Service manual

21
Service Information
CAUTION
If you use a vacuum pump with mineral oil to
evacuate an R-134a system, it is ABSOLUTELY
ESSENTIAL to have a shut-off valve between
pump and your manifold gauge set as shown
in Figure E2. The hand valve must be closed
during all times when vacuum pump is
not operating. This will prevent migration
of mineral oil vapor into R134a/Ester oil
system. If vacuum pump should stop during
evacuation for any reason, the hand pump
shut-off valve must be closed immediately.
Refrigerant Leaks
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lterpart
number5303918288.Youmustheatthecrankcase
areaofthecompressorusingaheatgunonthe
highheatsettingthoughout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crank-case
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
weknowisoftenusedtorepairproductsinthe
eld.TheSweepChargedoesnotadequately
removethemoisturefromtheoilinthecompressor.
InaR-134asystemyouwillneedtoreplaced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ow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.45%silversolderis
recommended.
Leak Detection
R-134asystemleakscanbepinpointedbymeansof
anelectronicleakdetectororbybubblesolution.
ElectronicleakdetectorsforR-134aserviceare
currentlyavailablefromseveralmanufacturers.The
leastexpensivemodelsarenon-selectivedetectors
thatwilldetectanytypeofemissionorvaporpresent,
regardlessofitschemicalcomposition.Somenon-
selectivedetectorsdesignedforusewithR-12
mayhaveamuchlowersensitivitywhenusedwith
R-134a.However,newlydesigneddetectorswith
goodR-134asensitivityarenowavailable.Besure
toconsultwiththemanufacturerbeforeselectingor
usinganon-selectivedetectorwithR-134a.
Halogen-specicdetectorsuseaspecializedsensor
thatallowsdetectionofcompoundscontaining
chlorine,uorine,bromine,andiodinewithoutbeing
activiatedbyotherspecies.Themajoradvantage
ofthistypeofdetectorisareductioninthenumber
of“nuisancealarms”.Halogen-specicdetectors
aregenerallymoreexpensivethannon-selective
detectorsbutfeaturehighersensitivity.