American Standard 21 Series Assembly instructions

Models :
4TXM2118A12N0A
4TXM2124A13N0A
4TXM2130A14N0A
4TXM2136A14N0A
4TXM2142A15N0A
Installer's Guide
Split System (R-410A)
21 Series Multi-Zone
Inverter System
18,000 Btu/h to 42,000 Btu/h
January 2023 MS-SVN085A-EN

WARNING
This equipment is to be serviced by professionally trained personnel
ONLY. Under NO circumstances should an unqualied person service it.
This equipment contains refrigerant under PRESSURE and operates at
HIGH VOLTAGE. Improperly installed, adjusted or altered equipment by an
unqualied person poses safety hazards including FIRE, ELECTROCUTION,
or EXPLOSION, which could result in death or serious injury.
Warnings and Cautions
Warnings are provided to alert others of the potential hazards that could
result in severe personal injury or death, while cautions are designed
to alert others of the conditions that could result in minor or moderate
injury.
Your personal safety and the proper operation of this machine depend
upon the strict observance of these precautions.
Attention: Warnings and Cautions appear at appropriate sections
throughout this literature. Read these carefully.
WARNING: Indicates a potentially hazardous situation which, if not
avoided, could result in death or serious injury.
CAUTION: Indicates a potentially hazardous situation which, if not
avoided, could result in minor or moderate injury. It may also be used
to alert against unsafe practices.
NOTICE:Indicates a situation that could result in equipment or
property damage.
WARNING
Electrocution and Fire Hazards with Improperly Installed and Grounded
Field Wiring!
Improperly installed and grounded eld wiring poses FIRE and
ELECTROCUTION hazards.To avoid these hazards, you MUST follow
requirements for eld wiring installation and grounding as described in
the National Electrical Codes (NEC) and your State and/or local electrical
codes. All eld wiring MUST be performed by qualied personnel.
Failure to follow these requirements could result in death or serious injury.

Warnings and Cautions
WARNING
R-410A Refrigerant under Higher Pressure than R-22!
The units described in this manual use R-410A refrigerant which operates at 50 to 70%
higher pressures than R-22. Use only R-410A approved service equipment. Refrigerant
cylinders may contain a "dip" tube to allow for charging of liquid refrigerant into the
system. For specic handling concerns with R-410A, please contact your local sales ofce.
Failure to use R-410A approved service equipment could result in standard equipment
exploding under R-410A higher pressure which could result in death or serious injury.
NOTICE
Use appropriate oil with R410A systems. Oil type is found at the bottom of Connection Pipe
Requirements table (included in the outdoor unit installation manual). R-410A systems
utilize POE (Polyolester) or PVE(Polyvinyl Ether) oil. Both oil types absorb moisture readily,
yet, lubrication properties vary. Do not leave the sealed system open to atmosphere except
during service for a short period of time. If the sealed system is left open longer than four
hours, the compressor oil must be changed.These systems utilize strainers placed before
and after the expansion device in the outdoor unit, if debris or moisture is suspected, these
strainers must be changed. Do not break a vacuum with air. Do not leak check the sealed
system with compressed air. Unless instructed by factory service representative, external
refrigeration driers are prohibited.
USE ONLY THE FACTORY RECOMMENDED OIL TYPE!
Important!
Environmental Concerns
Scientic research has shown that certain man-made chemicals can affect the earth's naturally occurring
stratospheric ozone layer when released to the atmosphere. In particular, several of the identied chemicals that
may affect the ozone layer are refrigerants that contain chlorouorocarbons (CFC's) and those containing hydro-
chlorouorocarbons (HCFC's). Not all refrigerants containing these compounds have the same potential impact
to the environment.The Company advocates the responsible handling of all refrigerants, including industry
replacements for CFC's such as HCFC's and HFC's.
Responsible Refrigerant Practices
The manufacturer believes that responsible refrigerant practices are important to the environment, our
customers, and the air conditioning industry. All technicians who handle refrigerants must be certied.The
Federal Clean Air Act (Section 608) sets forth the requirements for handling, reclaiming, recovering and recycling
of certain refrigerants and the equipment that is used in these service procedures. In addition, some states or
municipalities may have additional requirements that must also be adhered to for responsible management of
refrigerants. Know the applicable laws and follow them.

