Manual for Refrigeration Servicing Technicians - UNEP - Division of ...

Summary
This section will provide the technician with the
ability to understand the causes of main operational
problems presented by vapour compression
refrigeration or air conditioning systems. It is
important to understand how to avoid them through
the adoption of good practices, and to be aware of
the main precautions which should be taken when
servicing installations and systems.
Methods and techniques that are used when working
on systems, primarily during servicing exercises,
are discussed. In particular, this includes the
consideration of system cleanliness (moisture, acid,
non-condensable), and the means for overcoming
these problems, such as proper evacuation methods
and system purging. To avoid such issues in the first
place demands appropriate procedures associated
with tightness testing (“leak testing”) and refrigerant
charging, which are described.
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Servicing Practices
Technicians have the important role of making the operation of
RAC systems the most energy efficient and decreasing refrigerant
emissions. This can only be achieved by the adoption of good
practices. The section starts with the evaluation of the problems
due to the presence of moisture and contaminants in the system,
and how to avoid them through purging and evacuation, charging,
and leak testing. The important measurement instruments and
tools necessary to achieve good servicing practices are included.
A technician should be should be able to achieve the following
servicing operations:
• Leak detection, purging and evacuation.
• Charging refrigerants.
• Identifying the servicing-specific tubing tools and techniques
of sizing, un-rolling, cutting, bending, flaring, swaging,
piercing, pinching and welding.
• Identifying the proper use of servicing instruments: manifold
gauges, charging scales, and thermometers.