Refrigerant Piping Connections - Lennox MCB Series Installation Instruction

Four Field-provided Anchor Bolts
Figure 20. Securing Outdoor Unit to Slab
Figure 21. Securing Outdoor Unit to Rails
Securing Outdoor Unit to Hanging Brackets
If the outdoor unit is installed on field-provided wall
mounting brackets, use lag bolts or equivalent to secure
the outdoor unit to the bracket. Minimum rear clearance
can be reduced to 6 inches (152 mm) when mounted
on brackets and with no obstructions on the other three
sides. Allow for moisture disposal when placing units
above one another.
Air Outlet
Figure 22. Securing Outdoor Unit to Brackets

Refrigerant Piping Connections

Field piping consists of two copper lines connecting the
outdoor unit to the indoor unit. "Table 3. Refrigerant Piping
and Indoor Unit Connection Sizes" on page 11 lists
the connection sizes. The connections are made using
the provided brass flare nuts at the end of the refrigerant
piping connections.
1. Choose the correct pipe sizes for your application
using "Table 3. Refrigerant Piping and Indoor Unit
Connection Sizes" on page 11.
2. Confirm that you are using the correct diameter piping.
3. Determine the necessary piping length required for
the application.
Four Field-Provided
Anchor Bolts
6 in
152 mm
Air Inlet
4. Cut the selected pipes with a pipe cutter. Make the
cuts flat and smooth as illustrated in "Figure 23.
Cutting Piping".
Figure 23. Cutting Piping
5. Insulate the copper piping.
6. Insert a flare nut onto each pipe before flaring.
7. Use "Table 2. Flaring Pipe" to properly flare the pipe.
Table 2. Flaring Pipe
Flare Dimension
A (mm)
Pipe Diameter
Min
1/4" 8.3
3/8" 12.0
1/2" 15.4
5/8" 18.6
3/4" (22.9) 22.9
8. After flaring the pipe, temporarily sealed pipe ends
with adhesive tape to avoid contaminants from
entering the pipes.
9. 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.
10. CAREFULLY adjust refrigerant piping connections to
suit the application.
11. Slowly loosen one of the flare nuts to release the
factory nitrogen charge from the indoor units only.
12. Remove the flare nuts from the connections on the
unit and discard the seal from each of the piping
connections.
13. 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.
14. Apply recommended HFC­410A refrigerant lubricant
to the outside of the flared refrigerant lines.
10
Lean Crude Burr
Flare Shape
Max
8.7
- +
90 ° 4
12.4
15.8
A
19.1
R0.4~0.8
23.3