Honeywell T874 Product Data page 185

THERMOSTAT
1
H1
FALL
ANTICIPATOR
H1 2
4
H2
ANTICIPATOR
FALL
6
H2
RISE
8
CO
9
C1
ANTICIPATOR
10
RISE
C1
POWER SUPPLY. PROVIDE DISCONNECT MEANS
1
AND OVERLOAD PROTECTION AS REQUIRED.
Fig. 183. Schematic and hookup of T874G with Q674J. Used in heat pump applications.
THERMOSTAT
H1
ANTICIPATOR
FALL
H1
H2
ANTICIPATOR
FALL
H2
RISE
C1
C1
ANTICIPATOR
C2
ANTICIPATOR
RISE
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS
C2
AND OVERLOAD PROTECTION AS REQUIRED.
Fig. 184. Schematic and hookup of T874A,F with Q674G. Used in standard applications.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
SUBBASE
FAN
SWITCH
AUTO
ON
SYSTEM
SWITCH
EM. HT.
ON
OFF
SUBBASE
1
NO
FAN
SWITCH
4
6
SYSTEM
SWITCH
8
9
OFF
AUTO
10
11
185
SYSTEM COMPONENTS
O
COOL CHANGEOVER
VALVE
G
2BH
FAN RELAY
R
O. D. S.
1BH
E
L1
EM. HT.
COMPRESSOR
LED (RED)
FAILURE
X
AUX. HT.
LED (GREEN)
W
Y
COMPRESSOR
CONTACTOR
SYSTEM COMPONENTS
HEAT RELAY 1
W1
W2
HEAT RELAY 2
RH
RC
COMPRESSOR
CONTACTOR 1
Y1
Y2
COMPRESSOR
CONTACTOR 2
SH
1BH
1
L1 L2
(HOT)
M3950
1
L2
L1
(HOT)
L1
(HOT)
L2
1
M3953
60-2485—8