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

WARNING: FIRE OR ELECTRICAL SHOCK
HAZARD
Failure to follow this warning could result in intermittent
unit operation or performance satisfaction.
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.
B. 24-v Wiring
Make field 24-v thermostat connections at 24-v terminal block on
furnace control. Y wire from thermostat MUST be connected to
Y/Y2 terminal on furnace control, as shown in Fig. 28, for proper
cooling operation. The 24-v terminal block is marked for easy
connection of field wiring. (See Fig. 32.) The 24-v circuit contains
a 3-amp, automotive-type fuse located on furnace control. (See
Fig. 32.) Any electrical shorts of 24-v wiring during installation,
service, or maintenance may cause fuse to blow. If fuse replace-
ment is required, use only a fuse of identical size (3 amp) and type.
The furnace control will flash status code 24 when fuse needs
replacement.
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.
ALTERNATE
FIELD
LOCATION
Fig. 30—Relocating J-Box
NOTE: For additional thermostat connection diagrams, reference
Fig. 54-61.
C. Accessories
1. Electronic Air Cleaner (EAC)
2. Humidifier (HUM)
FACTORY
INSTALLED
IX. DIRECT VENTING
LOCATION
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 outdoor atmosphere, and all flue
gases are discharged to outdoor atmosphere. The venting system
shall be installed in accordance to these instructions.
A. Removal of Existing Furnaces from
Common Vent Systems
When an existing Category I furnace is removed or replaced, the
original venting system may no longer be sized to properly vent
the remaining attached appliances. An improperly sized Category
I venting system could cause the formation of condensate in the
furnace and vent, leakage of condensate and combustion products,
A00212
and spillage of combustion products into the living space, etc.
—22—
The furnace control EAC terminals are energized with 115v
(1.0-amp maximum) during blower operation.
Connect an accessory Electronic Air Cleaner (if used) using
1/4-in. female quick connect terminals to the two male
1/4-in. quick-connect terminals on the control board marked
EAC-1 and EAC-2. The terminals are rated for 115VAC,
1.0 amps maximum and are energized during blower motor
operation. (See Fig. 32.)
Connect an accessory 24 VAC, 0.5 amp maximum humidi-
fier (if used) to the 1/4-in. male quick-connect HUM
terminal and C -24V screw terminal on the control board
OM
thermostat strip. The HUM terminal is energized when
blower is energized in heating. (See Fig. 32.)
CAUTION: UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit compo-
nent damage.
DO NOT connect furnace control HUM terminal to HUM
(humidifier) terminal on Thermidistat™, Zone Controller
or similar device. See Thermidistat™, Zone Controller,
thermostat, or controller manufacturer's instructions for
proper connection.