Hitachi YUTAKI S Series Instruction Manual page 45

Commissioning
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.
• 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.
?
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).
27 PMML0574 rev.0 - 09/2021
"7.4 Test run / air purge".
"5.6 Setting of DIP switches and RSW
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.
This menu shows the following test to be launched:
• Unit Test Run
• Air Purge
• Screed Drying
• Pump down procedure
After "Test Run", "Air Purge" or "Pump down procedure" option
is selected, the YUTAKI user controller asks for the duration of
the test.