INSTALLATION AND MAINTENANCE INSTRUCTIONS
4AC16LT SERIES
Split System Air Conditioner
Save these instructions for future reference
WARNING
The equipment covered in this manual is to be installed by trained and experienced service
and installation technicians. Improper installation, modification, service, or use can cause
electrical shock, fire, 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
TABLE OF CONTENTS
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
INSTALLATION ....................................................2
in property damage, personal injury, or death.
START-UP ..........................................................12
OPERATION ......................................................16
MAINTENANCE .................................................20
CONNECTION DIAGRAM..................................22
WARNING
Installation and servicing of air conditioning equipment
can be hazardous due to internal refrigerant pressure
and live electrical components. Only trained and
qualified service personnel should install or service this
equipment. Installation and service performed by
unqualified persons can result in property damage,
personal injury, or death.
Manufactured By
Allied Air Enterprises, Inc.
A Lennox International Inc. Company
215 Metropolitan Drive
West Columbia, SC 29170
WARNING
Sharp metal edges can cause injury. When installing
the unit, use care to avoid sharp edges.
*506467-01*
506467-01
Issue 1008
Download from Www.Somanuals.com. All Manuals Search And Download.
Page 1
Thermostat Designations
Slab Mounting
Discharge Air
Building
Structure
Mounting Slab
Ground Level
See unit wiring diagram for power supply connections.
If the indoor unit is not equipped with a blower relay, one must be field
supplied and installed.
Figure 2
Do not connect C (common) connection between indoor unit and
thermostat except when required by the indoor thermostat. Refer to
thermostat installation instructions. C (common) connection between
indoor unit and outdoor unit required for proper operation.
Electrical Wiring
Figure 4
All field 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.
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 field-installed low and high voltage circuits.
WARNING
Unit must be grounded in accordance with national and
local codes. Failure to ground unit properly can result in
personal injury or death.
Refrigerant Piping
WARNING
Refrigerand 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.
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.
1. Install line voltage power supply to unit from a properly
sized disconnect switch. Any excess high voltage field wiring
should be trimmed or secured away from the low voltage
field wiring.
If the 4AC16LT 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.
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 fitting. Units are approved for use only with copper
conductors. 24V Class II circuit connections are made in
the low voltage junction box. Acomplete unit wiring diagram
is located inside the unit control box cover (see also page
22 of this instruction).
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 flushed 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 4AC16LT unit.
3. Install room thermostat on an inside wall that is not subject
to drafts, direct sunshine, or other heat sources.
Field refrigerant piping consists of liquid and suction lines
from the outdoor unit (sweat connections) to the indoor coil
(flare or sweat connections).
4. Install low voltage wiring from outdoor to indoor unit and
from thermostat to indoor unit (See Figure 3).
506467-01
Issue 1008
Download from Www.Somanuals.com. All Manuals Search And Download.
Page 3
Select line set diameters from Table 2 to ensure that oil return
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 Service.
WARNING
Polyolester (POE) oils used with R-410A refrigerant
absorb moisture very quickly. It is very important that
the refrigerant system be kept closed as much as
possible. DO NOT remove line set caps or service valve
stub caps until ready to make connections.
Table 2 shows the diameters for line sets up to 100’ although
vertical lift applications and trapping requirements need to
be reviewed with Technical Service for line sets over 50’.
Refrigerant Line Set Diameters (in.)
Installing Refrigerant Line
During the installation of an air conditioning system, it is
important to properly isolate the refrigerant line to prevent
unnecssary vibration. Line set contact with the structure
(wall, ceiling, or floor) 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. If refrigeration lines are routed
through a wall, seal and isolate the opening so vibration is
not transmitted to the building.
Liquid Line
Line S et Length and S ize
B T UH
12 f t. 25 ft. 50 ft. 75 ft. 100 ft.
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
1/2
1/2
3/8
1/2
1/2
1/2
24,000
36,000
48,000
60,000
Following are some points to consider when placing and
installing a high-efficiency outdoor unit:
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 verry high
level of sound transmission. Figure 4 shows how to place
the outdoor unit and line set to reduce line set vibration.
S uction L ine
L ine S et L ength a nd S ize
12 f t . 25 ft. 50 ft. 75 ft. 10 0 f t .
B T U H
3/4
3/4
7/8
3/4
7/8
3/4
7/8
24,000
7/8
36,000 7/8
48,000 7/8
1-1/8
1-1/8
1-1/8
1-1/8
1-1/8
Line Set Isolation
Illustrations on the pages 6 and 7 demonstrate procedures
which ensure proper refrigerant line set isolation. Figure 6
shows how to install line sets on horizontal runs. Figure 7
shows how to make a transition from horizontal to vertical.
