Install 4 oil traps for a height difference of 101 ft to 150 ft
(30.8 m to 45.7 m) between indoor and outdoor units.
A. Condensing unit
B. Liquid line
Insulation is necessary to avoid condensation from forming and
dropping from the suction line. Armflex (or satisfactory
equivalent) with ³⁄₈" (1 cm) minimum wall thickness is
recommended. In severe conditions (hot, high humidity areas),
¹⁄₂" (1.3 cm) insulation may be required. Insulation must be
installed in a manner which keeps tubing from damage and
Connect Refrigerant Lines
Refrigerant lines must be connected by a licensed, EPA certified
refrigerant technician in accordance with established procedures.
Connecting refrigerant lines must be clean, dehydrated,
refrigerant-grade copper lines. Heat pumps should be
installed only with specified line sizes for approved system
combinations with elevation differences up to 15 ft (4.6 m)
and total length of up to 50 ft (15.2 m). See the Suction Line
Sizes and Liquid Line Sizes charts.
Sharp bends or possible kinking in the lines will cause a
reduction in performance.
To avoid contamination of the refrigerant system, do not
remove the caps from the lines or system connection points
until connections are ready to be completed.
C. Suction line
D. Evaporator coil
Connect Liquid and Suction Lines
The compressor POE oil for R-410A units is extremely
susceptible to moisture absorption and could cause
compressor failure. Do not leave system open to
atmosphere any longer than necessary for installation.
To avoid the risk of fire or explosion, never use oxygen,
high pressure air or flammable gases for leak testing of a
To avoid possible explosion, the line from the nitrogen
cylinder must include a pressure regulator and a pressure
relief valve. The pressure relief valve must be set to open at
no more than 150 psig.
1. Route the suction and liquid lines from the fittings on the
indoor coil to the fittings on the heat pump. Run the lines in
as direct a path as possible, avoiding unnecessary turns and
2. For product efficiency, be sure that the suction line is
insulated over the entire exposed length and that both
suction and liquid lines are not in direct contact with floors,
walls, ductwork, floor joists, or other piping.
3. Remove valve cores.
4. Wrap the service valves with a wet rag or an approved
5. If a filter dryer is not provided, install a filter dryer in the liquid
line between the outdoor condensing unit and the indoor
NOTE: To reduce oxidation from forming and contaminating
the system, purge the line set/coil with nitrogen (1 to 2 psig)
during the brazing process.