LG ARWN Serie Manual De Instalación página 38

Refrigerant piping system
Calculation of amount of refrigerant
The calculation of the additional charge should take into account the length of pipe.
Product Charge(kg(lbs))
A
Additional charge (kg(lbs))
B
=
Total liquid pipe (m(ft)): Ø22.2mm(7/8inch)
+
Total liquid pipe (m(ft)): Ø19.05mm(3/4inch)
+
Total liquid pipe (m(ft)): Ø15.88mm(5/8inch)
+
Total liquid pipe (m(ft)): Ø12.7mm(1/2inch)
+
Total liquid pipe (m(ft)): Ø9.52mm(3/8inch)
+
Total liquid pipe (m(ft)): Ø6.35mm(1/4inch)
CF(kg(lbs))
+
(Correction Factor)
Total amount(kg(lbs))
CAUTION
If a negative result is obtained from
the calculation, no refrigerant needs
to be added.
u Special condition
In case of the No. of CST TQ/RAC SE/ARTCOOL SF models are over than 50% of the connected
indoor units when the total No. of connected indoor units are over than 50% of the max. connectable
indoor units.
Total amount(kg)
n Additional refrigerant charging amount (kg(lbs)) : Ⓒ
α
= (A x + B x ß) - (AVG x ß)
• A = Total No. of TQ, SE and SF Indoor units,
• B = Total No. of except TQ, SE and SF Indoor units,
• AVG = 50% of Max. No. of connectable Indoor units.
Example)
1) Installation Information
- Outside unit : 10HP
- Total indoor units : 6 units (TQ 3 units, SE 2 units, BH 1 unit)
2) Information from PDB
- Max. No. of connectable indoor units : 16 units
- Calculated additional refrigerant amount = 2kg (4.41lbs) : Ⓑ
3) Indoor refrigerant charging amount
= (5 units x 0.5+1 unit x 0.3) - (8 units x 0.3) = 0.4 kg(0.88lbs) : Ⓒ
▶ Revised the total additional charging amount = Ⓑ + Ⓒ = 2kg (4.41lbs) + 0.4 kg(0.88lbs)
38 Outside Unit
x 0.237 lbs/ft
x 0.178 lbs/ft
x 0.116 lbs/ft
x 0.079 lbs/ft
x 0.041 lbs/ft
x 0.015 lbs/ft
= +
A B
= + +
A B C
Ex) 10HP
Outside unit
Header branch
Indoor unit
A : Ø9.52(3/8), 50m(164ft)
B : Ø9.52(3/8), 10m(33ft)
C : Ø9.52(3/8), 10m(33ft)
D : Ø9.52(3/8), 10m(33ft)
E : Ø 6.35(1/4), 10m(33ft)
Additional Charge = A x 0.041 + B x 0.041 + C x 0.041
+ D x 0.041 + E x 0.015 + HR + CF
= 164 x 0.041 + 33 x 0.041 + 33 x 0.041
+ 33 x 0.041 + 33 x 0.015 + 0(CF)
= 11.3lbs(5.1kg)
α
= 0.5
ß = 0.3
= 2.4 kg(5.29lbs)