Leak Test; Evacuation; Refrigerant Charge - Danfoss BOCK UL-HGX44e Operating Manual

6 | Commissioning

6.3 Leak test

Carry out the leak test on the refrigerating plant in accordance with UL 207 or a corresponding
safety standard, while always observing the maximum permissible overpressure for the compressor.

6.4 Evacuation

First evacuate the system and then include the compressor in the evacuation process.
Relieve the compressor pressure.
Open the suction and pressure line shut-off valves.
Evacuate the suction and discharge pressure sides using the vacuum pump.
At the end of the evacuation process, the vacuum should be < 1.5 mbar when the pump is switched off.
Repeat this process as often as is required.

6.5 Refrigerant charge

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 vapor form
on the suction side, or, taking suitable precautions, also in liquid form at the inlet to the evapora-
tor.
© Danfoss | Climate Solutions | 2023.07
Risk of bursting!
The compressor must only be pressurized using nitrogen (N
Never pressurize with oxygen or other gases!
The maximum permissible overpressure of the compressor must
not be exceeded at any time during the testing process (see name
plate data)! Do not mix any refrigerant with the nitrogen as this
could cause the ignition limit to shift into the critical range.
Do not start the compressor if it is under vacuum. Do not apply
any voltage - even for test purposes (must only be operated with
refrigerant).
Under vacuum, the spark-over and creepage current distances of the
terminal board connection bolts shorten; this can result in winding and
terminal board damage.
Wear personal protective clothing such as goggles and protective
gloves!
Avoid overfilling the system with refrigerant!
To avoid shifts in concentration, zeotropic refrigerant blends must
always only be filled into the refrigerating plant in liquid form.
Do not pour liquid coolant through the suction line valve on
the compressor.
It is not permissible to mix additives with the oil and
refrigerant.
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