Lennox XC17 Series

Page 26
XC17
Table 3. Air Conditioner Control (A175) Jumpers and Terminals
Board ID Label Description
E12 PSC Fan 240 VAC output connection for outdoor fan.
E16 PSC Fan 240 VAC input connection for outdoor fan.
E18
W 24VAC output for defrost auxiliary heat output.
L Thermostat service light connection.
Y2 24VAC thermostat input/output for second stage operation of the unit.
Y1 24VAC thermostat input for first stage operation of the unit.
O 24VAC thermostat input for reversing valve operation
DS Humiditrol Input
C 24VAC system common (− Build −02 and later)
i−
Input/Output − RSBus data low. Used in communicating mode only with compatible indoor thermostat. (− Build
−02 and later)
i+
Input/Output − RSBus data high. Used in communicating mode only with compatible indoor thermostat. (−
Build −02 and later)
R 24VAC system power input
E21 and E22 LO−PS S4 connection for low−pressure switch (2.4 milliamps @ 18VAC)
E31 and E32 Y1 OUT 24VAC common output, switched for enabling compressor contactor.
E24 and E25 HS−PS S87 connection for high−pressure switch (E25) and 24VAC (E24) to A177 R" input.
E26 FAN 1
First Stage and second stage basic and precision dehumidification ECM fan motor 24VDC output connection
1.
E27 FAN 2 Second stage basic and precision dehumidification ECM fan motor 24VDC output connection 2.
E28 FAN C ECM common connection for ECM fan.
E30
Six position square pin header E30 provides connections for the temperature sensors.
DIS (YELLOW)
Pins 5 and 6
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 (BLACK)
Pins 3 and 4
AMB 3  Outdoor ambient temperature sensor supply.
AMB 4  Outdoor ambient temperature return.
Range is −40ºF to +140ºF
COIL (BROWN)
Pins 5 and 6
Not used
E33 Field Test
This jumper allows service personnel to defeat the timed off control, and field programming of unit capacity
feature. Placing a jumper across both pins on E33 will terminate the anti−short delay. It will also clear lockout
alarms
W1 Short DS To R Cut for Humiditrol (EDA) application. Use only in two−stage units.
* Factory default setting