Refrigerant And Water Piping; General Notes Before Performing Piping Work; Refrigerant Circuit; Refrigerant Charge - Hitachi RWH-4.0VNFE Instruction Manual

REFRIGERANT AND WATER PIPING

4 REFRIGERANT AND WATER PIPING

4.1 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.
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N O T E
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.

4.2 REFRIGERANT CIRCUIT

4.2.1 Refrigerant charge

The YUTAKI S80 has two refrigerant circuits. The R410A circuit
(1st cycle) works with this refrigerant while the indoor circuit
(2nd cycle) works with R134a refrigerant. Piping connections
must be performed in the R410A cycle between the outdoor unit
and the indoor unit.
Outdoor unit Indoor unit
R410A
• The 1st cycle (R410A) is factory charged in the outdoor unit
with a refrigerant charge amount for 30m of piping length
between outdoor and indoor unit. The maximum refrigerant
piping length is 30m so additional refrigerant charge is not
required.
• The 2nd cycle (R134a) connections are factory installed and
refrigerant charged so no piping work or refrigerant charge is
needed.
7 PMML0340B rev.1 - 03/2016
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R134a
H20
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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 NH3, as it can
damage copper pipe material and 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.
N O T E
Refer to the outdoor unit Installation and operation manual
the R410A refrigerant inside the indoor unit.
Remember to supply power to the indoor unit and switch the
DSW1-2 ON of its PCB1. Thereby, solenoid valves SV1 and SV2
of the indoor unit will open to allow the operation of vacuum
and refrigerant charge inside the indoor unit. It is very important
to remind to switch the DSW1-2 OFF when finishing the whole
procedure.
Refrigerant charge before shipment (W
Model
RAS-4WH(V)NPE
Outdoor unit
RAS-(5/6)WH(V)NPE
Indoor unit RWH-(4.0-6.0)(V)NF(W)E
to charge
(kg))
0
W (kg) W (kg)
0 0
R410A R134a
3.3 -
3.4 -
- 1.9