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

System maintenance

RNING

General

The maintenance operations are essential to maintain the efficiency 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.
WARNING! All activities of ordinary and extraordinary maintenance on the unit must be carried out by
qualified 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.
WARNING! 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
WARNING! 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.
WARNING! Beyond the cadences of checks recommended in the following, in order to keep the unit at optimum
levels of performance and efficiency and prevent incipient failures, we recommend periodic visits of inspection
and control of the unit by qualified personnel.
In particular, we recommend:
4 annual visits to units that operate about 365 days / year (quarterly)
2 visits per year for units with seasonal operation about 180 days / year (one start seasonal and a mid-season)
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.
ING

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 efficiency 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 qualified 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.

Sight check of the under pressure vessels state

The risks due to the pressure inside the circuit have benne 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 com-
ponents 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 superficial oxidisation and the corrosion are not properly controlled and stopped in time, cause a thick-
ness reduction with a consequent reduction of the vessel mechanical resistance.
Use antioxidant paint or products to protect.