Armstrong 4SHP 16 Series User manual

506860-01 Issue 1404 Page 1 of 35
INSTALLATION AND MAINTENANCE INSTRUCTIONS
4SHP 16/18LS SERIES
Split System Heat Pump
These instructions must be read and understood completely before attempting installation.
TABLE OF CONTENTS
INSTALLATION ....................................................2
CONNECTION DIAGRAM.....................................4
START-UP ...........................................................14
OPERATION........................................................17
ALERT CODE......................................................23
MAINTENANCE ..................................................28
WARRANTY ........................................................34
Manufactured By
Allied Air Enterprises LLC
A Lennox International Inc. Company
215 Metropolitan Drive
West Columbia, SC 29170
*P506860-01*
(p) 506860-01
The equipment covered in this manual is to be installed by trained and experienced service and installation
technicians. Improper installation, modication, service, or use can cause electrical shock, re, explosion, or
other conditions which may cause personal injury, death, or property damage. Use appropriate safety gear
including safety glasses and gloves when installing this equipment.
WARNING
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
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
Sharp metal edges can cause injury. When installing
the unit, use care to avoid sharp edges.
WARNING

506860-01Issue 1404Page 2 of 35
INSTALLATION 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.
Location of Unit
Outdoor units operate under a wide range of weather
conditions; therefore, multiple factors must be considered
when positioning the unit. The unit must be positioned to
give adequate clearances for sufcient airow and servicing.
Refer to Figure 1 for installation clearances.
• 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..
Table 1
Compressor Bolts 90 in. lbs.
#10 Machine Screws 28 in. lbs.
#8 Machine Screws 16 in. lbs.
Sheet Metal Screws 16 in. lbs.
Service Port Caps 8 ft. lbs.
Stem Caps 8 ft. lbs.
Fastener Torque
Torque Table
Figure 1
Installation Clearances
* A service clearance of 30” must be maintained on one of
the sides adjacent to the control box. Clearance to one
of the other three sides must be 36”. Clearance to one
of the remaining two sides may be 12” and the nal side
may be 6”.
A clearance of 24” must be maintained between units.
48” clearance required on top of unit. Maximum soffit
overhang is 36”.
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.
4SHP16/18LS condensing units use R410A 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 R410A is installed in the unit.
IMPORTANT: This product has been designed and
manufactured to meet ENERGY STAR criteria for energy
efciency when matched with appropriate coil components.
However, proper refrigerant charge and proper air ow are
critical to achieve rated capacity and efciency. Installation
of this product should follow the manufacturer’s refrigerant
charging and air ow instructions. Failure to conrm
proper charge and airow may reduce energy efciency
and shorten equipment life.
When servicing or repairing HVAC components, ensure the
fasteners are appropriately tightened. Table 1 shows torque
values for fasteners.

506860-01 Issue 1404 Page 3 of 35
Roof Mounting
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.
• Install the unit high enough above the ground or roof to
allow adequate drainage of defrost water and prevent
ice buildup.
• 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 construction 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.
Slab Mounting
When installing a unit at grade level, install on slab high
enough above grade so that water from higher ground will
not collect around the unit (See Figure 2). Slab should have
a slope tolerance away from the building of 2° or 2” per 5’.
This will prevent ice from building up under the unit during
a defrost cycle. Refer to following roof mounting section for
barrier construction if unit must face prevailing winter winds.
If unit coil cannot be mounted away from prevailing winter
winds, a wind barrier should be constructed (See Figure 3).
Size the barrier at least the same height and width as the
outdoor unit. Mount barrier 24” from the sides of the unit in
the direction of the prevailing winds.
Electrical Wiring
All eld wiring must be done in accordance with the National
Electrical Code (NEC) recommendations, Canadian
Electrical Code (CEC) and CSA Standards, or local codes,
where applicable.
Refer to the furnace or blower coil installation instructions
for additional wiring application diagrams and refer to unit
rating plate for minimum circuit ampacity and maximum
overcurrent protection size.
Figure 2
Slab Mounng
Discharge Air
Mounting Slab
Ground Level
Building
Structure
Figure 3
Line voltage is present at all components when unit is
not in operation on units with single pole contactors.
Disconnect all remote electric power supplies before
opening access panel. Unit may have multiple power
supplies. Failure to disconnect all power supplies could
result in personal injury or death.
WARNING
Unit must be grounded in accordance with national and
local codes. Failure to ground unit properly can result
in personal injury or death.
WARNING

