Outdoor Unit - Lennox 14HPX-018 Installation Instructions Manual

Table 14. Defrost Control Board Diagnostic LEDs
DS2 DS1
Green Red Condition/Code Possible Cause(s) Solution
OFF OFF Power problem No power (24V) to board termi- 1 Check control transformer power (24V).
nals R & C or board failure. 2 If power is available to board and LED(s) do
not light, replace board.
Simultaneous Normal operation Unit operating normally or in None required.
SLOW Flash standby mode.
Alternating 5-minute anti-short cycle Initial power up, safety trip, end of None required (Jumper TEST pins to override)
SLOW Flash delay room thermostat demand.
Simultaneous Ambient Sensor Problem Sensor being detected open or shorted or out of temperature range. Board will re-
FAST Flash vert to time/temperature defrost operation. (System will still heat or cool).
Alternating Coil Sensor Problem Sensor being detected open or shorted or out of temperature range. Board will not
FAST Flash perform demand or time/temperature defrost operation. (System will still heat or
cool).
ON ON Circuit Board Failure Indicates that board has internal component failure. Cycle 24 volt power to board. If
code does not clear, replace board.
FAULT & LOCKOUT CODES (Each fault adds 1 strike to that code's counter; 5 strikes per code = LOCKOUT)
OFF SLOW Low Pressure Fault
Flash
ON Low Pressure LOCKOUT
OFF High Pressure Fault
High Pressure LOCKOUT
Discharge Line Tempera-
ture Fault
Discharge Line Tempera-
ture LOCKOUT
Discharge Sensor Fault
Discharge Sensor
LOCKOUT
OFF
SLOW
Flash
ON OFF
SLOW ON
Flash
FAST ON
Flash
OFF Fast
Flash
Fast OFF
Flash
1 Restricted air flow over indoor or
outdoor coil.
2 Improper refrigerant charge in
system.
3 Improper metering device
installed or incorrect operation
of metering device.
4 Incorrect or improper sensor
location or connection to sys-
tem.
1 Remove any blockages or restrictions from
coils and/or fans. Check indoor and outdoor
fan motor for proper current draws.
2 Check system charge using approach & sub-
cooling temperatures.
3 Check system operating pressures and
compare to unit charging charts.
4 Make sure all pressure switches and sensors
have secure connections to system to prevent
refrigerant leaks or errors in pressure and
temperature measurements.
This code detects shorted sensor or high discharge temperatures. If the discharge
line temperature exceeds a temperature of 300°F (148°C) during compressor op-
eration, the board will de-energize the compressor contactor output (and the defrost
output if active). The compressor will remain off until the discharge temperature has
dropped below 225°F (107°C).
The board detects open sensor or out of temperature sensor range. This fault is
detected by allowing the unit to run for 90 seconds before checking sensor resist-
ance. If the sensor resistance is not within range after 90 seconds, the board will
count one fault. After 5 faults, the board will lockout.
WARNING
I
Maintenance and service must be performed by a qualified
installer or service agency. At the beginning of each cool-
ing season, the system should be checked as follows:
OUTDOOR UNIT
1. Clean and inspect outdoor coil (may be flushed with a
water hose). Ensure power is off before cleaning.
2. Outdoor unit fan motor is pre-lubricated and sealed.
No further lubrication is needed.
3. Visually inspect all connecting lines, joints and coils for
evidence of oil leaks.
4. Check all wiring for loose connections,
5. Check for correct voltage at unit (unit operating),
6. Check amp draw on outdoor fan motor.
Unit nameplate Actual
7. Inspect drain holes in coil compartment base and
clean if necessary,
NOTE - If insufficient heating or cooling occurs, the unit
should be gauged and refrigerant charge should be
checked.
505243 04/08
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