LG LMU185HV Manuel D'utilisation page 45

Charging
Charging
I Each outdoor unit is factory charged (see rating plate) for the evaporator as well as a 7.5m(25ft)
line set for each indoor line.
Any time total line set is used either shorter or longer than the nominal 7.5*ID No. m(25*ID No. ft)
line set length the refrigerant charge has to be adjusted.
I Whether the line set is made shorter or longer you must adjust the charge based on how many ft
of tubing are either added or removed based on 20g/m(0.22oz/ft) of R-410A per meter(foot).
Max total length
Outdoor Unit Max length of
of all pipes
Capacity each pipe
(A+B)/(A+B+C)/
(Btu/h class) (A/B/C/D)
(A+B+C+D)
18k 50(164) 25(82)
24k 75(246) 25(82)
36k 75(246) 25(82)
Important:
If you are ever uncertain of the unit charge, reclaim, evacuate and weigh in the correct charge using
the charge amount specified on the unit's rating plate, adjusting for line sets longer or shorter than
7.5m(25ft) for each indoor unit.
Additional charge(g) = [(A Room Installation Length - Standard Length ) x 0.22 oz/ft
+ (B Room Installation Length - Standard Length ) x 0.22 oz/ft +.. ]
- CF(Correction Factor) x 1.61 oz
❈ CF = Max. number of connectable indoor unit – Total number of connected indoor unit
A
Ex) A4UW363FA0
❈ If the total additional charge value after calculation comes out to be negative, then do not
consider additional charge.
44 Multi Air Conditioner
Max Elevation Max elevation
Min length of
between each between
each pipe
indoor unit and indoor units
(A/B/C/D)
outdoor unit (h1)
3(10) 15(49) 7.5(25)
3(10) 15(49) 7.5(25)
3(10) 15(49) 7.5(25)
Each branch pipe
9k
a
a=82ft
b=16ft
c=49ft
9k
b
Additional Charge
= (82-25) x 0.22
9k
c
+ (16-25) x 0.22
+ (49-25) x 0.22
- (4-3) x 1.61
= 12.54 - 1.98 + 5.28 - 1.61 =14.23 oz
Unit:m(ft)
Additional Piping
Refrigerant Length(no add'l
Unit : g/m (oz/ft) refrigerant)
(h2)
20(0.22) 22.5(74)
20(0.22) 37.5(128)
20(0.22) 37.5(128)