Filter
Top Products
3
TH
TR
MV
MV
GND
FP
HLO
HLI
PSO
PS
C
R
G
W
Y
EAC N
HUM N
XFMR N
LINE N
CIR N
IGN
IGN-N
IND
IND-N
HUM
EAC
XFMR
LINE
PARK
PARK
HEAT
COOL
IGNITOR
Y
W
G
R
THERMOSTAT
GAS
VALVE
HIGH LIMIT
(N. C.)
ROLLOUT
(N. C.)
AUX. HIGH
LIMIT (N. C.)
PRESSURE SWITCH (N. O.)
FLAME
SENSOR
PROBE
COMPRESSOR
CONTACTOR
ELECTRONIC
AIR CLEANER
HUMIDIFIER
INDUCER
CIRCULATOR
BLOWER
50A55
24 VAC
120 VAC
24 VAC CLASS II
TRANSFORMER
HOT
(LINE)
NEUTRAL
(LINE)
TH TR
Low Voltage (24 VAC)
Line Voltage (120 VAC)
LEGEND
N. C. = Normally closed switch
N. O. = Normally open switch
RO1
RO2
TYPICAL SYSTEM WIRING DIAGRAM
TWIN*TWIN*
50A55
in other
furnace(s)
—
TWINNING
APPLICATIONS
ONLY
* The twinning feature is available only on models with
six screw terminals; one of these terminals will be
designated “TWIN”. All 50A55 controls used in
twinning applications must have the “TWIN” terminal.
WIRING