Daikin EWAT016CZN-A1, Installation, Maintenance And Operation Manual

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EWYT~CZ / EWAT~CZ DEIMHP0140521_00EN
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When operating the unit in a low outdoor ambient
temperature, be sure to follow the instructions described
below.
To prevent exposure to wind and snow, install a baffle plate on the air
side of the outdoor unit: In heavy snowfall areas it is very important to
select an installation site where the snow will NOT affect the unit. If
lateral snowfall is possible, make sure that the heat exchanger coil is
NOT affected by the snow. If necessary, install a snow cover or shed
and a pedestal.
For instructions on how to install the snow cover, contact your dealer.
When installing the snow cover, do NOT obstruct the air
flow of the unit.
4.6. Noise and acoustic protection
The unit is a source of noise mainly due to rotation of compressors
and fans. The noise level for each model size is listed in sales
documentation. If the unit is correctly installed, operated and
maintained the noise emission level do not require any special
protection device to operate continuously close to the unit without
any risk.
4.7. Water circuit for connection with the unit
4.7.1. Water piping
Piping must be designed with the lowest number of elbows and the
lowest number of vertical changes of direction. In this way, installation
costs are reduced considerably, and system performance is
improved.
The water system must have:
1.
Antivibration mountings to reduce transmission of vibrations to
the structures.
2.
Isolating valves to isolate the unit from the water system during
maintenance.
3.
To protect the unit, the BPHE must be protected against freezing
by continuous monitoring of the water flow in the BPHE by a flow
switch. In most cases, on site, the flow switch is set to generate
an alarm only when the water pump turns off and the water flow
drops to zero. It is recommended to adjust the flow switch to
produce a “Water Leakage Alarm” when the water flow reaches
the minimum value of the flow allowable (see table 1); in this case
the BPHE is protected against freezing and the flow switch can
detect the clogging of the water filter.
4.
Manual or automatic air venting device at the system highest
point and drain device at the system lowest point.
5.
Neither the BPHE nor the heat recovery device must be positio-
ned at the system’s highest point.
6.
A suitable device that can maintain the water system under pres-
sure (expansion tank, etc.).
7.
Water temperature and pressure indicators to assist the operator
during service and maintenance.
8.
A filter or device that can remove particles from the fluid. The use
of a filter extends the life of the BPHE and pump and helps to
keep the water system in a better condition.
The water filter
must be installed as close as possible to the unit.
If the water
filter is installed in another part of the water system, the Installer
must guarantee the cleaning of the water pipes between the wa-
ter filter and the BPHE. Precautions for correct use:
• All water components and piping/hydraulic devices outside
the unit must therefore be protected against freezing.
• All water components and piping/hydraulic devices must be
emptied of water during the winter season, unless an ethylene
glycol mixture in appropriate percentage is added to the wa-
ter circuit.
• In case of unit substitution, the entire water system must be
emptied and cleaned before the new unit is installed. Regular
tests and proper chemical treatment of water are recommen-
ded before starting up the new unit.
• If glycol is added to the water system as antifreeze protection,
pay attention to the fact that suction pressure will be lower,
the unit performance will be lower and water pressure drops
will be greater. All unitprotection systems, such as antifreeze,
and lowpressure protection will have to be readjusted.
The maximum glycol percentage is 40% for all the unit.
In the following table are illustrated the minimum glycol percen-
tage for low ambient air temperature
AMBIENT T [°C] -3 -8 -15 -20
ETHYLENE GLYCOL 10% 20% 30% 40%
PROPYLENE GLYCOL 10% 20% 35% 40%
Table 2 – Minimum glycol percentage for low ambient air temperature
Protection of the water circuit is necessary in the winter season,
even with the unit not in operation.
• Before insulating water piping, check that there are no leaks.
The complete hydraulic circuit must be insulated to prevent
condensation and reduced refrigeration capacity. Protect the
water pipes from frost during winter (using for example a
glycol solution or a heating cable).
• Check that the water pressure does not exceed the design
pressure of the water side heat exchangers. Install a safety
valve on the water pipe downstream of the BPHE.
9. Select the piping diameter in relation to the required water flow
and available external static pressure of the pump. See the fol-
lowing table for the recommended water piping diameter.
Unit Water piping diameter
EWAT/EWYT016~040CZ(N/P/H)-A1 1 ¼”
EWAT/EWYT040~090CZ(N/P/H)-A2 2”
4.7.2. Flow switch
Flow switch is a standard component fitted to all units. To ensure
sufficient water flow through the plate exchanger, it is essential that a
flow switch be installed on the water circuit. It is already installed in
the standard supply. The purpose of the flow switch is to stop the unit
in the event of interrupted water flow, thus protecting the BPHE from
freezing.
This is a palette flow switch appropriate for uninterrupted use
outdoors (IP65).
The flow switch is set up to intervene when the water flow of the BPHE
reaches the minimum value of the flow acceptable (see the table
below).