69-0435—10 6Fig. 8—Internal schematic and typical wiring diagram for Y594G1526 (T874G1626/Q674F1436); autochangeover in heating.
M1592A
(HOT) L1 L2
1
LACO CHP
Y
B
E
G
L
X
W2
RODT 1
RTD 1 EHR 1 RTD 2
ODT 2
EHR 2 RTD 3
RD
COMPRESSOR
FAILURE
FAN RELAY
COMPRESSOR
CONTACTOR
HEAT
CHANGEOVER
VALVE EM. HT.
RELAY
RTD 1
AUX. HEAT
LED (GREEN)
EM. HT.
LED (RED)
FAN SWITCH
ON
AUTO
SYSTEM
SWITCH
EM. HT.
HEAT
AUTO
OFF
COOL
H2
FALL
H1
FALL 2
3
4
5
H1 ANTICIPATOR
H2
ANTICIPATOR
C1
RISE
FALL
7
8
9
10
C1
ANTICIPATOR
1POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
THERMOSTAT SUBBASE SYSTEM COMPONENTS
EHT1
CHANGEOVER
Fig. 9—Internal schematic and typical wiring diagram for T874D1165, T874E1016/Q674F1543. Exactreplacement for York model no. 2TB04700524.
H1
FALL
W1
G
W2
B
HEAT RELAY 1
HEAT
OFF
COOL
SYSTEM
SWITCH
H1 ANTICIPATOR
C1 ANTICIPATOR
AUTO
ON
FAN
SWITCH
1
2
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
LED IS NOT LABELED. JUMPER W2 TO X FOR AUXILIARY HEAT INDICATION. JUMPER E TO X FOR
EMERGENCY HEAT INDICATION. CONNECT SYSTEM MONITOR TO X TO IDENTIFY WHEN SYSTEM
NEEDS TO BE CHECKED.
M2982A
THERMOSTAT SUBBASE SYSTEM COMPONENTS
R
EM. HEAT RELAY
COMPRESSOR
CONTACTOR 2
COMPRESSOR
CONTACTOR 1
1
4
6
8
9
10
11
H2
FALL
C2 ANTICIPATOR
RISE
RISE
C1
C2
Y1
Y2
HEAT RELAY 2
L1
(HOT)
L2
1
2
LED
(RED)
H2
ANTICIPATOR
AUTO
EM. HT.
X
E
FAN RELAY