Section D - Refrigeration System & Service; Safety; Soldering; Refrigeration System - Electrolux FROST- FREE Service Manual

SECTION D - REFRIGERATION SYSTEM &
SERVICE
NOTICE: Instructions given here are furnished as a
guide. Persons attempting to use these to make
repairs to the sealed refrigeration system should
have a working knowledge of refrigeration and
previous training on sealed system repair.

Safety

Compressor Testing: Whenever
testing a compressor, extreme
caution should be used to prevent
damaging the terminals. A
compressor with a damaged
terminal or a ground terminal
winding can expel a terminal from
its insulated housing when the
compressor is energized. If this
happens, a mixture of refrigerant
and oil will be released that could
be ignited by an external heat
source (open flame, heater, etc.).
Also, if there is air in the system
when it happens, a spark at the
compressor shell could ignite the
refrigerant and oil mixture.
Charging Sealed Systems: Over
charging a freezer system with
refrigerant can be dangerous. If the
overcharge is sufficient to immerse
the major parts of the motor and
compressor in liquid refrigerant, a
situation has been created which,
when followed by a sequence of
circumstances, can lead to the
compressor shell seam separating.
A hydraulic block occurs preventing
the compressor from starting. This
condition is know as locked rotor.
Electrical current continues to flow
through the compressor motor
winding which become, in effect,
electrical resistance heaters. The
heat produced begins to vaporize
the excess refrigerant liquid,
causing a rapid increase in system
pressure. If the compressor
protective devices fail, the pressure
within the system may rise to
extremes far in excess of the design
limits. Under these conditions, the
weld seam around the compressor
shell can separate with explosive
force, spewing oil and refrigerant
vapor which could ignite.
To eliminate this exceedingly rare
but potential hazard, never add
refrigerant to a seal system. If
refrigerant is required, evacuate the
existing charge and recharge with
the correct measured amount of
refrigerant specified for the system.

Soldering

CAUTION Wear the proper and approved safety
glasses when working with or on any
pressurized system or equipment. Have
an approved dry type fire extinguisher
handy when using any type of gas
operated torch.
1. All joints to be soldered must have a proper fit. The
clearance between tubes to be soldered should be
from .001" to .006". It is not practical to actually
measure this, however you do not want a dry fit or a
loose fit. The tubing joints should overlap about the
distance of their diameter except for restrictor tubes
which should be inserted 1.25"
2. Clean all joint areas with fine steel wool or preferably
an abrasive cloth, such as grit cloth No. 23 or
"Scotch-Brite."
3. Apply a thin film of a liquid flux recommended for
silver soldering to the surfaces to be joined, and to
the surfaces immediately adjacent to the joint.
4. Align the tubing so that is no stress on the joint. Do
not move the tubing while the solder is solidifying or
leaks will result.
CAUTION During the application of heat, use wet
cloths to prevent the heat from
conducting to areas other than the
soldered joint. Use a sheet of metal as
a heat deflector to keep the flame away
from inflammable materials and
painted surfaces.
5. Use a torch of adequate capacity so that the joint
can be quickly heated with a minimum of heat travel
to other points. Use a good grade of silver solder.
6. Solder the connections. If the tubing is properly
cleaned and fluxed, solder will flow readily. Do not
use an excessive amount of solder, just enough to
make a good bond.
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