Servicing Precautions - Kenmore 4666812 Service Manual

SERVICING PRECAUTIONS
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./Test the relrigeration syslem connecting it electrically before
refilling operalion. ll is necessary to ascertain the function
of th€ motor-compressor and identily the defects
immedialely, ll defects have been found, empty the old
syslom of possiue R-l34a residue by breaking off the end
of lhe exlenslon piece at its narrow point. (Figure 1)
Replace lhe filter and any damaged components. Unsolder
and pull olf lhe piece remaining inside the service tube and
lhen allach an complete extension with male Hansen and
tl laal, solder it to the same tube again. (Figure 2)
ll ls necessary lo €xecute the soldering operation with
valve open so lhal the fumes caused by oil residue can
como oul freely wilhoul blowholes between two tubes
durlng the heating the of lhe point to be soldered.
The extension litted with the male Hansen is connected to
lhc female litting of the vacuum pump tube. (Figure 3)
Air evacuating from the sysiem begins as soon as lhe
pump starls. The refrigeration system must be kept under
vacuum until lhe reading on the low-pressure gauge
indicales vacuum (0 absolute, -1 atm., .760 mm hg) in any
case it is advisable to keep the pump running for about 30
minutes. (Figure 3)
In case that a considerable leakage occurs it will be
necessary to stop the vacuum pump and to add asmall
quantity of Freon to the system,.if vacuum should not be
obtained (pressure gauge can't fall to 1 atmosphere), start
the refrigeration unit and find the leakage with the special
leak-finder. When the delective soldering point is visible,
re-do it after opening the extension tube valve and
reestablishing the normal outside pressure inside the
group.
Because the melted allgy is sucked into the tubes and
block them, the pressure must be rebalanced when
vacuum is in the system in soldering. As soon as the
TO THE R-134A CYLINDER
TO THE REFRIGERATION
SYSTEM
Flgure 4
Iaclum operation is over, add the quantity in grams of
R-134a to the refrigeration system. RemehOei that every
system has an exact quantity of R-134a with a tolerance of
t5 grams that can be added. (Figure 4)
Before performing this operation (if the vacuum pump and
refilling cylinder are connected), make sure that'the ialve
placed between the vacuum pump and the refilling tube are
closed in order to keep the Freon for addition to tFe system.
(Figure 5)
In addition, check the graduated scale on the cylinder lor
the quantity ol R-13a to be added, for example, if we have
750 grams ol Freon in the cylinder and must add 140
grams to the group, lhis amount will be reached when
R-134a hasdropped to 610 grams, remembering that the
indicator shows a lower limit of meniscus. Do this after
choosing the scale corresponding to the gas pressure
different scales reported as the same gas pressure
indicated by the pressure gauge on the top of the column.
To make R-134a flow into the system, open the valve
placed at the base of the cylinder and connected to the
filling tube. The amount of Freon cannot be added to the
system all at once because it may cause a blocking of motor-
compr€ssor. Therefore, proceed by adding the original
quantity of about 20-30 grrams and close the valrre
immediat€ly.
The pressure rises and the motor compressor must start
sucking the gas and lowering the pressure again. Regulate
the valve again, maintaining the same manner until
-
reaching to the quantity of R-134a established for the
system being charged. When the system is running, the
suction pressure musl be stabilized between 0.30 to.
0.6(0.10 to 0.4) atmosphere.
CHARGE TUBE
EXTENSION
MALE HANSEN
SERVICE TUBE EXTENSION
SOLDERING POINT
Flgure 1
Figure 2
FEMALE
HANSEN
I
v
FILLING OR
VALVE TO BE OPENEO
CHABGE TUBE
WHEN REFILLING
TO THE CHABGE
CYLINDER
VALVE TO BE CLOSED
AFTER VACUUM
Flgure 5
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