Midea WHS-185C1, Service Manual

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Maintenance Service and Troubleshooting
During compressor’s normal operation, a faint and constant hum due to
undulation of electrical current can be heard; this is normal. However, if it
sounds like an impact sound inside the compressor, this means that a
large quantity of wet saturated vapor of refrigerant or refrigerating oil has
entered the compressor cylinder. If it sounds like a striking sound of
metal parts inside the compressor, this means that some part has
become loose. (Be sure to differentiate this sound from those formed
during the compressor starting or stopping.)
b.
Open the refrigerator door while compressor is in operation, and listen to
the sound of gas flow inside the evaporator. If it sounds like gentle
whistling accompanied by a sound similar to water flowing, this is the
sound produced by the normal circulation of refrigerant within the
evaporator. If only the gas flowing sound can be heard and there is no
water flowing sound, this indicates that the refrigerant has already
percolated. If neither sound can be heard, this means that the filter or
capillary is clogged.
3. Touch and Feel
a.
After the compressor has operated normally for 5–10 minutes, feel the
condenser. The temperature of its upper part should be higher than that
of its lower part (or its right part is hotter than its left part, depending on
the type of condenser coil). This indicates that the refrigerant is
circulating properly. If the condenser is not hot, this means the refrigerant
is leaking. If the condenser is hot for only a few minutes and then cools
down, this means that the filter and capillary are clogged. If the forced
air-cooling condenser has hot air blowing out, the system is out of order.
b.
Feel the filter's temperature. During normal operation, the temperature on
the filter's surface should be a little higher than the ambient temperature.
If condensation appears, it is because the filter’s temperature is lower
than the ambient temperature and the screen is clogged. This obstructs
the flow of refrigerant, causing a drop in temperature due to throttling.
c.
Feel the temperature of exhaust gas from the refrigeration system. The
exhaust gas should be extremely hot during normal operation. For
refrigerators with an enclosed compressor refrigeration system, there
should be no frost or condensation on the gas suction tube. Otherwise,
there is something wrong in the system. (It is normal for frost and
condensation to appear for a short period of time when starting the
machine.) Since a refrigerator is a combination of several components,
these elements are connected to and influence each other. If a problem
is discovered through any of the previously mentioned checkups, do not
make a hasty conclusion based on only one issue. It is advisable to
analyze and conduct troubleshooting comprehensively, with the aid of
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