FISCHER [CF] EASY User Manual page 80

4 Starting up & operation
Before commissioning, ensure that all valves on the condensing unit are fully opened.
4.1 Evacuation
IMPORTANT
The evacuation procedure is based upon achieving an actual system
vacuum standard and is NOT TIME DEPENDENT! Before commissioning
the system must be evacuate by the vacuum pump. Before the installation is
put into commission, it has to be evacuated with a vacuum pump. Proper
evacuation reduces residual moisture to 50 ppm. The installation of
adequately sized access valves at the furthest point from the compressor in
the suction and liquid lines is advisable. The system must be evacuated
down less than 3 mbar and if required break the vacuum by the dry nitrogen
repeated. Pressure must be measured using a vacuum pressure gauge on
the access valves and not on the vacuum pump; this serves to avoid
incorrect measurements resulting from the pressure gradient along the
connecting lines to the pump.
4.2 Charging procedure
4.2.1 Refrigerant charging procedure
The pre-charging must be done with liquid refrigerant through the service valve on the liquid line.
It is advisable to pre-fill the suction side with a partial filling to avoid the vacuum operation.
Further charging can be effected by careful filling into the suction line during observation of the
sight glass.
IMPORTANT
Inadequate charge! Overheating! The Scroll compressor design requires
system charging as quickly as possible with liquid refrigerant into the liquid
line. This will avoid running the compressor under conditions whereby
insufficient suction gas is available to cool not only the motor but also the
scrolls. Temperature builds up very quickly in the scrolls if this is not done!
Service valve closed! Compressor damage! Do not charge the
[ CF ] EASY unit by vapour (gas). The suction service valve must not be fully
closed at any time when the compressor is running. To do so would cause
damage to the compressor in the same manner as explained above. This
valve is provided for ease of connection and for the fitting of service gauges
without removing the unit panel.
It is recommended to charge the [ CF ] EASY unit with refrigerant via its service valves.
Service valves
Valve covers
Figure 20: Service valves for refrigerant charging
C6.1.6/0513-0515/E
Hexagone socket wrench
Shraeder valves
27