24-V Wiring; Accessories; Direct Venting; Removal Of Existing Furnaces From Common Vent Systems - Bryant 355MAV C Series Installation, Start-Up, And Operating Instructions Manual

size and fuse specifications. A disconnecting means must be
located within sight from and readily accessible to furnace.
NOTE: Proper polarity must be maintained for 115-v wiring. If
polarity is incorrect, control center fault code indicator light will
flash rapidly and furnace will NOT operate.
WARNING: The cabinet MUST have an uninterrupted
or unbroken ground according to NEC ANSI/NFPA
70-1993 and Canadian Electrical Code CSA C22.1 or
local codes to minimize personal injury if an electrical
fault should occur. This may consist of electrical wire or
conduit approved for electrical ground when installed in
accordance with existing electrical codes. Do not use gas
piping as an electrical ground. Failure to follow this
warning could result in electric shock, fire, or death.
J-BOX RELOCATION
1. Remove 2 screws holding auxiliary J-box. (See Fig. 24.)
2. Rotate J-box 180° and attach box to right side, using holes
provided.
Fig. 24—Relocating J-Box
CAUTION: If manual disconnect switch is to be
mounted on furnace, select a location where a drill or
fastener will not contact electrical or gas components.
II. 24-V WIRING
Make field 24-v thermostat connections at 24-v terminal block on
control center. Y wire from thermostat MUST be connected to Y
terminal on control center, as shown in Fig. 22, for proper cooling
operation. The 24-v terminal board is marked for easy connection
of field wiring. (See Fig. 23.) The 24-v circuit contains a 3-amp,
automotive-type fuse located on control center. (See Fig. 25.) Any
electrical shorts of 24-v wiring during installation, service, or
maintenance may cause fuse to blow. If fuse replacement is
required, use only a fuse of identical size (3 amp).
NOTE: Use AWG No. 18 color-coded copper thermostat wire for
lengths up to 100 ft. For wire lengths over 100 ft, use AWG No.
16 wire.
III. ACCESSORIES
1. Electronic Air Cleaner (EAC)
The control center EAC terminals are energized with 115v
(1.5-amp maximum) during blower operation.
a. Two extension leads are connected to the control center
EAC terminals to assist field installation of an EAC. (See
Fig. 25.) To use these leads, proceed with the following:
(1.) Strip EAC power lead insulation approximately
(2.) Insert stripped end into factory-supplied black
(3.) Strip EAC neutral lead insulation approximately
(4.) Insert stripped end into factory-supplied white
NOTE: If desired, cut butt connectors off factory leads and strip
insulation approximately 1/4-in and use field supplied wire nuts to
connect.
b. An alternate method to attach EAC lead to control center
is the following procedure:
(1.) Remove 2 screws securing the control box to
(2.) Remove and discard 2 factory-supplied leads from
(3.) Strip EAC power leads insulation approximately
NOTE: The control center EAC terminals are sized for 12 gage
maximum, solid or stranded wire.
(4.) Route EAC leads through right-hand wire grommet.
(5.) Insert EAC stripped leads into control center EAC
(6.) Reinstall control box to furnace blower shelf using
2. Humidifier (HUM)
Screw terminals (HUM and Com) are provided for 24-v
humidifier connection. (See Fig. 23.) HUM terminal is
energized with 24v (0.5-amp maximum) after inducer
motor prepurge period.
NOTE: A field-supplied, 115-v controlled relay connected to
A93051
EAC terminals may be added if humidifier operation is desired
during blower operation.
3. Dehumidification (DH)
A 1/4-in. male quick-connect terminal is provided on
control center to attach a normally open (N/O) humidistat
contact when dehumidification is desired. (See Fig. 25.)
Connect humidistat to thermostat R terminal and DH
terminal on control center. A 15 percent reduction of
cooling airflow or constant fan airflow will occur when DH
terminal is energized and a single- or 2-speed "call for
cooling" is received.
The 355MAV Furnaces require a dedicated (one 355MAV furnace
only) direct vent system. In a direct vent system, all air for
combustion is taken directly from outside atmosphere, and all flue
products are discharged to outside atmosphere.
I. REMOVAL OF EXISTING FURNACES FROM
COMMON VENT SYSTEMS
If furnace being replaced was connected to a common vent system
with other appliances, these steps shall be followed with each
appliance remaining connected to common vent system placed in
operation, while other appliances remaining connected to common
vent system are not in operation:
1. Seal any unused openings in common vent system.
2. Visually inspect vent system for proper size and horizontal
pitch. Determine there is no blockage or restriction, leak-
age, corrosion, and other deficiencies which could cause an
unsafe condition.
—19—
1/4-in.
lead's butt connector and crimp to secure.
1/4-in.
leads's butt connector and crimp to secure.
furnace blower shelf.
control center EAC terminals.
1/8-in.
terminals by depressing terminal's arm with a
screwdriver or finger. (See Fig. 26.)
2 screws removed earlier.

DIRECT VENTING