Checking The Refrigerant Circuit; Commissioning Procedure - Hitachi YUTAKI S Series Installation And Operation Manual

8.2.4 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.
8.3

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 25°C for 3 days.
2 Water set-point is set to the maximum Heating supply temperature (but always limited to ≤55°C)
for 4 days.
!
CAUTION
• Heating at lower water temperatures (approximately 10°C to 15°C) and lower outdoor ambient
temperatures (<10°C) can be damaging to the heat pump when defrosting.
• As a result, Heating up to 15°C when outdoor temperature is lower than 10°C is performed by
the Electrical Heater.

NOTE
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.
PMEN0643 rev.0 - 04/2023
"8.4 Test run / air purge".
8
60