Airease 4SCU16LS Series User manual

507607-03 Issue 1946 Page 1 of 24
Save these instructions for future reference
INSTALLATION INSTRUCTIONS
4SCU16LS SERIES
Two-Stage Split System Air Conditioner
(P) 507607-03
*P507607-03*
Manufactured By
Allied Air Enterprises LLC
A Lennox International, Inc. Company
215 Metropolitan Drive
West Columbia, SC 29170
This manual must be left with the homeowner for future reference.
Table of Contents
General........................................................................1
Installation ...................................................................2
Refrigeration Piping.....................................................4
Electrical Wiring.........................................................12
Start-Up .....................................................................14
Operation...................................................................15
Seven-Segment Alert and System Status Codes......15
Maintenance..............................................................22
Homeowner Information ............................................23
This is a safety alert symbol and should never be ignored. When you see this symbol on labels or in manuals, be alert to
the potential for personal injury or death.
Installation and servicing of air conditioning equipment
can be hazardous due to internal refrigerant pressure
and live electrical components. Only trained and
qualied service personnel should install or service
this equipment. Installation and service performed by
unqualied persons can result in property damage,
personal injury, or death.
WARNING
ELECTRICAL SHOCK HAZARD!
Risk of electrical shock. Disconnect all
remote power supplies before installing
or servicing any portion of the system.
Failure to disconnect power supplies
can result in property damage, personal
injury, or death.
WARNING
Sharp metal edges can cause injury. When installing
the unit, use care to avoid sharp edges.
WARNING
General
Read this entire instruction manual, as well as the
instructions supplied in separate equipment, before
starting the installation. Observe and follow all warnings,
cautions, instructional labels, and tags. Failure to comply
with these instructions could result in an unsafe condition
and/or premature component failure.
These instructions are intended as a general guide only
for use by qualied personnel and do not supersede any
national or local codes in any way. The installation must
comply with all provincial, state, and local codes as well as
the National Electrical Code (U.S.) or Canadian Electrical
Code (Canada). Compliance should be determined prior
to installation.

507607-03Issue 1946Page 2 of 24
This unit uses R-410A, which is an ozone-friendly HFC
refrigerant. The unit must be installed with a matching
indoor coil and line set. A lter drier approved for use with
R-410A is installed in the unit.
When servicing or repairing HVAC components, ensure
the fasteners are appropriately tightened. Table 1 shows
torque values for fasteners.
Fastener Torque
Stem Caps 8 ft. lbs.
Service Port Caps 8 ft. lbs.
Sheet Metal Screws 16 in. lbs.
#8 Machine Screws 16 in. lbs.
#10 Machine Screws 28 in. lbs.
Compressor Bolts 90 in. lbs.
Table 1. Torque Table
Inspection of Shipment
Upon receipt of equipment, carefully inspect it for possible
shipping damage. If damage is found, it should be noted
on the carrier’s freight bill. Take special care to examine
the unit inside the carton if the carton is damaged. Any
concealed damage discovered should be reported to the
last carrier immediately, preferably in writing, and should
include a request for inspection by the carrier’s agent.
If any damages are discovered and reported to the carrier
DO NOT INSTALL THE UNIT, as claim may be denied.
Check the unit rating plate to conrm specications are as
ordered.
Safety Precautions
Follow all safety codes. Wear safety glasses and work
gloves. Use quenching cloth for brazing operations.
Have re extinguisher available. Read these instructions
thoroughly and follow all warning or cautions attached to
the unit.
1. Always wear proper personal protection equipment.
2. Always disconnect electrical power before removing
panel or servicing equipment.
3. Keep hands and clothing away from moving parts.
4. Handle refrigerant with caution; refer to proper MSDS
from refrigerant supplier.
5. Use care when lifting, avoid contact with sharp edges.
Installation
NOTE: In some cases, noise in the living area has been
traced to gas pulsations from improper installation of
equipment.
• Locate unit away from windows, patios, decks, etc.
where unit operation sounds may disturb customer.
• Leave some slack between structure and unit to
absorb vibration.
• Place a sound-absorbing material, such as Isomode,
under the unit if it will be installed in a location or
position that will transmit sound or vibration to the
living area or adjacent buildings.
• In heavy snow areas, do not locate the unit where
drifting snow will occur. The unit base should be
elevated above the depth of average snows.
NOTE: Elevation of the unit may be accomplished
by constructing a frame using suitable materials. If a
support frame is constructed, it must not block drain
holes in unit base.
• When installed in areas where low ambient
temperatures exist, locate unit so winter prevailing
winds do not blow directly into outdoor coil.
• Locate unit away from overhanging roof lines which
would allow water or ice to drop on, or in front of, coil
or into unit.
When outdoor unit is connected to factory-approved indoor
unit, outdoor unit contains system refrigerant charge for
operation with matching indoor unit when connected by 15
ft. of eld-supplied tubing. For proper unit operation, check
refrigerant charge using charging information located on
control box cover.
Outdoor Section
Zoning ordinances may govern the minimum distance the
condensing unit can be installed from the property line.
Install on a Solid, Level Mounting Pad
The outdoor section is to be installed on a solid foundation.
This foundation should extend a minimum of 2” (inches)
beyond the sides of the outdoor section. To reduce the
possibility of noise transmission, the foundation slab
should NOT be in contact with or be an integral part of the
building foundation. See Figure 1.
If conditions or local codes require the unit be attached to
pad or mounting frame, tie down bolts should be used and
secured to unit base pan.

