Haier HB21FWRSS Service Manual

Also see for HB21FWRSS: Installation and user manual

Contents

Haier HB21FWRSS Service Manual Manual pdf 35 page image

3. Analysis of Troubles and TroubleshootingA. Poor Refrigerating EffectThe so-called “poor refrigerating effect “ refers to the fact that the refrigerator can operate andrefrigerator normally, but the temperature in the refrigerator cannot drop to the prescribedvalue under the stipulated working conditions. In view of there are many causes for thisphenomenon, we are going to discuss and analyze it in the following 7 aspects:1) Leakage of refrigerantAnalysis of TroubleThe leakage of refrigerant in the system will result in an insufficient refrigerating capacity, theresulting phenomena are its lower gas suction pressure and exhaust pressure as well ashigher exhaust gas temperature. The exhaust tube feels rather hot, and a continuous gasflowing sound louder than usual can be heard at the outlet of the capillary, and no frost or asmaller quantity of loose frost appears on the evaporator. After shut down, the balancepressure in the system is usually lower than the saturation pressure corresponding to thesame ambient temperature.RemedyIn case there is leakage of refrigerant from the system, do not hurry to recharge it withrefrigerant, manage to find out leak points immediately, and make a note of from where itleaks ---welding points and parts. After having them repaired, recharge refrigerant.There are so many joints and sealed surfaces in a refrigerator, accordingly, quite a lotpotential leak points do exist in the system. In troubleshooting, pay attention to those partsthat are liable to leak, check main connection points for oil seepage and tubing for cracks. Ifthere is no severer leak point, charge the system with nitrogen and detect leak points with thecommonly adopted method, repair them, evacuate, charge the system with refrigerant, andthen turn on the refrigerator to make a test run.2) Too much refrigerant charged into the systemAnalysis of Troublea) In case the amount of refrigerant charged into the system exceeds its nominal capacity, thesuperfluous refrigerant will of course take some space of the evaporator, thus reducing itsheat-dissipation area and hence the refrigerating efficiency of the system. The abnormalphenomena caused by this reason are as follows: the gas suction and exhaust pressures aregenerally higher than their respective normal values, the temperature of its condenser ishigher and the electric current of the compressor rises, loose frost forms on the evaporator,the refrigerator temperature drops slowly, and frost appears on the gas return tube .b) In case excessive refrigerant has been charged, the liquid refrigerant that can notevaporates in the evaporator will return to the compressor, and thus a phenomenon of “liquidstriking” will occur. The liquid refrigerant evaporates and effervesces as soon as it flows intothe refrigerating oil at the bottom of compressor .If the condition is severe, foams will fill allover inside the compressor housing and be sucked by the piston, causing damage to thecomponents of compressor.