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Additional Refrigerant Charge
Please refer to page 84 of the Installation Manual.
General Installation
8.3 Additional Refrigerant Charge Calculation
Table 8.1 Additional Refrigerant Charge Calculation
No. Symbol
Contents
Additional
Charge (kg)
1 W1 Additional Refrigerant Charge Calculation for Liquid Piping (W1 kg)
Pipe Diameter
(mm)
Total Piping Length
(m)
Refrigerant Amount
for 1m Pipe (kg/m)
Additional Charge
(kg)
φ
22.2
m × 0.36 =
φ
19.05
m × 0.26 =
φ
15.88
m × 0.17 =
φ
12.7
m × 0.11 =
φ
9.52
m × 0.056 =
φ
6.35
m × 0.024 =
Total Additional Charge For Liquid Piping =
NOTE:
In the case that the quantity calculated above is less than the minimum quantity indicated
in the table below, adopt the quantity in the table below as the additional refrigerant
quantity for piping liquid, regardless of the piping length.
Series
FSXN1
FSXNH
HP
8 10 12 14 16 5 6 8 10 12
Minimum Additional Charge
of Base Unit (kg)
2.0 2.0 3.0 3.0 3.0 2.0 2.0 2.0 2.0 3.0
For combination of the units, adopt the total minimum quantity of each base unit as the
minimum additional refrigerant quantity.
kg
2 W2 Additional Refrigerant Charge Quantity for Indoor Unit
(only for Heat Pump System) (W2 kg)
The additional refrigerant charge is required depending on the number of connected indoor
units. Select the refrigerant quantity from the following table.
Additional Refrigerant Charge Quantity (kg)
System
Heat Pump
Heat Recovery
Model
RCI-2.0FSN3 RCI-2.5FSN3 RCI-3.0-6.0FSN3 RCI-2.0-6.0FSN3
Connectable
Number
1
0.0
0.0
0.5
0.0
2
0.5
0.5
1.0
0.0
3
0.5
1.0
1.5
0.0
4 or more
1.0
1.5
2.0
0.0
kg
3 W3 Additional Refrigerant Charge Calculation for Indoor Unit (W3 kg)
Additional refrigerant charge is 1kg/unit of 8HP and 10HP indoor unit.
Additional refrigerant charge of less than 8HP indoor units is not needed.
8 and 10HP Total Indoor Unit Numbers Additional Charge
× 1.0kg/unit =
kg
4 W4 The Ratio of Indoor Unit Connection Capacity (Indoor Unit Total Capacity/Outdoor Unit
Capacity) Additional Charge (W4 kg)
Determine the ratio of indoor unit connection capacity.
Condition
Refrigerant Amount
• I.U. Capacity Ratio is less than 100%:
0.0kg
• I.U. Capacity Ratio is more than 100%:
0.5kg
kg
5 W
Calculation of Additional Charge (W kg) = W1 + W2 + W3 +W4
kg
NOTES:
1. Some refrigerant charge calculations differ when installing Wall Type (RPK-FSNSH3 Series) with the expansion
valve kit. Refer to the item “Additional Refrigerant Calculation for Wall Type (RPK-FSNSH3 Series) with the
Expansion Valve Kit” .
Although refrigerant has been char d into this unit in advance, additional refrigerant charge is required according
to piping length.
Determine the additional refrigerant quantity according to the following procedure, and charge the system with it.
Record the additional refrigerant quantity to facilitate maintenance and servicing activities thereafter.
(1) Calculating Method of Additional Refrigerant Charge (W kg)
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