Refrigerant Piping Connections - Lennox VRF VWMB Series Installation Instruction

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
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
flare 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 flare nuts to release the
factory nitrogen charge.
4. Remove the flare nuts from the connections on the
unit and discard the seal from each of the piping
connections.
5. Slide the flare nuts onto the ends of the field-provided
refrigerant piping before using a suitable flaring tool
to flare the end of the copper pipe.
6. Apply recommended HFC-410A refrigerant lubricant
to the outside of the flared refrigerant lines (figure
7-A).
IMPORTANT
The compressor in
oil (Polyvinylether). PVE
hydrofluorocarbon (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.
connections have been
this unit contains PVE
oil is formulated
Table 1. Refrigerant Piping Connections
Size
(Btuh)
7000
9000
12000
15000
18000
24000
30000
A
B
Figure 7. Making Connections
(Male to Female Connection)
7. Align the threaded connections with the flared
refrigerant lines. Tighten the flare nuts lightly at first to
obtain a smooth match (figure 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 flare nuts using table 2
recommendations. See figure 4. Do not over-tighten
a flared 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 flared connections.
Always use two wrenches when tightening flare nuts to
avoid twisting refrigerant piping. DO NOT over-tighten
flare nuts.
for
To Indoor Unit
Figure 8. Tighten Flare Nut
7
Liquid Line Vapor Line
in. in.
1/4 1/2
3/8 5/8
CANT ON THE OUTSIDE OF
THE FLARE
MALE FLARE
CONNECTION
IMPORTANT
Torque Wrench
To Outdoor Unit
Backup
Wrench