GEA Bock HGZ7 - Manual (Page 28)

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7| Commissioning
7.1 Preparations for start-up
7.4 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.
In addition to the suction or high pressure side, the intermediate pressure area of the compressor
must also be evacuated (use connection X, see page 16, fig. 20). The solenoid valve of the
subcooling system (page 17, fig. 21, item 3) must be opened.
The compressor has undergone trials in the factory and all functions have been tested. There are
therefore no special running-in instructions.
Check the compressor for transport damage!
7.2 Pressure strength test
The compressor has been factory-tested for pressure resistance. The following must be observed if
the entire plant is subjected to an additional pressure strength test:
Test the refrigeration circuit according to EN 378-2 or a corresponding safety standard.
7.3 Leak test
Carry out the leak test of the refrigerating system in accordance with EN 378-2 or a corresponding
safety standard without including the compressor.
INFO In order to protect the compressor against inadmissible operating
conditions, high pressure and low pressure pressostats are manda-
tory on the installation side.
DANGER Risk of bursting!
The compressor must only be pressurised using nitrogen (N
2
).
Never pressurise 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.
DANGER Risk of bursting!
Do not mix any refrigerant with the nitrogen (N
2
) as this could cau-
se the ignition limit to shift into the critical range.
ATTENTION 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.