Publicité
6. Make sure the area is adequately ventilated before intervening inside the system; a
continuous degree of ventilation must be present.
7. Before any operation, always check that:
• the condensers are unloaded. The operation must be carried out safely to avoid
the risk of producing sparks;
• there are no live electrical components and that the cables are not exposed while
loading, recovering or bleeding the system;
• there is continuity in the ground connection.
8. Periodically check that the cables are not subject to wear, corrosion, excessive
pressure, vibrations, sharp edges or any other hostile environmental situation.
9. When intervening inside the refrigerating circuit to carry out repairs or for any other
reason, the conventional procedures must be followed:
• remove the refrigerant;
• bleed the circuit with an inert gas;
• evacuate;
• bleed again with an inert gas;
• open the circuit by cutting or by means of brazing.
9a
Oxygen-Free Nitrogen (OFN) MUST be purged through the system both before and
.
during the brazing process.
9b
When the final OFN charge is used, the system must be discharged up to atmospheric
.
pressure to allow the execution of the work. This operation is absolutely essential if
it is desired to carry out brazing operations on the pipes.
10. The load of refrigerant must be stored in the specific custody cylinders. The system
must "cleaned" with OFN to make the unit safe. It may be necessary to repeat this
process several times. DO NOT use compressed air or oxygen for this operation.
10a
Make sure that contamination between different refrigerants does NOT occur when
.
a reloading equipment is used. The flexible pipes or ducts MUST be as short as
possible to reduce the quantity of refrigerant inside them to a minimum.
11. The cylinders must be kept in vertical position.
Only use cylinders suitable for collection of refrigerants. The cylinders must be
complete of a pressure-relief valve and switch off valves in good conditions.
A set of calibrated weighing scales must also be available.
12. The pipes must be equipped with couplings for disconnection and must NOT
present leaks. Before using the collection machine, check that it underwent correct
maintenance and that the possible associated electric components are sealed, to
prevent switching on in case of leak of refrigerant.
13. Make sure the refrigerating system is earthed before proceeding with reloading of
the system with refrigerant.
Label the system when reloading is complete.
Pay particular attention not to overload the refrigerating system.
14. Before proceeding with reloading, the system must undergo the pressure test with
OFN and the tightness test at the end of reloading, but before commissioning.
It is necessary to carry out an additional tightness test before leaving the site.
14a
Remove the refrigerant safely. Move the refrigerant in the cylinders suitable for
.
recovery. Make sure there is a correct number of cylinders to contain the charge
entirely. All cylinders are labelled for this type of refrigerant (special cylinders for
refrigerant recovery). The cylinders must be complete of a pressure relief valve and
of and of the corresponding closure valve in good conditions. Empty cylinders are
evacuated and, if possible, cooled down before recovery.
14b
Equipment for recovery must be within the range of the technician, in good
.
conditions, with a series of instructions and must be suitable for recovery of all the
refrigerants (even flammable ones). A series of calibrates scales must be available
and in good conditions. Check that the pipes are in good conditions and complete
of disconnection joints without losses.
14c
Before using the machine for recovery, check that it is in good operating conditions,
.
that it has been adequately maintained and that all the associated electric components
are sealed to prevent switching-in in case of release of refrigerant. In case of doubt,
EN - 6
Publicité
