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Soldering
WARNING
Wear 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 proper
fit. 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 loose fit. 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 liquid flux recommended
for silver soldering to surfaces to be joined
and to surfaces immediately adjacent to joint.
4.
Align tubing so no stress is on joint. Do not
move tubing while solder is solidifying or
leaks will result.
CAUTION
During application of heat, use wet cloths to
prevent heat from conducting to areas other
than the soldered joint. Use a sheet of metal
or torch guard pad as a heat deflector to keep
flame away from inflammable materials and
painted surfaces.
5.
Use a torch of adequate capacity so joint can
be quickly heated with a minimum of heat
travel to other points. Use a good grade of
silver solder.
6.
Solder connections. If tubing is properly
cleaned and fluxed, solder will flow readily.
Use only enough solder to make a good
bond.
7.
Allow joint to cool, then wash exterior with
water to remove flux.
Basic Components
The basic components of a refrigerator are
a compressor, condenser, evaporator, heat
exchanger (capillary tube and suction line), drier
and perimeter hot tube.
D - Refrigeration System
Refrigerant Cycle
The refrigerant cycle is a continuous cycle that
occurs whenever the compressor is in operation.
Liquid refrigerant is evaporated in the evaporator
by the heat that enters the cabinet through the
insulated walls and by the heat from product load
and door openings. The refrigerant vapor is then
drawn from the evaporator, through the suction
line to the compressor. Compression raises the
pressure and temperature of the vapor in the
compressor and the vapor is then forced through
the discharge valve into the discharge line and into
the condenser. Air passing over the condenser
surface removes heat from the high pressure
vapor which then condenses to a liquid. The liquid
refrigerant then flows from the condenser to the
evaporator through the small diameter liquid line
(capillary tube). Before it enters the evaporator,
the liquid refrigerant is sub-cooled in the heat
exchanger by the low temperature suction vapor in
the suction line.
Low/High Side Leak or
Undercharge
A loss of refrigerant can result in any of the
following:
1.
Excessive or continuous compressor
operation.
2.
Above normal freezer compartment
temperature.
3.
A partially frosted evaporator (depending on
amount of refrigerant loss).
4.
Below normal freezer compartment
temperature.
5.
Low suction pressure (vacuum).
6.
Low wattage.
The condenser will be "warm to cool", depending
on the amount of refrigerant lost.
When refrigerant is added, the frost pattern will
improve, the suction and discharge pressures
will rise, the condenser will become hot and the
wattage will increase.
In the case of a low side refrigerant leak resulting
in complete loss of refrigerant, the compressor
will run but will not refrigerate. Suction pressure
will drop below atmospheric pressure and air and
moisture will be drawn into the system saturating
the filter drier.
21
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