Figure 9 shows how to install line sets on vertical runs.
1-1/8 1-1/8
60,000
1-1/8 1-1/8
1-1/8
For installations exceeding 50’, contact
Technical Services.
Table 2
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
506467-01
Issue 1008
Download from Www.Somanuals.com. All Manuals Search And Download.
Page 4
copper-to-brass or copper-to-steel brazing) which are
rated for use with R410A refrigerant.
Outside Unit Placement
and Installation
4. Remove the Schrader core assemblies before brazing
to protect them from damage due to extreme heat.
Replace the cores when brazing is complete.
Install unit away
from windows
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 fitting during final assembly to
ensure proper seating, sealing, and rigidity.
7. Install a 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 8).
Two 90° elbows installed in lineset
will reduce lineset vibration
Figure 4
Refrigerant Line Sets: Installing Horizontal Runs
To hang line set from joist or rafter,
use either metal strapping material
or anchored heavy nylon wire ties.
Wire Tie
(around vapor line only)
8’
Strapping Material
(around vapor line only)
Floor Joist or
Roof Rafter
Tape or Wire Tie
8’
Strap the vapor line to the joist or rafter
at 8’ intervals then strap the liquid line
to the vapor line.
Metal Sleeve
Floor Joist or Roof Rafter
Tape or Wire Tie
Figure 5
506467-01
Issue 1008
Page 5
Download from Www.Somanuals.com. All Manuals Search And Download.
Refrigerant Line Sets: Transition from Vertical to Horizontal
Automotive
Muffler-Type
Hanger
Anchored
Heavy Nylon
Wire Tie
Strap Liquid
Line to Vapor
Line
Strap Liquid
Line to Vapor
Line
Wall
Stud
Wall
Stud
Liquid Line
Liquid Line
Vapor Line – Wrapped
Vapor Line – Wrapped
Metal Sleeve
in Armaflex
Metal Sleeve
in Armaflex
Figure 6
Refrigerant Line Sets: Installing Vertical Runs (new construction shown)
IMPORTANT: Refrigerant
lines must not contact wall.
Outside Wall
Vapor Line
Liquid Line
NOTE: Similar installation practices
should be used if line set is to be
installed on exterior of outside wall.
Wood Block
Between Studs
Wire Tie
Inside Wall
Strap
Sleeve
Vapor Line Wrapped
with Armaflex
Wire Tie
Liquid Line
Outside Wall
Wood Block
IMPORTANT:
Refrigerant
lines must not
contact structure.
Wire Tie
Strap
Caulk
Fiberglass
PVC Pipe
Insulation
Sleeve
Figure 7
506467-01
Issue 1008
Page 6
Download from Www.Somanuals.com. All Manuals Search And Download.
Flushing Existing Line Set and Indoor Coil
Flushing Procedure
This procedure should not be performed on systems
which contain contaminants, such as compressor
burn out.
IMPORTANT: The line set and/or indoor coil must be
flushed with at least the same amount of refrigerant that
previously charged the system. Check the charge in the
flushing cylinder before flushing the unit.
1. Remove existing R22 refrigerant using the appropriate
procedure.
CAUTION
When flushing 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 flush system as
explained in these instructions will void warranty.
If the existing outdoor unit is not equipped with shutoff
valves, or if the unit is not operational AND the existing
R22 refrigerant will be used to flush 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 R22
refrigerant from the existing system. Refer to the
gauges after shutdown to confirm that the entire system
is completely void of refrigerant. Disconnect the liquid
and suction lines from the existing outdoor unit.
Required Equipment
The following equipment is needed to flush the existing
line set and indoor coil (see Figure 8): Two clean R22
recovery bottles, an oil-less recovery machine with a
“pump down” feature, and two sets of gauges (one for use
with R22 and one for use with R410A).
If the existing outdoor unit is equipped with manual
shutoff valves AND new R22 refrigerant will be used
to flush the system:
Start the existing R22 refrigerant system in cooling mode
and close the liquid line valve. Pump all the existing R22
refrigerant back into the outdoor unit.
Flushing Connections
Note: The inverted R22 cylinder must contain
at least the same amount of refrigerant
as was recovered from the existing
system.
Figure 8
506467-01
Issue 1008
Page 7
Download from Www.Somanuals.com. All Manuals Search And Download.
(It may be necessary to bypass the low pressure switches
to ensure complete refrigerant evacuation.)
