Air Conditioner Control (A175) Jumpers And Terminals - Lennox XC21 Series Unit Information

Air Conditioner Control (A175) Jumpers and Terminals

TWO−STAGE
Table 3 provides additional information concerning
jumpers, links, and connections for the A175 Main
Control.
FIELD TEST
PINS (E33)
COMMUNICATING
STATUS INDICATOR
XC21
DS11 and DS14
LED ALERT
CODES
DS13 and DS15
LED ALERT
CODES
DS12
W1
FOR HUMIDITROL
(EDA) APPLICATION
(TWO−STAGE UNITS
ONLY)
Table 3. Main Control Jumpers and Terminals
Board ID Label
E12 PSC Fan
E16 PSC Fan
W
L
Y2
Y1
O
E18
DS
C
i−
i+
R
E21 and E22 LO−PS
E31 and E32 Y1 OUT
E24 and E25 HS−PS
E26 Y1 FAN
E27 Y2 FAN
E28 FAN C
Six position square pin header E30 provides connections for the
temperature sensors.
DIS
(YELLOW)
PINS 5 and
6
AMB
E30
(BLACK)
Pins 3 and
4
COIL
(BROWN)
Pins 1 and
2
E33 Field Test
Y2
E34
Solenoid
Short DS To
W1
R
Page 26
Description
240 VAC output connection for outdoor fan.
240 VAC input connection for outdoor fan.
24VAC output for defrost auxiliary heat output.
Thermostat service light connection.
24VAC thermostat input/output for second stage
operation of the unit.
24VAC thermostat input for first stage operation of
the unit.
24VAC thermostat input for reversing valve
operation
Humiditrol Input
24VAC system common
Input/Output − RSBus data low. Used in
communicating mode only with compatible indoor
thermostat.
Input/Output − RSBus data high. Used in
communicating mode only with compatible indoor
thermostat.
24VAC system power input
S4 connection for low−pressure switch (2.4
milliamps @ 18VAC)
24VAC common output, switched for enabling
compressor contactor.
S87 connection for high−pressure switch (E25) and
24VAC (E24) to A177 R" input.
First Stage and second stage basic and precision
dehumidification ECM fan motor 24VDC output
connection 1.
Second stage basic and precision dehumidification
ECM fan motor 24VDC output connection 2.
ECM common connection for ECM fan.
DIS 5 Discharge line temperature sensor supply.
DIS 6
Discharge line temperature sensor return
Range is 35ºF to 310ºF. Sensor is clipped on a 1/2"
copper tube.
AMB 3 Outdoor ambient temperature sensor
supply.
AMB 4 Outdoor ambient temperature return.
Range is 40ºF to +140ºF
COIL 1 Outdoor coil temperature sensor supply.
COIL 2
Outdoor coil temperature sensor return
This model does not utilize a coil sensor. The cable
harness assembly for the sensors incorporates a
10K resistor between pins 5 and 6.
This jumper allows service personnel to defeat the
timed off control, initiate or terminate a defrost and
field programming of unit capacity feature.
Second−stage compressor output.
Cut for Humiditrol (EDA) application. This sets the
outdoor fan speed to predefined speed. See table
15 for set speed based on unit capacity size. Use
only in two−stage units.
.