5156631-UIM-G-0417
Johnson Controls Unitary Products
15
SECTION X: FAULT CODE - INVERTER TROUBLESHOOTING
Inverter fault codes are displayed on the 7-segment displays shown in Figure 15. The first digit appears on the left 7-Segment Dis-
play 1 and the second digit appears on the right 7-Segment Display 2. To see a brief description of the fault code or how the LED
signal is displayed, the two digit code from Tables 9 through 13 can be used to reference the two digit code shown in Table 8. The
brief description of the fault code and the specific signal from the LED are recorded in the columns to the left of the 7-Segment Dis-
play codes in Table 8.
Fan inverter DC bus over and under voltage
RED (solid)
5
0
Fan inverter over current
RED (solid)
5
1
Compressor IPM fault – By low voltage of IGBT voltage
RED (solid)
5
2
Analog digital converter offset abnormal error
RED (solid)
5
3
Inverter drive
soft lockout (3 major faults in 30 minutes)
2 RED flashes
5
4
Inverter drive hard lockout (4 inverter drive soft lockouts in 2 hours)
3 RED flashes
5
5
Crankcase heater fault
RED (solid)
5
6
Inverter Drive - Minor Fault Codes
IPM over temperature (speed limiting)
RED (solid)
6
0
DC voltage low (speed limiting)
RED (solid)
6
1
Compressor inverter over current (speed limiting)
RED (solid)
6
2
DC voltage low (speed reducing)
RED (solid)
6
3
Compressor inverter over current (speed reducing)
RED (solid)
6
4
IPM over temperature (speed reducing)
RED (solid)
6
5
TABLE 8:
Fault Code Display (Continued)
Description
LED
7-Segment
Display 1
7-Segment
Display 2
TABLE 9:
High Pressure Switch (HPS) Fault
INVERTER
FAULT
CODE
FAULT
DESCRIPTION
POSSIBLE CAUSES
ACTIONS
01,
02,
03
HPS
Verify the system has the correct amount of refrigerant.
Refer to the Product Technical Guide.
Loose high pressure switch harness leads.
Check the high pressure switch harness.
Pressure switch wire is disconnected from outdoor unit
control board.
Check high pressure switch connection on the outdoor
inverter control.
“Cooling Mode” for outdoor airflow - too low or off.
Verify outdoor coil is clean. Verify outdoor fan motor is
functioning. Verify there is airflow through the coil.
“Heating Mode” for indoor airflow - too low or off.
Check Indoor coil for restriction. Check indoor blower for
proper operation / rotation. Check duct work for excessive
static pressure. If attached to zoning system, ensure
smallest zone can handle minimum cubic feet per minute
(CFM) requirements.
Troubleshoot the pressure switch.
Bypass the pressure switch on the inverter wire harness,
and Ohm out the high pressure switch.
If fault remains.
Contact JCI Technical Services.
