Refrigerant Charge; Additional Charge - LG MULTI F LMU18CHV Installation Manual

F
MULTI
F
MULTI MAX
LG Multi F and Multi F MAX outdoor units ship from the factory with a charge of
R410A refrigerant. A trim charge may need to be added to take into account
additional piping length.
To determine the additional refrigerant that is needed, apply the formulas below,
and record the results. If the total additional refrigerant charge value is a negative
number, then an additional trim charge does not need to be added to the system.
Multi F Systems
- CF (Correction Factor) x 5.29
• Number of installed length of branches depends on the specifications of the outdoor unit model.
•
Table 35:
Min. to Max. Piping
Outdoor
Length for One
Unit Model
Branch (ft.)
LMU18CHV 9.8 to 82
LMU24CHV 9.8 to 82
LMU30CHV 9.8 to 82
LMU36CHV 9.8 to 82
Figure 57: Multi F Additional Refrigerant Charge Example.
Example: LMU36CHV
REFRIGERANT PIPING PREPARATION
Max. Total System Chargeless Pipe Length
Piping Length (ft.) per Branch (L) (ft.)
164
246.1
246.1
246.1
A
B
C
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. "LG" is a registered trademark of LG Corp.
Table 34: Outdoor Unit Factory Charge.
Outdoor Unit
LMU18CHV
LMU24CHV
LMU30CHV
LMU36CHV
LMU480HV
LMU540HV
Piping Length (No Additional
Refrigerant [ft])
24.6
24.6
24.6
24.6
9,000
9,000

Additional Charge

= (82 - 24.6) x 0.22
9,000
+ (16 - 24.6) x 0.22
+ (49 - 24.6) x 0.22
- (4 - 3) x 5.29
= 10.82 oz.

Refrigerant Charge

Factory Charge
lbs. of R410A
3.96
3.96
6.18
6.18
9.7
9.7
Additional Charge
Needed (a) (oz./ft.)
49.2 0.22
73.8 0.22
98.4 0.22
98.4 0.22
Each branch pipe
A = 82 ft.
B = 16 ft.
C = 49 ft.
45