OPERATING INSTRUCTIONS
CO
2
/NH
3
CASCADE UNIT
250 - 1000 KW
_551511_om_kas_gbr_1_.doc 11
• CO
misalignment ≤ 0.25 mm) at the coupling is attained
again.
- vent line
2
• NH
3
- safety vent line
Then tighten the foundation bolts.
• Electrical connection cable (see electrical
connection diagram)
Installation with anti-vibration mounts
The frame of the cascade unit shall be aligned with
the levelling bolts until the coarse alignment (radial
and angular misalignment ≤ 0,25 mm) at the
coupling is attained again.
1.6 Start-up instructions
1.6.1 Basics
The cascade may only be operated by trained and
qualified personnel who are familiar with the
contents of the user manual for Grasso CO
Unless otherwise required by local conditions, the
permissible ambient temperatures for operation are
+15 to +40°C.
/NH
2 3
cacades.
The safety regulations for refrigerating plants must
always be correctly complied with in order to
prevent operating personnel injuries and damage to
the cascade.
All foundation calculations, the selection of materials
and the soil analysis are owner’s responsibility.
Outside influences (vibrations, jolts) must be
avoided.
The cascade is operated from the control panel of
the compressor control.
The unit may only be lifted for alignment by the
mounting rails or by a crane. See to it in this
connection that the cascade is evenly lifted by two
respective smallhoists in the transverse direction
when small hoists are used (e.g. hydraulic hoists).
After the setpoint values have been entered, both
automatic and manual mode are possible.
The compressor control equipment's software and
operating via the terminal are described elsewhere.
1.5 Assembly
1.6.2 First commissioning
Cascades dismantled in the factory for transport and
positioning purposes must be carefully reassembled
at the installation site according to the drawing and
the PID.
The following procedures should be completed in
the sequence in which they are described:
1.6.2.1 Leak test
The separation points (flanged connections) of cold
pipes must be insulated.
The necessary safety precautions must be taken
before carrying out the leak test. The leak test is
performed with dried, oil-free air or with dry
nitrogen.
All pipes and electrical cables must be connected so
that no mechanical stresses or strain occurs.
Connecting the pipes
To check for leaks, a 3-hour test is carried out with
dry air or dry nitrogen at any overpressure, but not
higher than the allowable operating overpressure of
the cascade.
• Before connecting the pipes, drain the cascade's
nitrogen filling by opening the vent valves.
• All pipe connections are to be made so as to
limit transmission of thermal expansion and
vibration to the cascade as far as possible.
During the 3 hours a pressure drop of 2% is allowed,
whereby fluctuations in the ambient temperature
must be taken into account.
• Rubber expansion joints can be used for water
connections.
Warning!
Control devices which may be damaged
at the given test pressure must be
removed or blocked off before the leak
test is performed.
• All pipe connections are to be fitted with fixed
points directly on the cascade.
The following are to be connected
• NH
3
connection to condenser
• Cooling water for oil cooler
A record should be kept of the leak test, in which
the the pressure in the lines to be tested, the
ambient temperature and the temperature outside
in the shade must be entered at hourly intervals.
• Connections for refrigerant-cooled oil cooler
• CO
pump discharge line
2
• CO
- return line
2
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