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temperature of discharged gas, and, for severe cases, condensation and frosting may
appear.
Remedy
Purge the tubing. After replacing, the dry filter or cleaning it thoroughly, refill the system
with refrigerant and seal the charging port.
No Refrigerating
“No refrigerating” refers to a situation where the compressor runs normally, but the
refrigerator’s temperature does not decrease. While servicing, careful attention will be
required to find correct the cause. The most common causes for this malfunction are
analyzed below.
1)
The entire refrigerant has leaked
Analysis of Trouble
Leak points in the refrigerating system have not been found and repaired timely, allowing
refrigerant to leak completely. There are two kinds of leaks: slow leaks
and fast leaks.
Symptoms of total leakage of refrigerant are:
•
The compressor can be started easily (if there is no damage to the compressor
parts)
•
The operating current becomes low
•
The gas suction pressure increases
•
The discharge pressure decreases
•
The temperature of the gas discharge tube drops
•
There is no sound of gas eruption from the liquid in the evaporator, and
•
No gas gushes out of the process tube when cut after shutdown
Remedy
Check the whole machine, particularly those locations which are liable to leak. After leak
points have been found, repair them or replace them with new parts according to specific
circumstances. Then evacuate the system and finally charge refrigerant.
2) Refrigerating system is clogged with ice
Analysis of Trouble
This is typically a result of a poor dryness treatment, improper air purging, or substandard
water content. The symptoms of this condition are:
•
Irregular refrigeration, extreme frosting at the clogged area,
•
Evaporation temperature drops below 0°C or 32°F,
•
Water accumulates and gradually clogs the narrow part of the capillary,
•
Frost to melt at the evaporator, there is no sound of gas flowing,
•
The gas suction pressure becomes a vacuum.
Note that these phenomena will appear intermittently. In order to know whether the system
is clogged with ice, heat the parts that are suspected with hot water. If the sound of gas
flowing is heard and the gas suction pressure rises, the trouble is that the system is clogged
by ice.
Remedy
If there is too much moisture in the refrigerating system, release the refrigerant, purge the
tubing with nitrogen, and then refill the system with the filtered refrigerant. Another method
