Schematic And Hookup Of T874G With Q674P. Used In Heat Pump Applications - Honeywell T874 Product Data

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
THERMOSTAT
H1 ANTICIPATOR
FALL
H1
FALL
H2
H2 ANTICIPATOR
CO
C1 ANTICIPATOR
RISE
RISE
C1
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
N.O. SWITCH INSTALLER ADDED, TO LIGHT EM. HT. LED WHEN COMPRESSOR OPERATION IS NOT NORMAL.
2
Fig. 126. Schematic and hookup of T874G with Q674P. Used in heat pump applications.
THERMOSTAT
H1 ANTICIPATOR
FALL
H1
FALL
H2 ANTICIPATOR
H2
RISE
C1
C1 ANTICIPATOR
POWER SUPPLY. PROVIDE
1
DISCONNECT MEANS AND
OVERLOAD PROTECTION
AS REQUIRED.
Fig. 127. Schematic and hookup of T874C with Q674L. Used in heat pump applications.
60-2485—8
1
FAN
SWITCH
AUTO
2
ON
4
6
8
SYSTEM
SWITCH
9
SUPL. HT.
10
HEAT
COOL
SUBBASE
2
FAN SWITCH
3
AUTO
ON
4
SYSTEM SWITCH
5
EM. HT.
6
HEAT
OFF
COOL
8
10
SUBBASE
SUPL. HT.
LED (RED)
R
RTD1
W3
RTD1
W2
AUX.HT.
LED (GREEN)
X
EM. HT.
COMPRESSOR
LED (RED)
FAILURE
L
G
O
E
LACO
Y
B
146
SYSTEM COMPONENTS
COOL CHANGEOVER
VALVE
O
FAN RELAY
G
R
OUTDOOR
THERMOSTAT
W2
HEAT RELAY 1
HEAT RELAY HEAT RELAY 2
CONTACT 1
E
HEAT RELAY 3
HEAT RELAY
2
CONTACT 2
L
C
Y
COMPRESSOR
CONTACTOR 1
SYSTEM COMPONENTS
ODT1
EHR1
RTD2
ODT2
EHR2
RD
FAN RELAY
EM. HT.
COOL CHANGEOVER
RELAY
VALVE
COMPRESSOR
CONTACTOR
L1
(HOT)
L2
1
M4722
L1
(HOT)
L2
1
RTD3
CHP
M5652A