4
INSTALLATION/VERIFICATION OF THE
SYSTEMS EXPANSION DEVICE
After outdoor and indoor unit placement has been determined,
refer to the Quick Reference Data sheet for information on the
appropriate TXV metering device to use for the equipment.
Verify that the installed expansion device matches those
requirements or install the correct expansion device. Outdoor
heat-pump units have the correct outdoor expansion device
pre-installed at the factory. Verify that the TXV provided
with the indoor unit matches the requirements in the Quick
Reference Data. The correct expansion device or kit is
available for all approved Nortek listed applications from
the parts department.
Connecting Refrigerant Tubing Between the Indoor
& Outdoor Unit
The SH3QE4M SERIES of units are equipped with single use
quick-connect couplings. Together with the indoor section
and an approved line-set, only four coupling connections are
required to provide a 100% sealed system. Pre-Charged
Line-Set Kits of various lengths may be found in the technical
sales literature for the unit.
• Tubing and quick connect couplers should be kept clean
of foreign debris during installation.
• The SH3QE4M units are equipped with a factory installed,
liquid line filter-drier within the outdoor unit. Installers
should ensure that only one filter-drier is installed in the
liquid line of the system.
After outdoor and indoor unit placement has been determined,
route refrigerant tubing between the equipment in accordance
with sound installation practices.
• Refrigerant tubing should be routed in a manner that
minimizes the length of tubing and the number of bends
in the tubing. If precise forming of refrigerant lines is
required, a copper tubing bender is recommended. Avoid
sharp bends and contact of the refrigerant lines with metal
surfaces.
• Refrigerant tubing should be supported in a manner that the
tubing will not vibrate or abrade during system operation.
• Every effort should be made by the installer to ensure that
the field installed refrigerant containing components of
the system have been installed in accordance with these
instructions and sound installation practices to insure
reliable system operation and longevity.
• The maximum recommended interconnecting refrigerant
line lengths is 75 ft. and the vertical elevation difference
between the indoor and outdoor sections should not exceed
20 ft.
• Optional equipment such as liquid line solenoid valves,
low ambient, etc., should be installed in strict accordance
with the manufacturer’s installation instructions.
Coupling the Line-Set to the Unit
Nortek approved line-sets are factory sealed assemblies,
vacuumed properly and pre-charged with a refrigerant holding
charge. Always verify that the refrigerant within the line-set
matches the refrigerant called out on the unit nameplate.
It is recommended to only work on and complete one quick-
connection coupling at a time. After the line-set has been
properly routed between the units, prepare the couplers and
connect them in accordance with the following.
1) Inspect the outside of the couplings and ensure that they
are free of any dirt or debris. Clean, if necessary.
2) Remove the protective caps and plugs from the couplings to
be joined. Inspect the interior of the coupling. If necessary,
clean the interior of the coupling with a clean, soft, lint-free
rag or cloth. Ensure that o-ring is in place and that the
threads are clean and undamaged.
3) Apply clean refrigerant oil to the entire surface of the
diaphragm, o-ring and threaded area of the male coupling
assembly. The amount of lubricant used must cover all
designated surfaces sufficiently. Ideal application is a
small brush with lubricant applied liberally. As an alternate,
another acceptable lubricant would be a refrigerant
compatible silicone grease product similar to Dow Corning
DC200/60,000 cst. Nortek approved line-set kits include
a packet of silicone grease for use.
4) Ensure that the couplers to be joined are properly aligned
with each other. The end faces of the couplers should be
parallel with each other and visually in-line down the center
axis of the couplers. By hand, start threading the nut on the
female coupler onto the male for 2-3 full thread rotations
of the union nut. This should bring the diaphragm of both
couplers into contact with each other. A sharp increase in
torque will be felt when they come into contact.
If the nut will not start by hand, or if it is difficult to rotate
the union nut by hand, adjust the position of the line-set
coupler to improve the alignment between the couplers.
There should be no side-load on the coupling during
assembly. DO NOT Proceed to the next step until any
misalignment is corrected and the union nut can easily
be threaded by hand.
5) Refer to table 1 for the appropriate wrench sizes and torque
values for the coupling being connected.
Once this operation is begun, the coupling seals will be
pierced, and the units’ refrigerant will be released into
the line. During the tightening operation, the o-ring seal
will prevent any refrigerant from escaping. However, if
for any reason it is decided to disassemble the coupling
after beginning this operation, the refrigerant charge will
need to be recovered from the unit and the line prior to
doing so.
Using both a back-up wrench on the female body of the
coupling and primary wrench on the female union nut,
tighten the union nut. Ensure that the female coupler body
does not rotate with respect to the male coupler during the
tightening operation. The nut should be tightened until a
definite increase in resistance is felt. This will be the metal
to metal contact of the permanent sealing surfaces. At this
point, the union nut will have covered all, or mostly all threads
on the male coupler body. (Some larger coupler sizes may
show approximately 1/2 of the last thread when properly
assembled.) Refer to the figure below for additional detail.
COUPLING
SIZE
TORQUE
MALE
COUPLING
FEMALE
COUPLING
NUT
FEMALE
COUPLING
BODY
3/8”
(10mm)
10-12 Ft-Lbs
(14-16 Nm)
3/4”
13/16”
5/8”
3/4”
(19mm)
35-45 Ft-Lbs
(47-61 Nm)
1-1/16”
1-5/16”
1”
7/8”
(22mm)
35-45 Ft-Lbs
(47-61 Nm)
1-1/8”
1-5/16”
1”
Table 1. Torque Values
