Lennox EL23XCV Series Manual page 75

TABLE 20. Outdoor Control 7-Segment Display Alert Codes and Inverter LED Flash Codes
NOTE - System fault and lockout codes take precedence over system status codes (cooling, heating operating percentages or defrost/dehumidifi-
cation). Only the latest active fault or lockout codes are displayed (if present). If no fault or lockout codes are active, then system status codes are
displayed. Alert codes are also displayed on the S30/S40 thermostat.
Inverter LED Flash
Code (number of
Alert Inverter
flashes)
Codes Code
Red LED
E 438 73 7 flashes
E 439 12 1 flash
E 440 13 1 flash
Priority Alarm Description
Green
LED
The inverter has detected a
PFC over current condition.
This would be caused by
a high load condition, high
pressure, or outdoor fan
failure. Outdoor control will
display the code when the
inverter has the error. After
Moderate /
3 flashes 3 minutes, the inverter will
Critical
reset and the compressor
will turn on again. If it
happens 10 times within
a 60 minute rolling time
period, the OD control will
lock out operation of the
outdoor unit and display a
critical code.
Compressor slowdown due
2 flashes Minor
to high input current.
Heat sink temperature
is approaching limit.
The compressor speed
automatically slows
to reduce heat sink
temperature. The control
3 flashes Minor
sets indoor CFM and
outdoor RPM to values
according to demand
percentage rather than
the actual Hz. Alarm is
automatically cleared.
Issue:
Possible issue is system running at high pressures.
Check for high pressure trips or other alert codes in room
thermostat and outdoor control.
To clear, disconnect power to the indoor unit (24VAC
power source to the outdoor control) which will power
off the outdoor control and will open the outdoor unit
contactor, which interrupts power to the inverter and then
re-apply power.
This error code is primarily for informational purposes
as the inverter controls the compressor to operate within
design parameters. Typically the inverter will make a
minor speed reduction of 4 Hz (approximately a 5-6%
speed reduction) for a brief period of time and to reduce
the input current and will then resume normal operation.
This error code is primarily for informational purposes as
the inverter controls the compressor speed to operate
within design parameters. Typically the inverter will
make a minor speed reduction of 4 Hz (approximately a
5-6% speed reduction) for a brief period of time and to
reduce the heat sink temperature and will then resume
normal operation. This may occur at high outdoor
temperatures (above 110ºF) for brief periods of time (3 –
4 minutes) and is normal and expected operation of the
inverter controlling the compressor safely within design
parameters.
The inverter finned aluminum heat sink is located on the
back side of the inverter in the condenser air stream. f
the alert code 440 occur frequently, especially at lower
outdoor temperatures, check the heat sink for debris that
may reduce heat transfer or possible obstructions that
may impact air flow across the heat sink.
The inverter will begin to briefly reduce the compressor
speed when the heat sink temperature rises above
185ºF and will allow the inverter to resume the requested
compressor demand speed once the inverter heat sink
reaches 176ºF. The heat sink temperature, compressor
speed in Hertz & the Inverter Compressor Speed
Reduction status ("On" or "Off ") notification can be
viewed under the outdoor unit Diagnostics section of the
thermostat dealer control center on units installed with an
S30 thermostat.
Page 75
Possible Causes and Clearing Alarm