System Maintenance; General; Maintenance; Sight Check Of The Under Pressure Vessels State - Trane CXAO Installation Operation & Maintenance

System maintenance

7 System maintenance
WARNING!
All activities of ordinary and extraordinary maintenance
on the unit must be carried out by qualifi ed personnel
who have been properly trained and familiar staff has
the equipment, their operation, the correct procedures
of assistance and knowing all the safety requirements as
well as both aware of the dangers.
The causes of repeated shutdowns due to the
intervention of the safety devices must be investigated
and corrected.
The simple reset of alarm occurrences can lead to
serious damage to the unit.
A proper charge of refrigerant and oil is essential for an
optimal functioning of the unit and for the protection of
the environment.
The recovery of oil and any refrigerant discharged from
the unit must be carried out in accordance with current
regulations.
7.1

General

Beyond the cadences of checks recommended in the
following, in order to keep the unit at optimum levels
of performance and effi ciency and prevent incipient
failures, we recommend periodic visits of inspection and
control of the unit by qualifi ed personnel.
In particular, we recommend:
No. 4 annual visits to units that operate about 365 days /
year (quarterly)
No. 2 visits per year for units with seasonal operation
about 180 days / year (one start seasonal and a mid-
season)
No. 1 annual visit for units with seasonal operation of
about 90 days / year (starting seasonal)
It is important that during the initial start-up and
periodically during operation, carry out the checks
and routine checks. Among them we must also
check the suction and condensation as well as the
sight glass located on the liquid line. Check through
the microprocessor installed on the unit, the unit is
working within normal parameters of superheating
and subcooling. A routine maintenance program
recommended is shown at the end of this chapter while
a card collection of operating data is at the end of this
manual. It is suggested to record on a weekly basis all
the operating parameters of the unit. The collection of
these data will be very useful to technicians, in case it is
requested technical assistance.
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Compressor Maintenance
Although the single-screw compressor is of the semi-
hermetic type and therefore does not need scheduled
maintenance in order to keep the compressor at
optimum levels of performance and effi ciency and
prevent incipient failures, it is recommended every
10,000 hours of operation, a check visual state of wear of
the satellites and measuring the tolerances of satellite-
lives. This inspection must be performed by qualifi ed and
trained personnel.
The analysis of vibration is a great tool for checking
the mechanical conditions of the compressor. It is
recommended to check the value of the vibration
immediately after starting and periodically on an
annual basis. The compressor load will be similar to the
previous load measurement for a reliability of measure.
7.2

Maintenance

The maintenance operations are essential to maintain
the effi ciency of the refrigeration unit, both from a
purely functional and energy consumption. Each unit
is equipped with a booklet on the unit, which will be
provided by the user, or the person who is authorized
on his behalf to the maintenance of the unit, return all
records required in order to keep a historical record
of the operation of the unit. The lack of records in the
booklet will serve as evidence of poor maintenance.
7.3 Sight check of the under pressure
vessels state
The risks due to the pressure inside the circuit have been
eliminated or (when it is not possible) reduced by means
of safety devices. It is important to check periodically the
status of these devices and to carry out the components
inspections and repositioning as follows.
Check at least once per year the under pressure vessels
state.
It is important to check that the surface does not get
rusty and that neither corrosion nor deformations are
visible.
In case the superfi cial oxidation and the corrosion are
not properly controlled and stopped in time, cause a
thickness reduction with a consequent reduction of the
vessel mechanical resistance.
Use antioxidant paint or products to protect.
RF-SVX003A-GB