Bryant 312AAV L Series Service And Maintenance Procedures Manual page 6

BLK BLK
WHT WHT
GND
115-VOLT FIELD-
SUPPLIED
FUSED
DISCONNECT
The control in this furnace is equipped with a Light-Emitting
Diode (LED) status code light to aid in installation, servicing, and
troubleshooting. It can be viewed through the sight glass or
window in blower access door. The control indicates status with
the LED on continuously, rapid flashing, or a code composed of 2
digits. The first digit is the number of short flashes, the second
digit is the number of long flashes.
For an explanation of status codes, refer to service label located on
blower access door or Fig. 9, and the troubleshooting guide at the
end of this procedure.
The control stores 5 status codes for a period of 72 hrs.
The stored status codes will NOT be erased from the control
memory, if 115- or 24-v power is interrupted.
1. To retrieve status codes, proceed with the following:
NOTE: NO thermostat signal may be present at control, and all
blower-OFF delays must be completed.
a. Leave 115-v power to furnace turned on.
b. Remove outer access door.
c. Look into blower access door sight glass for current LED
status. Removing blower access door will open blower
access door switch and terminate 115-v power to control
so that status code is not displayed.
d. BRIEFLY remove either wire from the main limit (LS)
or draft safeguard (DSS) switch until LED goes out, then
reconnect it.
NOTE: If wire to LS or DSS is disconnected longer than 4 sec,
main blower starts, and retrieval request is ignored.
2. When above items have been completed, the LED flashes a
status code 4 times. Record this status code for further
troubleshooting.
After the LED flashes a status code four times, BRIEFLY remove
wire again from LS or DSS switch until LED goes out, then
reconnect it to retrieve previous status code (if available). Repeat
as needed for more previous status codes.
3. Operate furnace through 1 heat cycle to test for proper
operation and check LED status.
4. If furnace is operating properly and continuously-lit LED
indicates proper operation, replace outer access door.
NOTE 2
W
FIVE
WIRE
THREE-WIRE
HEATING-
ONLY
W2
COM
W/W1
NOTE 1
Y/Y2
JUNCTION
BOX
R
CONTROL
BOX G
24-VOLT
TERMINAL
BLOCK
FURNACE
Fig. 6—Heating and Cooling Application Wiring Diagram
1-STAGE
THERMOSTAT
C Y R G
TERMINALS
CONDENSING
UNIT
NOTES: 1. Connect Y/Y2-terminal as shown for proper 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.
5. Component Test can also be initiated by performing the
following:
a. Remove outer access door.
b. Remove blower access door.
c. Manually close blower access door switch.
WARNING: Blower access door switch opens 115-v
power to control. No component operation can occur.
Caution must be taken when manually closing this switch
for service purposes. Failure to follow this warning could
result in electrical shock, personal injury, or death.
d. BRIEFLY short (jumper) TEST/TWIN, 3/16-in. quick-
connect male terminal on control (behind C
terminal), and C
(See Fig. 8.)
NOTE: If TEST/TWIN to C
longer than 2 sec, LED will flash rapidly, and test request will be
ignored.
e. Component Test will function as follows.
(1.) LED flashes a status code 4 times. Record this
(2.) Inducer motor starts on high-speed and continues to
(3.) Hot surface igniter is energized for 15 sec, then
(4.) Blower operates at LO-HEAT speed for 10 sec, then
(5.) Blower operates at HI-HEAT speed for 10 sec, then
(6.) Blower operates at COOL speed for 10 sec., then
—6—
FIELD 24-VOLT WIRING
FIELD 115-, 208/230-, 460-VOLT WIRING
FACTORY 24-VOLT WIRING
FACTORY 115-VOLT WIRING
FIELD-SUPPLIED
FUSED DISCONNECT
208/230- OR
460-VOLT
THREE
PHASE
208/230-
VOLT
SINGLE
PHASE
GND
-24V terminal on furnace control.
OM
-24V terminals are jumpered
OM
status code for further troubleshooting.
run until step (7.) of component test sequence.
de-energized.
turns off.
turns off.
turns off.
A95236
-24v
OM