Refrigerant Charge Amount - Hitachi FSN3E Installation And Operation Manual

REFRIGERANT PIPING & REFRIGERANT CHARGE

11.8 REFRIGERANT CHARGE AMOUNT

Although refrigerant has been charged into this unit, additional
refrigerant charge is required according to piping length.
• The additional refrigerant quantity should be determined
and charged into the system according to the following
procedure.
• Record the additional refrigerant quantity in order to facilitate
maintenance and servicing activities.

Refrigerant charge before shipment (W
W is the outdoor unit refrigerant charge before shipment
0
(Factory charge), and it's shown in the following table:
Refrigerant charge before shipment
Model
RAS-4FS(V)N(Y)3E
RAS-5FS(V)N(Y)3E
RAS-6FS(V)N(Y)3E
!
C A U T I O N
• When charging refrigerant, measure the amount precisely.
• Overcharging or undercharging of refrigerant may cause compressor
problems.

Additional refrigerant charge calculation
method
Calculate the additional refrigerant charge amount (Additional
charge) according to the following steps:
Step 1: Additional refrigerant charge calculation for
liquid piping (W (kg))
1
The additional refrigerant charge must be calculated by
multiplying the total piping length of each diameter per its
calculation factor according to the following table. The result is
the additional refrigerant charge for liquid piping.
Additional refrigerant charge factor
Pipe size (mm)
Ø9.52
Ø6.35
Step 2: Charging work
Charge refrigerant (R410A) into the system according to the
instructions in the Service Manual.
Step 3: Total refrigerant charge of the system (W
(kg))
The total refrigerant charge (Total charge) of this system is
calculated by the following formula:
W
TOT
System example (W ) =
TOT
W is the outdoor unit refrigerant charge before shipment
0
explained before, and it's shown in its specific table.
19 PMML0354A rev.1 - 03/2015
(kg))
0
(W (kg))
0
3.6
(kg/m)
x 0.05
x 0.02
TOT
= W + W
0
+ =
Finally, record the refrigerant charge quantity in the F-Gas label
order to facilitate maintenance and servicing activities.

Additional refrigerant charge calculation
example
Example of quadruple system for RAS-6FS(V)N(Y)3E
RAS-6HP
RCI-1.5HP RCI-2.5HP
Step 1: Additional refrigerant charge calculation for
liquid piping (W (kg))
1
Calculate the additional refrigerant charge for the liquid piping
as indicated below. Check the example and fill in the following
table.
Pipe size Total piping length
(mm) (m)
Ø9.52 10 + 5 + 5
Ø6.35 10 + 5
Step 2: Total refrigerant charge of the system (W
(kg))
The total refrigerant charge of this system is calculated by the
following formula:
kg
Refrigerant charge before shipment (W
specific table)
9.52
9.52
9.52
RCI-2.5HP
Additional
refrigerant
charge (kg/m)
x 0.05
x 0.02
TOTAL
W = W + W
TOT 0 1
) = 3.6 kg (Refer to its
0
W = 3.6 + 1.3 = 4.9 kg
TOT
RCI-1.0HP
Subtotal
(kg)
1.0
0.3
W = 1.3
1
TOT