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.
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 confirm
that the valves are not allowing refrigerant to flow back into
the low side of the system. Disconnect the liquid and suction
lines from the existing outdoor unit.
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 4AC16LT unit’s service valves.
11. Install the refrigerant expansion valve approved for use
with R410A refrigerant in the liquid line at the indoor coil.
2. Remove the existing outdoor unit. Set the new R410A
unit and follow the brazing connection procedure outlined
previously on this page to make line set connections. Do
not install the R410A thermal expansion valve at this
time.
Refrigerant Metering Device
4AC16LT units are designed for use with TXV systems only.
Expansion valves equipped with Chatleff-type fittings are
available from the manufacturer. See Table 3 for proper
TXV for each unit.
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.
TXV Data
4. Remover the existing R-22 refrigerant flow control orifice
or thermal expansion valve before continuing with flushing
procedures. R-22 flow control devices are not approved for
use with R410A refrigerant and may prevent proper flushing.
Use a field-provided fitting to reconnect the lines.
MODEL
PART NUMBER
4AC16LT -24, -36
4AC16LT -48
A4TXV01
A4TXV02
4AC16LT -60
A4TXV02
5. Remove the pressure tap valve cores from the 4AC16LT
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.
Table 3
To install an expansion valve (See Figure 9 above):
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.
1. Separate the distributor assembly and remove the piston
orifice and used teflon seal. Insert nozzle end of the
expansion valve along with a new teflon seal into the
distributor and tighten to 20 - 30 ft. lbs. Use backup wrench
on all wrench flats. Overtightening will crush the teflon
seal and may cause a leak.
7. Invert the cylinder of clean R-22 and open its valve to
allow liquid refrigerant to flow 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.
2. Attach liquid line portion of distributor assembly along
with new teflon seal to the inlet of the expansion valve.
Tighten to 20 - 30 ft. lbs. Use backup wrench on all wrench
flats. Overtightening will crush the teflon seal and may
cause a leak.
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.
3. Connect the external equalizer line to the equalizer port
on the suction line and tighten to 8 ft.lbs.
NOTE: Asingle system flush should remove all of the mineral
oil from the existing refrigerant lines and indoor coil. Asecond
flushing may be done (using clean refrigerant) if insufficient
amounts of mineral oil were removed during the first flush.
After each system flush, allow the recovery machine to
pull a vacuum on the system at the end of the procedure.
4. Strap the superheat sensing bulb to the suction header.
If installing an expansion valve on an indoor coil that
previously used a fixed orifice, be sure to remove the existing
fixed orifice. Failure to remove a fixed orifice when installing
an expansion valve to the indoor coil will result in improper
operation and damage to the system.
506467-01
Issue 1008
Download from Www.Somanuals.com. All Manuals Search And Download.
Page 8
Figure 9
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
11) 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. Aservice port cap protects
the Schrader valve from contamination and serves as the
primary leak seal.
Figure 10
To Close Liquid or Suction Line Service Valve:
1. Remove the stem cap with an adjustable wrench.
To Access the Schrader Port:
1. Remove the service port 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 firmly.
2. Connect gauge to the service port.
3. Replace the stem cap. Tighten finger tight, then tighten
an additional 1/6 turn.
3. When testing is completed, replace service port cap.
Tighten finger tight, then an additional 1/6 turn.
To Open Liquid or Suction Line Service Valve:
Remove stem cap with an adjustable wrench.
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.
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.
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.
Replace the stem cap. Tighten finger tight, then tighten an
additional 1/6 turn.
506467-01
Issue 1008
Download from Www.Somanuals.com. All Manuals Search And Download.
Page 9
2. With both manifold valves closed, connect the cylin-
der of R410A refrigerant. Open the valve on the
R410A cylinder (vapor only).
Ball Type Service Valve
(Valve Open)
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 maxi-
mum 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. Discon-
nect the R410A cylinder.
4. Connect a cylinder of nitrogen with a pressure regulat-
ing 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 pressur-
ize the line set and the indoor coil.
Use adjustable wrench. To open, rotate stem
counterclockwise 1/4 turn (90°). To close, rotate
stem clockwise 1/4 turn (90°).
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 lengths). Check all joints for leaks. Purge
nitrogen and R410A mixture. Correct any leaks and
recheck.
Figure 11
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.
Evacuation
Evacuating the system of noncondensables is critical for
proper operation of the unit. Noncondensables are defined
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.
WARNING
Fire, Explosion, and Personal Safety Hazard.
