Honeywell T874 Product Data page 137

THERMOSTAT
H1/C1
ANTICIPATOR
H1
C1
FALL
H2 ANTICIPATOR
H2
FALL
1 POWER SUPPLY. PROVIDE DISCONNECT
MEANS AND OVERLOAD PROTECTION
AS REQUIRED.
2 OPTIONAL FIELD WIRE JUMPER TO CYCLE
AUXILIARY HEAT RELAY WITH H1 INSTEAD
OF H2 (FASTER RESPONSE).
Fig. 116. Schematic and hookup of T874R with Q674L. Used in heat pump applications.
SUBBASE
2
FAN
SWITCH
AUTO
3
ON
4
5
SYSTEM
6
SWITCH
EM. HT.
HEAT
OFF
COOL
137
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
E
X
EM. HT.
LED (RED)
B
R
W2
2
H
A
COMP. FAULT
LED (YELLOW)
Y
G
O
SYSTEM COMPONENTS
EM. HT. RELAY
AUX. HT. RELAY
COMPRESSOR
CONTACTOR
L1
(HOT)
L2
1
Y R
COM
G
R8233B
ELEC.
W
HT. RELAY
EH
O
M2857
60-2485—8