D-EIMWC01008-16_03EN - 31/35
9
MAINTENANCE
9.1
Routine maintenance
This unit must be maintained by qualified technicians. Before beginning any work on the system the personnel shall assure
that all security precautions have been taken.
Personel working on the electrical or the refrigeration components must be authorized, train ed and fully qualified.
Maintenance and repair requiring the assistance of other skilled personnel should be carried out under the supervision of
the person competent in the use of flammable refrigerants. Any person conducting servicing or maintenance on a system
or associated parts of the equipment should be competent according to EN 13313.
Persons working on refrigerating systems with flammable refrigerants should have competence in safety aspects
of flammable refrigerant handling supported by evidence of appropriate training.
Always protect the operating personnel with personal protective equipment appropriate for the tasks to be performed.
Common individual devices are: Helmet, goggles, gloves, caps, safety shoes. Additional individual and group protecti ve
equipment should be adopted after an adequate analysis of the specific risks in the area of relevance, according to the
activities to be performed.
electrical
components
Never work on any electrical components, until the general supply to the unit has been cut using
the disconnect switch(es) in the control box. The frequency variators used are equipped with
capacitor batteries with a discharge time of 20 minutes; after disconnecting power wait 20 minutes
before opening the control box.
refrigerating
system
The following precautions should be taken before working on the refrigerant circuit:
-
obtain permit for hot work (if required);
-
ensure that no flammable materials are stored in the work area and that no ignition
sources are present anywhere in the work area;
-
ensure that suitable fire extinguishing equipment is available;
-
ensure that the work area is
properly ventilated
before working on the refrigerant circuit
or before welding, brazing or soldering work;
-
ensure that the leak detection equipment being used is non-sparking, adequately sealed
or intrinsically safe;
-
ensure that all maintenance staff have been instructed.
The following procedure should be followed before working on the refrigerant circuit:
1.
remove refrigerant (specify the residual pressure);
2.
purge circuit with
inert gas
(e.g. nitrogen);
3.
evacuate to a pressure of 0,3 (abs.) bar (or 0,03 MPa);
4.
purge again with
inert gas
(e.g. nitrogen);
5.
open the circuit.
The area should be checked with an appropriate refrigerant detector prior to and during any hot
work to make the technician aware of a potentially flammable atmosphere.
If compressors or compressor oils are to be removed, it should be ensured that it has been
evacuated to an acceptable level to ensure that there is no flammable refrigerant remaining within
the lubricant.
Only refrigerant recovery equipment designed for use with flammable refrigerants should
be employed.
If the national rules or regulations permit the refrigerant to be drained, this should be done safe ly,
using a hose, for example, through which the refrigerant is discharged into the outside atmosphere
in a safe area. It should be ensured that an inflammable explosive refrigerant concentration cannot
occur in the vicinity of an ignition source or penetrate into a building under any circumstance.
In the case of refrigerating systems with an indirect system, the heat -transfer fluid should be
checked for the possible presence of refrigerant.
After any repair work, the safety devices, for example refrigerant detectors and mechanical
ventilation systems, should be checked and the results recorded.
It should be ensured that any missing or illegible label on components of the refrigerant circuit is
replaced.
Sources of ignition should not be used when searching for a refrigerant leak.
Neglecting unit maintenance in these environments, could degrade all parts of the units (compressors, frames, pipes, etc..)
with negative effect on performances and functionality.
