14
INSTALLATION
Interconnecting Tubing (cont.)
Example: A 3-Ton heat pump unit is installed 50’
below the ID unit, requires a 75’ of 1/2” diameter
liquid line, and 4 90° LR elbows.
• Fitting Equivalent Length (ft.) = 4 x .9 = 3.6’
• Total Equivalent Length (ft.) = 75’ + 3.6’ = 78.6’
• Rounded-down value (ft.) = 75’
This application is acceptable because the 50’
vertical rise is less than the maximum rise of 75’ for
this application. The application is also considered
to have a long line set. Reference the long line set
section of the I&O for detail.
R-410A
System
Capacity
Model
Liquid Line
Size
Connection
Size (Inch
I.D.) [mm]
Liquid Line
Size (Inch
O.D.) [mm]
Liquid Line Size
Elevation (Above or Below) Indoor Coil
Total
Equiva l e nt
Length - Feet [m]
25 [7.62] 50 [15.24] 75 [22.86] 100 [30.48] 125 [45.72] 150 [45.72] 175 [53.34] 200 [60.96] 225 [68.58] 250 [76.20] 275 [83.82] 300 [91.44]
Max imum
Vertical Separation - Feet [m]
37 3/8" [9.53]
1/4 [6.35] 25 [7.62]
N/R N/R N/R N/R N/R N/R N/R N/R N/R N/R N/R
5/16 [7.94] 25 [7.62] 50 [15.24] 60 [18.29] 45 [13.72] 35 [10.67] 20 [6.1] 5 [1.52]
N/R N/R N/R N/R N/R
3/8 [9.53] 25 [7.62] 50 [15.24] 75 [22.86] 80 [24.38] 80 [24.38] 75 [22.86] 70 [21.34] 65 [19.81] 60 [18.29] 55 [16.76] 50 [15.24] 45 [13.72]
7/16 [11.12] 25 [7.62] 50 [15.24] 75 [22.86] 95 [28.96] 90 [27.43] 90 [27.43] 85 [25.91] 85 [25.91] 85 [25.91] 80 [24.38] 80 [24.38] 80 [24.38]
1/2 [12.71] 25 [7.62] 50 [15.24] 75 [22.86] 95 [28.96] 95 [28.96] 95 [28.96] 95 [28.96] 95 [28.96] 95 [28.96] 90 [27.43] 90 [27.43] 90 [27.43]
Long Line Set Applications
Long line set applications are defi ned as applica-
tions that require accessories or alternate construc-
tion methods. The following are special consider-
ations that need to be addressed when installing a
long line set application:
• Additional refrigerant charge
• Fitting losses and maximum equivalent length
considerations
• Refrigerant migration during the off cycle
• Oil return to the compressor
• Capacity losses
• System oil level adjustment
Table 2 is used to determine if the application is
considered to have a long line set. The region of
the chart that is shaded grey is considered to be
a long line set application.
Oil Level Adjustments for
Long Line Set Applications
Additional oil will need to be added for long line
set applications. (Ref. Table 2). Below is the equa-
tion for the oil level adjustment and the compressor
name plate oil charge for the diff erent od units.
Oil to be Added = [(Charge Adjustment + OD
Unit Name Plate Charge (oz.)) x (0.022) – [(0.10) x
(Compressor Name Plate Oil Charge (oz.))]
Example: An application requires 125ft of line set
with a liquid line diameter of 3/8”, Charge Adjust-
ment = 52.4 oz., Name Plate Charge = 107 oz.,
Name Plate Oil Charge = 25 oz., Oil to be Added =
((52.4 oz. +107 oz.) x .022) – (.10 x 25 oz.) = 1.0 oz.
(Exerpt from Table 2, page 17)
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