Fig. 10—Typical 24-v Circuit Connections using Carrier Model HP Thermostat with Smart Heat
and No Outdoor Thermostat, 1 Outdoor Thermostat, or 2 Outdoor Thermostats and
Carrier Model 2S Thermostat with FK4C/40FKA Fan Coil and Intelligent Staging
A97543
24 VAC HOT
R
G
W/W1
Y/Y2
O/W2
RVS COOLING
C
B
S1
S2
SUPPLEMENTAL
HEATING
RELAY
CARRIER
PROGRAMMABLE
THERMOSTAT
MODEL HP
FA, FB, FC, FH
FAN COIL WITH
SMART HEAT
HEAT
PUMP
Y1/W2
L
R
C
Y
G
O
W2T
W3
W2D
Y
0
R
C
O
W2
Y
INDOOR FAN
HEAT STAGE 2
COOL/HEAT
STAGE 1
NOT USED
24 VAC COM
NOT USED
TROUBLE
OPTIONAL
OUTDOOR
SENSOR
CONNECTION
CUT
JW1
SHR
SHR
ODT
A97541
24 VAC HOT
R
G
W/W1
Y/Y2
O/W2
RVS COOLING
C
B
S1
S2
CARRIER
PROGRAMMABLE
THERMOSTAT
MODEL HP
FA, FB, FC, FH
FAN COIL WITH
SMART HEAT
HEAT
PUMP
Y1/W2
L
R
C
Y
G
O
W2T
W3
W2D
Y
0
R
C
O
W2
Y
INDOOR FAN
HEAT STAGE 2
COOL/HEAT
STAGE 1
NOT USED
24 VAC COM
NOT USED
TROUBLE
OPTIONAL
OUTDOOR
SENSOR
CONNECTION
JW1
A98631
24 VAC HOT
R
G
W/W1
Y/Y2
Y/Y2
Y1/W2
R
DH
RVS COOLING
C
B
L
S1
S2
Y
W2
CARRIER
PROGRAMMABLE
THERMOSTAT
MODEL 2S
40FKA
FK4C
FAN COIL
HEAT
PUMP
G
O
O/W2
W2
Y1
C
W1
R
O
24 VAC COMM
HEAT STAGE 2
HEAT STAGE 3
COOL/HEAT
STAGE 1
FAN
RVS HEATING
TROUBLE
OUTDOOR
SENSOR
CONNECTION
C
J1 JUMPER
REMOVE
J2 JUMPER
FOR HEAT
STAGING
Intelligent Sequencing Application: Model 2S thermostat with
switch C OFF and switch D ON uses single-speed heat pump,
FK4 or 40FKA fan coil with selected 2:1 size ratio heaters. Provides 3
stages of auxiliary heat for even heating comfort via W/W1
and Y1/W2. Refer to FK4 or 40FKA Installation Instructions.
A97542
24 VAC HOT
R
G
W/W1
Y/Y2
O/W2
RVS COOLING
C
B
S1
S2
CARRIER
PROGRAMMABLE
THERMOSTAT
MODEL HP
ONE
OUTDOOR
THERMOSTAT
HEAT
PUMP
Y1/W2
L
R
C
Y
G
O
W2T
W3
W2D
Y
0
R
C
O
W2
Y
INDOOR FAN
HEAT STAGE 2
COOL/HEAT
STAGE 1
NOT USED
24 VAC COM
NOT USED
TROUBLE
OPTIONAL
OUTDOOR
SENSOR
CONNECTION
CUT
JW1
ODT
FA, FB, FC, FH
FAN COIL WITH
SMART HEAT
7
