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R R e e f f r r i i g g e e r r a a t t i i o o n n S S y y s s t t e e m m
V V a a c c u u u u m m P P u u m m p p M M a a i i n n t t e e n n a a n n c c e e
It is absolutely essential to maintain your vacuum
pump according to the manufacturer's instructions
including required oil changes at the recommend-
ed intervals. Vacuum pump oil should always be
changed after evacuating a contaminated system.
Vacuum pump performance should be checked
periodically with a micron gauge.
Vacuum pump suppliers may or may not
recommend changing the vacuum pump oil to the
same type that's in the system being evacuated.
Some manufacturers may recommend a vacuum
pump that's dedicated to R-134a systems.
Robinair has stated that their current and
discontinued vacuum pump models, using mineral
oil currently specified for use in their vacuum
pumps, can be used to evacuate R-134a/Ester oil
systems. Robinair also states that it is acceptable
to alternate between evacuating R-12/mineral oil
and R-134a/Ester oil systems without adversely
effecting the vacuum pump's performance.
For other brands of vacuum pumps, check with
the manufacturer for restrictions and guidelines
when using with R-134a.
CAUTION
I I f f y y o o u u u u s s e e a a v v a a c c u u u u m m p p u u m m p p w w i i t t h h m m i i n n e e r r a a l l o o i i l l t t o o
e e v v a a c c u u a a t t e e a a n n R R - - 1 1 3 3 4 4 a a s s y y s s t t e e m m , , i i t t i i s s A A B B S S O O L L U U T T E E L L Y Y
E E S S S S E E N N T T I I A A L L t t o o h h a a v v e e a a s s h h u u t t - - o o f f f f v v a a l l v v e e b b e e t t w w e e e e n n
p p u u m m p p a a n n d d y y o o u u r r m m a a n n i i f f o o l l d d g g a a u u g g e e s s e e t t a a s s s s h h o o w w n n o o n n
p p a a g g e e 4 4 - - 1 1 1 1 . . T T h h e e h h a a n n d d v v a a l l v v e e m m u u s s t t b b e e c c l l o o s s e e d d
d d u u r r i i n n g g a a l l l l t t i i m m e e s s w w h h e e n n v v a a c c u u u u m m p p u u m m p p i i s s n n o o t t
o o p p e e r r a a t t i i n n g g . . T T h h i i s s w w i i l l l l p p r r e e v v e e n n t t m m i i g g r r a a t t i i o o n n o o f f m m i i n n e e r r a a l l
o o i i l l v v a a p p o o r r i i n n t t o o R R 1 1 3 3 4 4 a a / / E E s s t t e e r r o o i i l l s s y y s s t t e e m m . . I I f f v v a a c c u u u u m m
p p u u m m p p s s h h o o u u l l d d s s t t o o p p d d u u r r i i n n g g e e v v a a c c u u a a t t i i o o n n f f o o r r a a n n y y
r r e e a a s s o o n n , , t t h h e e h h a a n n d d p p u u m m p p s s h h u u t t - - o o f f f f v v a a l l v v e e m m u u s s t t b b e e
c c l l o o s s e e d d i i m m m m e e d d i i a a t t e e l l y y . .
R R e e f f r r i i g g e e r r a a n n t t L L e e a a k k s s
A system with R-134a and Ester oil will become
saturated with moisture much faster than a system
with R-12 and mineral oil. If your leak was in the
low side of the refrigeration system when the
compressor is running the pressure in the low side
will go into a vacuum. As additional refrigerant
leaks out the system will go deeper into a vacuum.
The system running in this vacuum will allow air
and moisture to be pulled into the sealed system.
The moisture pulled in can then be mixed in to the
Ester oil in the compressor.
If the product has had a low side leak you will
need to install the two stage service dryer filter
part number 5303918288. You must heat the
crankcase area of the compressor using a heat
gun on the high heat setting throughout the 30
minutes you are running your vacuum pump to pull
a vacuum on the system. Every 4 to 5 minutes
while you are running your vacuum pump and
heating the crankcase area shake the compressor.
By heating the crankcase you are heating the oil in
the compressor. This will drive the moisture out of
the oil. By shaking the compressor this will allow
the moisture to come to the top of the oil faster so
the vacuum pump can remove the moisture from
the system.
Electrolux Home Products does not approve the
use of the Sweep Charge for sealed system repair.
This method of servicing sealed systems is often
used to repair products in the field. The Sweep
Charge does not adequately remove moisture from
the oil in the compressor. In a R-134a system you
will need to replace the compressor if the product
has had a low side leak and you are servicing with
the Sweep Charge procedure.
R-134a refrigerant molecules are smaller than R-12
molecules. This means that R-134a will pass more
minor leaks and the rate of flow will be greater
than for R-12. Therefore, it is now more important
than ever to follow good brazing practices. Use a
good grade of silver solder. A 45% silver solder is
recommended.
4-14
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