506860-01Issue 1404Page 4 of 35
1. Install line voltage power supply to unit from a properly
sized disconnect switch. Any excess high voltage eld
wiring should be trimmed or secured away from the low
voltage eld wiring.
2. Ground unit at unit disconnect switch or to an earth
ground. To facilitate conduit, a hole is in the bottom of
the control box. Connect conduit to the control box
using a proper conduit tting. Units are approved for
use only with copper conductors. 24V Class II circuit
connections are made in the low voltage junction box.
Refer to Figure 4 for high voltage eld wiring diagram.
A complete unit wiring diagram is located inside the unit
control box cover and in the back of this document.
3. Install room thermostat on an inside wall that is not
subject to drafts, direct sunshine, or other heat sources.
4. Install low voltage wiring from outdoor to indoor unit
and from thermostat to indoor unit. (See Wire Diagram
on page 32.)
5. Do not bundle any excess 24V control wire inside
control box. Run control wire through installed wire tie
and tighten wire tie to provide low voltage strain relief
and to maintain seperation of eld-installed low and
high voltage circuits. Figure 5
Typical Field Wiring Diagram
NON-COMMUNICATING
Figure 4
Non Communicang Thermostat Designaons
( Some connecons may not apply. Refer to
specic thermostat and indoor unit.)

506860-01 Issue 1404 Page 5 of 35
FIELD WIRING & ROUTING - COMMUNICATING CONTROLS
Maximum length of wiring (18 gauge) for all connections on the RSBus is 1500 feet (457 meters). Wires should be color
coded, with a temperature rating of 95ºF (35ºC) minimum, and solid core (Class II Rated Wiring). All low voltage wiring must
enter unit through provided bushing installed in electrical inlet.
Figure 6

506860-01Issue 1404Page 6 of 35
Placement
Be aware that some localities are adopting sound ordinances
based on how noisy the unit is at the neighbor’s home, not
at the original installation. Install the unit as far as possible
from the property line. When possible, do not install the unit
directly outside a bedroom window. Glass has a very high
level of sound transmission. Figure 7 shows how to place
the outdoor unit and line set to reduce line set vibration.
Line Set Isolation
Illustrations on pages 7 and 8 demonstrate procedures which
ensure proper refrigerant line set isolation. Figure 8 shows
how to install line sets on horizontal runs. Figure 9 shows
how to make a transition from horizontal to vertical. Figure
10 shows how to install line sets on vertical runs.
4. Remove the Schrader core assemblies before brazing
to protect them from damage due to extreme heat.
Replace the cores when brazing is complete.
5. Remove light maroon washers from service valves
and shield light maroon stickers to protect them during
brazing. Wrap a wet cloth around the valve body and
copper tube stub to protect it from heat damage.
6. Braze the line set to the service valve. Quench the
joints with water or a wet cloth to prevent heat damage
to the valve core and opening port. The tube end must
stay bottomed in the tting during nal assembly
to ensure proper seating, sealing, and rigidity.
7. Install the thermal expansion valve which is sold
separately and which is approved for use with R410A
refrigerant in the liquid line at the indoor coil (see
Refrigerant Metering Device on page 10).
Brazing Connection Procedure
1. Cut ends of refrigerant lines square (free from nicks or
dents). Debur the ends. The pipe must remain round;
do not pinch end of line.
2. Before making line set connections, use dry nitrogen to
purge the refrigerant piping. This will help to prevent
oxidation and the introduction of moisture into the
system.
3. Use silver alloy brazing rods (5% or 6% silver alloy for
copper-to-copper brazing or 45% silver alloy for copper-
to-brass or copper-to-steel brazing) which are rated for
use with R410A refrigerant.
Refrigerant Piping
If the 4SHP16/18LS unit is being installed with a new indoor
coil and line set, the refrigerant connections should be made
as outlined in this section. If an existing line set and/or
indoor coil will be used to complete the system, refer to this
section as well as the section that follows entitled- Flushing
Existing Line Set and Indoor Coil.
If this unit is being matched with an approved line set
or indoor coil which was previously charged with R-22
refrigerant, the line set and coil must be ushed prior to
installation. If the unit is being used with and existing indoor
coil which was equipped with a liquid line which served as
a metering device (RFCI), the liquid line must be replaced
prior to the installation of the 4SHP16/18LS unit.
Field refrigerant piping consists of liquid and suction lines
from the outdoor unit (sweat connections) to the indoor
Figure 7
Table 2
Refrigerant Line Set Diameters (in.)
For installations exceeding 50’, contact Technical Services.
Liquid Line
BTUH Line Set Length and Size
12 ft. 25 ft. 50 ft. 75 ft. 100 ft.
24,000 3/8 3/8 3/8 3/8 3/8
36,000 3/8 3/8 3/8 3/8 1/2
48,000 3/8 3/8 3/8 1/2 1/2
60,000 3/8 3/8 3/8 1/2 1/2
Suction Line
BTUH Line Set Length and Size
12 ft. 25 ft. 50 ft. 75 ft. 100 ft.
24,000 3/4 7/8 3/4 7/8 7/8
36,000 7/8 7/8 7/8 7/8 1-1/8
48,000 1-1/8 1-1/8 1-1/8 1-1/8 1-1/8
60,000 1-1/8 1-1/8 1-1/8 1-1/8 1-1/8

