Hitachi YUTAKI S COMBI Serie Manual De Instrucciones página 29

ELECTRICAL AND CONTROL SETTINGS
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.

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.
!
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).
11 PMML0573 rev.1 - 07/2021
"4.4.3 Additional hydraulic optional
5 ELECTRICAL AND CONTROL
SETTINGS
5.1 GENERAL CHECK
• Make sure that the following conditions related to power
supply installation are satisfied:
The power capacity of the electrical installation is large
-
enough to support the power demand of the YUTAKI
system (outdoor unit + indoor unit + DHW tank).
The power supply voltage is within ±10% of the rated
-
voltage.
- The impedance of the power supply line is low enough
to avoid any voltage drop of more than 15% of the rated
voltage.
• Following the Council Directive 2014/30/EU, relating to
electromagnetic compatibility, the table below indicates the
Maximum permitted system impedance Z
point of the user's supply, in accordance with EN61000-3-11.
Power
Model
supply
1~ 230V
50Hz
RWD-(2.0-3.0)
RW1E-220S(-K)
3N~ 400V
50Hz
1~ 230V
50Hz
RWD-(4.0-6.0)
NW1E-220S(-K)
3N~ 400V
50Hz
at the interface
max
Z
Operation mode
(Ω)
Without electric heaters
With electric heater
With DHW tank heater
With electric and DHW
0.27
tank heaters
Without electric heaters
With electric heater
With DHW tank heater
With electric and DHW
tank heaters
Without electric heaters
With electric heater 0.26
With DHW tank heater
With electric and DHW
0.18
tank heaters
Without electric heaters
With electric heater
With DHW tank heater
With electric and DHW
tank heaters
max
-
-
-
-
-
-
-
-
-
-
-
-
-