Venting The Refrigerant Circuit - GEA RedGenium Operating Instruction

Lower refrigerant levels in the containers are due to loss of refrigerant as a result
of leaks. For this reason, all pipes, connections and valve glands should be
checked regularly, especially in the initial period after assembly or commission-
ing.
The most striking feature if there is a leak in the filled refrigerant circuit is the
smell of refrigerant. The odour threshold of ammonia in air is about 5 ppm and
thereby far below the permitted MAK values.
Methods of leak detection:
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For the leak test for determining the leakage on the refrigerant side, e.g. with
escaping inert gas or refrigerant filling, a test pressure must be generated in the
refrigerant circuit which corresponds to the specified operating pressure. When
system parts are individually tested, the maximum operating pressure indicated
on the respective system part for the corresponding pressure chamber must not
be exceeded. The use of foaming agents gives the best results at test pressures
< 5 bar.
If leaks are determined, these must be sealed immediately. Relieve the test pres-
sure before starting repairs! Evacuate the system after repairs are perform
another leak test.
The supplier is not liable for losses of refrigerant caused by a lack of or improper
maintenance!
10.4.9

Venting the refrigerant circuit

When air penetrates into the refrigerant circuit, this makes itself felt in a fall-off in
performance, and the manometer on the discharge side of the compressor indi-
cates a higher pressure. Any leaking must be properly rectified. In extreme
cases, air in the circuit may interrupt the flow of the refrigerant and cause the oil
cooling to fail.
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19.12.2019
Regular visual inspections.
Smudges/dirt stains indicate leaking refrigerant/oil mixture.
Leak test with nitrogen with max. 0.5% ammonia by volume and a dwell time
> 3 h and brushing all connection areas with foaming agent. Oil-filled com-
pressors or circuit sections must only be filled with nitrogen, not with air, to
generate pressure.
Use of an NH leak detector.
3
Ammonia produces the following colours when leak tests are performed:
– Red litmus paper turns blue,
– Blotting paper impregnated with phenolphthalein turns red (moisten).
Caution!
Risk of explosion
► Never use oxygen to build up the pressure!
Maintenance
Maintenance work
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