LGRED Heat General Service Manual

Part 5. Trouble Shooting
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Trouble analysis
1. Check temperature difference between intake and discharge air, and check for the operating current too.
Case Symptom Supposed Caused
Temp. difference : approx. 0°C
Current : less than 80% of rated current
Temp. difference : approx. 8°C
Current : less than 80% of rated current
Temp. difference : less than 8°C
Current : over the rated current
Temp. difference : over 8°C
All amount of refrigerant leaked out.
Check refrigeration cycle.
Refrigerant leakage Clog of refrigeration cycle
Defective Compressor.
Excessive amount of refrigerant
Normal
Case 1
Case 2
Case 3
Case 4
Temperature difference between intake and discharge air depends on room air humidity. When the room air humidity is
relativery higher, temperature difference is smaller. When the room air humidity is relatively lower temperature difference
is larger.
2. Check temperature and pressure of refrigeration cycle in cooling mode.
1. The suction pressure is usually 8.5~9.5kg/cm2G(Cooling) at normal condition.(R410A)
2. The temperature can be measured by attaching the thermometer to the low pressure tubing and wrap it with putty.
NOTICE
NOTICE
Suction pressure
(Compared with Cause of Trouble Description
the normal value)
Defective compressor Current is low.
Defective 4-way reverse valve
Excessive amount of High pressure does not quickly
Normal refrigerant rise at the beginning of
operation.
Insufficient amount of Current is low.
Lower Higher refrigerant (Leakage)
Clogging
High
Higher
Temperature of Discharge
Air (Compared with the
normal valve)
5. Cycle Part