Emerson Vilter VSG128, Installation, Operation And Service Manual

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5 – 2
Section 5 • Maintenance/Service
HPLD Single Screw Compressor • Installation, Operation and Service Manual • Emerson • 35391HP
Recommendations When Servicing
When working on the compressor, care must be taken
to ensure that contaminants (i.e. water from melting ice,
dirt and dust) do not enter the compressor while it is be-
ing serviced. It is essential that all dust, oil or ice that
has accumulated on the outside of the compressor be
removed before servicing the compressor.
After servicing the compressor, all gaskets, O-rings, roll
pins and lock washers must be replaced when reassem-
bling the compressor.
Preparation of Unit For Servicing
WARNING
Follow local lock-out/tag-out procedure. Compressors
must be depressurized before attempting to do any
work on them. Failure to comply may result in serious
injury, death and/or damage to equipment.
A. Shut down the unit, open the electrical disconnect
switch and pull the fuses for the compressor motor
to prevent the unit from starting. Put a lock on the
disconnect switch and tag the switch to indicate that
maintenance is being performed.
WARNING
Be cautious when isolating sections of CO
2
piping.
CO
2
has a very steep pressure curve, and as sections
containing CO
2
warm up, pressures can rise
dramatically & well beyond system design.
WARNING
When working with LFG, NG or other dangerous
or fl ammable gases, ensure there are adequate
ventilation and vapor detectors. Refer to national fi re
and building codes. Failure to comply may result in
serious injury or death.
WARNING
Avoid skin contact with any condensate or oil. Wear
rubber gloves and a face shield when working with
condensate or oil. Failure to comply may result in
serious injury or death.
WARNING
If the high stage refrigeration system is shut off, CO
2
system pressures will gradually rise with the potential
to open pressure relief valves & vent excessive CO
2
pressure.
B. Isolate the unit by manually closing the discharge
Stop valve. Allow the unit to equalize to suction
pressure before closing the Suction Bypass. After
the unit has equalized to suction pressure and
suction valve closed, use an acceptable means to
depressurize the unit that complies with all Local,
State and Federal Ordinances.
WARNING
At shutdown, open any other valves that may trap
liquids to prevent serious injury and/or damage to
equipment.
NOTICE
Recover or transfer all gas vapor in accordance with
local ordinances before opening the compressor unit
to the atmosphere.
C. Remove drain plugs from the bottom of compressor
housing. Drain the oil into appropriate containers.