506860-01 Issue 1404 Page 7 of 35
Field refrigerant piping consists of liquid and suction lines
from the outdoor unit (sweat connections) to the indoor
coil (are or sweat connections).
Select line set diameters from Table 2 to ensure that oil
returns to the compressor. Size vertical suction riser
to maintain minimum velocity at minimum capacity.
Recommended line length is 50’ or less. If more than 50’ line
set is required, contact Technical Services. Table 2 shows
the diameters for line sets up to 100’ although vertical lift
applications and trapping requirements need to be reviewed
with Technical Services for line sets over 50’.
Installing Refrigerant Line
During the installation of an air conditioning system, it is
important to properly isolate the refrigerant line to prevent
unnecessary vibration. Line set contact with the structure
(wall, ceiling, or oor) may cause objectionable noise when
vibration is translated into sound. As a result, more energy
or vibration can be expected. Close attention to line set
isolation must be observed.
Figure 8
To hang line set from joist or rafter,
use either metal strapping material
or anchored heavy nylon wire ties.
Strapping Material
(around vapor line only)
8’
8’
Tape or Wire Tie
Strap the vapor line to the joist or rafter
at 8intervals then strap the liquid line
to the vapor line.
’
Floor Joist or
Roof Rafter
Metal Sleeve
Floor Joist or Roof Rafter
Tape or Wire Tie
Wire Tie
(around vapor line only)
When ushing existing line set and/or indoor coil, be sure to
empty all existing traps. Residual mineral oil can act as an
insulator, preventing proper heat transfer. It can also clog
the thermal expansion valve, reducing system performance
and capacity. Failure to properly ush system as explained
in these instructions will void warranty.
Refrigerant Line Sets: Installing Horizontal Runs

506860-01Issue 1404Page 8 of 35
Figure 9
Figure 10
Outside Wall
Wood Block
Between Studs
IMPORTANT: Refrigerant
lines must not contact wall.
Vapor Line Liquid Line
Wire Tie
Inside Wall
Strap
Sleeve
Wire Tie
Wire Tie
Strap
Wood Block
Sleeve
Vapor Line Wrapped
with Armaflex
Liquid Line
Caulk
PVC Pipe Fiberglass
Insulation
Outside Wall
IMPORTANT:
Refrigerant
lines must not
contact structure.
Anchored
Heavy Nylon
Wire Tie
Wall
Stud
Metal Sleeve Vapor Line Wrapped
in Armaflex
–
Liquid Line
Wall
Stud
Automotive
Muffler-Type
Hanger
Strap Liquid
Line to Vapor
Line
Metal Sleeve Vapor Line Wrapped
in Armaflex
–
Liquid Line
Strap Liquid
Line to Vapor
Line
Refrigerant Line Sets: Transison from Vercal to Horizontal
Refrigerant Line Sets: Installing Vercal Runs (new construcon shown)
NOTE: Similar installaon
pracces should be used if
line set is to be installed on
exterior of outside wall.

