Sequence Of Operation; Heating Mode - Bryant 393AAV Installation, Start-Up, And Operating Instructions Manual

THREE-WIRE
HEATING-ONLY
BLOWER DOOR SWITCH
BLK BLK
WHT WHT
GND
AUXILIARY
115-V FIELD-
J-BOX
SUPPLIED
DISCONNECT
VOLTS—
UNIT SIZE HERTZ—
PHASE
024070 115—60—1
036070 115—60—1
042091 115—60—1
048111 115—60—1
060135 115—60—1
060155 115—60—1
* Permissible limits of the voltage range at which the unit operates satisfactorily.
† Time-delay type is recommended.
‡ Length shown is as measured 1 way along wire path between unit and service panel for maximum 2 percent voltage drop.
CAUTION: This furnace is equipped with a manual
reset limit switch or fuse link in the gas control area. The
switch or fuse link opens and shuts off power to the gas
valve if a flame rollout or overheating condition occurs in
the gas control area. DO NOT bypass the switch. Correct
inadequate combustion air supply problem, and reset the
switch or replace the fuse link.
Before operating the furnace, check each manual reset switch for
continuity. If necessary, press the button to reset the switch.
The blower compartment door must be in place to complete the
115-v circuit to the furnace.
B. 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. Connect furnace ground wire to
earth ground.
Using the schematic diagram shown in Fig. 12, follow the
sequence of operation through the different modes. Read and
follow the wiring diagram very carefully.
NOTE 2
W C
FIVE WIRE
W
C
R
O
N
T
GND
R G
O
C
L
NOTE 1
Y
24-V
TERMINAL
BLOCK
NOTES:
FURNACE
Fig. 9—Heating and Cooling Application Wiring Diagram
TABLE 5—ELECTRICAL DATA
OPERATING
VOLTAGE RANGE
Maximum* Minimum*
127 104
127 104
127 104
127 104
127 104
127 104
FIELD 24-V WIRING
FIELD 115-, 208/230-, 460-V WIRING
FACTORY 24-V WIRING
FACTORY 115-V WIRING
THERMOSTAT
R G Y
TERMINALS
CONDENSING
UNIT
TWO
WIRE
1. Connect Y-terminal in furnace as shown for proper blower operation.
2. Some thermostats require a "C" terminal connection as shown.
3. If any of the original wire, as supplied, must be replaced, use
same type or equivalent wire.
MAXIMUM MINIMUM
UNIT AMPS WIRE GAGE
5.9 14
8.7 14
9.0 14
10.1 14
13.3 12
14.0 12
NOTE: If there is a power interruption and any thermostat call,
the control initiates a 90-sec blower-only on-period before starting
a cycle.

1. Heating mode

When the wall thermostat "calls for heat," the R-W circuit
closes. The furnace control performs a self-check, verifies
the pressure switch contacts are open, and starts inducer
motor.
a. Prepurge period—As the inducer motor comes up to
speed, the pressure switch contacts close to begin a
15-sec prepurge period.
b. Igniter warm-up—At the end of the prepurge period, the
igniter is energized for a 17-sec igniter warm-up period.
c. Ignition sequence—When the igniter warm-up period is
completed, the gas valve opens, permitting gas flow to
the burners where it is ignited. After 5 sec, the igniter is
de-energized and a 2-sec flame-sensing period begins.
d. HUM terminal is energized with the gas valve. See
accessories in the Electrical Connections section.
e. Flame-sensing—When burner flame is sensed, the con-
trol begins the blower-on delay period and continues
holding the gas valve open. If burner flame is not sensed,
the control closes the gas valve and repeats ignition
sequence.
—9—
FIELD-SUPPLIED
DISCONNECT
208/230- OR
460-V
THREE
PHASE
208/230-V
SINGLE
PHASE
GND
MAXIMUM FUSE
MAXIMUM
OR CKT BKR
WIRE LENGTH (FT)‡
47
32
31
28
33
31
A98521
AMPS†
15
15
15
15
20
20