Honeywell T874 Product Data page 193

THERMOSTAT
H1 ANTICIPATOR
H1
FALL
H2
H2
FALL ANTICIPATOR
CO
RISE
C1 ANTICIPATOR
10
C1
RISE
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
Fig. 199. Schematic and hookup of T874G with Q674F. Used in heat pump applications.
THERMOSTAT
H1
C1
H2 ANTICIPATOR
RISE
H2
C1 ANTICIPATOR
FALL
11
H1 ANTICIPATOR
12
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
Fig. 200. Schematic and hookup of T874R with Q674L. Used in heat pump applications.
SUBBASE
FAN SWITCH
2
AUTO
ON
3
4
5
SYSTEM
SWITCH
OFF
8
EM. HT.
HEAT
9
AUTO
COOL
11
12
SUBBASE
1
FAN SWITCH
AUTO
2
ON
3
4
5
SYSTEM
SWITCH
6
EM. HT.
HEAT
OFF
COOL
193
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
W3
G
R
W2
AUX. HT. LED
(GREEN)
E
EM. HT.
LED (RED)
L
CHECK
LED
X
(RED)
B
O
Y
T
W2
G
SERVICE
LED
R
(YELLOW)
X
Z
K
EM. HT.
LED (RED)
Y
W1
SYSTEM COMPONENTS
L1
(HOT)
W3 RELAY
L2
FAN RELAY
AUX. HT. RELAY
EM. HT. RELAY
COMPRESSOR
FAULT
HEAT CHANGEOVER
VALVE
COOL CHANGEOVER
RELAY
COMPRESSOR
M2977
CONTACTOR
SYSTEM COMPONENTS
L1
(HOT)
L2
OUTDOOR
THERMOSTAT
SEQ 2
OUTDOOR
THERMOSTAT
FAN RELAY
SERVICE
SEQ 1
COMPRESSOR
CONTACTOR
HEAT CHANGEOVER
VALVE
M2978
60-2485—8
1
1