506860-01 Issue 1404 Page 9 of 35
Flushing Existing Line Set and Indoor Coil
This procedure should not be performed on systems
which contain contaminants, such as compressor burn
out.
Required Euipment
The following equipment is needed to ush the existing line
set and indoor coil (See Figure 11). Two clean R-22 recovery
bottles, an oil-less recovery machine with a “pump down”
feature, and two sets of gauges (one for use with R-22 and
one for use with R-410A).
Flushing Procedure
IMPORTANT: The line set and/or indoor coil must be
ushed with at least the same amount of refrigerant that
previously charged the system. Check the charge in the
ushing cylinder before ushing the unit.
1. Remove existing R-22 refrigerant using the appropriate
procedure.
If the existing outdoor unit is not equipped with shutoff
valves, or if the unit is not operational AND the existing
R-22 refrigerant will be used to ush the system:
Disconnect all power to the existing outdoor unit. Connect
the existing unit, a clean recovery cylinder, and the recovery
machine according to the instructions provided with the
recovery machine. Remove all R-22 refrigerant from the
existing system. Refer to the gauges after shutdown
to conrm that the entire system is completely void of
refrigerant. Disconnect the liquid and suction lines from
the existing outdoor unit.
If the existing outdoor unit is equipped with manual shutoff
valves AND new R-22 refrigerant will be used to ush the
system:
Start the existing R-22 refrigerant system in cooling mode
and close the liquid line valve. Pump all the existing R-22
refrigerant back into the outdoor unit.
(It may be necessary to bypass the low pressure switches
to ensure complete refrigerant evacuation.)
When the low side system pressures reach 0 psig, close
the suction line valve. Disconnect all power to the existing
outdoor unit. Refer to the gauges after shutdown to conrm
that the valves are not allowing refrigerant to ow back into
the low side of the system. Disconnect the liquid and suction
lines from the existing outdoor unit.
2. Remove the existing outdoor unit. Set the new R-410A
unit and follow the brazing connection procedure
outlined previously on this page to make line set
connections. Do not install the R-410A thermal
expansion valve at this time.
3. Make low voltage and line voltage connections to the
new outdoor unit. Do not turn on power to the unit
or open the outdoor unit service valves at this time.
Figure 11
Flushing Connecons
Note: The inverted R22 cylinder must
contain at least the same amount of
refrigerant as was recovered from the
exisng system.

506860-01Issue 1404Page 10 of 35
4. Remover the existing R-22 refrigerant ow control
orice or thermal expansion valve before continuing
with ushing procedures. R-22 ow control devices are
not approved for use with R-410A refrigerant and may
prevent proper ushing. Use a eld-provided tting to
reconnect the lines.
5. Remove the pressure tap valve cores from the
4SHP16/18LS units service valves. Connect an R-22
cylinder with clean refrigerant to the suction service
valve. Connect the R-22 gauge set to the liquid line
valve and connect a recovery maching with an empty
recovery tank to the gauge set.
6. 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 coil.
7. Invert the cylinder of clean R-22 and open its valve to
allow liquid refrigerant to ow in to the system through
the suction line valve. Allow the refrigerant to pass from
the cylinder and through the line set and the indoor coil
before it enters the recovery machine.
8. After all of the liquid refrigerant has been recovered,
switch the recovery machine to vapor recovery so that
all of the R-22 vapor is recovered. Allow the recovery
machine to pull a vacuum on the sytem.
NOTE: A single system ush should remove all of the
mineral oil from the existing refrigerant lines and indoor coil.
A second ushing may be done (using clean refrigerant) if
insufcient amounts of mineral oil were removed during the
rst ush. After each system ush, allow the recovery
machine to pull a vacuum on the system at the end of
the procedure.
9. Close the valve on the inverted R-22 cylinder and the
gauge set valves. Pump the remaining refrigerant out
of the recovery machine and turn the machine off.
10. Use nitrogen to break the vacuum on the refrigerant lines
and indoor coil before removing the recovery machine,
gauges, and R-22 refrigerant drum. Re-install pressure
tap valve cores into the 4SHP16/18LS unit’s service
valves.
11. Install the xed orice (or thermal expansion valve
approved for use with R-410A refrigerant) in the liquid
line at the indoor coil.
Refrigerant Metering Device
4SHP16/18LS units are designed for use with TXV systems.
Refer to the appropriate following section for information on
installing the chosen refrigerant metering device.
An R410A system will not operate properly with an R-22
metering device.
Install the refrigerant metering device as shown in Figure
12. Do not twist cap tubes when loosening the seal nut from
the orice housing. Use wrench to back up the distributor.
Expansion Valve Systems
Expansion valves equipped with Chatleff-type ttings are
available from the manufacturer. See Table 3 for proper
TXV for each unit.
To install an expansion valve (See Figure above):
1. Separate the distributor assembly and remove the piston
orice and used teon seal. Insert nozzle end of the
expansion valve along with a new teon seal into the
distributor and tighten to 20 - 30 ft. lbs. Use backup
wrench on all wrench ats. Overtightening will crush
the teon seal and may cause a leak.
2. Attach liquid line portion of distributor assembly along
with new teon seal to the inlet of the expansion valve.
Tighten to 20 - 30 ft. lbs. Use backup wrench on all
wrench ats. Overtightening will crush the teon
seal and may cause a leak.
Figure 12
Metering Device Installation
If necessary, remove R22 ow control device (xed orice/thermal
expansion valve) from existing line set before installing R410A
approved orice or expansion valve.
Table 3
TXV Data
Model Part Number
4SHP18LT-24, -36 A4TXV01
4SHP18LT-48,-60 A4TXV03
4SHP16LT-24,-36 H4TXV01
4SHP16LT-48 H4TXV02
4SHP16LT-60 H4TXV03

