GEA HGX5/725-4 R134a, Assembly Instructions Manual

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6 | Commissioning
CAUTION! Wear personal protective clothing such as goggles and protective
gloves!
Make sure that the suction and pressure line shut-off valves are open.
With the compressor switched off, add the liquid refrigerant directly to the condenser or receiver,
breaking the vacuum.
If the refrigerant needs topping up after starting the compressor, it can be topped up in vapour
form on the suction side, or, taking suitable precautions, also in liquid form at the inlet to the
evaporator.
INFO! Avoid overfilling the system with refrigerant!
In order to prevent shifts in concentration, zeotropic refrigerant
blends (e.g. R407C) must always only be added to the refrigerating
system in liquid form.
Do not pour liquid refrigerant through the suction line shut-off val -
ve on the compressor.
It is not permissible to mix additives with the oil and refrigerant.
6.5 Refrigerant filling
6.6 Commissioning
WARNING! Ensure that both shut-off valves are open before starting the
compressor!
Check that the safety and protection devices (pressure switch, motor protection, electrical con -
tact protection measures, etc.) are functioning properly.
Switch on the compressor and let it run for at least 10 minutes.
Check the
oil level : The oil must be visible in the sight glass.
ATTENTION! If larger quantities of oil have to be topped up, there is a risk of oil
impact effects. If this is the case, check the oil return!
6.7 Avoid slugging
ATTENTION! Slugging can result in damage to the compressor and cause
refrigerant to leak.
To prevent slugging:
The complete refrigeration plant must be properly designed.
All components must be compatibly rated with each other with regard to output (particularly the
evaporator and expansion valves).
Suction gas superheating at the compressor input
should be min. 7 - 10 K
(check the setting of
the expansion valve).
The system must reach a state of equilibrium.
Particularly in critical systems (e.g. several evaporator points), measures such as the use of liquid
traps, solenoid valve in the liquid line, etc. are recommended.
There should be no movement of
refrigerant in the compressor while the system is at a standstill.