Hitachi YUTAKI S COMBI Serie Manual De Instrucciones página 23

REFRIGERANT AND WATER PIPING
4.3.6 Water filling
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Space heating
1 Check that a water check valve (ATW-WCV-01 accessory)
with a shut-down valve (field supplied) is connected to the
water filling point (water inlet connection) for filling the space
heating hydraulic circuit (see
2 Make sure all the valves are open (water inlet/outlet shut-
down valves and the rest of valves of the space heating
installation components).
3 Ensure that the air purgers of the indoor unit and installation
are open (turn the indoor unit air purger twice at least).
4 Check that the drain pipes connected to the safety valve
(and to the drain pan in case of installing the "Cooling kit"
accessory) are correctly connected to the general draining
system. The safety valve is later used as an air purging
device during the water filling procedure.
5 Fill the space heating circuit with water until the pressure
displayed on the manometer reaches approximately 1.8 bar.
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N O T E
• When the pressure of the manometer indicates 1.8 bar, set the
pin 2 of the DSW4 to ON. Then, the DHW valve is forced to ON
position to allow the filling of the heating coil of the DHW tank.
When the pressure returns to 1.8 bars approximately stop the
water filling procedure.
• While the system is being filled with water, it is highly recommended
to operate the safety valve manually so as to help with the air
purging procedure.
6 Remove as much air from inside the water circuit as possible
through the indoor air purger and other air vents in the
installation (fan coils, radiators...).
7 Start the air purge procedure test. There are two modes
(Manual or Automatic) which helps to totally fill the water
circuit of the indoor unit.
a. Manual: Start and stop the unit manually using the unit
controller (Run/Stop button) and also using the DSW4
pin 2 of the PCB1 (ON: Forced to derive to DHW coil;
OFF: Forced to derive to space heating).
b. Automatic: Select the air purge function using the
user controller. When the automatic air purge function
is running, the pump speed and the position of the
3-way valve (space heating or DHW) are automatically
changed:
Water
pump
ON
DHW
3Wv
OFF
8 In both test procedures (Manual or Automatic), use the
manual air purger located between the T-branch and the
DHW coil inlet in order to remove as much air as possible
from the unit during the air purge test procedure.
13 PMML0338B rev.1 - 03/2016
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"4.3 Space heating and DHW").
Repeat...
Seconds
Repeat...
Seconds
9 If a little quantity of air is still remaining in the water circuit,
it will be removed by the automatic air purger of the indoor
unit during the first hours of operation. Once the air in the
installation has been removed, a reduction of water pressure
in the circuit is very likely to occur. Therefore, additional
water should be filled until water pressure returns to an
approximate level of 1.8 bar.
?
N O T E
• The indoor unit is equipped with an automatic air purger (factory
supplied) at the highest location of the indoor unit. Anyway, if there
are higher points in the water installation, air might be trapped
inside water pipes, which could cause system malfunction. In that
case, additional air purgers (field supplied) should be installed to
ensure no air enters into the water circuit. The air vents should be
located at points which are easily accessible for servicing.
• The water pressure indicated on the indoor unit manometer may
vary depending on the water temperature (the higher temperature,
the higher pressure). Nevertheless, it must remain above 1 bar in
order to prevent air from entering the circuit.
• Fill in the circuit with tap water. The water in the heating installation
must comply with EN directive 98/83 EC. Non-sanitary controlled
water is not recommended (for example, water from wells, rivers,
lakes, etc.) (See "Water quality" section at the CD-ROM).
• The maximum water pressure is 3 bar (nominal opening pressure
of the safety valve). Provide adequate reduction pressure device
in the water circuit to ensure that the maximum pressure is NOT
exceeded.
• For heating floor system, air should be purged by means of an
external pump and an open circuit to prevent the formation of air
pockets.
• Check carefully for leaks in the water circuit, connections and
circuit elements.
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Domestic hot water tank and DHW circuit
1 Open the outlet water taps of the DHW installation one after
each other, to expel all the air from inside the water circuit.
2 Open the main DHW inlet valve in order to fill the tank. If
there is a shut-down valve installed in the DHW outlet, open
it to allow circulation through the DHW installation.
3 When water begins to flow from the outlet water taps of the
DHW installation, close all these taps.
4 Finally, close the main DHW inlet valve when the pressure
reaches approximately 6 bars.
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C A U T I O N
• Check carefully for leaks in the water circuit, connections and
circuit elements.
• Check that the water pressure in the circuit is lower than 7 bars.
• A pressure and temperature relief valve should be installed at the
DHW inlet connection (See
elements (For DHW)" section). If it is the case, manually operate
its relief valve to ensure that the water flows free through the
discharge pipe.
• Fill in the circuit with tap water. The water in the heating installation
must comply with EN directive 98/83 EC. Non-sanitary controlled
water is not recommended (for example, water from wells, rivers,
lakes, etc.) (See "Water quality" section at the CD-ROM).
"4.3.3 Additional hydraulic optional