Contents
Safety Precautions ...............................................................................................5
Pre-Installation Checklist .....................................................................................6
Product Introduction .............................................................................................7
Ductless Multi-Split Approved Combinations........................................................8
Operating Temperature Ranges ...........................................................................9
Preparation for Installation..................................................................................10
Selecting the Installation Location......................................................................10
Installing the Outdoor Unit.................................................................................. 11
Condensate Management of the Outdoor Unit................................................... 11
Refrigerant Piping Between the Indoor and Outdoor Units ................................ 11
Refrigeration and Condensate Piping Tips .........................................................13
Connection Pipe Requirements..........................................................................14
Refrigerant Piping Precautions...........................................................................14
Nitrogen Purging While Brazing .........................................................................14
Installing the Refrigerant Piping..........................................................................16
Insulating the Refrigeration Piping and Connections .........................................16
Refrigerant Piping Between the Indoor and Outdoor Units ................................17
Vacuum and Refrigerant Leakage Detection......................................................19
Wiring Precautions .............................................................................................20
Outdoor Wiring Connections ..............................................................................20
Stranded Wiring Connections.............................................................................21
Electrical Connections........................................................................................22
Post Installation Checklist ..................................................................................22
Refrigerant System Diagrams ............................................................................24
Electrical Connections at the Outdoor Unit.........................................................25
Wiring Diagrams.................................................................................................26
Dimensional Diagrams .......................................................................................29
Troubleshooting..................................................................................................31
Error Codes ........................................................................................................32
Maintenance.......................................................................................................33
List of Resistance for Temperature Sensor ........................................................34
Parts Replacement.............................................................................................37
After-Sales Service.............................................................................................37

MS-SVN085A-EN
5
21 Series Multi-Split
WARNING This mark indicates a potentially hazardous situation which, if not avoided,
could result in death or serious injury.
CAUTION
This mark indicates a potentially hazardous situation which, if not avoided,
could result in minor or moderate injury. It may also be used to alert against
unsafe practices.
NOTICE This mark indicates a situation which could result in equipment and/or
property damage.
Safety Precautions
Your personal safety and the proper operation of this equipment depend upon the strict observance of
these precautions.
WARNING
1. Installation should performed by a qualied HVAC professional. Industry Standard Personal
Protective Equipment (PPE) and gear for height related safety should be worn during installation.
Improper personal safety precautions and installation may cause death or serious injury.
2. Install the air conditioner according to the instructions given in this manual. Incomplete installation
work may cause water leakage, electrical shock or re.
3. Use the supplied or specied installation parts. Use of other parts may cause the unit to come
loose, resulting in water leakage, electrical shock or re.
4. Install the unit in a location that can support the weight of the unit. An inadequate support
structure or incomplete installation may cause injury or property damage in the event the unit falls
o󰀨 of the installation location. Refer to the installation specications for additional requirements.
5. Electrical work should be carried out in accordance with the installation manual and local, state
and National Electric Code (NEC). Insu󰀩cient capacity or incomplete electrical work may cause
electrical shock or re.
6. Use a dedicated power circuit. Never use a power supply shared by another appliance.
7. For wiring, use a cable that is long enough to cover the entire distance without splicing. Do not
use an extension cord. Do not put other loads on the power supply; use a dedicated power circuit.
Failure to do so may cause abnormal heat, electric shock or re.
8. Use the specied types of wires for electrical connections between the indoor and outdoor units.
Firmly clamp the interconnecting wires so their terminals receive no external stresses. Incomplete
connections or clamping may cause terminal overheating or re.
9. After joining the interconnecting and supply wiring, shape the cables so that they do not put undue
force on the electrical covers or panels. Install covers over the wires. Incomplete cover installation
may cause terminal overheating, electrical shock, or re.
10. If any refrigerant leaks out during the installation, ventilate the room. The refrigerant produces a
toxic gas if exposed to ames.
11. When installing or relocating the system, keep the refrigerant circuit free from substances
other than the specied refrigerant (R-410A), such as air. The presence of air or other foreign
substances in the refrigerant circuit can cause an abnormal pressure rise or rupture, which could
result in injury and damage.

