Thermostatic Expansion Device; Refrigerant; High-Pressure Switch; High And Low-Pressure Side Safety Valves - Carrier Aquasnap 30RW Installation, Operation And Maintenance Instructions

NOTES: Monitoring during operation, re-qualification,
re-testing and re-testing dispensation:
• Follow the regulations on monitoring pressurised
equipment.
• It is normally required that the user or operator sets
up and maintains a monitoring and maintenance file.
• If there are no regulations or to complement them
follow the control programmes of EN 378.
• If they exist follow local professional recommenda-
tions.
• Regularly inspect the condition of the coating (paint)
to detect blistering resulting from corrosion. To do
this, check a non-insulated section of the container
or the rust formation at the insulation joints.
• Regularly check for possible presence of impurities
(e.g. silicon grains) in the heat exchange fluids. These
impurities maybe the cause of the wear or corrosion
by puncture.
• Filter the heat exchange fluid check and carry out
internal inspections as described in EN 378-2, annex C.
• In case of re-testing take the possible maximum
pressure difference of 25 bar into consideration.
• The reports of periodical checks by the user or operator
must be included in the supervision and maintenance
file.
Repair
Any repair or modification of the plate heat exchangers is
forbidden.
Only the replacement of the complete heat exchanger by
an original heat exchanger supplied by the manufacturer is
permitted. The replacement must be carried out by a
qualified technician.
• The heat exchanger replacement must be shown on
the monitoring and maintenance file.
Recycling
The plate heat exchanger is 100% recyclable. After use it
contains refrigerant vapours and oil residue.
operating life
This unit is designed for:
• prolonged storage of 15 years under nitrogen charge
with a temperature difference of 20 K per day.
• 900000 cycles (start-ups) with a maximum difference of
6 K between two neighbouring points in the container,
based on 12 start-ups per hour over 15 years at a usage
rate of 57%.

14.4 - Thermostatic expansion device

The expansion devices used are thermostatic hermetic
monobloc devices for sizes 30RW/30RWA 020 to 070 and
modular devices for sizes 30RW/30RWA 080 to 300. They
are factory-set to maintain between 5 and 6 K superheat in
all operating conditions any do not require any change in
setting, including for operation at part load. All models
have a charge (MOP) for the thermostatic assembly that
permits the maximum evaporating pressure to protect the
compressor.
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14.5 - Refrigerant

30RW/30RWA units operate exclusively with R-407C.

14.6 - High-pressure switch

30RW/30RWA units are equipped with a manually reset
safety pressure switch. Refer to the controls manual for
the alarm acknowledgements.

14.7 - High and low-pressure side safety valves

30RW units are equipped with safety valves in accordance
with the European directive 97/23/CE. These safety valves
are calibrated and sized in accordance with the original
high and low-pressure side equipment. The originally supplied
safety valves for the 30RWA units are sized to protect the
original equipment. To protect equipment that has been
added on the high-pressure side, refer to the applicable
regulations and standards to determine which protection
accessories may be required.

14.8 - Moisture indicator

Located in the liquid line, permits control of the unit charge,
as well as the presence of moisture in the circuit. Bubbles in
the sight glass indicate an insufficiant charge or the presence
of non-condensibles. If moisture is present, the colour of
the indicator paper in the sight glass changes.

14.9 - Filter drier in the refrigerant circuit

The filter keeps the circuit clean and moisture-free. The
moisture indicator shows when it is necessary to change
the filter cartridges. A temperature difference between the
filter drier inlet and outlet indicates a contamination of the
cartridges.
14.10 - Fixed-speed cold water loop pump
(evaporator side)
This pump is factory-installed as standard to guarantee the
nominal flow in the chilled water loop.
This is a fixed-speed pump with available system pressure.
See the pump flow/pressure curve.
The nominal system flow rate must be adjusted with the
manual control valve, located on the leaving water piping
(see chapter on the control of the nominal system pressure).
The maximum permitted concentration of the glycol
additives is 35%.
The maximum pump suction pressure is limited to 4 bar due
to the valve installed on the entering water piping.