Hitachi YUTAKI S COMBI Serie Manual De Instrucciones página 42

COMISSIONING
• Do not touch any electrical components for more than three minutes
after turning OFF the main switch.
• Check the dip switch settings of the indoor unit and the outdoor unit
are connected as shown in the corresponding chapter.
• Check to ensure the electrical wiring of the indoor unit and the outdoor
unit are connected as shown in the chapter.
• Check to ensure the external wiring is correctly fixed. To avoid
problems with vibrations, noises and cut out wires with the plates.
7.2.3 Hydraulic circuit checking (space heating
and DHW)
• Check that the circuit has been properly flushed and filled
with water and that the installation has been drained: the
pressure of the heating circuit must be 1.8 bar.
• The pressure of the DHW circuit in the tank has to be lower
than 7 bars.
• Check that the water tank heating coil is completely filled.
• Check for any leakage in water cycle. Pay special attention
to the water piping connections.
• Make sure the system's internal water volume is correct.
• Make sure the DHW tank internal water volume is correct.
• Check that the hydraulic circuit's valves are fully open.
• Check to see that electrical heater is completely filled with
water by operating pressure of safety valve.
• Check to see that additional water pumps (WP2 or/and WP3)
are correctly connected to terminal board.
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C A U T I O N
• Operating the system with closed valves will damage the unit.
• Check to see that air purge valve is open and that the hydrau lic circuit
is air purged. The installer is responsible of com pletely air purging the
installation.
• Check that the water pump of the space heating circuit works within
the pump operating range and that the water flow is over the pump's
minimum. If the water flow is under 12 litres/minute (6 litres/minute
for 2.0/2.5/3.0HP unit) (with flow switch tolerance), alarm will be
displayed on the unit.
• Remember that water connection must be accordance with local
regulations.
• Water quality must comply with EU directive 98/83 EC.
• Electrical heater operation when not completely filled with water will
damage the heater.
7.2.4 Checking the refrigerant circuit
• Check to ensure that the stop valves on the gas and liquid
lines are fully open.
• Check that the size of the piping and the refrigerant charge
comply with the applicable recommendations.
• Check the inside of the unit for refrigerant leakage. If there is
a refrigerant leak, call your dealer.
• Check outdoor unit commissioning procedure manual.
7.3 COMMISSIONING PROCEDURE
This procedure is valid regardless of what options are on the
module.
• When installation is complete and all necessary settings
(Dip-switches in PCBs and user controller configuration)
have been carried out, close the electrical box and place the
cabinet as shown in the manual.
24 PMML0573 rev.1 - 07/2021
• Make the start-up wizard configuration in the user controller.
• Make a test run as shown in item
• After test run is completed, start the entire unit or the
selected circuit by pressing the OK button.

Initial start-up at low outdoor ambient
temperatures
During commissioning and when water temperature is very
low, it is important for the water to be heated gradually.
Additional optional function can be used for starting at low water
temperature conditions: Screed drying function:
The screed function is used exclusively for the process of
-
drying a newly applied screed to the floor heating system.
The process is based on EN-1264 par 4.
- When user activates screed function, the water set point
follows a predetermined schedule:
1 Water set point is kept constant at 25ºC for 3 days
2 Water set-point is set to the maximum Heating supply
temperature (but always limited to ≤ 55ºC) for 4 days.
!
C A U T I O N
• Heating at lower water temperatures (approximately 10ºC to 15ºC)
and lower outdoor ambient temperatures (<10ºC) can be damaging to
the heat pump when defrosting.
• As a result, Heating up to 15ºC when outdoor temperature is lower
than 10ºC is performed by the Electrical Heater.
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N O T E
In case of Heater Forced OFF (by optional dip switch setting) these
condition is not performed and heating is performed by Heat Pump.
Hitachi is not responsible for its operation.
!
C A U T I O N
It is recommended start the unit (first power ON) with heater forced OFF
and compressor forced OFF (See
switches"). In order to circulate water by water pump and remove possible
air into the heater (Check heater completely filled).
7.4 TEST RUN / AIR PURGE
Test run is a working mode used when commissioning the
installation. Some settings are made to let the installer an easy
job. Air purge function drives the pump in a way for evacuating
air bubbles in the installation.
"7.4 Test run / air purge".
"5.6 Setting of DIP switches and RSW