Lennox iComfort G71MPP-03 Setup Manual page 31

Table 10. Alert Codes and Troubleshooting
Alert
Priority Alert Text
Code
The liquid line temperature sensor has
424 Moderate
malfunctioned.
Outdoor control has increased minimum
425 Minor compressor speed to allow for proper oil
return due to low ambient temperature.
426 Critical Excessive inverter alarms
Moderate / The inverter has detected a DC peak fault
427
Critical condition
Moderate / The inverter has detected a high main input
428
Critical current condition
Moderate / The inverter has detected a DC link low
429
Critical voltage condition
Moderate /
430 Compressor start-up failure
Critical
Moderate / The inverter has detected a PFC circuit
431
Critical
over-current condition
Moderate / The inverter has detected a DC link high
432
Critical voltage condition.
Moderate /
433 Compressor phase current is too high.
Critical
Moderate / Outdoor control has lost communications
434
Critical
with the inverter for greater than 3 minutes.
Moderate /
435 Inverter internal error.
Critical
Moderate / Inverter heat sink temperature exceeded
436
Critical limit
.
Heat sink temperature sensor fault has
Moderate / occurred (temperature less than 4 ºF or
437
Critical
greater than 264ºF after 10 minutes of
operation)
Moderate / The inverter has detected a PFC circuit
438
Critical
over-current condition
Compressor slowdown due to high input
439
Moderate
current.
Compressor slowdown due to high heatsink
440
Moderate
temperature.
Compressor
441
Moderate
compressor current.
®
iComfort Wi-Fi
.
.
.
.
.
.
slowdown due to high
Critical alerts are displayed on Home (user) screen, in the Homeowner alert button, and in the
Installer alert button. Minor and Moderate alerts are found only in the Installer alert button.
Steps to clear
In normal operation after outdoor control recognizes sensors, the alarm will be sent if valid
temperature reading is lost. Compare liquid line sensor resistance to temperature/resistance
charts in unit installation instructions. Replace sensor pack if necessary. At the beginning of
(any) configuration, furnace or airhandler control will detect the presence of the sensor(s). If
detected (reading in range), appropriate feature will be set as 'installed' and shown in the
®
iComfort WiFi thermostat 'About' screen. The alarm / fault will clear upon configuration, or
sensing normal values.
Outdoor ambient temperature is below system limit. Control will attempt to run at lowest al
lowed compressor speed to allow for proper oil return. Automatically clears when outdoor am
bient temperature rises above limit for more then 5 minutes.
After ten faults within one hour control will lockout. To clear disconnect power to outdoor unit
and restart. Inverter alarms 12 to 14 and 53 do not count towards this lockout condition.
If condition (55A or higher) is detected, outdoor unit will stop (compressor and fan). Anti-short
cycle is initiated. If peak current (55A or higher) occurs 10 times within an hour, system will
lockout. To clear, disconnect power to outdoor unit and restart.
If condition is detected, outdoor unit will stop (compressor and fan). Anti-short cycle is initi
ated. If condition occurs 10 times within an hour, system will lockout. To clear, disconnect
power to outdoor unit and restart.
Error occurs when DC link voltage drops below 14VDC. If condition is detected, outdoor unit
will stop (compressor and fan). Anti-short cycle is initiated. If condition occurs 10 times within
an hour, system will lockout. To clear, disconnect power to outdoor unit and restart.
If condition is detected, outdoor unit will stop (compressor and fan). Anti-short cycle is initi
ated. If condition occurs 10 times within an hour, system will lockout. To clear, disconnect
power to outdoor unit and restart.
Error occurs when PFC detects a over current condition of 100A peak. If condition is detected,
outdoor unit will stop (compressor and fan). Anti-short cycle is initiated. If condition occurs 10
times within an hour, system will lockout. To clear, disconnect power to outdoor unit and re
start.
Error occurs when the DC link capacitor voltage is greater than 480VDC. If condition is detec
ted, outdoor unit will stop (compressor and fan). Anti-short cycle is initiated. If condition occurs
10 times within an hour, system will lockout. System will stop. To clear, disconnect power to
outdoor unit and restart.
Error occurs when compressor peak phase current is greater than 28A. Inverter will issue
code 14 first and slow down to try to reduce the current. If the current remains high, outdoor
unit will stop (compressor and fan). Antishort cycle is initiated. If condition occurs 5 times
within an hour, system will lockout. To clear disconnect power to outdoor unit and restart.
This error will occur when communication checksum error occurs for 3 minutes. Outdoor con
trol will stop all compressor demands, recycle power to the inverter by deenergizing the con
tactor for 2 minutes.
When this error occurs, the outdoor control will cycle power to the inverter by opening the con
tactor for 2 minutes. Outdoor control will cycle power to the inverter 3 times and then outdoor
unit is locked out
.
This occurs when the heat sink temperature exceeds the inverter limit. Inverter will issue code
13 first and slow down to try to cool the heat since. If temperature remains high, outdoor unit
will stop (compressor and fan). Antishort cycle is initiated. If condition occurs 5 times within
an hour, system will lockout. System will stop. To clear, disconnect power to outdoor unit and
restart.
This occurs when the temperature sensor detects a temperature less than 0.4ºF or greater
than 264ºF after 10 minutes of operation. If condition is detected, outdoor unit will stop (com
pressor and fan). Antishort cycle is initiated. If condition occurs 5 times within an hour, system
will lockout. To clear disconnect power to outdoor unit and restart.
Error occurs when PFC detects an input over current condition of 35A peak. If condition is
detected, outdoor unit will stop (compressor and fan). Anti-short cycle is initiated. If condition
occurs 10 times within an hour, system will lockout. To clear, disconnect power to outdoor unit
and restart.
Input current is approaching a high limit. Compressor speed will automatically slow down. The
control continues sending the inverter speed demanded by the thermostat. The control will set
indoor CFM and outdoor RPM to values according to demand percentage rather than the actu
al Hz. Alarm is automatically clear.
Heat sink temperature is approaching limit. The compressor speed will automatically slow
down to reduce heatsink temperature. The control will set indoor CFM and outdoor RPM to
values according to demand percentage rather than the actual Hz. Alarm is automatically
cleared.
Compressor current is approaching high limit. The compressor speed will automatically slow
down. The control will set indoor CFM and outdoor RPM to values according to demand per
centage rather than the actual Hz. Alarm is automatically cleared.
7-Day Programmable Communicating Thermostat
Page 31
table continued on next page