Caution Of The Pressure By Check Joint; Refrigerant Charge Quantity - Hitachi UTOPIA RAS-4HVRP2E Service Manual

3 Piping work and refrigerant charge
Refrigerant charge

3.4.1 Caution of the pressure by check joint

When the pressure is measured, use the check joint of gas stop valve (A), and use the check joint of liquid piping (B) in
the figure 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.
Check joint for gas stop valve -A-
Check joint for piping -B-
Check joint for liquid stop valve -C-
?
N O T E
Be careful that refrigerant and oil do not splash to the electrical parts at removing the charge hoses.

3.4.2 Refrigerant charge quantity

Although refrigerant has been charged into this unit, additional refrigerant charge is required according to piping length.
1 The additional refrigerant quantity should be determined and charged into the system according to the following
procedure.
2 Record the additional refrigerant quantity in order to facilitate maintenance and servicing activities.
!
C A U T I O N
• When charging refrigerant, measure the amount precisely. Overloading or underloading of refrigerant may cause compressor prob-
lems. If the actual piping length is less than 5 m consult your dealer.
Appropriate refrigerant
•
The refrigerant used in each unit is identified on the specification label and manuals of the unit. Hitachi shall not be held liable for any
failure, trouble, malfunction or accident caused by units illegally charged with refrigerants other than the specified one.
Consequences of charging non-specified refrigerant
•
• It may cause mechanical failure, malfunction and other accidents. It may cause operational failure of protection and safety devices of
air conditioners. It may also cause lubrication failure of the sliding part of the compressor due to deterioration of refrigerant oil.
• In particular, hydrocarbon refrigerants (such as propane, R441A, R443A, GF-08, etc.) are not allowed, since these are combustible
and may cause major accidents such as fire and explosion in case of improper handling.
• Once a non-specified refrigerant has been charged, no further servicing (including draining of refrigerant) shall be performed, even
in case of malfunction. Improper handling of refrigerant may be a cause of fire and explosion, and servicing in such cases may be
considered an illegal act.
• End clients and costumers shall be informed that servicing is not approved, and the installer who charged the non-specified refrigerant
shall be asked to fix the unit.
60 SMGB0136 rev.0 - 07/2021
RAS-3HVRC2 RAS-(4-6)H(V)(R/N)(C/P)2E
C
A
Cooling operation
Low pressure
High pressure
Exclusive for vacuum pump and refrigerant charge
B
C
A
Heating operation
High pressure
Low pressure