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31-5000751 Rev. 0
Polyvinyl ether (PVE) oils used with HFC-410A
refrigerant absorb moisture very quickly. It is very
important that the refrigerant system be kept closed
as much as possible. DO NOT remove line set caps
or service valve stub caps until you are ready to make
connections.
WARNING
Do
NOT
attempt to flush and re-use existing line sets
or indoor coil when the system contains contaminants
(i.e., compressor burn out).
CAUTION
“Clean refrigerant” is any refrigerant in a system that
has not had compressor burnout. If the system has
experienced burnout, it is recommended that the
existing line set and indoor coil be replaced.
NOTE
In lieu of R-410A, an industry-standard flushing agent
may also be used.
NOTE
Heat Pump System (HFC410A)
•
Total equivalent length equals 180 feet (piping and all
fittings included).
NOTE:
Length is general guide. Lengths may be
more or less, depending on remaining system design
factors.
•
Maximum linear (actual) length = 150 feet.
•
Maximum linear liquid lift = 60 feet.
NOTE:
Maximum lifts are dependent on total length,
number of elbows, etc. that contribute to total pressure
drop.
•
Maximum length vapor riser = 60 feet.
•
Up to 50 Linear Feet: Use rated line sizes listed in
Table 3.
•
Between 51 and 150 Linear Feet: Crankcase heater
and nonbleed port TXV factory installed. No additional
components required. Vertical vapor riser must be
sized to the vapor riser listed in the Table 4 on systems
with line sets longer than 51 feet. Use Table 4 and
Table 5 to determine the correct liquid and vapor line
sizes.
•
Over 150 Linear Feet: not recommended.
•
Additional oil is not required for systems with line
lengths up to 150 feet.
Suction Traps
For systems with the outdoor unit 5 - 60 feet above the
indoor unit, one trap must be installed at the bottom of the
suction riser.
NOTE:
Special consideration must be taken for line sets
over 50 feet. See Refrigerant Piping Guidelines.
Tonnage *
Valve Size Connections
Recommended Line Sets
Liquid Line
Suction Line
Line Set Length
-24
3/8” (10mm)
3/4” (19mm)
30’ (9.1m)
-36
40’ (12.2m)
-48
7/8” (22mm)
50’ (15.2m)
-60
1-1/8” (29mm) **
Field-fabricated
* Applicable to all minor revision numbers unless otherwise specified.
** Some applications may require a field-provided 1-1/8” to 7/8” adapter.
Table 3. Standard Refrigerant Line Set – Up to 50 Linear Feet in Length
Tonnage
Maximum Total
Equivalent
Length (ft)
Maximum Linear
(actual) Length
(ft)
Maximum Vapor
Riser (ft)
Maximum Linear
Liquid Lift (ft)
Preferred Vapor
Line Sizes for
Horizontal Runs
Required Vapor
Riser Size
-24
180
150
60
60
7/8”
5/8”
-36
3/4”
-48
7/8”
-60
Table 4. NS18HM Line Set Guidelines – 51 to 150 Linear Feet in Length