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(1) At normal operation conditions, the temperature around the
surface of freezer evaporator is nearly the same; the thickness of
frost layer is similar. If there is no frost at the surface of
evaporator (bed type freezer at all of its inner wall), or only a small
part at the upper, conclusion can be made that the operation of
refrigeration system is not normal, the refrigerant is insufficient or
there is leakage.
(2) Check the system tubing and make sure there is no leakage,
especially at the joint connections. Refrigerant has good
permeability, and it also contains a little refrigerant oil. If there is
leak, there will be traces of oil at the leak points.
12.1.4 Troubleshooting by sounds
(1) When the freezer is working normal, high-pressure liquid
refrigerant
flows
into
the
low-pressure
evaporator
via
acapillarytube, a gas flowing sound and water flowing sound can
be heard. Open the freezer door and access to the evaporator, you
can hear the sound. If there is no sound or there is sound a little
now and then, there must be leakage of system refrigerant or
insufficient charge.
MAINTENANCE SERVICE AND TROUBLE SHOOTING
Maintenance Service and Trouble Shooting
(2) After switching on power, Listen to the running sound of the
compressor whether it is normal or not. Whether or not hear
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