MS-SVN085A-EN 6
21 Series Multi-Split
12. If a system pump-down is performed, turn o󰀨 the associated equipment and close service valves
prior to removing the refrigerant piping. Failure to do so will introduce non-condensables in the
system, causing abnormal pressure in the refrigeration cycle which could lead to injury and
damage.
13. Before system start-up, attach the refrigerant piping securely. Failure to do so will introduce non-
condensables into the system when the compressor is running, causing abnormal pressure in the
refrigeration cycle which could lead to injury and damage.
14. Establish a complete ground. Do not ground the unit to a utility pipe, arrester, or telephone
ground. An incomplete ground may cause electrical shock, or re. A high surge current from
lightning or other sources may cause damage to the air conditioner.
15. If the power supply cable is damaged, it must be replaced by the manufacturer, its service agent
or another qualied professional in order to avoid electrical risk during and after replacement.
Pre-Installation Checklist
1. Unpack and inspect each unit.
2. Check for any damage to the unit.
3. Check the model numbers to ensure a proper match.
4. Check the unit nameplate to ensure the proper electrical requirements will be met.
5. Check the installation locations to ensure the weight of the units can be supported.
6. Check the refrigerant pipe sizes and ensure they have been or will be installed according to the
requirements in this manual.
7. Check the outdoor unit nameplate for electrical power supply and wiring requirements to ensure the
proper wiring has been installed prior to connection.
8. Check the indoor unit for coil leakage. The pressure relief valve on the gas pipe should release
pressurized nitrogen which ensures the unit has not leaked during shipping.
CAUTION
1. Do not install the unit in a place where there is danger of exposure to ammable gas leakage. If
gas leaks and builds up around the unit, it may result in re.
2. After system installation is completed, make sure no refrigerant leakage is present.
3. This appliance is not intended for use by persons with a lack of experience and knowledge, unless
they have been given adequate supervision or instruction concerning use of the appliance by a
person responsible for their safety.
4. Children should be supervised to ensure that they do not play with the appliance.
NOTICE
1. Establish drain piping according to the instructions in this manual. Inadequate piping may cause
ooding.
2. Tighten the are nut according to the specied method. If the are nut is tightened too hard, the
are nut may crack and cause refrigerant leakage.

MS-SVN085A-EN
Product Introduction
The 21 Series Multi-split system utilizes inverter compressor technology, which enables the outdoor unit to
send refrigerant to multiple indoor units of varying capacities. It is critical, however, that heat loss and heat
gain calculations be performed to properly size the multi-split system.
Table 1: OD Unit Component Identication
Table 2: Number of Indoor Units
Note: When the total capacity of the indoor units exceeds the total capacity of the outdoor unit, the system
will be restricted by the capacity of the outdoor unit. All indoor units would not be able to operate at full
capacity at the same time. If the indoor unit combined capacity is less than 100% of the outdoor units'
capacity, the system capacity is limited to the indoor unit(s) combined capacity.
MODEL 4TXM2118A12 4TXM2124A13 4TXM2130A14 4TXM2136A14 4TXM2142A15
Minimum number of connectable indoor
units 2 2 2 2 2
Maximum number of connectable
indoor units 2 3 4 4 5
No. 1 2 3 4 5
Name Motor Fan Electric Box Vapor Valve Assembly Liquid Valve Assembly
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21 Series Multi-Split

