 373LAV Downflow
A99285
VENT PIPE
ENCLOSURE
BLOCKED
VENT
SAFEGUARD
MANUAL
RESET LIMIT
SWITCHES
AUXILIARY
LIMIT
SWITCH
(WHEN USED)
MOUNTING
SCREWS
RELIEF
BOX
C
OM 24V HUM
G R Y W
CONTROL
PRESSURE
SWITCH
GAS
VALVE
FLUE
COLLAR
TABLE 3—SPEED SELECTOR
COLOR SPEED
FACTORY-
ATTACHED TO
Black High Cool
Yellow (When
present)
Medium-High Spare
Blue Medium-Low Heat
Red Low Spare
White Common L2/COM
—4—