Hitachi FSXN Series Service Manual page 354

12 Maintenance notes
12.5 Precautions in the event of refrigerant leaks
C A U T I O N
Installers and designers of the installations must strictly follow local and national legislation, and local codes
regarding safety requirements in the event of refrigerant leaks.
12.5.1 Maximum permissible concentration of hydrofluorocarbon (HFC)
The R410A refrigerant gas, used in the equipment, is non-flammable and non-toxic.
D A N G E R
In the event of a leak, the gas will spread around the room, displacing the air, and could therefore result in asphyxia.
The maximum permissible concentration of HFC R410A gas in the air is 0.44 kg/m
Consequently, effective measures must be adopted to maintain the concentration of R410A gas in the air below 0.44 kg/
3
m in case of leakage.
12.5.2 Calculation of the refrigerant concentration
1 Calculate the total quantity of refrigerant R (kg) charged in the system; to do so, connect all the indoor units of the rooms
in which you need air conditioning systems.
2 Calculate the volume V (m
3 Calculate the refrigerant concentration C (kg/m
R: total quantity of refrigerant charged (kg).
3
V: volume of the room (m
C: concentration of refrigerant (= 0.44 kg/m
Particularly for the SET FREE series, whose outdoor units can be connected to multiple indoor units at a distance, the
refrigerant charge is greater than for individual units.
D A N G E R
Check that the room where the indoor units will be installed can maintain the refrigerant concentration below the
lower limit established in case of leakage. Otherwise, take the necessary action to correct this situation.
12.5.3 Countermeasures in the event of refrigerant leaks
The room should have the following characteristics in case of a leak of refrigerant:
1 Opening without shutter to permit the circulation of fresh air in the room.
2 Opening without door measuring 0.15%, or greater, of the floor surface.
3 A ventilator with a capacity of at least 0.4 m
should be installed.
Model
RAS-8FSXN
RAS-10FSXN
RAS-12FSXN
RAS-14FSXN
RAS-16FSXN
RAS-18FSXN
RAS-20FSXN
RAS-22FSXN
RAS-24FSXN
352
SMGB0065 rev. 1 - 12/2010
3
) of each room.
3
) of the room in accordance with the following formula:
).
3
for R410A gas).
3
/min per refrigeration ton or greater, connected to a gas leak detector,
Ton
4.11
4.11
4.11
6.08
6.08
6.51
8.22
10.19
10.19
R / V = C
Model
RAS-32FSXN
RAS-34FSXN
RAS-36FSXN
RAS-38FSXN
RAS-40FSXN
RAS-42FSXN
RAS-44FSXN
RAS-46FSXN
RAS-48FSXN
3
, according to standard EN 378-1.
Ton
12.16
12.59
13.02
14.30
14.30
14.73
16.70
16.70
17.13