506860-01 Issue 1404 Page 11 of 35
3. Connect the external equalizer line to the equalizer port
on the suction line and tighten to 8 ft.lbs.
4. Strap the superheat sensing bulb to the suction header.
If installing an expansion valve on an indoor coil that
previously used a xed orice, be sure to remove the existing
xed orice. Failure to remove a xed orice when installing
an expansion valve to the indoor coil will result in improper
operation and damage to the system.
Manifold Gauge Set
Manifold guage sets used with systems charged with R410A
refrigerant must be capable of handling the higher system
operating pressures. The gauges should be rated for use
with pressures 1 - 800 on the high side and a low side of 30”
vacuum to 250 psi with dampened speed to 500 psi. Gauge
hoses must be rated for use at up to 800 psi of pressure
with a 4000 psi burst rating.
Liquid and Suction Line Service Valves
The liquid line and suction line service valves (See Figure
13) and service ports are used for leak teating, evacuation,
charging, and checking charge.
Each valve is equipped with a service port which has a
factory-installed Schrader valve. A service port cap protects
the Schrader valve from contamination and serves as the
primary leak seal.
To Access the Schrader Port:
1. Remove the service port cap with an adjustable wrench.
2. Connect gauge to the service port.
3. When testing is completed, replace service port cap.
Tighten nger tight, then an additional 1/6 turn.
To Open Liquid or Suction Line Service Valve:
Remove stem cap with an adjustable wrench.
Use service wrench with a hex-head extension to back the
stem out counterclockwise as far as it will go. Use a 3/16”
hex head extension for liquid line service valves and a
5/16” extension for suction line service valves.
Replace the stem cap. Tighten nger tight, then tighten an
additional 1/6 turn.
To Close Liquid or Suction Line Service Valve:
1. Remove the stem cap with an adjustable wrench.
2. Use a service wrench with a hex-head extension to turn
the stem clockwise to seat the valve. Tighten rmly.
3. Replace the stem cap. Tighten nger tight, then tighten
an additional 1/6 turn.
Suction Line (Ball Type) Service Valve
Suction line (ball type) service valves function the same
way as the other valves; the difference is in the construction
(See Figure 14).
The ball valve is equipped with a service port with a factory-
installed Schrader valve. A service port cap protects the
Schrader valve from contamination and serves as the
primary seal.
Leak Testing
After the line set has been connected to the indoor and
outdoor units, the line set connections and indoor unit must
be checked for leaks.
Figure 13

506860-01Issue 1404Page 12 of 35
Using an Electronic Leak Detector
1. Connect the high pressure hose of the manifold gauge
set to the suction valve service port. (Normally the
high pressure hose is connected to the liquid line port;
however, connecting it to the suction ports helps to
protect the manifold gauge set from damage caused
by high pressure.)
2. With both manifold valves closed, connect the cylinder
of R410A refrigerant. Open the valve on the R410A
cylinder (vapor only).
3. Open the high pressure side of the manifold to allow
R410A into the line set and indoor unit. Weigh in a trace
amount of R410A. (A trace amount is a maximum of 2
oz. of refrigerant or 3 lbs. pressure.) Close the valve on
the R410A cylinder and the valve on the high pressure
side of the manifold gauge set. Disconnect the R410A
cylinder.
4. Connect a cylinder of nitrogen with a pressure regulating
valve to the center port of the manifold gauge set. When
using high pressure gas such as nitrogen for this
purpose, be sure to use a regulator that can control
the pressure down to 1 or 2 psig.
5. Adjust nitrogen pressure to 150 psig. Open the valve
on the high side of the manifold gauge set to pressurize
the line set and the indoor coil.
6. After a short period of time, open a refrigerant port to
make sure that an adequate amount of refrigerant has
been added for detection (refrigerant requirements will
vary with lenths). Check all joints for leaks. Purge
nitrogen and R410A mixture. Correct any leaks and
rechecks.
Evacuation
Evacuating the system of noncondensables is critical for
proper operation of the unit. Noncondensables are dened
as any gas that will not condense under temperatures and
pressures present during operation of an air conditioning
system. Noncondensables and water vapor combine with
refrigerant to produce substances that corrode copper piping
and compressor parts.
Use a thermocouple or thermistor electronic vacuum gauge
that is calibrated in microns. Use an instrument that reads
down to 50 microns.
1. Connect the manifold gauge set to the service valve
ports as follows:
• Low pressure gauge to suction line service valve
• High pressure gauge to liquid line service valve.
2. Connect micron gauge.
3. Connect the vacuum pump (with vacuum gauge) to the
center port of the manifold gauge set.
Figure 14
Do Not use a compressor to evacuate a system. Avoid
deep vacuum operation. Extremely low vacuums can
cause internal arcing and compressor failure. Danger of
equipment damage. Damage caused by deep vacuum
operation will void warranty.
WARNING
Refrigerant can be harmful if inhaled. Refrigerant must
always be used and recovered responsibly. Incorrect
or irresponsible use of refrigerant can result in personal
injury or death.
WARNING
Never use oxygen to pressurize refrigeration or air
conditioning systems. Oxygen will explode on contact
with oil and could cause personal injury or death.
WARNING

