Indoor Unit - Hitachi 4FSVN1Q Installation & Maintenance Manual

Never use the refrigerant charged in the outdoor unit for air purging.
Insufficient refrigerant will lead to failure.
Thermal Insulation Finishing Work
Wind tape from outside of
thermal insulating of gas piping
and liquid piping
Gas Line
Manifold
Gauge
Vacuum Pump
1. Maximum Permissible Concentration of HFC GAS R410A. R410A is an incombustible
and non-toxic gas.
However, if leakage occurs and gas fills a room, it may cause suffocation. The maximum permissible
concentration of HCFC gas, R410A in air is 0.3kg/m
standard (KHK S 0010) by the KHK (High Pressure Gas Protection Association) Japan. Therefore, some
effective measure must be taken to lower the R410A concentration in air below 0.3kg/m
2. Calculation of Refrigerant Concentration
(1) Calculate the total quantity of refrigerant R (kg) charged in the system connecting all the indoor units of
objective rooms.
(2) Calculate the room volume V (m
(3) Calculate the refrigerant concentration C (kg/m
R: Total Quantity of Charged Refrigerant (kg)
If local codes or regulations are specified, follow them.
Cover the flare nut and union of the
piping connection with thermal insulation.
Liquid Line
Cover the liquid line
with thermal insulation.
Liquid Line Stop Valve
Gas Line Stop Valve
Nitrogen Tank
for Air Tight Test
and
Nitrogen Blow
during Brazing
3
) of each objective room.
3
V: Room Volume (m )

Indoor Unit

Insulate the liquid pipe for
prevention of the capacity
decrease according to the
ambient air conditions and
the dewing on the pipe surface
by the low pressure.
Check to ensure that there is
no gas leakage. When large
amount of the refrigerant leaks,
the troubles as follows may occur;
1. Oxygen Deficiency
2. Generation of Harmful Gas
Due to Chemical Reaction
with Fire.
G At the test run, fully open the spindle.
If not fully opened, the devices will be damaged.
G An excess or a shortage of refrigerant is the main
cause of trouble to the units.
Charge the correct refrigerant quantity according
to the description of label at the inside of service
cover.
G Check for refrigerant leakage in detail. If a large
refrigerant leakage occurs, it will cause difficulty
with breathing or harmful gases would occur if a
fire was being used in the room.
3 , according to the refrigeration and air conditioning facility
3 ) of the room according to the following equation.
= C: Refrigerant Concentration
16
3 , in case of leakage.
0.3 (kg/m 3 )