Bryant GAMA 331JAV - Manual (Page 13)

(3.) When thermostat is satisfied, R to G-and-Y cir-
cuits are opened. The outdoor unit stops, and
furnace blower motor BLWM continues operating
on high-cool speed for an additional 90 sec.
b. Two-Speed Cooling Outdoor Unit
(See Fig. 12 for thermostat connections.)
(1.) The thermostat closes R to G-and-Y1 circuits for
low cooling or closes R to G-and-Y1-and-Y/Y2
circuits for high cooling. The R-Y1 circuits start
outdoor unit on low-cooling speed, and R-G circuit
starts furnace blower motor BLWM on low-cooling
speed (same speed as for low-gas heat). The R to
Y1-and-Y2 circuits start outdoor unit on high-
cooling speed, and R to G-and-Y2 circuits start
furnace blower motor BLWM on high-cooling
speed.
NOTE: Y1 is not located on furnace control, but is found in
outdoor unit. The furnace control CPU controls blower motor
BLWM speed by sensing only G for low-cooling speed and Y/Y2
for high-cooling speed.
(2.) The EAC terminals EAC-1 and EAC-2 are ener-
gized with 115v when blower motor BLWM is
operating on either cooling speed.
(3.) When thermostat is satisfied, R to G-and-Y1 or
R to G-and-Y1-and-Y/Y2 circuits open. The out-
door unit stops, and furnace blower continues op-
erating on cooling speed for an additional 90 sec.
4. Continuous Blower Mode
a. When R to G circuit is closed by thermostat, blower
motor BLWM operates on low-gas-heat speed (identical
to low-cool speed). Terminals EAC-1 and EAC-2 are
energized with 115v as long as blower motor BLWM is
energized.
b. During "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 ex-
changers to heat up quickly.
(1.) The blower motor BLWM reverts to continuous
blower speed after heating cycle is completed. In
high-gas heat, furnace control CPU holds blower
motor BLWM at high-gas-heat speed during se-
lected blower off delay period before reverting to
continuous blower speed.
(2.) When thermostat "calls for low cooling," blower
motor BLWM continues to operate on low-cool
speed. When thermostat is satisfied, blower motor
BLWM continues on continuous blower speed.
(3.) When thermostat "calls for high cooling," blower
motor BLWM operates on high-cool speed. When
thermostat is satisfied, blower motor BLWM oper-
ates an additional 2 sec on high-cool speed before
reverting back to continuous blower speed.
(4.) When R to G circuit is opened, blower motor
BLWM continues operating for an additional 90 sec
if no other function requires blower motor BLWM
operation.
5. Heat Pump
NOTE: An accessory interface kit is required with single-speed
heat pumps. See interface kit Installation Instructions for single-
speed heat pump thermostat and interface connections. No inter-
face kit is needed for 2-speed heat pumps. See 2-speed heat pump
Installation Instructions for thermostat connections.
a. Single-Speed Heat Pump Cooling
(1.) The thermostat and interface kit close R to G-and-
Y/Y2 circuit to start furnace blower motor BLWM
on high-cooling speed. (Y/Y2 input to furnace
control is necessary to provide adequate cooling
airflow.)
(2.) The EAC terminals EAC-1 and EAC-2 are ener-
gized with 115v when blower motor BLWM is
operating.
(3.) When thermostat is satisfied, furnace blower motor
BLWM continues operating on high-cooling speed
for an additional 90 sec.
b. Two-Speed Heat Pump Cooling
(1.) The thermostat R to G circuits start furnace blower
motor BLWM on low-cooling speed. Thermostat
R to G-and-Y/Y2 circuits start furnace blower mo-
tor BLWM on high-cool speed.
NOTE: The furnace control CPU controls blower motor BLWM
speed by sensing only G (for low-cooling speed) and Y2 (for
high-cooling speed).
(2.) The EAC terminals EAC-1 and EAC-2 are ener-
gized with 115v when blower motor BLWM is
operating on either cooling speed.
(3.) When thermostat is satisfied, furnace blower motor
BLWM continues operating on cooling speed 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 start furnace blower motor
BLWM on heat pump high-heat speed (identical to
high-cool speed).
(2.) The EAC terminals EAC-1 and EAC-2 are ener-
gized with 115v when blower motor BLWM is
operating.
(3.) When thermostat is satisfied, furnace blower motor
BLWM continues operating on heat pump high-heat
speed for an additional 90 sec.
d. Two-Speed Heat Pump Heating
(1.) The thermostat closes R to G circuit for low heat
and starts furnace blower motor BLWM on heat
pump low-heat speed (identical to low-cooling
speed). Closing R-Y/Y2 circuit to furnace provides
blower motor BLWM heat pump high-heat speed.
NOTE: The furnace control CPU controls blower motor BLWM
speed by sensing only G (for heat pump low-heat speed) and Y2
(for heat pump high-heat speed).
(2.) The EAC terminals EAC-1 and EAC-2 are ener-
gized with 115v when blower motor BLWM is
operating on either heating speed.
(3.) When thermostat is satisfied, R to G or R to G-
and-Y2 circuits are opened. After opening R to
G-and-Y2 circuit, the furnace blower motor BLWM
continues operating on heating speed for an addi-
tional 90 sec.
(4.) Opening R-Y2 circuit reduces blower motor
BLWM speed to heat pump low-heat speed.
6. Defrost
a. When furnace control R to W/W1-and-Y/Y2 circuits are
closed, furnace control CPU continues blower motor
BLWM operation at heat pump heating speed until end
of prepurge period, then shuts off until end of HSI ignitor
on period (22 sec).
—13—