506860-01 Issue 1404 Page 13 of 35
4. Open both manifold valves and start vacuum pump.
5. Evacuate the line set and indoor unit to a minimum
of 500 microns or lower. During the early stages of
evacuation, it is desirable to close the manifold gauge
valve at least once to determine if there is a rapid rise in
pressure. A rapid rise in pressure indicates a relatively
large leak. If this occurs, the leak testing procedure
must be repeated.
6. When 500 microns or lower is maintained, close the
manifold gauge valves, turn off the vacuum pump, and
disconnect the manifold gauge center port hose from
the vacuum pump. Attach the manifold gauge center
port hose to a nitrogen cylinder with pressure regulator
set to 150 psig and purge the hose. Open the manifold
gauge valves to break the vacuum in the line set and
indoor unit. Close the manifold gauge valves.
7. Shut off the nitrogen cylinder and remove the manifold
gauge hose from the cylinder. Open the manifold gauge
valves to release the nitrogen from the line set and
indoor unit.
8. Reconnect the manifold gauge to the vacuum pump,
turn the pump on, and continue to evacuate the line set
and indoor unit until 500 microns is maintained within
a 20 minute period after shutting off the vacuum pump
and closing the manifold gauge valves.
9. When the requirements above have been met,
disconnect the manifold hose from the vacuum pump.
Open the service valves to break the vacuum in the line
set and indoor unit.

506860-01Issue 1404Page 14 of 35
START-UP
1. Rotate fan to check for frozen bearings or binding.
2. Inspect all factory and eld-installed wiring for loose
connections.
3. After evacuation is complete, open liquid line and
suction line service valves to release refrigerant charge
(contained in outdoor unit) into system.
4. Replace the stem caps and secure nger tight, then
tighten an additional 1/6 of a turn.
5. Check voltage supply at the disconnect switch. The
voltage must be within the range listed on the unit
nameplate. If not, do not start equipment until the power
company has been consulted and the voltage condition
corrected.
6. Set thermostat for cooling demand, turn on power to
indoor blower, and close the outdoor unit disconnect
switch to start the unit.
7. Recheck unit voltage with unit running. Power must be
within range shown on unit nameplate.
Refrigerant Charging
This system is charged with R-410A refrigerant which
operates at much higher pressures than R-22. The liquid
line drier provided with the unit is approved for use with
R-410A. Do not replace it with one designed for use with
R-22. This unit is NOT approved for use with coils which
use capillary tubes as a refrigerant metering device.
R410A refrigerant cylinders are rose colored. Refrigerant
should be added through the suction valve in the liquid
state.
Certain R-410A cylinders are identified as being
equipped with a dip tube. These allow liquid refrigerant
to be drawn from the bottom of the cylinder without
inverting the cylinder. Do not turn this type of cylinder
upside down to draw refrigerant.
Units are factory charged with the amount of R410A
refrigerant indicated on the unit rating plate. This charge is
based on a matching indoor coil and outdoor coil with 15’
line set. For varying lengths of line set, refer to Table 4 for
refrigerant charge adjustment. A blank space is provided
on the unit rating plate to list the actual eld charge.
If the system is void of refrigerant, clean the system using
the procedure described below.
1. Use dry nitrogen to pressurized the system and check
for leaks. Repair leaks, if possible.
2. Evacuate the system to remove as much of the moisture
as possible.
3. Use dry nitrogen to break the vacuum.
4. Evacuate the system again.
5. Weigh the appropriate amount of R-410A refrigerant
(listed on unit nameplate) into the system.
6. Monitor the system to determine the amount of moisture
remaining in the oil. Use a test kit to verify that the
moisture content is withing the kit’s dry color range.
It may be necessary to replace the lter drier several
times to achieve the required dryness level. If system
dryness is not veried, the compressor will fail in
the future.
The outdoor unit should be charged during warm weather.
However, applications arise in which charging must occur in
the colder months. The method of charging is determined
by the unit’s refrigerant metering device and the outdoor
ambient temperature.
Table 4
Refrigerant Charge Adjustment
* If line length is greater than 15 ft. , add this amount.
If line length is less than 15 ft., remove this amount.
If unit is equipped with a crankcase heater, it should
be energized 24 hours before unit start-up to prevent
compressor damage as a result of slugging.
CAUTION
Mineral oils are not compatible with R-410A. If oil must
be added, it must be a polyolester oil.
IMPORTANT