Failure to follow this warning could result in
damage, personal injury, or death.
WARNING
Never use oxygen to pressurize or purge
refrigeration lines. Oxygen, when exposed to
a spark or open flame, can cause damage by
fire and/or an explosion, that could result in
personal injury or death.
Do not use a compressor to evacuate a sys-
tem. 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.
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.)
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
506467-01
Issue 1008
Page 10
Download from Www.Somanuals.com. All Manuals Search And Download.
of 22 of 222. Connect micron gauge.
3. Connect the vacuum pump (with vacuum gauge) to
the center port of the manifold gauge set.
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.
506467-01
Issue 1008
Page 11
Download from Www.Somanuals.com. All Manuals Search And Download.
START-UP
CAUTION
Refrigerant Charge Adjustment
Liquid Line Set
Diameter
Oz. per 5 ft. adjust
from 15 ft. line set*
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.
3/8 in.
3 oz. per 5 ft.
* If line length is greater than 15 ft., add this amount.
If line length is less than 15 ft., remove this amount.
1. Rotate fan to check for frozen bearings or binding.
Table 4
2. Inspect all factory and field-installed wiring for loose
connections.
IMPORTANT
3. After evacuation is complete, open liquid line and
suction line service valves to release refrigerant
charge (contained in outdoor unit) into system.
Mineral oils are not compatible with R410A. If
oil must be added, it must be a polyol ester oil.
4. Replace the stem caps and secure finger tight, then
tighten an additional 1/6 of a turn.
If the system is void of refrigerant, clean the system using
the procedure described below.
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.
1. Use dry nitrogen to pressurize the system and check
for leaks. Repair leaks, if possible.
2. Evacuate the system to remove as much of the
moisture as possible.
6. Set thermostat for cooling demand, turn on power to
indoor blower and close the outdoor unit disconnect
switch to start the unit.
3. Use dry nitrogen to break the vacuum.
4. Evacuate the system again.
7. Recheck unit voltage with unit running. Power must be
within range shown on unit nameplate.
5. Weigh the appropriate amount of R410A refrigerant
(listed on unit nameplate) into the system.
Refrigerant Charging
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 within the kit’s dry color
range. It may be necessary to replace the filter drier
several times to achieve the required dryness level. If
system dryness is not verified, the compressor
will fail in the future.
This system is charged with R410A refrigerant which
operates at much higher pressures than R22. The liquid line
drier provided with the unit is approved for use with R410A.
Do not replace it with one designed for use with R22. This
unit is NOT approved for use with coils which use
capillary tubes as a refrigerant metering device.
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 deter-
mined by the outdoor ambient temperature.
R410A refrigerant cylinders are rose colored. Refriger-
ant should be added through the vapor valve in the
liquid state.
Certain R410A cylinders are identified as being
equipped with a dip tube. These allow liquid refriger-
ant 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.
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:
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.
•
•
Low pressure gauge to suction line service valve
High pressure gauge to liquid line service valve
506467-01
Issue 1008
Page 12
Download from Www.Somanuals.com. All Manuals Search And Download.
2. Close manifold gauge set valves. Connect the center
manifold hose to an upright cylinder of R410A.
Blocking Outdoor Coil
Outdoor coil should be
3. If room temperature is below 70°F, set the room thermo-
stat to call for heat. This will create the necessary load
for properly charging the system in the cooling cycle.
blocked one side at a time
with cardboard or plastic
sheet until proper testing
pressures are reached.
4. Use a digital thermometer to record the outdoor
ambient temperature.
Cardboard or Plastic Sheet
5. When the heating demand has been satisfied, 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.
Figure 12
4. Subtract the liquid line temperature from the satura-
tion temperature (according to the chart) to determine
subcooling.
6. The outdoor temperature will determine which charg-
ing method to use. Proceed with the appropriate
charging method.
_____ ° Saturation Temperature °F
Charge Using Weigh-In Method
–
_____ ° Liquid Line Temperature °F
=
_____ ° Subcooling Value °F
If the system is void of refrigerant, or if the outdoor ambient
temperature is cool, first locate and repair any leaks then
use the weigh-in method to charge the unit.
5. Compare the subcooling value with those shown in
Table 6 on page 14. If subcooling is greater than
shown, recover some refrigerant. If subcooling is less
than shown, add some refrigerant.
1. Recover the refrigerant from the unit.
2. Conduct a leak check, then evacuate as previously
outlined.
Charge Using Approach Method –
Outdoor Temperatures 65°F or Above
3. Weigh in the charge according to the total amount
shown on the unit nameplate.
