Lennox XC20-036-230-01 Installation And Service Procedure page 72

Table 18. 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/dehumidification).
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 iComfort Wi-Fi
Inverter
Code
Alert Inverter
flashes)
Code
Codes
Red LED
E 427 21 2 flashes
E 428 22 2 flashes
E 429 23 2 flashes
E 430 26 2 flashes
E 431 27 2 flashes
E 432 28 2 flashes
XC20
®
®
or iComfort
LED Flash
(number of
Priority
Green LED
Moderate
1 flash
/ Critical
Moderate
2 flashes
/ Critical
Moderate
3 flashes
/ Critical
Moderate
6 flashes
/ Critical
Moderate
7 flashes
/ Critical
Moderate
8 flashes
/ Critical
S30 thermostat.
Alarm Description
The inverter has detected a
DC peak fault condition
.
The inverter has detected a
high main input current con­
dition
.
On a call for compressor op­
eration, if DC link power in in­
verter does not rise above
180 VDC for 2 and 3 ton mod­
els, 250 VDC for 4 and 5 ton
models, within 30 seconds,
the control will display a mod­
erate code. If condition is de­
tected, outdoor unit will stop
(Compressor and fan). Anti-
short cycles is initiated. If
condition occurs 10 times
within a 60 minute rolling time
period, system will lock out
and display a critical code.
Compressor start failure
.
Error occurs when PFC de­
tects an over-current condi­
tion of 100A, the control will
display a moderate code. If
condition is detected, out­
door unit will stop (Com­
pressor and fan). Anti-short
cycle is initiated. Inverter is
unavailable to communicate
with the outdoor control for 3
minutes. If condition occurs
10 times within a 60 minute
rolling time period, system
will lock out and display a crit­
ical code.
The inverter has detected a
DC link high voltage condi­
tion.
72
Possible Causes and Clearing Alarm
If condition (55A or higher) is detected, outdoor unit will
stop (compressor and fan). Anti­short cycle is initiated. If
peak current (55A or higher) occurs 10 times within an
hour, system will lock out.
Indicates high pressure, condenser fan failure, locked
compressor rotor or overcharge.
To clear, disconnect power to outdoor unit and restart.
If condition is detected, outdoor unit will stop (compressor
and fan). Anti­short cycle is initiated. If condition occurs 5
times within an hour, system will lock out.
Indicates high pressure, condenser fan failure or over­
charge. To clear, disconnect power to outdoor unit and
restart.
Issues:
(1) If DC link power in inverter does not rise above 180
VDC for 2- and 3-ton models, 250 VDC for 4- and 5-ton
models, within 30 seconds, the outdoor control will dis­
play a moderate code.
(2) Capacitors on inverter do not properly charge.
Corrective Actions:
(1) check for proper main power to outdoor unit and for
any loose electrical connections.
(2) Outdoor control boards with part # 103686-03 have
software update to delay the de-energizing of the revers­
ing valve by four seconds when coming out of defrost.
If condition is detected, outdoor unit will stop (compressor
and fan). Anti­short cycle is initiated. If condition occurs
10 times within an hour, system will lock out.
Indicates poor connection at compressor harness, im­
proper winding resistance, locked compressor rotor, or
flooded compressor.
To clear, disconnect power to outdoor unit and restart.
Issues:
(1) Indicates power interruption, brownout, poor electrical
connection or loose inverter input wire.
(2) System testing was set up and code was generated
when the reversing valve is de-energized coming out of
defrost (code appears with or without 30 compressor
delay).
Corrective Actions:
(1) Check for proper main power to outdoor unit and for
any loose electrical connections.
(2) Outdoor control boards with part # 103686-03 have
software update to delay the de-energizing of the revers­
ing valve by four seconds when coming out of defrost.
Error occurs when the DC link capacitor voltage is greater
than 480VDC. If condition is detected, outdoor unit will
stop (compressor and fan). Anti­short cycle is initiated. If
condition occurs 10 times within an hour, system will lock
out. System will stop. To clear, disconnect power to out­
door unit and restart.