LG LBC24360ST Service Manual - Page 49

11-4 Check D D1. Activate Protection logic Cycle check with protection logic - We have to check Condenser fan and Freezer fan before performing Check D - Locked Piston, Current trip and stroke trip can be activated by other problems then the driver or compressor. High Pressure Side Restricted → When process line on compressor is opened, and refrigerant is not expelled because it has accumulated in condenser. → If fault is corrected after refrigerant is recaptured from sealed system, change dryer. Locked piston Stroke trip Low Side Restriction Over charging Refrigerant → Low side restriction can cause a stroke trip. → If fault is corrected after refrigerant is recaptured, perform a sealed system evacuation and dryer replacement. → Check Suction line → If refrigerant is overcharged and suction line temperature is lower than ambient temperature (About 5~10¡C) or frost is present 150mm from where the suction line enters the compressor.. Current trip Low side Refrigeration leak Refrigerant leak → Temp. of compressor and discharge line is normal to slightly higher. High side pressure is normal to slightly higher than normal conditions. This is because condenser cannot condense the air that is trapped in the condenser. The high side pressure and temperature will not mimic the low side pressures and temperatures. → Customer complains of longer run times and poor cooling performance. → Lack of refrigerant can, in some incidents, cause piston over travel. → Pressure of refrigerant cycle is usually higher than ambient pressure, therefore oil will flow out with the refrigerant at leak point. D2. sealed system diagnosis - Check as follows; Sealed system Check for Oil leaks Yes In machine compartment No Check for oil Yes Remaining in drip tray No Check Temp of Discharge line and Condenser No Is there frost on Suction Line? No Comp,Cond T > Ambient temp+5deg Yes Sealed System is OK Yes A Repair leak at point where Oil is present. A In/Out Leakage Check for Oil leakage at each joint of the Evaporator Evaporator Leakage A Replace Evaporator A A Check frost status Of Evaporator Frost only Evaporator inlet Heat Inlet tubing No using heat gun. Welding point 1. Comp process stub, 2. Comp discharge 3. Hot Line inlet 4. Drier inlet 5. Drier outlet 6. Evaporator inlet 7. Evaporator outlet 8. suction pipe Sealed system repair Is frost pattern uniform? Yes Sealed System is OK 49 Is frost patern Uniform? Yes OK No A