Start-Up, Adjustment, And Safety Check; General; Sequence Of Operation - Bryant 311AAV Series 100 Installation, Start-Up, And Operating Instructions Manual

Two male 1/4–in quick-connect terminals, marked EAC-1
and EAC-2 are provided for EAC connection. (See Fig. 22.)
These terminals are energized with 115-v, (1.0-amp maxi-
mum) during blower motor operation. To connect EAC
power leads to furnace control, install 1/4–in. female
quick-connect terminals on EAC power leads.
2. Humidifier (HUM)
Screw terminals HUM (1/4-in male quick-connect) and
C -24V are provided for 24-v humidifier connection. The
OM
terminals are energized with 24-v 0.5-amp maximum when
gas valve is energized.
WARNING: DO NOT connect furnace control HUM
terminal to HUM (humidifier) terminal on Thermidistat,
Zone Controller or similiar device. See Thermidistat™,
Zone Controller, thermostat, or controller manufacturer's
instructions for proper connection. A failure to follow this
warning could cause result in fire.
NOTE: A field-supplied, 115-v controlled relay connected to
EAC terminals may be added if humidifier operation is desired
during blower operation.
D. Venting
See Fig. 20, Venting Orientation for approved vent configurations.
Refer to the national or local installtion code such as NFGC in the
U.S. or the NSCNGPIC in Canada for proper vent sizing and
installation requirements.See Venting Orientation Guide for ap-
proved vent configurations. Use the enclosed Installation Instruc-
tions (Single-Stage Vent Tables for Category I Fan-Assisted
Furnaces) for a quick, easy reference.
NOTE: Vent sizing length starts at furnace vent elbow.
Rotate furnace vent elbow to position desired. Remove U-shaped
cut-out (knockout) on door to clear the vent pipe. Support the vent
pipe at the furnace with metal pipe strap.
After fully assembling the vent connector to the furnace vent
elbow, securely fasten the vent connector to the vent elbow with
two field-supplied, corrosion-resistant, sheet metal screws located
180° apart.
The horizontal portion of the venting system shall maintain a
minimum of 1/4-in. upward slope per linear ft and it shall be
rigidly supported every 5 ft or less with hangers or straps to ensure
that there will be no movement after installation.
Chimney Adapter Kit No.KGACA01014FC may be required for
some exterior masonry chimney applications. See Installation
Instructions Single-Stage Vent Tables for Category I Fan-Assisted
Furnaces to determine applicability.

START-UP, ADJUSTMENT, AND SAFETY CHECK

I. GENERAL
NOTE: Proper polarity must be maintained for 115-v wiring. If
polarity is incorrect, control status indicator light will flash rapidly
and furnace will not operate.
The furnace must have a 115-v power supply properly connected
and grounded. Proper polarity must be maintained for correct
operation. Thermostat wire connections at R, W, C, and Y must be
made at the 24-v terminal block on the furnace control. The gas
service pressure must not exceed 0.5 psig (14-in. wc), but must be
no less than 0.16 psig (4.5-in. wc).
CAUTION: This furnace is equipped with manual reset
limit switches in the gas control area. The switches open
and shut off power to the gas valve, if a flame rollout or
overheating condition occurs in the gas control area. DO
NOT bypass the switches. Correct inadequate combustion
air supply problem and reset the switches.
Before operating furnace, check each manual-reset switch for
continuity.
The blower compartment door must be in place to complete the
115–v circuit to the furnace.
II. SEQUENCE OF OPERATION
CAUTION: Furnace control must be grounded for
proper operation or control will lockout. Control is
grounded through green wire routed to gas valve and
burner bracket screw.
Using the schematic diagram in Fig. 23, follow the sequence of
operation through the different modes. Read and follow the wiring
diagram very carefully.
NOTE: If a power interruption occurs during a call for heat (W),
the control will start a 90-second blower-only ON period two
seconds after power is restored, if the thermostat is still calling for
gas heating. The green LED light will flash code 12 during the
90-second period, after which the LED will be ON continuous, as
long as no faults are detected. After the 90-second period, the
furnace will respond to the thermostat normally.
The blower door must be installed for power to be conducted
through the blower door interlock switch ILK to the furnace
control CPU, transformer TRAN, inducer motor IDM, blower
motor BLWM, hot-surface igniter HSI, and gas valve GV.
1. Heating (See Fig. 21 for thermostat connections.)
The wall thermostat "calls for heat", closing the R to W
circuit. The furnace control performs a self-check, verifies
the pressure switch contacts PRS is open, and starts the
inducer motor IDM.
a. Inducer Prepurge Period- As the inducer motor IDM
comes up to speed, the pressure switch contacts PRS
close to begin a 15-second prepurge period.
b. Igniter Warm-Up- At the end of the prepurge period,
the Hot-Surface Igniter HSI is energized for a 17-second
igniter warm-up period.
c. Trial-for-Ignition
warm-up period is completed the main gas valve relay
contacts GVR-1 and -2 close to energize the gas valve
GV, the gas valve opens, and 24 vac power is supplied
for a field-installed humidifier at the HUM terminal. The
gas valve GV permits gas flow to the burners where it is
ignited. After 5 seconds, the igniter HSI is de-energized
and a 2-second Flame-Proving period begins.
d. Flame-Proving- When the burner flame is proved at the
flame-proving sensor electrode FSE, the furnace control
CPU begins the blower-ON delay period and continues
to hold the gas valve GV open. If the burner flame is not
proved within two seconds, the control CPU will close
the gas valve GV, and the control CPU will repeat the
ignition sequence for up to three more Trials-For-
Ignition before going to Ignition-Lockout. Lockout will
be reset automatically after three hours, by momentarily
interrupting 115 vac power to the furnace, or by inter-
rupting 24 vac power at SEC1 or SEC2 to the furnace
control CPU (not at W, G, R, etc.)
—14—
Sequence-
When the igniter