Charging - LG LMU366HV Installation Instructions Manual

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
of all pipes
Capacity
(A+B)/(A+B+C)/
(Btu/h class)
(A+B+C+D)
18k 50(164)
24k 75(246)
36k 75(246)
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
❈ 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 length of Min length of
each pipe each pipe
(A/B/C/D) (A/B/C/D)
25(82)
25(82)
25(82)
+ (B Room Installation Length - Standard Length ) x 0.22 oz/ft +.. ]
- CF(Correction Factor) x 1.61 oz
a
b
c
Max Elevation
between each
indoor unit and
outdoor unit (h1)
3(10) 15(49)
3(10) 15(49)
3(10) 15(49)
Each branch pipe
9k
a=82ft
b=16ft
c=49ft
9k
Additional Charge
= (82-25) x 0.22
9k
+ (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
Max elevation
Additional
between
Refrigerant
indoor units
Unit : g/m (oz/ft)
(h2)
7.5(25) 20(0.22)
7.5(25) 20(0.22)
7.5(25) 20(0.22)
Unit:m(ft)
Piping
Length(no add'l
refrigerant)
22.5(74)
37.5(128)
37.5(128)