Page 17 of 21
508270-01M
Issue 2225
Control
Locations
Control Label
or Description Purpose
Function
P1
50, 70, 90, 100
Defrost Temperature
Termination Shunt
(Jumper) Pins
The control board has selections which are: 50, 70, 90, and 100°F
(10, 21, 32 and 38°C). The shunt termination pin is factory-set at 50°F
(10°C). If the temperature shunt is not installed, the default termination
temperature is 90°F (32°C).
P2
W
24VAC Thermostat Input
/ Output
24VAC input / output from indoor thermostat to indoor unit.
C
24VAC Common
24VAC common.
L
Thermostat Service Light
Thermostat service light connection.
R
24VAC
24VAC.
Y2
Thermostat Input
Controls the second stage operation of the unit. Not applicable in single
stage unit.
O
Thermostat Input
Reversing valve solenoid.
Y1
Thermostat Input
Controls the operation of the unit.
P3
165, 140, 100,
60
Nominal Defrost Time
Selection
Provides selection of the nominal defrost time. Valid options are 140, 100,
60, and 165 minutes.
P4
DIS-YEL
Coil Sensor
(P4-5) Ground connection for outdoor coil temperature sensor.
(P4-6) Connection for outdoor coil temperature sensor.
AMB-BLACK
Ambient Sensor
(P4-3) Ground connection for outdoor ambient temperature sensor.
(P4-4) Connection for outdoor ambient temperature sensor.
P5
DELAY
Delay Mode
The control board has a field-selectable function to reduce occasional
sounds that may occur while the unit is cycling in and out of the defrost
mode. When a jumper is installed on the DELAY pins, the compressor will
be cycled off for 30 seconds going in and out of the defrost mode. Units
are shipped with jumper installed on DELAY pins.
NOTE - The 30-second off cycle is NOT functional when TEST pins on
P1 are jumpered.
P6
TST, PS DF, C,
R, O, Y1, Y2
Factory Test Connectors
No field use.
DS1
RED LED
Diagnostic LED
Control board LEDs may be OFF, ON, or FLASHING to indicate
diagnostic conditions which are described in Table 6.
DS2
GREEN LED
FAN
TWO
CONNECTORS Condenser Fan Operation These two connections provide power for the condenser fan.
O OUT
O OUT
24 VAC output
24 VAC output connection for reversing valve.
LO-PS
LO-PS
Low-Pressure Switch
When the low pressure switch trips, the control board will cycle off the
compressor, and the strike counter in the control board will count one
strike. The low pressure switch is ignored under the following conditions:
• during the defrost cycle and 90 seconds after the termination of defrost
• when the average ambient sensor temperature is below 0°F (-18°C)
• during 90 seconds following the start of the compressor during TEST
mode.
Y2 OUT
Y2 OUT
24 VAC Output
24 VAC output for second-stage compressor solenoid.
Y1 OUT
Y1 OUT
24 VAC Common Output
24 VAC common output, switched for enabling compressor contactor.
HS-PS
HS-PS
High-Pressure Switch
When the high pressure switch trips, the control board will cycle off the
compressor, and the strike counter in the control board will count one
strike.
L
L
Service Light Output
24VAC service light output.
Table 7.
Control Board Inputs, Outputs and Configurable Settings
