Hitachi YUTAMPO Serie Installations- Und Betriebshandbuch Seite 12

UNIT INSTALLATION
• Do not use insulation material that contains NH3, as it can
damage copper pipe material and become a source of future
leakage.
• It is recommended to use flexible joints for the inlet and outlet
of water piping, in order to avoid the transmission of vibration.
• The refrigerant and water circuits must be installed and
inspected by a licensed technician and must comply with all
the relevant European and national regulations.
• It is recommended to perform a thorough water pipe
inspection after completion of piping work to make sure that
there is no water leakage in the space heating circuit.
5.3.2 DHW pipe connection
The connection between the DHW installation and the DHW tank
must be done taking the following considerations into account:
1 A pressure and temperature relief valve must be installed at
the DHW inlet connec tion (as close as possible to the tank) to
provide the following functions:
• Pressure protection
• No-return function
• Shut-down valve
• Filling
• Draining
If not, a specific device for each function should be installed.
2 A shut-down valve (field supplied) must also be installed in
the DHW system.
!
D A N G E R
Do not connect the power supply to the indoor unit prior to filling the
DHW circuit with water and checking water pressure and the total
absence of any water leakage.
Illustrative example:
Tank unit
Purge valve
Hot water
outlet
Drainpipe
Water check valve
Cold water inlet
Drain valve
Drain pipe
?
N O T E
The discharge pipe should always be open to the atmosphere, free of frost
and obstruction, and in continuous descending slope in order to let water
out in case that a leakage occurs.
6 PMML0451 rev.2 - 03/2018
Mixed tap
Hot water supply line
Pressure
reduction valve
Water valve
Pressure-relief valve
Hopper
5.3.3 Requirements and recommendations for
the hydraulic circuit
• When the unit is stopped during shutdown periods and the
ambient temperature is very low, the water inside the pipes
may freeze, thus damaging the pipes. In these cases, the
installer shall ensure that the water temperature inside the
pipes does not fall below the freezing point.
• Fresh water must circulate inside the water circuit of the
DHW tank at least once every day during the first days
after the installation has been performed. Additionally, it is
advised to flush the system with fresh water when there is no
consumption of DHW during long periods of time.
• A pressure with a nominal value of 7 bar must be fitted in
case that the pressure of domestic cold water inlet is higher
than the design pressure of the equipment (6 bar).
• The installation must satisfy the requirements of applicable
legislation in terms of piping connection and materials,
hygienic measures and testing, as well as the possible
requirements for the use of some specific components such
as thermostatic mixing valves, differential pressure overflow
valves, etc.
5.3.4 Filling the DWH tank with water
Follow the steps below when starting up the unit for the first time
or when it has not been used for an extended period of time
1 Open the outlet water taps of the DHW, to expel all the air
from inside the tank.
2 Turn on all the connected mixer taps (hot water side).
3 Open the inlet valve of the DHW tank in order to fill the tank.
If there is a shut-down valve installed in the DHW tank outlet,
open it to allow circulation through the DHW installation.
4 When water begins to flow from the outlet water taps of the
DHW installation, close all these taps.
5 Turn off all the connected mixer taps.
6 Inspection
- 1 After filling the tank, check all pipe, heater and anode
joints and the tank for leakage.
Cold water
- 2 Check operation of the pressure relief valve.
supply line
- 3 After heating water for the first time, check water
leakage from the pipe, heater and anode joints and the
tank once more.
!
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.
• Fill the circuit with tap water. Water that conforms to the drinking
water regulation in each country must be used. Do not use water from
sources not subject to sanitary control like wells, rivers or lakes, since
it may have a high content of impurities, salinity, lime, etc.
• Please install the a water softening device when the hardness of water
is high. (Maximum hardness French degree 25 °F or equivalent rules)