Tracing The Emergency Heat And Em Ht Led Circuit; Tracing The Cooling Circuit - Honeywell T874 Product Data

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.
Fig. 22. Tracing the emergency heat and EM. HT. LED circuit.
THERMOSTAT
H1/C1
ANTICIPATOR
2
FALL
H1
C1
3
4
H2
ANTICIPATOR
5
H2 6
FALL
1 POWER SUPPLY. PROVIDE
DISCONNECT MEANS AND
OVERLOAD PROTECTION
AS REQUIRED.
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
SUBBASE
FAN SWITCH
AUTO
ON
SYSTEM
SWITCH
EM. HT.
HEAT
OFF
COOL
SUBBASE
FAN SWITCH
AUTO
ON
SYSTEM
SWITCH
EM. HT.
HEAT
OFF
COOL
Fig. 23. Tracing the cooling circuit.
19
SYSTEM COMPONENTS
R
ODT 1
RTD 1 EHR 1
W3
ODT 2
EHR 2
W2
AUX. HT. RTD 1
LED
(GREEN)
X
EM. HT.
SYSTEM
RD
LED (RED)
MONITOR
L
G
O
CHANGEOVER
VALVE
E
LACO
Y
COMPRESSOR
B CONTACTOR
SYSTEM COMPONENTS
R
ODT 1
RTD 1 EHR 1
W3
ODT 2
EHR 2
W2
RTD 1
AUX. HT.
LED
(GREEN)
X
EM. HT.
SYSTEM
RD
LED (RED)
MONITOR
L
G
O
CHANGEOVER
VALVE
E
LACO
Y
COMPRESSOR
B CONTACTOR
L1
(HOT)
L2
1
RTD 2
RTD 3
FAN RELAY
EM. HT.
RELAY
CHP
M5844
L1
(HOT)
L2
1
RTD 2
RTD 3
FAN RELAY
EM. HT.
RELAY
CHP
M5845
60-2485—8