Refrigerant Piping Work; Piping Materials; Piping Connection - Hitachi airCore 700 Operation Installation Maintenance Manual

(4) Perform the heat insulation work over the duct for dew protection.
CAUTION
!
•
This duct unit return air outside need to be connected 1 meter duct at least in field.
•
Ducted IDU machine must be connected with the return air duct, direct inhalation of high
temperature air in the attic is prohibited.
•
If a lower sound level is further required, install silencer (field-supplied).
•
Design duct arrangement as "Unit External Static Pressure=Pressure Drop of Duct+Pressure Drop of
Air Outlet and Air Inlet". If duct design is not appropriate, big sound and splash will occur.
•
Before unit starting up, use wired remote controller to operate auto ESP function or ensure the setting
ESP is almost same with field duct pressure. If are not appropriate, big sound and splash will occur.
4.3.9 Setting of External Static Pressure
Refer to "7.5 Setting of External Static Pressure".

5. Refrigerant Piping Work

DANGER
!
•
Use refrigerant R32 in the refrigerant cycle. Do not charge oxygen, acetylene or other flammable and
poisonous gases into the refrigerant cycle when performing a leakage test or an air-tight test. These
types of gases are extremely dangerous and cause an explosion. It is recommended that dry nitrogen
be used for these types of tests.

5.1 Piping Materials

(1) Prepare locally-supplied copper pipes.
(2) Select clean copper tubes making sure there is no dust and moisture inside the tubes. Before connecting
pipes, blow the inside of the tubes with nitrogen or dry air, to remove any dust or foreign materials.

5.2 Piping Connection

CAUTION
!
•
Cap the end of the pipe when the pipe is to be inserted through a hole.
•
Do not put pipes on the ground directly without a cap or vinyl tape at the end of the pipe.
•
An excess or a shortage of refrigerant is the main cause of trouble to the units. Charge the correct
refrigerant quantity.
Silencer Canvas Duct
Thermal
Insulation
Indoor Unit
Truss
Keep Horizontal
Air Outlet
Fig.4.15 Duct Connection
Correct
Damper for Canvas Duct
Adjusting Air Volume
Vibration
Absorbing
Mat (10t)
Wooden Bar
Service Access Panel
(450mm x 450mm)
Incorrect
-12-
5. Refrigerant Piping Work
Silencer
Air Inlet