General Notes Before Performing Piping Work; R32 Refrigerant Circuit; General Notes R32 Refrigerant - Hitachi YUTAKI S COMBI Series Installation And Operation Manual

5.1

General notes before performing piping work

• Prepare locally-supplied copper pipes.
• Select the piping size with the correct thickness and correct material able to withstand sufficient
pressure.
• Select clean copper pipes. Make sure that there is no dust or moisture inside the pipes. Blow
the inside of the pipes with oxygen free nitrogen to remove any dust and foreign materials
before connecting them.

NOTE
A system with no moisture or oil contamination will give maximum performance and lifecycle
compared to that of a poorly prepared system. Take particular care to ensure that all copper piping
is clean and dry internally.
• Cap the end of the pipe when pipe is to be inserted through a wall hole.
• Do not put pipes on the ground directly without a cap or vinyl tape at the end of the pipe.
• If piping installation is not completed until next day or over a longer period of time, braze off
the ends of the piping and charge with oxygen free nitrogen through a Schrader valve type
access fitting to prevent moisture and particle contamination.
• It is advisable to insulate the water pipes, joints and connections in order to avoid heat loss and
dew condensation on the surface of the pipes or accidental injures due to excessive heat on
piping surfaces.
• Do not use insulation material that contains NH
become a source of future leakage.
• It is recommended to use flexible joints for the water piping inlet and outlet in order to avoid
vibration transmission.
• Refrigerant circuit and Water circuit must be performed and inspected by a licensed technician
and must comply with all relevant European and national regulations.
• Proper water pipe inspection should be performed after piping work to assure there is no water
leakage in the space heating circuit.
5.2

R32 Refrigerant circuit

5.2.1 General notes R32 refrigerant
This appliance is filled with R32, an odourless flammable refrigerant gas with low burning velocity
(A2L class pursuant to ISO 817). If the refrigerant is leaked, there is a possibility of ignition if it
enters in contact with an external ignition source.
Make sure that unit installation and refrigerant piping installation comply with applicable legislation
in each country. Also, in Europe, EN378 must be complied, as it is the applicable standard.
PMEN0645 rev.0 - 04/2023
, as it can damage copper pipe material and
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