Charging Sealed Systems; Soldering - Electrolux 5995502399 Service Manual

Charging Sealed Systems

Overcharging a refrigeration 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 known as locked rotor.
Electric current continues to flow through the compressor
motor windings which become, in effect, electric
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, 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 sealed system. If refrigerant
is required, evacuate the existing charge and recharge
with the correct measured amount of the refrigerant
specified for the system.
NOTE: Attach an approved self tapping line tap valve to
the process tube. Connect refrigerant recovery system
to tap valve. Turn on recovery system, open the line
tap valve, and allow refrigerant to flow into an approved
tank.
Always make sure your equipment is in good condition
and all manufacturer's instructions are followed to
prevent the accidental rupture of a hose, connection
fitting, or a tank, this could cause a serious injury. Run
equipment until system has reached 13 inches of
vacuum. Shut system down and allow to set for two
minutes, if pressure remains below (0) pounds per
square inch, disconnect equipment and proceed. If
pressure does not stay below (0) pounds per square
inch, repeat above procedure until all refrigerant is
removed and system remains in a vacuum.
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.

Soldering

1. All joints to be soldered must have a 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 prefer-
ably 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.
During application of heat, use wet cloths to pre-
vent 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.
4. Align tubing so no stress is on joint. Do not move
tubing while solder is solidifying or leaks will result.
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.
7-5
Sealed System