Refrigeration System Components - EdgeStar CWB8420DZ Service Manual

2.3 Refrigeration System Components

Compressor
The compressor is the "heart" of the refrigeration unit, consisting of an electrical motor and a
"pump" sealed inside a steel case. The compressor used on R134A refrigerant systems is
virtually the same in external appearance as the compressor used with R600a refrigerants.
However, due to changes in lubricants and other internal differences, the compressors are not to
be interchanged, otherwise system failure will result. If a new compressor is to be installed, pull
one of the plugs to ensure that it is properly pressurized. If no pressure is observed, do not use
the compressor. If unit is pressurized, reinstall the plug and keep the compressor sealed until it
is installed and ready for solder connections. Whenever the compressor is replaced, the sealed
system must be flushed especially for R134a system.
Condenser
The condenser is a long folded tube with steel wires which receives the hot, high pressure vapor
from the compressor. While the most common problem is keeping the condenser clean from lint
and dirt buildup which prevents proper airflow and the required transfer of the heat to the
surroundings, it is possible that due to an un-repairable leak or a non-removable restriction, the
condenser could require replacement. Do not remove the plugs on the condenser inlet and outlet
tubes until the new condenser is mounted in place and made ready for brazing. The inlet side will
connect to the hot pipe and the outlet to the filter dryer for built-in models and for built-in models
the condenser can be replaceable. But for free-standing models the inlet side will connect to the
discharge pipe of compressor and the outlet to filter dryer, it is non-replaceable.
Evaporator
The evaporator is a fin tube type within the rear side of cabinet and can be replaced. If a leak
is present in the evaporator, it is not repairable and must be replaced. After mounting the
evaporator in place, connect the capillary tube to the replacement filter drier. Again, whenever
the evaporator assembly is replaced the sealed system should be flushed.
Filter Dryer
Whenever the sealed system is entered, the filter dryer must be replaced. The filter dryer is
stamped with an arrow which indicates the direction of refrigerant flow. The dryer inlet has two
lines. O ne connects to the condenser and the other will be used as a process tube through
which the system sweep and final charge will be made. The dryer outlet will be connected to the
capillary tube. Care should be taken to ensure that the capillary is not inserted too far into the filter
dryer to make contact with its internal screen, yet in far enough to prevent restricting the small
diameter capillary tube opening with the solder alloy.
Hot Pipe
The hot pipe is a non-replaceable component of the sealed system routed within the walls of the
cabinet. To diagnose the hot pipe, the tubing must be isolated from the sealed system. If the
hot pipe fails to hold the vacuum, a heater repair assembly is to be installed and the hot pipe
bypassed by connecting the condenser outlet tube directly to the inlet of filter drier.
Capillary
The capillary tube meters the flow of refrigerant and creates a pressure drop. Size and length of
the capillary is critical to the efficiency of the system.