Honeywell T874 Product Data page 164

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
THERMOSTAT
H1 ANTICIPATOR
FALL
H1
H2 ANTICIPATOR
H2
FALL
H1 ANTICIPATOR
CO
RISE
C1
RISE
Fig. 154. Schematic and hookup of T874G with Q674F. Used in heat pump applications.
60-2485—8
SUBBASE
1
FAN
SWITCH
2
AUTO
ON
4
SYSTEM
6
SWITCH
OFF
EM. HT.
8
HEAT
AUTO
COOL
9
10
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND
OVERLOAD PROTECTION AS REQUIRED.
2
OPTIONAL FIELD WIRE JUMPER TO CYCLE W2 WITH H1
IN EM. HEAT(FASTER RESPONSE).
164
SYSTEM COMPONENTS
R
L2
L1
W2
(HOT)
E
EM. HT.
LED (RED)
X
2
H
A
COMP. FAULT
LED (YELLOW)
Y Y R
G G
R8233B
W
O O
C DF RS
L1
L2
(HOT)
REVERSING
SOLENOID
EM. HT. RELAY
1 CONTACT 1
T6031
REFRIGERATION
TEMPERATURE
CONTROLLER
EM. HT.
EM. HT. RELAY
COMPRESSOR
CONTACTOR
COM
SEQUENTIAL
RELAY
EH
FAN
FAN
M2858