MS-SVN085A-EN
Table 3: Ductless Multi-Split Approved Combinations
Indoor Unit Combinations
Outdoor Unit Two Units
4TXM2118A12N0A
18,000 BTUH
9 + 9 12+12
9 + 12
Outdoor Unit Two Units Three Units
4TXM2124A13N0A
24,000 BTUH
9+9 9+12 9+9+9 9+12+12 12+12+12
9+18 12+12 9+9+12 9+9+18
12+18 18+18
Outdoor Unit One Indoor Two Indoor Three Indoor Four Indoor Five Indoor
4TXM2130A14N0A
30,000 BTUH
9K+9K 9K+9K+9K 9K+9K+9K+9K
9K+12K 9K+9K+12K 9K+9K+9K+12K
9K+18K 9K+9K+18K 9K+9K+9K+18K
9K+24K 9K+9K+24K 9K+9K+12K+12K
12K+12K 9K+12K+12K 9K+12K+12K+12K
12K+18K 9K+12K+18K
12K+24K 9K+12K+24K
18K+18K 9K+18K+18K
18K+24K 12K+12K+12K
12K+12K+18K
Outdoor Unit One Indoor Two Indoor Three Indoor Four Indoor Five Indoor
4TXM2136A14N0A
36,000 BTUH
9K+9K 9K+9K+9K 9K+9K+9K+9K
9K+12K 9K+9K+12K 9K+9K+9K+12K
9K+18K 9K+9K+18K 9K+9K+9K+18K
9K+24K 9K+9K+24K 9K+9K+9K+24K
12K+12K 9K+12K+12K 9K+9K+12K+12K
12K+18K 9K+12K+18K 9K+9K+12K+18K
12K+24K 9K+12K+24K 9K+9K+12K+24K
18K+18K 9K+18K+18K 9K+9K+18K+18K
18K+24K 9K+18K+24K 9K+12K+12K+12K
24K+24K 12K+12K+12K 9K+12K+12K+18K
12K+12K+18K 12K+12K+12K+12K
12K+12K+24K 12K+12K+12K+18K
12K+18K+18K
12K+18K+24K
18K+18K+18K
Outdoor Unit One Indoor Two Indoor Three Indoor Four Indoor Five Indoor
4TXM2142A15N0A
42,000 BTUH
9K+12K 9K+9K+9K 9K+9K+9K+9K 9K+9K+9K+9K+9K
9K+18K 9K+9K+12K 9K+9K+9K+12K 9K+9K+9K+9K+12K
9K+24K 9K+9K+18K 9K+9K+9K+18K 9K+9K+9K+9K+18K
12K+12K 9K+9K+24K 9K+9K+9K+24K 9K+9K+9K+9K+24K
12K+18K 9K+12K+12K 9K+9K+12K+12K 9K+9K+9K+12K+12K
12K+24K 9K+12K+18K 9K+9K+12K+18K 9K+9K+9K+12K+18K
18K+18K 9K+12K+24K 9K+9K+12K+24K 9K+9K+9K+12K+24K
18K+24K 9K+18K+18K 9K+9K+18K+18K 9K+9K+9K+18K+18K
24K+24K 9K+18K+24K 9K+9K+18K+24K 9K+9K+12K+12K+12K
9K+24K+24K 9K+12K+12K+12K 9K+9K+12K+12K+18K
12K+12K+12K 9K+12K+12K+18K 9K+12K+12K+12K+12K
12K+12K+18K 9K+12K+12K+24K 9K+12K+12K+12K+18K
12K+12K+24K 9K+12K+18K+18K 12K+12K+12K+12K+12K
12K+18K+18K 9K+12K+18K+24K
12K+18K+24K 9K+18K+18K+18K
12K+21K+24K 12K+12K+12K+12K
12K+24K+24K 12K+12K+12K+18K
18K+18K+18K 12K+12K+12K+24K
18K+18K+24K 12K+12K+18K+18K
Note: Heating and cooling capacity capacity can be diminished with more that 100% indoor connected load.
8
21 Series Multi-Split

MS-SVN085A-EN
The gure below illustrates that multiple indoor high wall units may be used on a single 4TXM21 multi-port
system, provided the combination is approved. Please reference the multi-zone approved combinations
matrix on page 8.
When the total capacity of the indoor units exceeds the total capacity of the outdoor unit, the system will be
restricted by the capacity of the outdoor unit. All indoor units would not be able to operate at full capacity
at the same time. If the indoor unit combined capacity is less than 100% of the outdoor units' capacity, the
system capacity is limited to the indoor unit(s) combined capacity.
Note: Please see the product data information for total cooling capacities down to 0 degrees F.
Table 5: Operating Temperature Ranges
Cooling Operating Range Outdoor Temperature -22 - 118 °F (-30 - 48 °C)
Heating Operating Range Outdoor Temperature -22 - 75 °F (-30 - 24 °C)
Combinations for Outdoor and Indoor Units
Table 4: Ductless Multi-Split Quick Reference
Multi-Split Heat Pump Outdoor
18,000 BTUH 24,000 BTUH 30,000 BTUH 36,000 BTUH 42,000 BTUH
4TXM2118A12N0A 4TXM2124A13N0A 4TXM2130A14N0A 4TXM2136A14N0A 4TXM2142A15N0A
Maximum number of 2 indoor units in any unit type combination for 4TXM2118
Maximum number of 3 indoor units in any unit type combination for 4TXM2124
Maximum number of 4 indoor units in any unit type combination for 4TXM2130
Maximum number of 4 indoor units in any unit type combination for 4TXM2136
Maximum number of 5 indoor units in any unit type combination for 4TXM2142
Wall Mounted
Indoor Unit
Wall Mounted
Indoor Unit
Wall Mounted
Indoor Unit
Wall Mounted
Indoor Unit
Wall Mounted
Indoor Unit
9
21 Series Multi-Split

