LG LMNH122LRA0 Service Manual page 49

Refrigerant Charge
• Direct Piping Circuit
Indoor Unit Capacity
(Btu/h)
48k
Extra refrigerant per circuit = (Extended length - Rated length) x Additional refrigerant
• Distributor Piping Circuit
The calculation of the additional charge should take account of the length of pipe.
Additional charge (g)
=
Total Main pipe length - rated length
+
12k Branch pipe length - rated length
+ 18k~36k Branch pipe length - rated length
Rated length = Main pipe : 5m
Additional Charge of Circuit 1
• Total main pipe(A) = 30m
• Each branch pipe(a, b, c) = 10m
• Additional Charge = (30-5)m x 60g/m
Pipe Size
Gas
3/4"(19.05mm) 3/8"(9.52mm)
Branch pipe : 7.5m
+ (10-5)m x 30g/m x 3
= 1950g
Rated
Liquid Length Length
7.5m
x 60g/m
B
x 20g/m
Circuit 2
x 30g/m
Additional Charge of Circuit 2
• Total main pipe(B) = 30m
• Each branch pipe(d, e) = 10m
• Additional Charge = (30-5)m x 60g/m
Max Additional
Refrigerant
50m 60g/m
Circuit 1
A
a b
18k 18k
d
24 k
+ (10-5)m x 30g/m x 2
= 1800g
Service Manual 49
Installation
c
18k
e
24 k