Hitachi YUTAKI M RASM-2VRE Instruction Manual page 21

REFRIGERANT AND WATER PIPING
In case of blowing strong wind to air outlet the wind guard
(optional) is available to avoid strong wind.
Wind guard model
Model Number of set required
WSP-264
8 REFRIGERANT AND WATER PIPING
8.1 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.
?
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.
• 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
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.
• Water circuit must be performed and inspected by a licensed
technician and must comply with all relevant European and
9 PMML0506 rev.1 - 09/2019
Wind guard
1
, as it can
3
national regulations.
• Proper water pipe inspection should be performed after
piping work to assure there is no water leakage in the space
heating circuit.
8.2 REFRIGERANT CIRCUIT
8.2.1 Refrigerant charge
The R32 refrigerant is factory charged in the outdoor unit.
8.2.2 Precautions in the event of gas refrigerant
leaks
The installers and those responsible for drafting the
specifications are obliged to comply with local safety codes and
regulations in the case of refrigerant leakage.
!
C A U T I O N
• Do not charge OXYGEN, ACETYLENE, or other flammable and
poisonous gases into the refrigerant because an explosion can occur.
It is recommended that oxygen free nitrogen be charged for these
types of tests cycle when performing a leakage test or an airtight test.
These types of gases are extremely dangerous.
• Insulate the unions and flare-nuts at the piping connection part
completely.
• Insulate the liquid piping completely to avoid a decrease of
performance; if not, it will cause sweating on the surface of the pipe.
• Charge refrigerant correctly. Overcharging or insufficient charging
could cause a compressor failure.
• Check for refrigerant leakage in detail. If a large refrigerant leakage
occurred, it would cause difficulty with breathing or harmful gases
would occur if a fire were being used in the room.
• If the flare nut is tightened too hard, the flare nut may crack after a
long time and cause refrigerant leakage.
9 DRAIN PIPING
9.1 WATER DRAIN DISCHARGE
CONNECTION (ACCESSORY)
When the base of the outdoor unit is temporarily utilized as a
drain receiver and the drain water in it is discharged, this drain
boss is utilized to connect the drain piping.
Model
Connecting procedure
1 Insert the plastic cap into the drain boss up to the extruded
portions.
2 Insert the boss into the unit base up to the extruded portions.
3 Size of the drain boss is Ø15 mm (O.D.)
4 A drain pipe should be field-supplied.
DBS-12L