
Page 76
31-5000751 Rev. 0
GF= Gas Furnace, AH=Air Handler, ID=Indoor unit (GF or AH), HP=Heat Pump, AC=Air Conditioner, OD=Outdoor Unit (AC or HP), ZA=Zone system and TS=Thermostat
Alert
Code
Inverter
Code
Inverter Flash
Code
Priority
Condition
Actual Displayed
Alert Text
Component or System Operational State and Troubleshooting
Tip
How to Clear Alert
Code
Red
LED
Green
LED
432
28
2
flashes
8
flashes
Service Soon/
Service
Urgent
OD Inverter DC
Link High Voltage
The inverter has detected a DC link high voltage condition.
•
Error occurs when the DC link capacitor voltage is greater than 480
VDC.
•
If condition is detected, outdoor unit will stop (compressor and fan)
– moderate condition.
•
Anti-short cycle timer is initiated.
•
If condition occurs 10 times within 60 consecutive minutes, the
system will lockout – critical condition.
•
Inverter LEDs will flash code 28.
•
Refer to the unit service documentation for detailed troubleshooting
procedures.
Inverter flash code 28.,
The sequence is:
•
Red LED: Two Flashes
•
Green LED: Eight Flashes
NOTE:
Inverter normal operations with no error code present is as
follows. Red LED is ON and Green LED is OFF.
Troubleshooting Suggestions:
•
Check wire connections (U, V and W) at inverter plug in harness
and compressor.
•
Check the resistance of compressor windings. If not in range,
replace compressor.
•
Check compressor to ground. If ground issue, replace compressor.
•
Check input power (Single Phase - 208/230VAC
+
10%. If out of
range, correct main power issue.
•
Check DC Link voltage and MICOM Sensing voltage. If out of
range, replace inverter. if okay, possible mechanical issue with
compressor.
Go to outdoor unit service manual for detail troubleshooting
procedures and require values for testing DC link voltages and
various insulation resistance characteristics.
To clear, disconnect
power to outdoor unit
and restart.
Table 24. Outdoor Control 7-Segment Display Alert Codes and Inverter LED Flash Codes