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AIR
CONDITIONING
CHECKING THE EFFICIENCY OF THE AIR CONDITIONING SYSTEM
Interpretation of the measurements.
«m»:High pressure.«s»: Over-heating (SC).
«n»:High temperature.«t»:Ambient air temperature.
«p»:Under-cooling (SR).«u»:Blown air temperature.
«q»:Low pressure.«v»:Humidity.
«r»: Low temperature.«w»: Temperature T3.
Over-heating (SC).
The over-heating represents the difference between the aircon fluid temperature at the evaporator outlet
and the evaporation temperature.
The over-heating gives the quantity of aircon fluid (in the liquid state) in the air conditioning circuit
Values for over-heating (SC).
Values «s» Origins Solutions
2° < SC < 15°CCorrect quantity
SC > 15°CLack of aircon fluid in the cooling circuitAdd some
aircon fluid
SC < 2°CExcess aircon fluid in the cooling circuitRemove some
aircon fluid
Blown air temperature «u».
The blown air temperature should be between 2°Cand 10°C.
E5AP2FBC
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AIR
CONDITIONING
CHECKING THE EFFICIENCY OF THE AIR CONDITIONING SYSTEM
Aircon circuit diagnosis table
Principal problem Symptom Possible causes
Low pressure normal and high pressure too high Presence of air in the aircon circuit
Low pressure normal and high pressure too lowAircon pressostat defective
Evaporator sensor defective
Abnormal levels of pressure Low pressure too high and high pressure normal Aircon pressure reducer jammed open
Filtering and drying cartridge saturated or
Low pressure too low and high pressure normal clogged
Aircon pressure reducer iced up
Under cooling too weak Lack of aircon fluid
Air conditioning operating inExcess aircon fluid
back-up mode
Under cooling excessive Presence of air in the aircon circuit
Filtering and drying cartridge clogged
NOTE: In all cases, measure the excessive heating (SC)and the blow air temperature.
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