Carrier 40MBDAQ - Page 26

40MBDAQ: Service Manual
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26
DIAGNOSIS AND SOLUTION (CONT.)
EC (Refrigerant Leakage Detection Diagnosis and Solution)
Description: Define the compressor’s evaporator coil temperature(T2) as it starts running as Tcool.
In the first 5 minutes after the compressor starts up, if T2 < Tcool-1°C(1.8°F) does not maintain for 4 seconds and the
compressor running frequency (higher than 50Hz) does not maintain for 3 minutes, and this situation occurs 3 times, the
display area displays “EC” and air conditioner turns off.
Recommended parts to prepare:
• T2 sensor
• Indoor PCB
• Additional refrigerant
Troubleshooting
Power o, then restart the unit 2 minutes later.
Are any leaks present?
Check the system for blocks
and clear if any.
Does a problem remain?
Put your hands in front of the
indoor air outlet.
YES
Is there cool air
air blowing out from
indoor air outlet?
Is it
securely attached?
Replace the
indoor PCB.
YES
Check the T2 sensor.
YES
Check system for leaks.
NO
NO
Repair the leak and
recharge the refrigerant.
YES
NO