GEA Grasso - Steps to be Followed before Starting the System after Major Repairs; Repair Information; Pressure Test, Leak Test; Vacuum Test

OPERATING INSTRUCTIONS
CO
2
/NH
3
CASCADE UNIT
250 - 1000 KW
50 _551511_om_kas_gbr_1_.doc
4.7 Steps to be followed before starting the
system after major repairs
4.7.1 Repair information
When repairing the chiller system, it should be borne
in mind that new and advanced refrigeration plant is
expected to meet the following standards as regards
the technology and manufacturing processes they
embody. Requirements:
• Absolute tightness of all devices and pipes.
• Dryness and cleanliness of the entire system.
• Use of welding methods causing only a minimum
amount of dirt to collect in the system.
• Pipes bent on a pipe-bending machine only using
refrigerating oil.
• If repairing the piping system from your own
stocks, you are recommended to use a pipe with
NBK surface quality (soft-annealed and
descaled, mechanically or chemically descaled
after soft annealing).
• When carrying out repairs to piping systems,
care should be taken to maintain the original
piping routes.
• Only pipes of sufficient quality should be used
which are certified according to DIN 8975.
4.7.2 Pressure test, leak test
See operating manual, start-up instructions
4.7.3 Vacuum Test
After the pressure test has been completed, the
system is evacuated and subjected to a vacuum test
for 3 hours.
Evacuation is used to remove air and moisture from
the refrigerant circuit (see operating instructions).
4.8 Repair work
Modifications and repair work may only be carried
out by experts or persons with suitable training with
the manufacturer's agreement and must strictly
comply with the rules set out in the maintenance
instructions for the components concerned.
Particular attention is to be paid to the
aforementioned maintenance instruction.
Danger!
Before carrying out any maintenance or
repair work the personal protective
clothing must be checked.
Only spare parts made by the original equipment
manufacturer may be used for repairs and for
replacing wearing parts. They are available from the
customer service department of Grasso GmbH
Refrigeration Technology under the following
address:
Grasso GmbH Refrigeration Technology
Holzhauser Straße 165
D - 13509 Berlin
Tel.: +40 (0) 30 435 92 766
Tel.: +40 (0) 30 435 92 759
Please remember to carry out the following steps
before starting up the system again following repair
or maintenance:
• Check the charge of the unit / CO
/NH
2 3
cascade
with service media/resources (refrigerant,
refrigerating machine oil, heat transfer medium)
and set specified charge levels (sight glasses,
level indicator). Charge using the built-in
charging lines and record the charge volumes in
the machine's log book.
• Set all fittings according to the operating
instructions.
• Check all important technical parameters after
switching on the unit /CO
/NH
2 3
cascade until a
stable operating condition is reached.
Non-permissible operating conditions result in the
shutdown of the refrigerating system or part thereof
by the automatic safety system. If this happens, the
causes of the shutdown must be determined and
rectified.
The safety devices should be checked at least once a
year and the switching values confirmed.