The following procedure is intended as a general guide
and is for use on expansion valve systems only. For best
results, indoor temperature should 70°F to 80°F. Monitor
system pressures while charging.
If weighing facilities are not available, use one of the
following procedures to charge the unit.
Charge Using Subcooling Method –
Outdoor Temperatures Below 65°F
1. Record outdoor ambient temperature using a digital
thermometer.
When the outdoor ambient temperature is below 65°F, the
subcooling method can be used to charge the unit. It may
be necessary to restrict the air flow through the outdoor
coil to achieve pressures in the 200-250 psig range.
These higher pressures are necessary for checking the
charge. Block equal sections of air intake panels and
move obstructions sideways until the liquid pressure is in
the 200-250 psig range (see Figure 12).
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 on page 15. Minor variations in these pres-
sures may be expected due to differences in installa-
tions. Significant 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.
1. With the manifold gauge hose on the liquid service
port and the unit operating stably, use a digital ther-
mometer to record the liquid line temperature.
2. At the same time, record the liquid line pressure reading.
4. Use the same digital thermometer to check liquid line
temperature.
3. Use the temperature/pressure chart (Table 5 on page 14)
to determine the saturation temperature for the liquid line
pressure reading.
5. Subtract the outdoor ambient temperature from the
liquid line temperature to determine the approach
temperature.
506467-01
Issue 1008
Page 13
Download from Www.Somanuals.com. All Manuals Search And Download.
R410A Temperature/Pressure Chart
Subcooling Values
Temp.
(F
Pressure
Psig
Temp.
(F
Pressure
Psig
Temp.
(F
Pressure
Psig
32
33
100.8
102.9
74
75
214.0
217.4
116
117
396.0
401.3
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
105.0
107.1
109.2
111.4
113.6
115.8
118.0
120.3
122.6
125.0
127.3
129.7
132.2
134.6
137.1
139.6
142.2
144.8
147.4
150.1
152.8
155.5
158.2
161.0
163.9
166.7
169.6
172.6
175.5
178.5
181.6
184.3
187.7
190.9
194.1
197.3
200.6
203.9
207.2
210.6
76
77
220.9
224.4
228.0
231.6
235.3
239.0
242.7
246.5
250.3
254.1
258.0
262.0
266.0
270.0
274.1
278.2
282.3
286.5
290.3
295.1
299.4
303.8
308.2
312.7
317.2
321.8
326.4
331.0
335.7
340.5
345.3
350.1
355.0
360.0
365.0
370.0
375.1
380.2
385.4
390.7
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
406.7
412.2
417.7
423.2
428.8
434.5
440.2
445.9
451.8
457.6
463.5
469.5
475.6
481.6
487.8
494.0
500.2
506.5
512.9
519.3
525.8
532.4
539.0
545.6
552.3
559.1
565.9
572.8
579.8
586.8
593.8
601.0
608.1
615.4
622.7
630.1
637.5
645.0
Table 6
78
79
80
81
°
°
°
Liquid Line Temperature °F
Outdoor Ambient Temperature °F
Approach Temperature °F
_
82
83
=
84
85
86
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.
87
88
89
90
91
92
93
94
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.
Significant deviations could mean that the system is not
properly charged or that a problem exists with some
component in the system.
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
Approach Values for TXV Systems
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
72
73
207.2
210.6
114
115
385.4
390.7
Table 5
506467-01
Issue 1008
Download from Www.Somanuals.com. All Manuals Search And Download.
Page 14
Normal Operating Pressures
L = Liquid S = Suction
Values provided above are typical pressures. Indoor unit matchup, indoor air quality, and indoor load
will cause pressures to vary.
Table 8
506467-01
Issue 1008
Page 15
Download from Www.Somanuals.com. All Manuals Search And Download.
Thermostat Demand Wiring
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.
The diagnostic module requires a thermostat demand
signal to operate properly. The thermostat demand signal
input, labeled Y on the module, should always be con-
nected to the compressor contactor coil so that when the
coil is energized, the demand signal input is 24VAC. When
the coil is not energized, the demand signal input should be
less than 0.5VAC.
System Diagnostic Module
4AC16LT units contain a diagnostic module for trouble-
shooting air conditioning system failures. By monitoring
and analyzing data from the compressor and thermostat
demand, the module can accurately detect the cause of
electrical and system related failure without any sensors.
If a system problem occurs, a flashing LED indicator
communicates the failure code.
