314Have a focus inspection on the following area:
a. Each pipe union joint and valve connection.
b. All hose, especially near the pipe union.
c. Compressor shaft seal, front and rear cover, gasket, oil fill plug.
d. Area on the surface of the condenser and evaporator that is scratched, bruised or damaged.
e. Expansion valve inlet and outlet connection and temperature sensor element and the welding position.
3. Check the Refrigerant
Observing from the sight glass, you may understand the refrigerant status and analyze the possible faults:
4. Check Other Parts
Other parts needed to be checked and their check points:Conditions obse rvedP ossible proble ms
Cle ar, no a ir bubble , A/C e mits c ool wind Re frige ra tion system is normal
Cle ar, no a ir bubble , A/C e mits warm wind Re frige ra nt le a ke d, the re is le aka ge in the syste m
Occ a tiona l a ir bubble . Expa nsion va lve is froste d There is wa te r mixe d in the re frigeration syste m
Occational air bubble. Insufficient refrigerant or air mixed in the system
Cle ar, the re is oil stripe on the gla ss Outle t is not c old, no refrige ra nt
Foamy and turbid Excessive freezing oilChecked PartCheck Points
The re sha ll be no dirt and rust on the radiator tha t hinde r the he at
exchange;
The ra dia tor surfa ce ha s no da mage , fissure a nd hidde n trouble tha t ma y
cause refrigerant leakage.
Elec tromagne tic Clutc hClutc h ope ration is norma l. Whe n switche d on, the c ompre ssor sha ll
operate, clutch can not slip.
Compre ssor Be lt Be lt te nsion of 250N is normal, belt is not broke n and dama ged.
WireThe electromagnetic clutch and blower power cable shall be not damaged
and overheated; the connection shall be reliable, and the protective
gromme t through the me tal plate sha ll be ke pt good a nd without da ma ge .
HoseRefrigerant hose and condenser pipe shall be secured and shall not be
dama ged by a pproac hing the othe r ove rhe ate d pa rts, moving pa rts a nd
sha rp parts. Eva pora tor Conde nse r
315II. A/C System Diagnosis and TroubleshootingTable 1 Abnormal high pressure of the high pressure pipelineAbnormal low pressure of the high pressure pipeline Abnormal high pressure of the low pressure pipelineAbnormal low pressure of the low pressure pipelineHigh and low pressure can not be establishedSight glass has air bubble Compressor inlet side is frosted Compressor noise Abnormal heating on the compressorEvaporator is frostedDrier filter ices up A/C does not refrigerate or the cold air is insufficient× × × × Excessive refill of refrigerantDrain p rop er amount of
refrigerant
× × × × T oo lit t le refill of refrigerantRep air t he gas leak area, refill
p rop er amount of refrigerant
× × × × Refrigerant is leaked allRep air t he gas leak area, refill
p rop er amount of refrigerant
×× ××× ×T here is non-clot t ed gas in
the sy stemLoos en receiver and
condenser inlet connect or,
discharge t he non-clot t ed gas
××Excessive freez ing oil in t he
sy stemCheck comp ressor freez ing
oil level, adjus t it
× Excessive high t emp erat ure
of condenser inletPerform t he check at t he
p lace w it h good vent ilat ion
T here is dus t in t he
condens er core, air channel
w it hin t he condens er is
blocked or suffocat edU s e comp res s ed air or w at er
t o flush and remove t he dirt
on t he condenser
Condenser fan faulty or
brokenCheck the wiring status and
t he fan mot or, correct or
rep lace it
×× Exces s ively low t emp erat ure
of condenser inletStop the op eration of the
refrigerat ion sy st em
× × × Drier blocked Clean
A ir channel in t he evap orat or
blocked or suffocat edRemove t he dirt on t he
evap orat or
Evap orat or fan fault , p oor
blower mot or w ire connect ionCheck the wiring status and
t he fan mot or, correct or
rep lace it
×× ×T here is dirt in evap orat or
coreU s e t he comp res s ed air t o
clean t he evap orat or core × ×
××××
× P roblem Sy mp t om
Possible Cause T roubleshoot ing
×
