WAKL5N0802A
Edition: 07.02.2022
Page: 10/18
The filter dryer needs to be mounted as indicated (flow direction). The flow marker (arrow on the
filter dryer) points the direction of expansion valve. Remove the protective caps on both sides of
the filter dryer only immediately prior to mounting.
Evacuate the area between manual shut-off valve and magnetic valve
at the service connection.
With an ambient temperature of ca. 20°C, a vacuum of less than 20 mbar must be achieved in
order to ensure optimal evaporation of any humidity that may have entered the system with
humid air.
Manual shut-off v
alve to „bring normal position“ and mount cap.
Balance the pressure in the high and low pressure areas of the refrig-
erant circuit with the aid of the shut-off valves on the manometer com-
bination. For this purpose,
open the “Red” and “Blue” shut-off valves of
the manometer combination for approx. 5 sec.
Pressure in the low pressure volume must exceed 2.1 bar, other-
wise the air conditioner does not operate (Low Pressure Malfunc-
tion).
Set the service shut-off valves ND (6) and HD
at the refrigerant compressor again to “Normal”
(turn spindle counter-clockwise until stop).
Start the air conditioner and check for any
leakage. Attach or close and secure service
flaps on the roof air conditioner.
3.6. Function check of high pressure switch (8)
Connect the blue manometer (to atmospheric pressure) to service connection (1) of the service
shut-off valve ND
– low pressure - (6) and the red manometer (to atmospheric pressure) to service
connection (5) of the service shut-off valve ND
– low pressure - (2) of the refrigerant compressor.
Set service shut-
off valve ND (6) and HD (2) in “Service Position” (turn spindle clockwise ca. three
full circles) and then evacuate.
Interrupt operation of the condenser fan (e.g. disconnect plug connections or remove fuses of the
condenser fan).
1
3
4
2
Oil sight glass
5
7
6
8
Flow direction
