Honeywell T874 Product Data page 190

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
THERMOSTAT
H1
ANTICIPATOR
H1
FALL
H2
FALL
H2 ANTICIPATOR
RISE
C1
C1 ANTICIPATOR
C2 ANTICIPATOR
C2
RISE
Fig. 193. Schematic and hookup of T874D with Q674E. Used in standard applications.
THERMOSTAT
FALL
H1
FALL
H2
RISE
CO
RISE
C1
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
Fig. 194. Schematic and hookup of T874G with Q674F. Used in heat pump applications.
60-2485—8
1 FAN
SWITCH
4
6
8
9
10
11
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
2 JUMPER RH, RC FOR SINGLE TRANSFORMER.
2
H1
AUTO
ANTICIPATOR
3
ON
FAN
SWITCH
4
H2
ANTICIPATOR
6
SYSTEM
SWITCH
OFF
8
EM. HT.
9
HEAT
C1
ANTICIPATOR
AUTO
10
COOL
SUBBASE
AUTO
ON
SYSTEM
SWITCH
OFF
HEAT
AUTO
COOL
SUBBASE
CHECK
LED
(GREEN)
EM. HT.
LED (RED)
190
SYSTEM COMPONENTS
RH
W1
HEAT RELAY 1
W2
HEAT RELAY 2
B
CHANGEOVER
RELAY (HEAT)
O
CHANGEOVER
RELAY (COOL)
2
G
FAN RELAY
Y2
COMPRESSOR
CONTACTOR 2
Y1
COMPRESSOR
CONTACTOR 1
RC
SYSTEM COMPONENTS
Y1
COOL
FAN RELAY
CHANGEOVER VALVE
G
R
DR
TDR 2
HBTH
X
W2
TDR 1
E
C
COMPRESSOR
CONTACTOR
W1
HPA
L1
(HOT)
L2
1
1
L2
L1
(HOT)
M3203B
1
L1 L2
(HOT)
M3977