7
Refrigerant Piping Connections
WARNING
!
Refrigerant leaks are unlikely; however, if a refrigerant leak
occurs, open a door or windows to dilute the refrigerant
in the room. Turn off the unit and all other appliances that
may cause a spark. Call a licensed professional HVAC
technician (or equivalent) to repair the leak.
Use only R410A refrigerant to charge this system. Use of
other refrigerant or gas will damage the equipment.
Do not allow air or other contaminants to enter system
during installation of refrigerant piping. Contaminants
will result in lower system capacity and abnormally high
operating pressures and may result in system failure or
explosion.
Insulate all refrigerant piping.
Refrigerant pipes may be very hot during unit operation.
Do not allow contact between wiring and bare copper
pipes.
After refrigerant piping connections have been completed,
check the system for leaks per commissioning instructions.
Field piping consists of two copper lines connected to the
indoor unit. Table 1 lists the connection sizes at the indoor
unit. The connections are made using the provided brass
fl are nuts at the end of the refrigerant piping connections.
Both lines must be individually insulated.
1. The seal on the unit refrigerant piping connections
should remain in place until the last possible moment.
This will prevent dust or water from getting into the
refrigerant piping before it is connected.
2. CAREFULLY adjust refrigerant piping connections to
suit the application (straight back, right or left).
3. Slowly loosen one of the fl are nuts to release the factory
nitrogen charge.
4. Remove
the
fl are nuts from the connections on the unit
and discard the seal from each of the piping connections.
5. Slide
the
fl are nuts onto the ends of the fi eld-provided
refrigerant piping
before
using a suitable fl aring tool to
fl are the end of the copper pipe.
6. Apply recommended HFC-410A refrigerant lubricant to
the outside of the fl ared refrigerant lines (fi gure 7-A).
IMPORTANT!
The compressor in this unit contains PVE
oil (Polyvinylether). PVE oil is formulated for
hydrofl uorocarbon (HFC) refrigerants, such as R-
410a, which this system contains. While it may have
some miscibility properties with mineral-based oil
and POE oil (Polyolester), it is not recommended to
mix PVE oil with any other type of refrigerant oil.
Size
(Btuh)
Liquid Line
in.
Vapor Line
in.
7000
12000
15000
1/4
1/2
18000
24000
30000
36000
48000
3/8
5/8
Table 1. Refrigerant Piping Connections
7. Align the threaded connections with the fl ared refrigerant
lines. Tighten the fl are nuts lightly at fi rst to obtain a
smooth match (fi gure 7-B).
8. Once snug, continue another half-turn on each nut
which should create a leak-free joint. A torque wrench
may be used to tighten fl are nuts using table 2
recommendations. See fi gure 4.
Do not over-tighten
a fl ared joint. Flared connections should always
be accessible and must be insulated to prevent
condensation.
9. After refrigerant piping has been installed and checked
for leaks, apply insulation over the connector pipe and
all fl ared connections.
A
B
CANT ON THE OUTSIDE OF
THE FLARE
MALE FLARE
CONNECTION
Figure 7. Making Connections
(Male to Female Connection)
IMPORTANT!
Always use two wrenches when tightening fl are
nuts to avoid twisting refrigerant piping. DO
NOT over-tighten fl are nuts.
TORQUE WRENCH
TO INDOOR
UNIT
TO OUTDOOR UNIT
BACKUP
WRENCH
Figure 8. Tighten Flare Nut
