Hitachi RAS-3HVNC1 - Refrigerant Charge; Refrigerant Charging Quantity; Caution of the Pressure by Check Joint

8.4 REFRIGERANT CHARGE
! CAUTION
• Do not charge OXYGEN, ACETYLENE, or other ammable 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 are-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 insufcient charging
couldcauseacompressorfailure.
• Checkforrefrigerantleakageindetail.Ifalargerefrigerantleakage
occurred, it would cause difculty with breathing or harmful gases
wouldoccurifarewerebeingusedintheroom.
• Ifthearenutistightenedtoohard,thearenutmaycrackaftera
longtimeandcauserefrigerantleakage.
8.5 REFRIGERANT CHARGING QUANTITY
In case of the actual piping length is more than the specied length, the additional refrigerant quantity should be charged according
to the table below:
Outdoor unit refrigerant
charge (kg)
Chargeless length (m) Additional refrigerant charge (P) (g/m)
Max additional
charge (kg)
1 IU 2 IU 1 IU 2 IU
RAS-2HVNP1 1.6 30 0 30 30 1.5
RAS-2.5HVNP1 1.6 30 0 30 24 1.2
RAS-3HVNC1
1.9 20
20
40 40
1.2
RAS-3HVRNS3 1.9 20 20 40 40 1.2
1 Determine an additional refrigerant quantity according to the
following procedure, and charge it into the system.
2 Record the additional refrigerant quantity to facilitate service
activities thereafter.
! CAUTION
• When charging refrigerant accurately measure refrigerant to be
charged.
• Overchargingorunderchargingofrefrigerantcancausecompressor
trouble.
• Incaseofactualpipinglengthlessthan5m,consultyourdistributor.
• Charge refrigerant correctly. Overcharging or insufcient charging
couldcauseacompressorfailure.
8.6 CAUTION OF THE PRESSURE BY CHECK JOINT
When the pressure is measured, use the check joint of gas stop
valve, and use the check joint of liquid piping in the gure below.
At that time, connect the pressure gauge according to the
following table because of high pressure side and low pressure
side changes by operation mode.
Cooling
Operation
Heating
Operation
Check Joint for Gas Stop Valve Low Pressure High Pressure
Check Joint for Liquid Stop Valve
Exclussive for Vacuum Pump
and Refrigerant Charge
? NOTE
Becarefulthatrefrigerantandoildonotsplashtotheelectricalpartsat
removingthechargehoses.
Stop valve (liquid)
Stop valve (gas)

Setting of Pipe Length DSW
DSW2 setting will be required only when the refrigerant pipe
length is shorter than 5 m or longer than 30 m. Pipe length
setting shall be performed as shown below.
(The  side in the table below shows the DSW location)
DSW2 on Outdoor PCB1
Factory setting Pipe Length ≤ 5m Pipe Length ≥ 30m
REFRIGERANT PIPING & REFRIGERANT CHARGE
PMML0398B rev.0 - 11/2015 - P5416651
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