MS-SVN085A-EN
Preparation for Installation
valve cover
Space to the wall
12 in. or more
20 in. or more
20 in. or more
12 in. or more
or more.ni
97
Space to the obstruction
Air outlet side
Space to the wall
Air inlet side
Outdoor Unit
1. Select a location where equipment noise and air discharge won't be distracting.
2. Select a location where there is sufcient ventilation.
3. Make sure the air inlet and outlet are not blocked by any obstacles
4. Select a location capable of supporting four times the weight of the unit, that will not increase
vibration, and where installation work can be carried out safely.
5. Select a location away from ammable gas or gas leaks.
6. Ensure installation of the outdoor unit conforms to the clearance specications in this manual.
7. Locate the outdoor unit away from any bedroom windows.
NOTICE
Installing the unit in one of the following locations could result in unit malfunction:
1. Places where oil (machine oil) is used.
2. Seaside places with high levels of salt in the air.
3. Places with high levels of sulphur gas such as areas with hot springs.
4. Places where high-frequency waves are generated by radio equipment, welders and medical
equipment.
5. Other unusual places where unit operation may be altered.
6. Places where minimum clearances cannot be met.
WARNING
1. Install the unit on a level surface or on supports that are level.
2. If the location is subject to strong winds, the additional force must be accounted for
and the unit must be xed securely to the base. Refer to local codes for additional
requirements.
Selecting the Installation Location
10
21 Series Multi-Split

MS-SVN085A-EN
11
21 Series Multi-Split
Installing the Outdoor Unit
When the outdoor unit is surrounded by walls or other obstructions, the installation space
of the unit should be no less than the clearances indicated below. For e󰀩cient operation,
leave three of four directions of peripheral constructions open when possible.
WARNING
1. Install the unit on a level surface or on supports that are level.
2. If the location is subject to strong winds, the additional force must be accounted for
and the unit must be xed securely to the base. Refer to local codes for additional
requirements.
＞12(305)
＞20(508)
＞79(2000) ＞12 (305)
＞12(305)
＞20(508)
＞79(2000)
inch(mm)
Select the installation location that provides easy access to the indoor unit.
1. Make sure the location can support at least four times the weight of the unit.
2. Secure the outdoor unit on the selected base location with expansion screws.
3. The outdoor unit should be installed at least 1 1/4 inch above the ground or base in order to
install a drain pipe and connector (shown below).
At least 1 1/4 inch (31.8mm) clearance
Condensate Management of the Outdoor Unit
1. The outdoor unit(s) should be located where condensate poses no hazard or safety risk. Each
unit is supplied with a drain pipe connector.
2. Before installing the drain pipe tting, appropriately plug all other base pan holes not used.
3. Install the drain pipe tting into the appropriate hole located at the base of the unit and then
connect the drain pipe to it.
4. In heating mode - ice can be created in freezing conditions.

MS-SVN085A-EN
Foot holes
Foot holes
12
21 Series Multi-Split
5. Place the outdoor unit on the support base.
6. Secure the foot holes of the outdoor unit with bolts (shown below).

MS-SVN085A-EN
If the outdoor unit is installed higher than
the indoor unit:
1. Taping should be done from the lower to
the upper part. Do not wrap too tightly
to avoid compression of the insulation,
otherwise its e󰀨ectiveness is reduced.
2. All pipes are bound and taped together
and also should be trapped to prevent
water from returning to the room.
3. Secure all pipes to the wall with saddles.
4. NOTE: Oil traps are sometimes needed
when the outdoor unit is installed higher
than the indoor unit. An oil trap is needed
for each 20 ft. (6m) of vertical rise on the
gas pipe.
Refrigeration and Condensate Piping Tips
If the outdoor unit is installed lower than the indoor unit:
1. If indoor unit condensate line follows refrigeration lines, then the drain pipe termination should
be above ground in order that the end of the pipe should not dip into water.
2. Taping pipes must be done from bottom to top. Do not wrap too tightly to avoid compression of
the insulation, otherwise its e󰀨ectiveness is reduced.
3. All pipes are bound together by pipe tape and secured to the wall with saddles.
4. NOTE: Oil traps are sometimes needed when the outdoor unit is installed lower than the
indoor unit. One oil trap is required for each 33 ft. (10m) of vertical gas pipe length.
ODU
IDU
Drain
Pipe
Oil Trap
Liquid
Pipe
Gas Pipe
Oil Trap
Oil Trap
Drain
Pipe
Outdoor Unit Installed Lower than
Indoor Unit
Outdoor Unit Installed Higher than
Indoor Unit
13
21 Series Multi-Split

