LG Multi F MAX PMBD3640 - Refrigerant Charging Guidelines

45
Refrigerant Piping Connections
Due to our policy of continuous product innovation, some specifications may change without notification.
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MULTI
F
MAX
MULTI
F
Refrigerant Charge
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.
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- CF (Correction Factor) x 5.29
Outdoor
Unit Model
Min. to Max. Piping
Length for One
Branch (ft.)
Max. Total System
Piping Length (ft.)
Chargeless Pipe Length
per Branch (L) (ft.)
Piping Length (No Additional
Refrigerant [ft])
Additional Charge
Needed (a) (oz./ft.)
LMU18CHV 9.8 to 82 164 24.6 49.2 0.22
LMU24CHV 9.8 to 82 246.1 24.6 73.8 0.22
LMU30CHV 9.8 to 82 246.1 24.6 98.4 0.22
LMU36CHV 9.8 to 82 246.1 24.6 98.4 0.22
Outdoor Unit
Factory Charge
lbs. of R410A
LMU18CHV 3.96
LMU24CHV 3.96
LMU30CHV 6.18
LMU36CHV 6.18
LMU480HV 9.7
LMU540HV 9.7
Table 34: Outdoor Unit Factory Charge.
Multi F Systems
• Number of installed length of branches depends on the specifications of the outdoor unit model.
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Table 35: 0XOWL)2XWGRRU8QLW3LSLQJ6SHFL¿FDWLRQV
Figure 57: Multi F Additional Refrigerant Charge Example.
Each branch pipe
A = 82 ft.
B = 16 ft.
C = 49 ft.
Additional Charge
A
B
C
9,000
9,000
9,000
Example: LMU36CHV
= (82 - 24.6) x 0.22
+ (16 - 24.6) x 0.22
+ (49 - 24.6) x 0.22
- (4 - 3) x 5.29
= 10.82 oz.
REFRIGERANT PIPING PREPARATION