Tracing The Changeover Relay Circuit - Diagram; Tracing The Heat 1 And Anticipation Circuit - Diagram - Honeywell T874 Product Data

THERMOSTAT
H1/C1
ANTICIPATOR
FALL
2
H1
C1
3
4
H2
ANTICIPATOR
5
6
H2
FALL
1 POWER SUPPLY. PROVIDE
DISCONNECT MEANS AND
OVERLOAD PROTECTION
AS REQUIRED.
THERMOSTAT
H1/ C1
ANTICIPATOR
2
FALL
H1
C1
3
4
H2
ANTICIPATOR
5
6
H2
FALL
1
POWER SUPPLY. PROVIDE
DISCONNECT MEANS AND
OVERLOAD PROTECTION
AS REQUIRED.
SUBBASE
FAN SWITCH
AUTO
ON
SYSTEM
SWITCH
EM. HT.
HEAT
OFF
COOL
Fig. 18. Tracing the changeover relay circuit.
SUBBASE
FAN SWITCH
AUTO
ON
SYSTEM
SWITCH
EM. HT.
HEAT
OFF
COOL
Fig. 19. Tracing the heat 1 and anticipation circuit.
17
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
R
RTD 1
W3
W2
RTD 1
AUX. HT.
LED
(GREEN)
X
EM. HT.
SYSTEM
LED (RED)
MONITOR
L
G
O
E
LACO
Y
B
R
RTD 1
W3
W2
AUX. HT. RTD 1
LED
(GREEN)
X
EM. HT.
SYSTEM
LED (RED)
MONITOR
L
G
O
E
LACO
Y
B
SYSTEM COMPONENTS
L1
(HOT)
ODT 1
L2
1
EHR 1
RTD 2
ODT 2
EHR 2 RTD 3
RD
FAN RELAY
EM. HT.
RELAY
CHANGEOVER
VALVE
CHP
COMPRESSOR
CONTACTOR
M5840
SYSTEM COMPONENTS
L1
(HOT)
ODT 1
L2
1
EHR 1 RTD 2
ODT 2
EHR 2 RTD 3
RD
FAN RELAY
EM. HT.
RELAY
CHANGEOVER
VALVE
CHP
COMPRESSOR
CONTACTOR
M5841
60-2485—8