Daikin EWAT016CZN-A1, Installation, Maintenance And Operation Manual

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EWYT~CZ / EWAT~CZ DEIMHP0140521_00EN
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refrigerating
system The following precautions should be taken before
working on the refrigerant circuit:
• obtain permit for hot work (if required);
• ensure that no flammable materials are stored in
the work area and that no ignition sources are
present anywhere in the work area;
• ensure that suitable fire extinguishing equipment
is available;
• ensure that the work area is properly ventilated
before working on the refrigerant circuit or befo-
re welding, brazing or soldering work;
• ensure that the leak detection equipment being
used is nonsparking, adequately sealed or intrin-
sically safe;
• ensure that all maintenance staff have been in-
structed.
• Always perform the following procedure before
working on the refrigerant circuit:
• remove refrigerant (specifying residual pressu-
re);
• purge circuit with inert gas (e.g. nitrogen);
• evacuate at a pressure of 0.3 bar (ass.) (or 0.03
MPa);
• purge circuit with inert gas (e.g. nitrogen) again;
• open the circuit.
If compressors or compressor oils are to be remo-
ved, it should be ensured that it has been evacuated
to an acceptable level to ensure that there is no flam-
mable refrigerant remaining within the lubricant.
Only refrigerant recovery equipment designed
for use with flammable refrigerants should be
employed.
If the national rules or regulations permit the refrige-
rant to be drained, this should be done safely, using
a hose, for example, through which the refrigerant is
discharged into the outside atmosphere in a safe
area. It should be ensured that an inflammable
explosive refrigerant concentration cannot occur
near an ignition source or penetrate into a building
under any circumstance.
In the case of refrigerating systems with an indirect
system, the heat transfer fluid should be checked for
the possible presence of refrigerant.
After any repair work, the safety devices, for example
refrigerant detectors and mechanical ventilation sy-
stems, should be checked and the results recorded.
It should be ensured that any missing or illegible label
on components of the refrigerant circuit is replaced.
Sources of ignition should not be used when sear-
ching for a refrigerant leak.
7.1. Pressure / temperature table
°C Bar °C Bar °C Bar °C Bar
28 2.97 2 7.62 24 16.45 50 31.41
26 3.22 0 8.13 26 17.35 52 32.89
24 3.48 2 8.67 28 18.30 54 34.42
22 3.76 4 9.23 30 19.28 56 36.00
20 4.06 6 9.81 32 20.29 58 37.64
18 4.37 8 10.43 34 21.35 60 39.33
16 4.71 10 11.07 36 22.45 62 41.09
14 5.06 12 11.74 38 23.60 64 42.91
12 5.43 14 12.45 40 24.78 66 44.79
10 5.83 16 13.18 42 26.01 68 46.75
8 6.24 18 13.95 44 27.29 70 48.77
6 6.68 20 14.75 46 28.61 72 50.87
4 7.14 22 15.58 48 29.99 74 53.05
Table 9 – R32 Pressure/Temperature
7.2. Routine maintenance
This unit must be maintained by qualified technicians. Before
beginning any work on the system, the personnel shall assure that all
security precautions have been taken.
Neglecting unit maintenance could degrade all parts of the units
(coils, compressors, frames, pipes, etc.) with negative effect on
performances and functionality.
There are two different levels of maintenance, which can be chosen
according to the type of application (critical/noncritical) or to the
installation environment (highly aggressive).
Examples of critical applications are process cooling, data centres,
etc.
Highly Aggressive Environments can be defined as the follows:
• Industrial environment (with possible concentration of fumes
result of combustion and chemical process);
• Coastal environment;
• Highly polluted urban environment;
• Rural environment close to of animal excrement and fertili-
zers, and high concentration of exhaust gas from diesel gene-
rators;
• Desert areas with risk of sandstorms;
• Combinations of the above.
Table 10 lists all Maintenance activities for standard applications and
standard environment.
Table 11 lists all Maintenance activities for critical applications or
highly aggressive environment.
Unit exposed to a highly aggressive environment can face corrosion
in a shorter time than ones installed on a standard environment.
Corrosion causes a rapid rusting of the frame core, consequently
decreases unit structure life time. To avoid that, it is necessary to
wash periodically the frame surfaces with water and suitable
detergents.
In case of part of unit frame paint came off, it is important to stop its
progressive deterioration by repainting the exposed parts using
proper products. Please contact factory to get the required products
specifications.
In case of just salt deposits are present, it is enough to rinse the parts
with fresh water.
7.2.1. Air Heat Exchanger Maintenance
Routine cleaning of air heat exchanger surfaces is essential to
maintain proper operation of the unit, avoid corrosion and rusting.
Elimination of contamination and removal of harmful residues will
greatly increase the life of the coil and extend the life of the unit.
Remove surface dirt, leaves, fibers, etc. with a vacuum cleaner
(preferably with a brush or other soft attachment rather than a metal
tube), compressed air blown from the inside out, and/or a soft bristle
(not wire!) brush. Do not impact or scrape the coil with the vacuum
tube, air nozzle, etc.
Use of a water stream, such as a garden hose, against a surface
loaded coil will drive the fibers and dirt into the coil. This will make
cleaning efforts more difficult. Surface loaded fibers must be
completely removed prior to using low velocity clean water rinse.
NOTE A monthly clean water rinse is recommended for coils
that are applied in coastal or industrial environments to
help to remove chlorides, dirt and debris. It is very
important when rinsing that the water temperature is
below 55 °C.
Galvanic corrosion of the connection Copper/Aluminum can occurre
in corrosive atmosphere under the plastic protection; during the
maintenance operations or periodic cleaning, check the aspect of the
plastic protection of the copper/aluminum connection. If it is inflated,
damaged or took off contact the manufacturer representative for
advice and information.