Miswired Module Codes
Depending on the system configuration, some ALERT
flash codes may not be active. The presence of safety
switches affects how the system alerts are displayed by
the module.
LED Description
Miswiring the diagnostic module will cause false LED
codes. Table 11 on page 19 describes LED operation
when the module is miswired and what troubleshooting
action is required to correct the problem.
POWER LED (Green) indicates voltage is present at the
power connection of the module.
ALERT LED (Yellow) communicates an abnormal system
condition through a unique flash code. The ALERT LED
will flash a number of times consecutively, pause, and
then repeat the process. The number of consecutive
flashes correlates to a particular abnormal condition.
TRIP LED (Red) indicates there is a demand signal from
the thermostat but no current to the compressor is de-
tected by the module. The TRIP LED typically indicates
the compressor protector is open or may indicate missing
supply power to the compressor.
Interpreting the Diagnostic LEDs
When an abnormal system condition occurs, the diagnostic
module displays the appropriate ALERT and/or TRIP LED.
The yellow ALERT LED will flash a number of times
consecutively, pause, and then repeat the process. To
identify a flash code number, count the number of consecu-
tive flashes. Refer to Table 9 on page 17 and Table 10 on
page 18 for information on the flash codes.
Every time the module powers up, the last ALERT LED
flash code that occurred prior to shutdown is displayed for
60 seconds. The module will continue to display the
previous flash code until the condition returns to normal or
24VAC is removed from the module. TRIP and ALERT
LEDs flashing at the same time means control circuit
voltage is too low for operation.
24VAC Power Wiring
The diagnostic module requires a constant nominal 24VAC
power supply. The wiring to the module’s R and C terminals
must be directly from the indoor unit or thermostat.
506467-01
Issue 1008
Page 16
Download from Www.Somanuals.com. All Manuals Search And Download.
Flash Codes
LED
Status
Fault Description
Troubleshooting Information
POWER
(Green)
Module has power
Supply voltage is present at module terminals
1. Compressor protector is open
* Check for high head pressure
Thermostat demand
signal Y1 is present,
but the compressor
is not running
* Check compressor supply voltage
TRIP
(Red)
2. Outdoor unit power disconnect is open
3. Compressor circuit breaker or fuse(s) is open
4. Broken wire or connector is not making contact
5. Low pressure switch open if present in system
6. Compressor contactor has failed open
1. Low refrigerant charge
2. Evaporator blower is not running
* Check blower relay coil and contacts
* Check blower motor capacitor
* Check blower motor for failure or blockage
* Check evaporator blower wiring and connector
* Check indoor blower control board
* Check thermostat wiring for open circuit
3. Evaporator coil is frozen
* Check for low suction pressure
* Check for excessively low thermostat setting
* Check evaporator airflow (coil blockages or return air filter)
* Check ductwork or registers for blockage
4. Faulty metering device
Long Run Time
Compressor is
running
extremely long run
cycles
ALERT
(Yellow)
Flash
Code 1
* Check TXV bulb installation (size, location, and contact)
* Check if TXV/fixed orifice is stuck closed or defective
5. Condenser coil is dirty
6. Liquid line restriction (filter drier blocked if present in system)
7. Thermostat is malfunctioning
* Check thermostat sub-base or wiring for short circuit
* Check thermostat installation (location, level)
1. High head pressure
* Check high pressure switch if present in system
* Check if system is overcharged with refrigerant
* Check for non-condensable in system
2. Condenser coil poor air circulation (dirty, blocked, damaged)
3. Condenser fan is not running
System
Pressure Trip
Discharge or suction
pressure
ALERT
(Yellow)
Flash
out of limits or
compressor
* Check fan capacitor
* Check fan wiring and connectors
Code 2
overloaded
* Check fan motor for failure or blockage
4. Return air duct has substantial leakage
5. If low pressure switch present in system, check Flash Code 1 info
Table 9
506467-01
Issue 1008
Page 17
Download from Www.Somanuals.com. All Manuals Search And Download.
Flash Codes (cont.)
