Figure 6-42.A cutaway view of an automatic ice machine.
What design factor makes remote refrigeration
equipment different from self-contained
Reach-in refrigerators are operated at a
temperature that falls within what range, in
Reach-in refrigeration units are equipped with
what type of evaporator?
Why are walk-in refrigerators manufactured and
constructed in sections?
Domestic refrigerators come in what two design
What are the two types of automatic defrosting in
the two-door refrigerator-freezer combination
What component of a water cooler precools the
fresh water line to the evaporator?
Q27. What design factor is the primary difference in
the different types of ice machines?
INSTALLATION OF REFRIGERATION
Learning Objective: Recall refrigeration
requirements and the types of installation for
Utilitiesman are often tasked to installation
refrigeration systems. Therefore, it is important for
you to understand the basic requirements applicable to
the installation of the various types of the equipment.
When installing a refrigeration or air-conditioning
plant, you must not allow dirt, scale, sand, or moisture
to enter any part of the refrigerant system. Since air
contains moisture, its entrance into the circuit should
be controlled as much as possible during installation.
Most maintenance problems come from careless
erection and installation. All openings to the
refrigerant circuitpiping, controls, compressor,
condensers, and so onmust be adequately sealed
when work on them is not in progress. The R-12
refrigerant is a powerful solvent that readily dissolves
foreign matter and moisture that may have entered the
system during installation. This material is soon
carried to the operating valves and the compressor. It
becomes a distinct menace to bearings, pistons,
cylinder walls, valves, and the lubricating oil. Scoring
of moving parts frequently occurs when the equipment
is first operated, starting with minor scratches that
increase until the operation of the compressor is
Under existing specifications, copper tubing and
copper piping needed for installation should be
cleaned, deoxidized, and sealed. When there is a
question about cleanliness of tubing or piping to be
used, each length of pipe should be thoroughly blown
out. Use a strong blast of dry air when blowing out, and
clean the tubing with a cloth swab attached to copper
wire pulled back and forth in the tube until it is clean
and shiny. Then the ends of the tubes should be sealed
until connected to the rest of the system.
EFFECTS OF MOISTURE
As little as 15 to 20 parts of moisture per million
parts of R-12 can cause severe corrosion in a system.
The corrosion results from hydrochloric acid formed
by R-12 in contact with water. A chemical reaction
takes place between the acid and the iron and copper in