Valtra VALMETSERIES Service Manual page 7

83. Air conditioner
Earlier air conditioner which has the control panel fitted in the front part of the cab
roof.
Figure 3. Air conditioner on Valmet 6100---8100 tractors.
1. Condenser
2. Compressor
3. Drier
A=Inspection glass
B=Moisture indicator
4. Expansion valve
5. Evaporator
6. Temperature switch
7. Re ---circulation nozzles
8. Air inlet into cab
9. There are valves in the outlet pipes for condensing water.
The valves prevent air from entering into the evaporator hous-
ing. Water becomes condensed in the housing when the
warm cab air flows through the cold evaporator.
Compressor (2) is driven by an extra belt pulley at the front
end of the crankshaft. The compressor belt pulley is fitted with
an electromagnetic clutch, which switches the compressor off
and on according to the required cooling effect. The com-
pressor is shown on page 831/9.
The expansion valve (4) regulates the amount of refrigerant in
the evaporator (5) so that the refrigerant vaporizes in the best
possible way. The expansion valve lets only as much refriger-
ant flow into the evaporator as the evaporator can vaporize.
The expansion valve is shown on the next page.
Model
15. 6. 1992
1. 1. 1994
Wiring diagram:
F21 = Air conditioner fuse
F15 = Fan fuse
S3 = Fan switch
S8 = Temperature switch
S19 = Pressure switch
Y5 = Electromagnetic clutch
M2 = Fan
K6 = Relay, max speed III of fan
Temperature switch sensor (6) (capillary tube) is pushed
between the evaporator fins and it senses evaporator tem-
perature in its coldest place. The sensor switches off the com-
pressor when the evaporator temperature drops below
+2...+3˚C (prevents icing on the evaporator), and switches
on again when the evaporator temperature has risen over
+6...+7˚C (or up to +19˚C when the temperature switch is
in min position).
1139
Code Page
6000-- 8750 830 5