Lennox MMDA048S4-*P Installation Instructions

14
2. Conrm that you are using the correct diameter piping.
3. Determine the necessary piping length required for the
application.
4. Cut the selected pipes with a pipe cutter. Make the
cuts at and smooth as illustrated in “Figure 26.
Cutting Pipe”.
90
Lean
Crude
Burr
o
Figure 26. Cutting Pipe
5. Insulate the copper piping.
6. Insert a are nut onto each pipe before aring.
7. Use “Table 2. Flaring Pipe” to properly are the pipe.
Table 2. Flaring Pipe
Pipe Diameter
Flare Dimension
A (mm)
Flare Shape
Min Max
1/4” (6.35) 8.3 8.7
R0.4~0.8
A
45
°
90°
4
-
+
3/8” (9.62) 12.0 12.4
1/2” (9.52” 15.4 15.8
5/8” (15.9) 18.6 19.1
3/4” (22.9) 22.9 23.3
8. After aring 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 are nuts to release the
factory nitrogen charge from the indoor units only.
12. Remove the are nuts from the connections on the
unit and discard the seal from each of the piping
connections.
13. Slide the are nuts onto the ends of the eld-provided
refrigerant piping before using a suitable aring tool to
are the end of the copper pipe.
14. Apply recommended HFC-410A refrigerant lubricant
to the outside of the ared refrigerant lines.
IMPORTANT
The compressor in this unit contains PVE oil
(Polyvinyl ether). PVE oil is formulated for
hydrouorocarbon (HFC) refrigerants, such as HFC-
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.
15. Align the threaded connections with the ared
refrigerant lines. Tighten the are nuts lightly at rst to
obtain a smooth match as illustrated in
Table 3. Refrigerant Piping and Indoor Unit
Connection Sizes
Size
(Btuh)
Liquid Line
in.
Gas Line
in.
9000 1/4 3/8
12000 1/4 1/2
18000 1/4 1/2
24000 3/8 5/8
36000 & 48000 3/8 5/8
A
B
CANT ON THE OUTSIDE OF
THE FLARE
MALE FLARE
CONNECTION
Figure 27. Making Connections
(Male to Female Connection)
16. Once snug, continue another half-turn on each
nut which should create a leak-free joint. A torque
wrench may be used to tighten are nuts using table
4 recommendations (“Table 4. Flare Nut Torque
Recommendations and Tightening Procedure” on
page 15). Do not over-tighten a ared joint.
Flared connections should always be accessible
and must be insulated to prevent condensation.
17. After refrigerant piping has been installed and checked
for leaks, apply insulation over all ared connections.

Lennox MMDA048S4-*P Specifications

General

Brand	Lennox
Model	MMDA048S4-*P
Category	Air Conditioner
Language	English