Carrier 38QUS012D8S Service Manual page 117

2.4.1.6. Refrigerant Leakage Detection
Malfunction conditions
Potential causes
Shut off the power supply and
turn it on 2 minutes later. Is it
still displaying the error code?
Yes
Is there cool air blowing
out from indoor air outlet?
No
Is there any leakage, especially
in connective components such
as the gas valve and the liquid
valve?
No
Are there any blockages in areas such as
the capillary or the welded points of the
pipes?
Yes
Clear the
blockages
Electrical Control System
Define the evaporator coil temperature T2 of the compressor starts
running as Tcool.
If the following occurs 3 times, the display shows "EC" and the unit
switches off:
In the first 8 minutes after the compressor starts up, if T2 ＜Tcool－2℃ is
not maintained for 4 seconds and compressor running frequency is not
higher than 50Hz for 3 minutes
T2 sensor error
●
Indoor PCB error
●
Refrigerant system error, such as leakage or blockages
●
Check if T2 sensor is well
fixed. Correct the installation
Yes
or replace T2 sensor. Does
the problem still remain?
Replace indoor PCB
Yes
Repair the leakage and
recharge the refrigerant
Yes
Troubleshooting
115