507607-03 Issue 1946 Page 3 of 24
Discharge Air
Mounting Slab
Ground Level
Building
Structure
Mounting slab must slope slightly away from
building, not to exceed 1/4” per foot.
Figure 1. Slab Mounting
Elevate Unit
Accumulation of water and ice in base pan may cause
equipment damage.
CAUTION
Elevate unit per local climate and code requirements to
provide clearance above estimated snowfall level and
ensure adequate drainage of unit. Use snow stand in areas
where prolonged freezing temperatures are encountered.
If conditions or local codes require the unit be attached to
pad or mounting frame, tie down bolts should be used and
fastened through knockouts provided in unit base pan.
Clearance Requirements
When installing, allow su󰀩cient space for airow clearance,
wiring, refrigerant piping, and service. For proper airow,
quiet operation and maximum e󰀩ciency. Position so water,
snow, or ice from roof or eaves cannot fall directly on unit.
Refer to Table 2 for installation clearances.
Location Minimum Clearance
Service box 30”
Top of unit* 48”
Between units 24”
Against wall 6”
* Maximum so󰀩t overhang is 36”.
NOTE: At least one side should be unobstructed by a wall or
other barrier.
Table 2. Clearances
30” around
Control
Box
24”
6”*
NOTE: See Table 2 for specific minimum
clearance guidelines.
Figure 2.
DO LOCATE THE UNIT:
• With proper clearances on sides and top of unit
• On a solid, level foundation or pad (unit must be level
to within ± 1/4 in./ft. per compressor manufacturer
specications)
• To minimize refrigerant line lengths
DO NOT LOCATE THE UNIT:
• On brick, concrete blocks or unstable surfaces
• Near clothes dryer exhaust vents where debris
accumulates
• Near sleeping area or near windows
• Under eaves where water, snow or ice can fall directly
on the unit
• With clearance less than 2 ft. from a second unit
• With clearance less than 4 ft. on top of unit
Rooftop Installations
Install unit at a minimum of 6” above surface of the roof
to avoid ice buildup around the unit. Locate the unit
above a load bearing wall or area of the roof that can
adequately support the unit. Consult local codes for rooftop
applications.
If unit cannot be mounted away from prevailing winds, a
wind barrier should be constructed. Due to variation in
installation applications, size and locate barrier according
to the best judgment of the installer.

507607-03Issue 1946Page 4 of 24
Refrigeration Piping
• Use only refrigerant grade copper tubes.
• Split systems may be installed with up to 50 feet of
line set (no more than 20 feet vertical) without special
consideration (see long line set guidelines).
• Ensure that vapor and liquid tube diameters are
appropriate to capacity of unit.
• Run refrigerant tubes as directly as possible by
avoiding unnecessary turns and bends.
• When passing refrigerant tubes through the wall, seal
opening with RTV or other silicon-based caulk.
• Avoid direct tubing contact with water pipes, duct work,
oor joists, wall studs, oors, walls, and any structure.
• Do not suspend refrigerant tubing from joists and
studs with a rigid wire or strap that comes in direct
contact with tubing.
• Ensure that tubing insulation is pliable and completely
surrounds vapor tube.
It is important that no tubing be cut or seals broken until you
are ready to actually make connections to the evaporator
and to the condenser section. DO NOT remove rubber
plugs or copper caps from the tube ends until ready to
make connections at evaporator and condenser. Under no
circumstances leave the lines open to the atmosphere for
any period of time, if so unit requires additional evacuation
to remove moisture.
Table 3. Refrigerant Line Set Diameters (in.)
Model 16 SEER
Liquid Line Suction Line
24 3/8 3/4
36 3/8 7/8
48 3/8 7/8
60 3/8 1-1/8
For lines longer than 50 ft., refer to long line set guidelines.
Be extra careful with sharp bends. Tubing can “kink” very
easily, and if this occurs, the entire tube length will have
to be replaced. Extra care at this time will eliminate future
service problems.
It is recommended that vertical suction risers not be up-
sized. Proper oil return to the compressor should be
maintained with suction gas velocity.
Filter Drier
The lter drier is very important for proper system operation
and reliability. If the drier is shipped loose, it must be
installed by the installer in the eld. Unit warranty will be
void, if the drier is not installed.
Installation of Line Sets
DO NOT fasten liquid or suction lines in direct contact with
the oor or ceiling joist. Use an insulated or suspension
type of hanger. Keep both lines separate, and always
insulate the suction line. Liquid line runs (30 feet or more)
in an attic will require insulation. Route refrigeration line
sets to minimize length.
DO NOT let refrigerant lines come in direct contact with
foundation. When running refrigerant lines through the
foundation or wall, openings should allow for a sound
and vibration absorbing material to be placed or installed
between tubing and foundation. Any gap between
foundation or wall and refrigerant lines should be lled with
a vibration damping material.
If ANY refrigerant tubing is required to be buried by state
or local codes, provide a 6 inch vertical rise at service
valve.
CAUTION
Installation into an Existing R-22 System
If the unit will be installed in an existing system that uses
an indoor unit or line sets charged with R-22 refrigerant,
installer must perform the following procedures to convert
the system to an R-410A system.
Remove Existing Expansion Valve
1. On fully cased coils, remove the coil access and
plumbing panels.
2. Remove any shipping clamps from the liquid line and
distributor assembly.
3. Disconnect the equalizer line from the check expansion
valve equalizer line tting on the vapor line.
4. Remove the vapor line sensing bulb.
5. Disconnect the liquid line from the check expansion
valve at the liquid line assembly.
6. Disconnect the check expansion valve from the liquid
line orice housing. Take care not to twist or damage
distributor tubes during this process.
7. Remove and discard check expansion valve and the
two Teon® rings (see Figure 3).
8. Use a eld-provided tting to temporarily reconnect the
liquid line to the indoor unit’s liquid line orice housing.

