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1.3 - Maintenance safety considerations
Engineers working on the electric or refrigeration components must be authorized, trained and fully qualified to do so. All
refrigerant circuit repairs must be carried out by a trained person, fully qualified to work on these units. He must have been
trained and be familiar with the equipment and the installation. All welding operations must be carried out by qualified
specialists.
Any manipulation (opening or closing) of a shut-off valve must be carried out by a qualified and authorized engineer.
These procedures must be carried out with the unit shut-down.
NOTE: The unit must never be left shut down with the liquid line valve closed, as liquid refrigerant can be trapped between
this valve and the expansion device. (This valve is situated on the liquid line before the filter drier box.)
During any handling, maintenance and service operations the engineers working on the unit must be equipped with safety
gloves, glasses, shoes and protective clothing.
Never operate on a unit that is still energized.
Never operate on any of the electrical components, until the general power supply to the unit has been cut using the
disconnect switch(es) in the control box(es).
If any maintenance operations are carried out on the unit, lock the power supply circuit in the open position ahead of the
machine.
If the operating is interrupted, always ensure that all circuits are still de-energized before resuming the operating.
ATTENTION: Even if the unit has been switched off, the power circuit remains energized, unless the unit or circuit
disconnect switch is open. Refer to the wiring diagram for further details. Attach appropriate safety labels.
Operating checks:
Important information regarding the refrigerant used:
• This product contains fluorinated greenhouse gas covered by the Kyoto protocol. Refrigerant type: R-134a Global
Warming Potential (GWP): 1300 Periodic inspections for refrigerant leaks may be required depending on China or local
legislation. Please contact your local dealer for more information.
• During the life-time of the system, inspection and tests must be carried out in accordance with national regulations. While
working in the fan area, especially when grilles or casings are removed, disconnect the fan power supply to prevent their
automatic restart. Safety device checks:
• The safety devices must be checked on site once a year for safety devices (high-pressure switches), and every five years for
external overpressure devices (safety globe valves).
• Check manual "30XQ Pro-Dialog Control" for a detailed explanation of the high-pressure switch test method. At least
once a year thoroughly inspect the protection devices (valves). If the machine operates in a corrosive environment, inspect
the protection devices more frequently. Regularly carry out leak tests and immediately repair any leaks. Ensure regularly
that the vibration levels remain acceptable and close to those at the initial unit start-up. Before opening a refrigerant circuit,
purge and consult the pressure gauges.
Change the refrigerant when there are equipment failures, following a procedure such as the one described in NFE 29-795
or carry out a refrigerant analysis in a specialist laboratory. Plug all openings whenever the refrigerant circuit is opened
for up to one day. For longer openings place a nitrogen charge in the circuit.
1.4 - Repair safety considerations
All installation parts must be maintained by the personnel in charge, in order to avoid material deterioration and injuries to
people. Faults and leaks must be repaired immediately. The authorized technician must have the responsibility to repair the
fault immediately. Each time repairs have been carried out to the unit, the operation of the safety devices must be re-checked.
Comply with the regulations and recommendations in unit and HVAC installation safety standards, such as: EN 378, ISO 5149,
etc.
If a leak occurs or if the refrigerant becomes contaminated (e.g. by a short circuit in a motor) remove the complete charge
using a recovery unit and store the refrigerant in mobile containers.
Repair the leak detected and recharge the circuit with the total R-134a charge, as indicated on the unit name plate. Certain parts
of the circuit can be isolated. Only charge liquid refrigerant R-134a at the liquid line.
Ensure that you are using the correct refrigerant type before recharging the unit.
Charging any refrigerant other than the original charge type (R-134a) will impair machine operation and can even lead to
Carrier Yileng - Shanghai, China
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