Honeywell T874 Product Data page 194

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
THERMOSTAT
H1
C1
RISE
H2
C1 ANTICIPATOR
RISE
H1 ANTICIPATOR
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
Fig. 201. Schematic and hookup of T874R with Q674L. Used in heat pump applications.
THERMOSTAT
H1
FALL
H1 ANTICIPATOR
H2
H2
FALL ANTICIPATOR
C1
RISE
C1 ANTICIPATOR
C2
RISE
C2 ANTICIPATOR
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED
Fig. 202. Schematic and hookup of T874D with Q674G. Used in standard applications.
60-2485—8
RESET
1
H2
ANTICIPATOR
FAN SWITCH
2
3
4
5
6
EM. HEAT
11
12
1
4
NO
FAN
SWITCH
5
6
7
8
SYSTEM
9
SWITCH
10
11
12
SUBBASE
AUTO
ON
SYSTEM
SWITCH
HEAT
OFF
EM. HT.
COOL
LED (RED)
SUBBASE
SERVICE
LED (RED)
SERVICE
LED (RED)
OFF
AUTO
194
SYSTEM COMPONENTS
C815A
OUTDOOR
THERMISTOR
T
OUTDOOR
THERMOSTAT
W2
FAN RELAY
G
SERVICE
LED
R
(YELLOW)
X
SERVICE
Z
K
COMPRESSOR
CONTACTOR
Y
HEAT CHANGEOVER
VALVE
W1
SYSTEM COMPONENTS
A2
HEAT RELAY 1
W1
A1
HEAT RELAY 2
W2
"T" RELAY
T
RC
FAN RELAY B
B
RH
FAN RELAY O
O
Y2
COMPRESSOR
CONTACTOR 2
Y1
COMPRESSOR
CONTACTOR 1
L1
(HOT)
L2
1
SEQ 2
OUTDOOR
THERMOSTAT
SEQ 1
M2979
L1
(HOT)
L2
1
1
L1
(HOT)
L2
M2980