506860-01 Issue 1404 Page 15 of 35
Measure the liquid line temperature and the outdoor ambient
temperature as outlined below:
1. Connect the manifold gauge set to the service valve
ports as follows (See Figure 15 above):
• Low pressure gauge to suction line service valve
• High pressure gauge to liquid line service valve
2. Close manifold gauge set valves. Connect the center
manifold hose to an upright cylinder of R-410A.
3. If room temperature is below 70°F, set the room
thermostat to call for heat. This will create the necessary
load for properly charging the system in the cooling
cycle.
4. Use a digital thermometer to record the outdoor ambient
temperature.
5. When the heating demand has been satised, switch
the thermostat to cooling mode with a set point of
68°F. When pressures have stabilized, use a digital
thermometer to record the liquid and suction line
temperatures.
6. The outdoor temperature will determine which charging
method to use. Proceed with the appropriate charging
method.
Charge Using Weigh-In Method (Fixed Orifice/TXV
Systems) - Outdoor Temperatures Below 65°F
If the system is void of refrigerant, or if the outdoor ambient
temperature is cool, use the weigh-in method to charge the
unit. Do this after any leaks have been repaired.
1. Recover the refrigerant from the unit.
2. Conduct a leak check, then evacuate as previously
outlined.
3. Weigh in the charge according to the total amount shown
on the unit nameplate.
If weighing facilities are not available or if unit is being
charged during warm weather, use one of the following
procedures.
Charge Using Subcooling Method (Fixed Orice/TXV
Systems) - Outdoor Temperatures 65°F or Above
If charging a xed orice or TXV system when the outdoor
ambient temperature is 65°F or above, the subcooling
method can be used to charge the unit.
1. With the manifold gauge hose still on the liquid
service port and the unit operating stably, use a digital
thermometer to check the liquid line temperature.
For best results, use the same digital thermometer
to check both the outdoor ambient and the liquid line
temperatures.
2. At the same time, record the liquid line pressure reading.
3. Use the temperature/pressure chart (Table 5) to
determine the saturation temperature for the liquid line
pressure reading.
4. Subtract the liquid line temperature from the saturation
temperature (according to the chart) to determine
subcooling.
Figure 15

506860-01Issue 1404Page 16 of 35
Table 5
5. Compare the subcooling value with those shown in Table
6. If subcooling is greater than shown, recover some
refrigerant. If subcooling is less than shown, add some
refrigerant.
Charge Using Approach Method (TXV System) - Outdoor
Temperatures 65°F or Above
The following procedure is intended as a general guide and
is for use on expansion valve systems only. For best results,
indoor temperature should be 70°F to 80°F. Monitor system
pressures while charging.
1. Record outdoor ambient temperature using a digital
thermometer.
2. Attach high pressure gauge set and operate unit for
several minutes to allow system pressures to stabilize.
3. Compare stabilized pressures with those provided in
Table 8. Minor variations in these pressures may be
expected due to differences in installations. Signicant
differences could mean that the system is not
properly charged or that a problem exists with some
component in the system. Pressures higher than
those listed indicate that the system is overcharged.
Pressures lower than those listed indicate that the
system is undercharged. Verify adjusted charge using
the approach method.
4. Use the same digital thermometer to check liquid line
temperature.
5. Subtract the outdoor ambient temperature from the liquid
line temperture to determine the approach temperature.
R-410A Temperature/Pressure Chart
T e m p .
F
Pre ss ure
Ps ig
T e m p .
F
Pre ss ure
Ps ig
T e m p .
F
Pre ss ure
Ps ig
32
10 0.8
74
21 4.0
11 6
39 6.0
33
10 2.9
75
21 7.4
11 7
40 1.3
34
10 5.0
76
22 0.9
11 8
40 6.7
35
10 7.1
77
22 4.4
11 9
41 2.2
36
10 9.2
78
22 8.0
12 0
41 7.7
37
11 1.4
79
23 1.6
12 1
42 3.2
38
11 3.6
80
23 5.3
12 2
42 8.8
39
11 5.8
81
23 9.0
12 3
43 4.5
40
11 8.0
82
24 2.7
12 4
44 0.2
41
12 0.3
83
24 6.5
12 5
44 5.9
42
12 2.6
84
25 0.3
12 6
45 1.8
43
12 5.0
85
25 4.1
12 7
45 7.6
44
12 7.3
86
25 8.0
12 8
46 3.5
45
12 9.7
87
26 2.0
12 9
46 9.5
46
13 2.2
88
26 6.0
13 0
47 5.6
47
13 4.6
89
27 0.0
13 1
48 1.6
48
13 7.1
90
27 4.1
13 2
48 7.8
49
13 9.6
91
27 8.2
13 3
49 4.0
50
14 2.2
92
28 2.3
13 4
50 0.2
51
14 4.8
93
28 6.5
13 5
50 6.5
52
14 7.4
94
29 0.3
13 6
51 2.9
53
15 0.1
95
29 5.1
13 7
51 9.3
54
15 2.8
96
29 9.4
13 8
52 5.8
55
15 5.5
97
30 3.8
13 9
53 2.4
56
15 8.2
98
30 8.2
14 0
53 9.0
57
16 1.0
99
31 2.7
14 1
54 5.6
58
16 3.9
10 0
31 7.2
14 2
55 2.3
59
16 6.7
10 1
32 1.8
14 3
55 9.1
60
16 9.6
10 2
32 6.4
14 4
56 5.9
61
17 2.6
10 3
33 1.0
14 5
57 2.8
62
17 5.5
10 4
33 5.7
14 6
57 9.8
63
17 8.5
10 5
34 0.5
14 7
58 6.8
64
18 1.6
10 6
34 5.3
14 8
59 3.8
65
18 4.3
10 7
35 0.1
14 9
60 1.0
66
18 7.7
10 8
35 5.0
15 0
60 8.1
67
19 0.9
10 9
36 0.0
15 1
61 5.4
68
19 4.1
11 0
36 5.0
15 2
62 2.7
69
19 7.3
11 1
37 0.0
15 3
63 0.1
70
20 0.6
11 2
37 5.1
15 4
63 7.5
71
20 3.9
11 3
38 0.2
15 5
64 5.0
72
20 7.2
11 4
38 5.4
73
21 0.6
11 5
39 0.7
72
20 7.2
11 4
38 5.4
73
21 0.6
11 5
39 0.7
Table 6

