Maintenance Safety Considerations - Carrier AQUASNAP 30RQ Installation, Operation And Maintenance Instructions

1.4 - Maintenance safety considerations

Engineers working on the electric or refrigeration components
must be authorized, trained and fully qualified to do so.
All refrigerant circuit work 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.
Aquasnap Puron units use high-pressure R-410A refrigerant
(the unit service pressure is above 40 bar, the pressure at 35°C
air temperature is 50% higher than for R-22). Special
equipment must be used when working on the refrigerant
circuit (pressure gauge, charge transfer, etc.).
Any manipulation (opening or closing) of a shut-off valve
must be carried out by a qualified and authorised engineer,
observing applicable standards (e.g. during draining opera-
tions). The unit must be switched off during all operations.
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 work on a unit that is still energized.
Never work on any of the electrical components, until the
general power supply to the unit has been cut.
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 work is interrupted, always ensure that all circuits are
still deenergized before resuming the work.
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.
While working in the fan area, especially when grilles or
casings are removed, disconnect the fan power supply to
prevent their automatic restart.
Operating checks: During the life-time of the system,
inspection and tests must be carried out in accordance with
national regulations.
The information on operating inspections given in annex C of
standard EN278-2 can be used if no similar criteria exist in
the national regulations.
Safety device checks (annex C6 – EN378-2): The safety
devices must be checked on site once a year (high-pressure
switches), and every five years for external overpressure
devices (safety globe valves).
Check manual "30RB/RQ Pro-Dialog Plus 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.
1.5 - Repair safety considerations
All installation parts must be maintained by the personnel in
charge, in order to avoid deterioration and injury. 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 e.g: EN 378, ISO 5149, etc.
Do not use oxygen to purge lines or to pressurize a machine
for any purpose. Oxygen gas reacts violently with oil, grease,
and other common substances.
Never exceed the specified maximum operating pressures.
Verify the allowable maximum high- and low-side test
pressures by checking the instructions in this manual and the
pressures given on the unit name plate.
Do not use air for leak testing. Use only refrigerant or dry
nitrogen.
Do not unweld or flamecut the refrigerant lines or any refri-
gerant circuit component until all refrigerant (liquid and
vapour) has been removed from heat pump. Traces of vapour
should be displaced with dry air nitrogen. Refrigerant in
contact with an open flame produces toxic gases.
The necessary protection equipment must be available, and
appropriate fire extinguishers for the system and the
refrigerant type used must be within easy reach.
Do not siphon refrigerant.
Avoid spilling liquid refrigerant on skin or splashing it into
the eyes. Use safety goggles. Wash any spills from the skin
with soap and water. If liquid refrigerant enters the eyes,
immediately and abundantly flush the eyes with water and
consult a doctor.
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