Hitachi YUTAKI RAS-4WHVNPE Instruction Manual page 26

REFRIGERANT PIPING & REFRIGERANT CHARGE
8.4 REFRIGERANT CHARGE
!
C A U T I O N
• Do not charge OXYGEN, ACETYLENE, or other flammable 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 flare-nuts at the piping connection part
completely.
8.5 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"
8.6 REFRIGERANT CHARGING QUANTITY
Outdoor Units has been charged with refrigerant for 15m
of actual piping length. An additional refrigerant charged is
required in systems with actual piping length longer than 15m.
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.
!
C A U T I O N
• 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.
11 PMML0372B rev.5 - 01/2021
Cooling Heating
Operation Operation
Low Pressure High Pressure
High Pressure Low Pressure
Exclusive for Vacuum Pump
and Refrigerant Charge
• 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 insufficient charging
could cause a compressor failure.
• Check for refrigerant leakage in detail. If a large refrigerant leakage
occurred, it would cause difficulty with breathing or harmful gases
would occur if a fire were being used in the room.
• If the flare nut is tightened too hard, the flare nut may crack after a
long time and cause refrigerant leakage.
?
N O T E
Be careful that refrigerant and oil do not splash to the electrical parts at
removing the charge hoses.
B
C
A
W (kg) is the outdoor unit refrigerant charge before shipment
0
explained before, and it's shown in the following table:
Refrigerant
charge before
Model
shipment
(W (kg))
0
RAS-4WHVNPE 3.3
RAS-5WHVNPE 3.4
RAS-6WHVNPE 3.4
RAS-4WHNPE 3.3
RAS-5WHNPE 3.4
RAS-6WHNPE 3.4
RAS-8WHNPE 5.0
RAS-10WHNPE 5.3
Additional refrigerant charge calculation method
For all units use the following formula:
W
1
There may be gas trapped
at the "O-ring screw" part,
which may produce a
sound when released upon
removal of the cap.
However, this is not a gas
leakage.
Additional Maximum
refrigerant additional
charge (P) charge
(g/m) (kg)
60 3.9
60 3.9
60 3.9
60 3.9
60 3.9
60 3.9
65 10.3
65 12.1
= (L-15) x P