LED
Status
Fault Description
Troubleshooting Information
1. Thermostat demand signal is intermittent
2. Time delay relay or control board defective
3. If high pressure switch present, go to Flash Code 2 info
4. If low pressure switch present, go to Flash Code 1 info
ALERT
(Yellow)
Flash
Short Cycling
Compressor is
running
Code 3
only briefly
1. Run capacitor has failed
ALERT
(Yellow)
Flash
2. Low line voltage (contact utility if voltage at disconnect is low)
* Check wiring connections
3. Excessive liquid refrigerant in compressor
4. Compressor bearings are seized
*Measure compressor oil level
Locked Rotor
Code 4
1. Outdoor unit power disconnect is open
2. Compressor circuit breaker or fuse(s) is open
3. Compressor contactor has failed open
* Check compressor contactor wiring and connectors
* Check for compressor contactor failure (burned, pitted, or open)
* Check wiring and connectors between supply and compressor
* Check for low pilot voltage at compressor contactor coil
4. High pressure switch is open and requires manual reset
5. Open circuit in compressor supply wiring or connections
6. Unusually long compressor protector reset time due to extreme ambient temperature
7. Compressor windings are damaged
ALERT
(Yellow)
Flash
Open Circuit
Code 5
* Check compressor motor winding resistance
1. Run capacitor has failed
ALERT
(Yellow)
Flash
Open Start Circuit
Current only in run
circuit
2. Open circuit in compressor start wiring or connections
* Check wiring and connectors between supply and the compressor S terminal
3. Compressor start winding is damaged
Code 6
* Check compressor motor winding resistance
ALERT
(Yellow)
Flash
1. Open circuit in compressor run wiring or connections
* Check wiring and connectors between supply and the compressor R terminal
2. Compressor run winding is damaged
Open Run Circuit
Current only in start
circuit
Code 7
* Check compressor motor winding resistance
ALERT
(Yellow)
Flash
Welded Contactor
Compressor always
runs
1. Compressor contactor has failed closed
2. Thermostat demand signal not connected to module
Code 8
ALERT
(Yellow)
Flash
Low Voltage
Control circuit less
than 17VAC
1. Control circuit transformer is overloaded
2. Low line voltage (contact utility if voltage at disconnect is low)
* Check wiring conditions
Code 9
Table 10
506467-01
Issue 1008
Page 18
Download from Www.Somanuals.com. All Manuals Search And Download.
Miswired Module Troubleshooting
Miswired Module Indication
Recommended Troubleshooting Action
Determine if both R and C module terminals are connected. Verify voltage is present
at module's R and C terminals. Review 24VAC Power Wiring section on page 16 for
R and C wiring.
Green LED is not on,
module does not power up.
Green LED intermittent,
module powers up only
when compressor runs.
Determine if R and Y terminals are wired in reverse. Verify module's R and C
terminals have a constant source. Review 24VAC Power Wiring section on page 16
for R and C wiring.
TRIP LED is on but system
and compressor check OK.
Verify Y terminal is connected to 24VAC at contactor coil. Verify voltage at contactor
coils falls below 0.5VAC when off.
TRIP LED and ALERT LED
flashing together.
Verify R and C terminals are supplied with 19-28VAC.
ALERT Flash Code 3
(Compressor Short Cycling)
displayed incorrectly.
Verify Y terminal is connected to 24VAC at contactor coil. Verify voltage at contactor
coil falls below 0.5VAC when off.
ALERT Flash Code 5, 6, or 7
(Open Circuit, Open Start
Circuit, or Open Run Circuit)
displayed incorrectly.
Check that compressor run and start wires are through module's current sensing
holes. Verify Y terminal is connected to 24VAC at contactor coil. Verify voltage at
contactor coil falls below 0.5VAC when off.
ALERT Flash Code 6
(Open Start Circuit)
displayed for Code 7
(Open Run Circuit
or vice versa.
Check that compressor run and start wires are routed through correct module
sensing holes.
Determine if module's Y terminal is connected. Verify Y terminal is connected to 24VAC at
contactor coil. Verify 24VAC is present across Y and C when thermostat demand signal is
present. If not, R and C are reverse wired. Verify voltage at contactor coil falls below
0.5VAC when off. Review Thermostat Demand Wiring on page 16 for Y and C wiring.
ALERT Flash Code 8
(Welded Contactor)
displayed incorrectly.
Table 11
506467-01
Issue 1008
Page 19
Download from Www.Somanuals.com. All Manuals Search And Download.
4. Check all wiring for loose connections.
5. Check for correct voltage at unit (with unit operating).
6. Check amp-draw on blower motor.
MAINTENANCE
WARNING
Before performing maintenance operations on
system, turn the electric power to unit OFF at
disconnect switch(es). Unit may have multiple
power supplies. Electrical shock could cause
personal injury or death.
Unit nameplate _________ Actual _________
Maintenance and service must be performed by a quali-
fied installer or service agency.
At the beginning of each cooling season, the system
should be checked as follows:
1. Clean and inspect condenser coil. Coil may be
flushed with a water hose. Be sure the power is off
before using water to clean the coil.
