LG ARUB290DT2, Installation Manual

Page: 36 / 91

36 Outdoor Unit
◆
The amount of Refrigerant
The calculation of the additional charge should take into account the length of pipe.
Product Charge(kg(lb))
Additional charge (kg(lb))
=
+
+
+
+
+
+ =
+
x 0.354(kg/m)
→
0.237 lb/ft
x 0.266(kg/m)
→
0.178 lb/ft
x 0.173(kg/m)
→
0.116 lb/ft
x 0.118(kg/m)
→
0.079 lb/ft
x 0.061(kg/m)
→
0.041 lb/ft
x 0.022(kg/m)
→
0.015 lb/ft
CF(kg(lb))
(Correction Factor)
If a negative result is obtained from
the calculation, no refrigerant needs
to be added.
A
A B
B
CAUTION
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)
Total amount(kg(lb))
B B B
B B
A
B
C
X
b
a
c d
3 4 5
2 1
e
Outdoor Unit
Indoor Unit
A : ø9.52(3/8), 40m(131ft)
B : ø9.52(3/8), 20m(65.6ft)
C : ø9.52(3/8), 20m65.6ft)
Ex 10HP
Additional charge = A*0.041 + B*0.041 + C*0.041
+(a+b+c+d+e)*0.015 + CF
= 40*0.041+20*0.041+65.6*0.041
+ (32.8*5)*0.015 + (0)(CF)
= 7.61(lb)
a : ø6.35(1/4), 10m(32.8ft)
b : ø6.35(1/4), 10m(32.8ft)
c : ø6.35(1/4), 10m(32.8ft)
d : ø6.35(1/4), 10m(32.8ft)
e : ø6.35(1/4), 10m(32.8ft)
36 Outdoor Unit
◆
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.
■
Additional refrigerant charging amount (kg) :
= (A x + B x ß) - (AVG x ß)
• A = Total No. of TQ,SE and SF Indoor units, = 0.5
• B = Total No. of except TQ,SE and SF Indoor units, ß = 0.3
• AVG = 50% of Max. No. of connectable Indoor units.
Example)
1) Installation Information
- Outdoor unit : 6HP
- Total indoor units : 6 units (TQ 3 units, SE 2 units, BH 1 unit)
2) Information from PDB
- Max. No. of connectable indoor units : 10 units
- Calculated additional refrigerant amount = 2kg(0.91 lb) :
3) Indoor refrigerant charging amount
= (5 units x 0.5+1 unit x 0.3) - (5 units x 0.3) = 1.3kg(0.59 lb) :
Revised the total additional charging amount = = 2kg(0.91 lb) +1.3kg(0.59 lb)
= 3.3kg(1.50 lb)
+ =
Total amount(kg(lb)) A B
+
C