Continuous Blower Mode; Heat Pump Mode - Bryant 333B-AV-036060-AA-JA Troubleshooting Manual

PSC—Two-speed high-cooling airflow is 100% of
single-speed cooling airflow.
ICM—Two-speed high-cooling airflow is 105% of
single-speed cooling airflow.
NOTE: Y1 is found in outdoor unit. The furnace controls blower
motor BLWM airflow by sensing only G (PSC) or G-and-Y1
(ICM) for low-cooling airflow and Y/Y2 (PSC) or G-and-Y1-and-
Y/Y2 (ICM) for high-cooling airflow.
b. EAC terminals EAC-1 and EAC-2 are energized with
115 vac when blower motor BLWM is operating at
either cooling airflow.
c. When thermostat is satisfied, R to G-and-Y1 or
R to G-and-Y1-and-Y/Y2 circuits open. The outdoor
unit stops, and furnace blower continues operating at the
same cooling airflow for an additional 90 sec.
IV. CONTINUOUS BLOWER MODE
1. When R-G circuit is closed by thermostat, blower motor
BLWM operates at:
PSC—Low-gas-heat airflow (identical to low-cooling air-
flow).
ICM—Low, Med, or High (50%, 65%, or 100% of single-
speed cooling airflow; different than low-gas-heat
airflow). Low, Med, and High selection is described
in Set-Up Procedures section of Appendix B.
Terminals EAC-1 and EAC-2 are energized with 115 vac as
long as blower motor BLWM is operating.
2. During a "call for heat," blower motor BLWM stops during
ignitor warm-up (17 sec), ignition (7 sec), and blower on
delay (45 sec), allowing furnace heat exchangers to heat up
quickly, after which blower motor BLWM operates at
appropriate gas heating airflow.
3. The blower motor BLWM reverts to continuous blower
airflow after heating cycle is completed.
PSC—In high-gas heat, the furnace control CPU holds
blower motor BLWM at high-gas-heat airflow dur-
ing selected blower off delay period before reverting
to continuous blower airflow.
ICM—In high-gas heat, the furnace control CPU and ICM
motor control hold blower motor BLWM at low-gas-
heat airflow for a 90-sec blower off delay period
(irrespective of selected blower off delay) before
reverting to continuous blower airflow.
4. When thermostat "calls for low-cooling," blower motor
operates as follows:
PSC—The blower motor BLWM continues to operate at
low-cooling (continuous blower) airflow.
ICM—The blower motor BLWM switches to low-cooling
airflow or 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.
5. When thermostat is satisfied, blower motor operates as
follows:
PSC—The blower motor BLWM continues to operate at
continuous blower airflow.
ICM—The blower motor BLWM switches to continuous
blower airflow.
6. When thermostat "calls for high-cooling," blower motor
BLWM operates at high-cooling airflow. When thermostat
is satisfied, blower motor BLWM operates an additional 2
sec at high-cooling airflow before reverting back to con-
tinuous blower airflow.
7. When R-G circuit is opened, blower motor BLWM contin-
ues operating for an additional 90 sec, if no other function
requires blower motor BLWM operation.
V. HEAT PUMP MODE
NOTE: A dual-fuel thermostat or accessory interface kit is
required with single-speed heat pumps. See dual-fuel thermostat or
interface kit 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 Instruc-
tions to determine whether a standard or dual-fuel heat pump
thermostat is required and for thermostat connections.
1. Single-Speed Heat Pump Cooling
a. The thermostat and interface kit close R to G-and-Y/Y2
(-and-O with an ICM blower motor) circuit(s) to operate
furnace blower motor BLWM at cooling airflow. The
Y/Y2 input to furnace control is necessary to provide
adequate cooling airflow.
b. EAC terminals EAC-1 and EAC-2 are energized with
115 vac when blower motor BLWM is operating.
c. When thermostat is satisfied, furnace blower motor
BLWM continues operating at cooling airflow for an
additional 90 sec.
2. Two-Speed Heat Pump Cooling
a. PSC—The thermostat R-G circuit operates furnace
blower motor BLWM at low-cooling airflow.
ICM—The thermostat R to G-and-Y1-and-O circuits
operate furnace blower motor BLWM at low-
cooling airflow.
b. The thermostat R to G-and-Y/Y2 (-and-Y1-and-O with
an ICM blower motor) circuits operate furnace blower
motor BLWM at high-cooling airflow.
PSC—100% of single-speed cooling airflow.
ICM—105% of single-speed cooling airflow.
NOTE: The furnace controls blower airflow by sensing:
(1.) Only G for low-cooling airflow with a PSC blower
motor.
(2.) G, Y1, and O for low-cooling airflow with an ICM
blower motor.
(3.) Y2 (with or without Y1) for single-speed cooling or
2-speed high-cooling airflow with a PSC blower
motor.
(4.) G, Y1, Y/Y2, and O for 2-speed high-cooling
airflow with an ICM blower motor.
c. EAC terminals EAC-1 and EAC-2 are energized with
115 vac when blower motor BLWM is operating at
either cooling airflow.
d. When thermostat is satisfied, furnace blower motor
BLWM continues operating at the same cooling airflow
for an additional 90 sec.
3. Single-Speed Heat Pump Heating
a. The thermostat (and accessory interface kit) R to G-and-
Y/Y2 circuits operate furnace blower motor BLWM at
heat pump heating airflow (identical to cooling airflow
with a PSC blower motor). Heating airflow is same as
cooling airflow for Airflow Selector HP-EFFY selection
and 90% of cooling airflow for HP-CMFT selection.
b. EAC terminals EAC-1 and EAC-2 are energized with
115 vac when blower motor BLWM is operating.
c. When thermostat is satisfied, furnace blower motor
BLWM continues operating at the same heat pump
heating airflow for an additional 90 sec.
—5—