2. Outdoor fan motor is pre-lubricated and sealed. No
further lubrication is needed.
3. Visually inspect connecting lines and coils for evi-
dence of oil leaks.
4. Check wiring for loose connections.
5. Check for correct voltage at unit (with unit operating).
6. Check amp-draw outdoor fan motor.
Unit nameplate _________ Actual _________
NOTE – If owner complains of insufficient cooling, the
unit should be gauged and refrigerant charge checked.
Refer to the Refrigerant Charging section on page 12.
Indoor Coil
1. Clean coil, if necessary.
2. Check connecting lines and coils for evidence of oil
leaks.
3. Check condensate pan line and clean, if necessary.
Indoor Unit
1. Clean or change filters.
2. Adjust blower speed for cooling. Measure the pressure
drop over the coil to determine the correct blower CFM.
3. Belt drive blowers: Check belt for wear and proper
tension.
506467-01
Issue 1008
Page 20
Download from Www.Somanuals.com. All Manuals Search And Download.
Start-Up and Performance Checklist
Job Name _______________________________
Job No. ________________
City ___________________
City ___________________
Date ______________
State ______________
State ______________
Job Location _____________________________
Installer _________________________________
Unit Model No.______________
Serial No. ___________________
Service Technician ________________________________________
Nameplate Voltage ______________
Outdoor Fan ___________________
Rated Load Ampacity ________
Compressor _______________
Maximum Fuse or Circuit Breaker________________________
Electrical Connections Tight?
Indoor Filter Clean?
Supply Voltage (Unit Off) ________________
Indoor Blower RPM _____________
S.P. Drop Over Indoor (Dry) ____________
Voltage with Compressor Operating _____________
Vapor Pressure ____________
Outdoor Coil Entering Air Temperature _____________
Discharge Pressure___________
Refrigerant Charge Checked?
Refrigerant Lines: Leak Checked?
Service Valves: Fully Opened?
Outdoor Fan Checked?
Properly Insulated?
Caps Tight?
Thermostat: Calibrated?
Properly Set?
Level?
506467-01
Issue 1008
Page 21
Download from Www.Somanuals.com. All Manuals Search And Download.
LT BLUE
OUTDOOR
FAN
DUAL
CAPACITOR
PURPLE
BLACK
TO 24 VAC
POWER SOURCE
20 VA MINIMUM
NEC CLASS 2
F
C
H
ORANGE
Y2
YELLOW
R
C
Y1
RED
BLUE
R
C
L
Y2
BLACK
Y1
R
S
C
COMPRESSOR
CRANKCASE HEATER
(IF USED)
L2
L1
GROUND
LUG
208-230/60/1
GROUND
B1
S
R
C
1
BLACK
L1
S4 HIGH
PRESSURE
SWITCH
S24 LOSS
OF CHARGE
SWITCH
K1-1
A132
Y2
Y1
L
R
C
208-230/60/1
L2
YELLOW
RED
ORANGE
BLACK
S24
S4
HR1
K1
H
C
C12
F
EQUIPMENT
GROUND
R
B4
PURPLE
C
Y2 Y1
TO 24 VAC
POWER SOURCE
20 VA MINIMUM
NEC CLASS 2
FOR USE WITH COPPER CONDUCTORS ONLY. REFER TO UNIT RATING
PLATE FOR MINIMUM CIRCUIT AMPACITY AND MAXIMUM OVERCURRENT
PROTECTION SIZE.
1
DESCRIPTION
WARNING--
KEY
A4
A132
B1
COMPONENT
ELECTRIC SHOCK HAZARD, CAN CAUSE INJURY OR DEATH.
UNIT MUST BE GROUNDED IN ACCORDANCE WITH NATIONAL
AND LOCAL CODES.
CONTROL - TIMED OFF
DIAGNOSTIC MODULE
COMPRESSOR
B4
C12
HR1
K1-1
S4
S24
MOTOR - OUTDOOR FAN
CAPACITOR - DUAL
HEATER - COMPRESSOR
CONTACTOR - COMPRESSOR
SWITCH - HIGH PRESSURE
SWITCH - LOSS OF CHARGE
LINE VOLTAGE FACTORY INSTALLED
LINE VOLTAGE FIELD INSTALLED
24 VOLT FACTORY INSTALLED
CLASS II VOLTAGE FIELD INSTALLED
Wiring Diagram P/N 48440-002
Figure 13
506467-01
Issue 1008
Page 22
Download from Www.Somanuals.com. All Manuals Search And Download.
|