Equipment And Components Under Pressure; Maintenance Safety Considerations - Carrier Aquasnap 30RQS Series Installation, Operation And Maintenance Instructions

Relief valves must be checked periodically. See paragraph
"Repair safety considerations".
If the relief valves are installed on a reversing valve
(changeover), this is equipped with a relief valve on each of
the two outlets. Only one of the two relief valves is in
operation, the other one is isolated. Never leave the reversing
valve in the intermediate position, i.e. with both ways open
(locate the control element in the stop position). If a relief
valve is removed for checking or replacement please ensure
that there is always an active relief valve on each of the
reversing valves installed in the unit.
Provide a drain in the discharge circuit, close to each relief
valve, to avoid an accumulation of condensate or rain water.
All precautions concerning handling of refrigerant must be
observed in accordance with local regulations.
Accumulation of refrigerant in an enclosed space can displace
oxygen and cause asphyxiation or explosions.
Inhalation of high concentrations of vapour is harmful and
may cause heart irregularities, unconsciousness, or death.
Vapour is heavier than air and reduces the amount of oxygen
available for breathing. These products cause eye and skin
irritation. Decomposition products can be hazardous.

1.4 - Equipment and components under pressure

These products incorporate equipment or components under
pressure, manufactured by Carrier or other manufacturers.
We recommend that you consult your appropriate national
trade association or the owner of the equipment or
components under pressure (declaration, re-qualification,
retesting, etc.). The characteristics of this equipment/these
components are given on the nameplate or in the required
documentation, supplied with the products. These units
comply with the European Pressure Equipment Directive.
The units are intended to be stored and operate in an
environment where the ambient temperature must not be
less than the lowest allowable temperature indicated on the
nameplate.
Do not introduce high static and dynamic pressure compared
with the existing operating pressures - either service or test
pressures - in the refrigerant circuit or in the heat transfer circuit,
especially:
• limiting the elevation of the condensers or evaporators
• taking the circulating pumps into consideration.

1.5 - Maintenance safety considerations

Carrier recommends the following drafting for a logbook (the
table below should not be considered as reference and does not
involve Carrier responsibility):
Intervention Name of the
commissioning
Date Nature
(1)
engineer
(1) Maintenance, repairs, regular verifications (EN 378), leakage, etc.
6
Applicable Verification
national Organism
regulations
Engineers working on the electric or refrigeration components
must be authorized, trained and fully qualified to do so (e.g.
electricians trained and qualified in accordance with IEC 60364
Classification BA4).
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 units use high-pressure R-410A refrigerant (the unit
operating 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 operations). The unit
must be switched off while this is done.
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 and lead to the risk of a
pressure increase. 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 and secure the
machine upstream with a padlock.
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 customer circuit
disconnect switch is open. Refer to the wiring diagram for further
details. Attach appropriate safety labels.
If any work is carried out in the fan area, specifically if the grilles
or casings have to be removed, cut the power supply to the fans
to prevent their operation.
It is recommended to install an indicating device to show if part
of the refrigerant has leaked from the valve. The presence of oil
at the outlet orifice is a useful indicator that refrigerant has
leaked. Keep this orifice clean to ensure that any leaks are
obvious. The calibration of a valve that has leaked is generally
lower than its original calibration. The new calibration may
affect the operating range. To avoid nuisance tripping or leaks,
replace or re-calibrate the valve.
OPERATING CHECKS:
Important information regarding the refrigerant used:
This product contains fluorinated greenhouse gas covered by the
Kyoto protocol.
Fluid type: R410A
Global Warming Potential (GWP): 2088