Performance Checks - EdgeStar CWB8420DZ Service Manual

After the leak test, check the temperature of each part. Check (by touch) if the CONDENSER
and Hot Pipe are warm. Confirm that frost is uniformly distributed on the surface of the
EVAPORATOR.

2.5 Performance Checks

The following general information explains several methods for checking the performance of the
refrigeration system. The correct operation of a refrigeration system is dependent upon the proper
function of each of the parts comprising the system. If the system does not operate properly (long
run periods, warmer than normal temperatures), the trouble may be caused by one of the following
conditions:
Restricted Capillary Tube
The opening of a capillary tube is about the same diameter as the period at the end of this
sentence. Because of this, it is easy to restrict the tube. Extra precautions should be taken when
any service procedure involves moving or touching the capillary tube. The slightest kink can
cause a complete tube restriction.
Restrictions of the capillary tube may be caused by: (1) moisture freeze-up (2) foreign particles
lodged in the tube or (3) a bend or kink.
If the capillary tube is restricted, there will be a noticeable lack of frost on all cooling surfaces. The
compressor may operate for a short period of time and cycle on the overload. When moisture
freeze-up causes a restriction it usually occurs at the outlet end of the capillary tube. Normally,
frost buildup can be detected in this area.
At the discharge end of the capillary, apply heat by using the hairdryer. If there is enough head
pressure, and if the restriction is caused by moisture freeze-up, you will be able to hear a gurgling
noise as the heat releases the refrigerant through the tubing. It is possible that this moisture will
be absorbed by the filter drier and remedy the trouble. However, if the freeze-up reoccurs, you
must replace the filter drier.
A kink in the capillary tube will have the same symptoms as a moisture freeze-up, except for the