Electrolux R134A - DIAGNOSIS AND SEALED SYSTEM DIAGNOSIS

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1-101-10
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Sealed system diagnosis of R134A refriger-
ant systems is to be performed identically
to that of R12 systems. In fact, as shown in
the following flow chart, the service proce-
dures are virtually the same, except for low
side leaks, plugged capillary tube or com-
pressor failure which results in a system
flush.
IDENTIFY REFRIGERANTIDENTIFY REFRIGERANT
IDENTIFY REFRIGERANTIDENTIFY REFRIGERANT
IDENTIFY REFRIGERANT
R12R12
R12R12
R12
R134aR134a
R134aR134a
R134a
RECOVERRECOVER
RECOVERRECOVER
RECOVER
RECOVERRECOVER
RECOVERRECOVER
RECOVER
REPREP
REPREP
REP
AIRAIR
AIRAIR
AIR
REPREP
REPREP
REP
AIRAIR
AIRAIR
AIR
SWEEPSWEEP
SWEEPSWEEP
SWEEP
LOW SIDE LEAK,LOW SIDE LEAK,
LOW SIDE LEAK,LOW SIDE LEAK,
LOW SIDE LEAK,
PLUGGED CAPILLARYPLUGGED CAPILLARY
PLUGGED CAPILLARYPLUGGED CAPILLARY
PLUGGED CAPILLARY
TUBE, COMPRESSORTUBE, COMPRESSOR
TUBE, COMPRESSORTUBE, COMPRESSOR
TUBE, COMPRESSOR
REPLACEMENT?REPLACEMENT?
REPLACEMENT?REPLACEMENT?
REPLACEMENT?
FINAL CHARGEFINAL CHARGE
FINAL CHARGEFINAL CHARGE
FINAL CHARGE
NONO
NONO
NO
YESYES
YESYES
YES
FLUSH*FLUSH*
FLUSH*FLUSH*
FLUSH*
FINAL CHARGEFINAL CHARGE
FINAL CHARGEFINAL CHARGE
FINAL CHARGE
REFRIGERAREFRIGERA
REFRIGERAREFRIGERA
REFRIGERA
TT
TT
T
OR DIAGNOSISOR DIAGNOSIS
OR DIAGNOSISOR DIAGNOSIS
OR DIAGNOSIS
SWEEPSWEEP
SWEEPSWEEP
SWEEP
SEALED SYSTEMSEALED SYSTEM
SEALED SYSTEMSEALED SYSTEM
SEALED SYSTEM
* FLUSH INCLUDES COMPRESSOR
REPLACEMENT
Remember, before entering the sealed sys-
tem, all other systems must be tested and
properly repaired. These include the elec-
trical system, defrost system, control op-
eration, and air flow systems: evaporator
and condenser motors.
Before "turning aBefore "turning a
Before "turning aBefore "turning a
Before "turning a
screwdriver", many checks can be madescrewdriver", many checks can be made
screwdriver", many checks can be madescrewdriver", many checks can be made
screwdriver", many checks can be made
simply by using your senses:simply by using your senses:
simply by using your senses:simply by using your senses:
simply by using your senses:
DIAGNOSISDIAGNOSIS
DIAGNOSISDIAGNOSIS
DIAGNOSIS
LISTEN:LISTEN:
LISTEN:LISTEN:
LISTEN:
 What is the customer complaint?
 Are the fans operating?
 Is the compressor operating?
LOOK:LOOK:
LOOK:LOOK:
LOOK:
 Are ice cubes present?
 Is the light on/off when the switch is
operated?
 Are the controls set properly?
 Do door gaskets seal properly?
 Is there an ice buildup on the
evaporator cover?
 Are the return air ducts free of ice?
TOUCH:TOUCH:
TOUCH:TOUCH:
TOUCH:
 Is the evaporator cover warm?
 Is air felt exhausting from the kick
plate?
 Is air circulating in the freezer and
fresh food compartments?
 Is the quarter inch discharge line
from the compressor hot?
 Is the condenser warm?
SEALED SYSTEM DIAGNOSISSEALED SYSTEM DIAGNOSIS
SEALED SYSTEM DIAGNOSISSEALED SYSTEM DIAGNOSIS
SEALED SYSTEM DIAGNOSIS
Once it has been determined that the other
refrigerator systems are working properly,
a probable sealed system problem can be
confirmed through the use of a wattmeter
and checks of low and high side pressures.
Access valves are not to be left on a sealedAccess valves are not to be left on a sealed
Access valves are not to be left on a sealedAccess valves are not to be left on a sealed
Access valves are not to be left on a sealed
system after service.system after service.
system after service.system after service.
system after service. To measure low side
pressure, a temporary access valve can be
installed on the compressor process tube.
To remove the valve after repair, a pinch off
tool may be used to seal the tube while the
valve is removed and the hole brazed shut.
To check high side pressure, a temporary
access valve should be installed on the dis-
charge line. When the high side valve is in-