Premium PFR70800M, Service Manual

Maintenance Service and Trouble Shooting   

ambient temperature ,this means that most meshes of its screen has been 

clogged ,resulting in an obstructed flowing of refrigerant ,thus causing a 

drop in temperature due to throttling . 

d)    Feel the temperature of exhaust gas from the refrigerating 

system .the exhaust gas should be very hot and this is the normal working 

state .For those Freezer with enclosed type of compressor refrigerating 

system, no frost or dew drop will from on the gas suction 

tube ,otherwise ,there is something wrong in the system (Frosting and dew 

condensation may appear for a very short time period when just starting the 

machine ,this is a normal phenomenon ). 

Because a Freezer is a combination of several components ,they are 

related and have influence on each other In case an abnormal 

phenomenon has been found through the above-mentioned checkups ,you 

need not to make a hasty conclusion based on only one abnormal 

phenomenon .It is advisable to find out two or more abnormal 

phenomenon ,or conduct troubleshooting comprehensively with the aid of 

instruments or other ways ,because several kinds of troubles may share a 

common abnormal phenomenon ,and two or more abnormal phenomena 

may occur simultaneously due to a certain trouble .With this method ,you 

can reject some suspicious troubles and finally make a correct judgment . 

7 Analysis of Troubles and Troubleshooting 

A.   Poor Refrigerating Effect 

The so-called "poor refrigerating effect " refers to the fact that the 

Freezer can operate and Freezer normally ,but the temperature in 

the Freezer cannot drop to the prescribed value under the stipulated 

working conditions .In view of there are many causes for this 

phenomenon ,we are going to discuss and analyze it in the following 7 

aspects : 

1)   Leakage of refrigerant 

Analysis of Trouble 

The leakage of refrigerant in the system will result in an insufficient 

refrigerating capacity ,the resulting phenomena are its lower gas suction 

pressure and exhaust pressure as well as higher exhaust gas 

temperature. The exhaust tube feels rather hot ,and a continuous gas 

flowing sound louder than usual can be heard at the outlet of the 

capillary ,and no frost or a smaller quantity of loose frost appears on the 

evaporator .After shut down ,the balance pressure in the system is usually 

lower than the saturation pressure corresponding to the same ambient 

temperature . 

Remedy 

In case there is leakage of refrigerant from the system ,do not hurry to 

recharge it with refrigerant ,manage to find out leak points immediately ,and 

make a note of from where it leaks ---welding points and parts .After having 

them repaired ,recharge refrigerant . 

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