569-0435—10Fig. 7—Internal schematic and typical wiring diagram for Y594G1419 (T874G1642/Q674F1444),Y594G1476 (T874G1741/Q674F1477) and Y594G1534 (T874G1824/Q674F1477 sold only in Australia); autochangeover in heating and cooling; fixed anticipation. CHECK LED has isolated terminals. Factory-installed W1-Y1 jumper is equivalent to Y terminal.
CHANGEOVER
(HEAT)
FALL
H2
FALL
RISE
H1 FALL
L1
(HOT)L2
1
2
1
2
RISE
C1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
W1 - Y1 JUMPER IS Y TERMINAL; REMOVE JUMPER WHEN W1 RELAY IS USED.
THERMOSTAT SUBBASE SYSTEM COMPONENTS
M1230A
1
2
3
4
5
6
8
9
10
11
Y1
W1
B
O
X
X1
E
W2
R
G
W3
X2
W3 RELAY
FAN RELAY
AUX. HEAT
RELAY
EM. HT.
RELAY
COMPRESSOR
FAULT
CHECK
LED (RED)
AUX.
HT. LED
(GREEN)
EM. HT.
LED (RED)
SYSTEM
SWITCH
OFF
EM. HT.
HEAT
AUTO
COOL COOL CHANGEOVER
RELAY
HEAT CHANGEOVER
RELAY
W1 RELAY
COMPRESSOR
CONTACTOR
C1
ANTICIPATOR
CHANGEOVER
(COOL)
H2 ANTICIPATOR
H1
ANTICIPATOR
FAN
SWITCH
AUTO
ON