506860-01 Issue 1404 Page 17 of 35
6. Compare the approach value with those shown in Table
7. If the values do not agree with those provided in Table
7, add refrigerant to lower the approach temperature
or recover refrigerant from the system to increase the
approach temperature.
Check Charge Using Normal Operating Pressures
Use Table 8 to perform maintenance checks. Table 8 is not
a procedure for charging the system. Minor variations in
these pressures may be due to differences in installations.
Signicant deviations could mean that the system is not
properly charged or that a problem exists with some
component in the system.
OPERATION
Outdoor unit and indoor blower cycle on demand from
the room thermostat. When the thermostat blower switch
is moved to the ON position, the indoor blower operates
continuously.
Filter Drier
The unit is equipped with a large capacity bi-ow lter
which keeps the system clean and dry. If replacement is
necessary, replace with one of similar design and capacity.
The replacement lter drier must be suitable for use with
R410A refrigerant.
Crankcase Heater
If unit is equipped with a crankcase heater, it should
be energized 24 hours before unit start-up to prevent
compressor damage as a result of slugging.
Emergency Heat Function (Room Thermostat)
An emergency heat function is designed into some room
thermostats. This feature is applicable when isolation of
outdoor unit is required or when auxiliary electric heat is
stage by outdoor thermostats. When the room thermostat
is placed in the emergency heat position, the outdoor unit
control circuit is isolated from power and the eld-supplied
relays bypass the outdoor thermostats. An amber indicating
light simultaneously comes on to remind the homeowner that
the unit is operating in the emergency heat mode.
Emergency heat is usually used during an outdoor shutdown,
but it should also be used following a power outage if power
has been off for over an hour and the outdoor temperature
is below 50°F. System should be left in the emergency
heat mode at least 6 hours to allow the crankcase heater
sufcient time to prevent compressor slugging.
Approach value is the liquid line temperature minus
the outdoor ambient temperature (“1°F).
Note: For best results, use the same digital
thermometer to check both outdoor ambient and
liquid temperatures
Table 7

506860-01Issue 1404Page 18 of 35
Table 8
L - Liquid S - Suction
Values provided above are typical pressures. Indoor unit matchup, indoor air quality equipement, and indoor load will cause
pressures to vary.
4SHP18

506860-01 Issue 1404 Page 19 of 35
Values provided above are typical pressures. Indoor unit matchup, indoor air quality equipment, and indoor
load will case pressures to vary.
L - Liquid S- Suction
Table 8
4SHP16

506860-01Issue 1404Page 20 of 35
Figure 16
DEFROST CONTROL BOARD