Bryant 333JAV Installation, Start-Up, And Operating Instructions Manual page 16

NOTE: Y1 is found in the furnace and in the outdoor unit. The
furnace control CPU controls BLWM airflow by sensing only
G-and-Y1 for low-cooling airflow and G-and-Y1-and-Y/Y2 for
high-cooling airflow.
(2.) Terminals EAC-1 and EAC-2 are energized with
115v when the BLWM is operating on either
cooling airflow.
(3.) When the thermostat is satisfied, the R to G-and-Y1
or R to G-and-Y1-and-Y/Y2 circuits open. The
outdoor unit stops, the furnace blower continues
operating on same cooling airflow for an additional
90 sec.
4. Continuous-Blower Mode
a. When R to G circuit is closed by the thermostat, BLWM
operates at LOW, MED, or HI (50 percent, 65 percent, or
100 percent of single-speed cooling airflow; different
than low-gas heat airflow). LOW, MED, and HI selec-
tions are described in Set-up Procedures. Terminals
EAC-1 and EAC-2 are energized with 115v as long as
the BLWM is operating.
b. During a call for heat, the BLWM stops during igniter
warm-up (17 sec), ignition (7 sec), and blower-on delay
(45 sec), allowing the furnace heat exchangers to heat up
quickly, after which the BLWM operates at the appro-
priate gas heating airflow.
c. The BLWM reverts to continuous blower airflow after
the heating cycle is completed. In high-gas heat, the
furnace control CPU and ICM2+ motor control hold the
BLWM at low-heat airflow for a 90-sec blower-off delay
period (regardless of selected blower-off delay) before
reverting to continuous-blower airflow.
d. When thermostat "calls for low-cooling," the BLWM
switches to low-cool airflow or the selected continuous-
blower airflow, whichever is greater. Note that a HI
selection for continuous-blower airflow will provide
more than normal airflow during 2-speed low-cooling.
When the thermostat is satisfied, the BLWM switches to
continuous-blower airflow.
e. When the thermostat calls for high cooling, the BLWM
operates at high-cool airflow. When the thermostat is
satisfied, BLWM operates an additional 2 sec at high-
cool airflow before reverting back to continuous-blower
airflow.
f. When R-G circuit is opened, BLWM continues operating
for an additional 90 sec, if no other function requires
BLWM operation.
5. Heat Pump Mode
NOTE: A dual-fuel thermostat is required with single-speed heat
pumps. See dual-fuel thermostat Installation Instructions for
single-speed heat pump thermostat and interface connections. No
interface kit is needed for 2-speed heat pumps. See 2-speed heat
pump Installation Instructions to determine whether a standard or
dual-fuel heat pump thermostat is required and for thermostat
connections.
a. Single-Speed Heat Pump Cooling
(1.) The thermostat and interface kit close the R to
Y/Y2-and-G-and-O circuits to operate the furnace
BLWM at cooling airflow. The Y/Y2 input to the
furnace control is necessary to provide adequate
cooling airflow.
(2.) Terminals EAC-1 and EAC-2 are energized with
115v when BLWM is operating.
(3.) When thermostat is satisfied, furnace BLWM con-
tinues operating at cooling airflow for an additional
90 sec.
b. Two-Speed Heat Pump Cooling
(1.) The thermostat R to G-and-Y1-and-O circuits op-
erate the furnace BLWM at low-cool airflow. The
thermostat R to G-and-Y/Y2-and-Y1-and-O circuits
operate the furnace BLWM at high-cool airflow
(105 percent of single-speed cooling airflow).
NOTE: The furnace control CPU controls blower airflow by
sensing G, Y1, and O for low-cool airflow and G, Y1, Y/Y2, and
O for 2-speed high-cool airflow.
(2.) Terminals EAC-1 and EAC-2 are energized with
115v when the BLWM is operating at either cooling
airflow.
(3.) When the thermostat is satisfied, the furnace
BLWM continues operating at the same cooling
airflow for an additional 90 sec.
c. Single-Speed Heat Pump Heating
(1.) The thermostat and accessory interface kit R to G-
and-Y/Y2 circuits operate the furnace BLWM at
heat pump heating airflow. Heating airflow is the
same as cooling airflow for airflow selection HP-
EFFY and 90 percent of cooling airflow for HP-
CMFT selection.
(2.) Terminals EAC-1 and EAC-2 are energized with
115v when the BLWM is operating.
(3.) When thermostat is satisfied, the furnace BLWM
continues operating at same heat pump heating
airflow for an additional 90 sec.
d. Two-Speed Heat Pump Heating
(1.) The thermostat closes R to Y1-and-G circuits for
low heat and operates the furnace BLWM at heat
pump low-heat airflow (may not be identical to
low-cooling airflow, depending on HP selection at
airflow selector). Closing R-Y/Y2, Y1 and G cir-
cuits to furnace provides BLWM heat pump high-
heat airflow.
NOTE: The furnace control CPU controls BLWM airflow by
sensing G and Y1 for heat pump low-heat airflow, and G, Y1, and
Y/Y2 for heat pump high-heat airflow (105 percent of single-speed
heating airflow).
(2.) Terminals EAC-1 and EAC-2 are energized with
115v when BLWM is operating at either heating
airflow.
(3.) When the thermostat is satisfied, the furnace
BLWM continues operating at same heating airflow
for an additional 90 sec.
(4.) Opening only R-Y/Y2 circuit switches BLWM to
heat pump low-heat airflow.
6. Defrost
a. When furnace control R to W/W1-and-Y/Y2 circuits are
closed, furnace control CPU continues BLWM operation
at heat pump heating airflow until the end of prepurge
period, then shuts off until the end of HSI igniter-on
period (22 sec).
b. When installed with a heat pump, the furnace control
CPU automatically holds the blower-off time to 22 sec
during HSI igniter-on period. After 17 sec of the HSI
igniter-on period, a trial-for-ignition sequence occurs as
described above for gas heating. After flame is proven
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