Compressor; Expansion Valve; Evaporator; Condenser - Valtra 6000 Workshop Manual

83. Air conditioner
D. Compressor
1. Normal function
--- When the compressor is functioning properly, it starts and
stops regularly. With max cooling effect the compressor runs
often but not as long as in min cooling. Unusual sound must
not be heard from the compressor. Check the compressor
belts regularly.
2. Continuing running, no cooling
--- The compressor is faulty and should be changed. Also
icing caused by moisture can cause this kind of malfunction
(check the moisture indicator colour). In this case also tem-
perature difference between high and low pressure pipes is
diminutive.
3. Continuing running, max cooling
--- The compressor is in order but a fault lies in the temperature
switch which does not switch off current to the compressor
when the evaporator temperature is under +2...+3 ˚C. Make
sure that the temperature switch sensor is correctly fitted
between the evaporator fins. This malfunction causes icing on
the evaporator which lowers the cooling effect.
4. Irregular running
--- Check the compressor belt tightness.
--- Change for faulty compressor
5. Unusual sound
Compressor engaged:
--- Check the compressor attachment.
--- Electromagnetic clutch slips, faulty bearings or valves in the
compressor can cause an unusual sound.
--- Wrong refrigerant filling in the system can cause unusual
sound.
--- Change faulty compressor
Compressor disengaged:
--- electromagnetic clutch clearance is wrongly adjusted.
Note! If the compressor front end is oily and moist, the com-
pressor shaft seal can be leaking. If the compressor does not
run at all, the fault is in the electrical system.
15. 6. 1992
1. 1. 1994
E. Expansion valve
Note! The expansion valve is accessible after removing the
cab roof and the evaporator housing cover. In addition, the
evaporator is covered by insulating mass.
--- A faulty expansion valve causes a poor cooling effect.
--- If the expansion valve is noisy (continuing whistle), there is
too little refrigerant in the system which causes bubbles to
appear in the inspection glass of the drier.
--- If the expansion valve does not function (stuck fast or frozen
in open or closed position) the cooling effect is insufficient.
--- If the air conditioner blows first cool air, then warm and then
again cool, there is ice in the expansion valve which prevents
refrigerant from flowing into the evaporator.
F. Evaporator
Note! The evaporator is accessible after removing the cab
roof and the evaporator housing cover.
--- If there is icing on the evaporator, the fault lies in the tem-
perature switch or its sensor is wrongly positioned between
the evaporator fins.
Note! Do not use the air conditioner if the outdoor tempera-
ture is below +20 ˚C.
--- Make sure that the drain pipes for the condensing water are
open i.e. water can flow away from the evaporator housing
bottom. Otherwise icing can appear on the evaporator. If there
is water on the evaporator housing bottom, the drain pipes
should be checked e.g. with compressed air.
G. Condenser
--- If malfunctions occur, always check and clean externally
the condenser from impurities. Cleaning can be carried out
with compressed air. In the later air conditioners, the tractor
front covering can be raised up and the condenser has hinges
for easier cleaning.
1146
Model Code
6000-- 8750 831
Page
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