507607-03 Issue 1946 Page 5 of 24
SENSING
LINE
TWO-PIECE PATCH PLATE
(UNCASED COIL ONLY)
VAPOR
LINE
DISTRIBUTOR
ASSEMBLY
DISTRIBUTOR
TUBES
LIQUID
LINE
MALE EQUALIZER
LINE FITTING
EQUALIZER
LINE
CHECK
EXPANSION
VALVE
TEFLON®
RING
STUB END
TEFLON®
RING
SENSING BULB
LIQUID LINE
ORIFICE
HOUSING
LIQUID LINE
ASSEMBLY WITH
BRASS NUT
Figure 3. Remove Existing Expansion Valve
(uncased coil shown)
Flushing Line Sets
If the unit will be installed in an existing system that uses
an indoor unit or line sets charged with R-22 refrigerant,
installer must perform the following ushing procedure.
NOTE: Existing system components (including line set
and indoor coil) must be an AHRI match with the unit in
order to fulll unit warranty requirements.
Refrigerant must be reclaimed in accordance with
national and local codes.
WARNING
Do NOT attempt to ush and re-use existing line sets
or indoor coil when the system contains contaminants
(i.e., compressor burn out).
CAUTION
“Clean refrigerant” is any refrigerant in a system that
has not had compressor burnout. If the system has
experienced burnout, it is recommended that the
existing line set and indoor coil be replaced.
NOTE
In lieu of R-410A, an industry-standard ushing agent
may also be used.
NOTE
LOW
HIGH
EXISTING
INDOOR
UNIT
GAUGE
MANIFOLD
CYLINDER CONTAINING
CLEAN R-410A TO BE
USED FOR FLUSHING
(Positioned to deliver liquid
refrigerant)
LIQUID LINE SERVICE
VALVE
INLET
DISCHARGE
TANK
RETURN
CLOSED
OPENED
RECOVER
Y
CYLINDER
RECOVERY MACHINE
NEW
OUTDOOR
UNIT
VAPOR LINE
SER
VICE VALVE
VAPOR
LIQUID
1
A
B
C
D
ACylinder with clean R-410A (positioned to deliver liquid refrigerant) to the
vapor service valve.
BRefrigerant gauge set (low side) to the liquid line valve.
CRefrigerant gauge set center port to inlet on the recovery machine with
an empty recovery tank connected to the gauge set.
DConnect recovery tank to recovery machine per machine instructions.
Figure 4.
1. Connect gauges and equipment as shown in Figure 4.
2. Set the recovery machine for liquid recovery and start
the recovery machine. Open the gauge set valves to
allow the recovery machine to pull a vacuum on the
existing system line set and indoor unit coil.
3. Position the cylinder of clean R-410A for delivery of
liquid refrigerant and open its valve to allow liquid
refrigerant to ow into the system through the vapor
line valve. Allow the refrigerant to pass from the
cylinder and through the line set and the indoor unit
coil before it enters the recovery machine.
4. After all of the liquid refrigerant has been recovered,
switch the recovery machine to vapor recovery so
that all of the R-410A vapor is recovered. Allow the
recovery machine to pull the system down to 0.
5. Close the valve on the inverted R-410A drum and the
gauge set valves. Pump the remaining refrigerant out
of the recovery machine and turn the machine o󰀨.