11
Tubing
INSTALLATION
Interconnecting Tubing (cont.)
Interconnecting Tubing and
Fitting Losses
Refrigerant tubing is measured in terms of actual
length and equivalent length. Actual length is used
for refrigerant charge applications. Equivalent
length takes into account pressure losses from
tubing length, ttings, vertical separation, acces
-
sories, and lter dryers. The table below references
di erent commonly used equivalent lengths.
Equivalent Length for Fi
!
ngs (
"
)
Line Size
(in)
90° Short
Radius
Elbow
90° Long
Radius
Elbow
45°
Elbow
Solenoid
Valve
Check
Valve
Site
Glass
Filter
Dryer
3/8
1.3
0.8
0.3
6
4
0.4
6
1/2
1.4
0.9
0.4
9
5
0.6
6
5/8
1.5
1
0.5
12
6
0.8
6
3/4
1.9
1.3
0.6
14
7
0.9
6
7/8
2.3
1.5
0.7
15
8
1
6
1-1/8
2.7
1.8
0.9
22
12
1.5
6
Liquid Line Selection
The purpose of the liquid line is to transport warm
sub-cooled liquid refrigerant from the outdoor unit
to the indoor unit. It is important not to allow the
refrigerant to ash any superheated vapor prior
to the expansion device of the indoor coil. The
ashing of refrigerant can occur for the following
reasons:
• ow refrigerant charge
• Improperly selected liquid line si e
• Absorption of heat prior to expansion device
• xcessive vertical rise between the condenser
and evaporator
Table 2 lists the equivalent length per 25’ of liquid
line at various diameters up to 300’. The total pres-
sure drop allowed for the liquid line is 50 PSI. The
procedure for selecting the proper liquid line is as
follows:
•
easure the total amount of vertical rise
•
easure the total amount of liquid line needed
• Add all of the equivalent lengths associated with
any ttings or accessories using the table above.
• Add the total length and tting pressure drop.
This will equal your total equivalent length.
• eference Table 2 to verify the calculated
equivalent length is compatible with the required
vertical rise and diameter of liquid line.
Table 1
Note: Eleva
!
on is defined as the
highest point of the line set to the
lowest
Figure 1
Summary of Contents for RA17 Series
Page 16: ...16 N R Application not recommended INSTALLATION Table 2 Tubing...
Page 17: ...17 N R Application not recommended INSTALLATION Table 3 Tubing...
Page 54: ...54 R C For Single Phase Models WIRING DIAGRAMS Wiring Diagrams...
Page 55: ...55 WIRING DIAGRAMS Wiring Diagrams...
Page 56: ...56 NOTES...