MS-SVN085A-EN
Connection Pipe Requirements
NOTICE
The maximum distance of the connection piping in both height and total length is provided in the
table below. Do not install these units in locations that exceed these specications.
Table 6: Piping Information for 4TXM21
Heat
Pump
Circuits
Liquid
inch
(mm)
Gas
inch
(mm)
Factory
Charge
oz (kg)
Additional
oz/ft (g/m)
Max
Length
Circuit
ft (m)
Min.
Line
Length
ft (m)
Max
Length
System
ft (m)
Max
Height
ODU
to IDU
ft (mm)
Max
Height
IDU to
IDU
ft (mm)
Max
Length
without
adding
refrigerant
ft (mm)
4TXM2118
B
1/4
(φ6)
3/8
(φ9.52)
45.9
(1.3)
0.2
(20)
82
(25)
15
(4.57)
131.2
(40)
49.2
(15)
49.2
(15)
32.8
(10)
A
4TXM2124
C
84.7
(2.4)
196.8
(60)
49.2
(15)
49.2
(15)
131.2
(40)
B
A
4TXM2130
D
105.8
(3.0)
262.5
(80)
82
(25)
82
(25)
131.2
(40)
C
B
A
4TXM2136
D
130.5
(3.7)
262.5
(80)
82
(25)
82
(25)
131.2
(40)
C
B
A
4TXM2142
E
134
(3.8)
328.1
(100)
82
(25)
82
(25)
164
(50)
D
C
B
A
14
21 Series Multi-Split
Refrigerant Piping Precautions
Nitrogen Purging While Brazing
NOTICE
System Component Damage!
Do not remove the seal caps from the refrigerant connections and piping until prepared to
braze refrigerant pipes to the connections. Excessive exposure to atmosphere (greater than 5
minutes) may allow moisture or other particulates to contaminate the system, damaging valve
seals and causing ice formation in the system components during operation.
NOTICE
Avoid Unit Damage!
Never braze pipe connections without performing nitrogen purging. Failure to perform this
procedure will damage the unit, resulting in capacity loss and reduced long-term reliability.

MS-SVN085A-EN
15
21 Series Multi-Split
Nitrogen purging while brazing refrigerant pipes
Flow meter
Pressure regulator
Stop valve
Nitrogen
Nitrogen
While brazing refrigerant pipes, continuously purge them with nitrogen gas. Use a pressure
regulator to maintain a ow rate of 1.76 ft³/h (0.05 m³/h) or more.
All indoor units are individually connected to ports at the outdoor unit. (As shown below)
• If any refrigerant ports are not connected to indoor units, please tighten the cap to seal o󰀨 the
port. Paired ports are labeled A, B, C, D and E for up to ve indoor units.
• During the connection of the indoor unit and the refrigerant pipe, never pull any joints of the
indoor unit by force, otherwise the pipes may crack which would then result in leakage.
• The refrigerant pipe should be supported by brackets, in order to not place stress on the
indoor and outdoor unit. If the piping connection size of the outdoor unit does not match the
piping connection size of the indoor unit, use the piping connection dimension of the indoor
unit. Use the appropriate supplied connector tube to make the transition at the outdoor unit.
DO NOT INSTALL TRANSITION TUBES AT THE INDOOR UNIT.
• Each pipe should be labeled to tell which indoor system it belongs to avoid mistaken or
inaccurate piping connections.
Refrigerant Piping Between the Indoor and Outdoor Units
Wall Mounted
Indoor Unit
Wall Mounted
Indoor Unit
Wall Mounted
Indoor Unit
Wall Mounted
Indoor Unit
Wall Mounted
Indoor Unit

MS-SVN085A-EN
Bending Pipes
Installing the Refrigerant Piping
Flaring Process
1. Hold the pipe downward to prevent cuttings from entering the pipe.
2. Using an appropriate tube cutter and deburring tool, cut and deburr the refrigerant pipe.
3. Remove the are nuts at the stop valve of the outdoor unit and inside the accessory bag of
the indoor unit, put them onto the refrigerant pipe as shown below then are the refrigerant
pipe with a aring tool.
4. When aring copper tubing, only use aring tools that utilize an orbiting mandrel and
clutched handle. These are typically referenced as R410A aring tools. By using this type of
aring tool, the copper tubing is rolled while being pressed, thereby reducing the probability
of copper are cracking.
5. Check if the are is even length, smooth and the inside is shiny with no imperfections.
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1. Use a refrigerant pipe bending tool to shape refrigerant piping; smaller diameter piping may
allow for light hand bending, providing minimum diameter of 6 inches.
2. Do not bend the pipes in an angle more than 90°.
3. When pipes are repeatedly bent or stretched, the material will be prone to damage, which may
lead to refrigerant leaks. Do not bend or stretch the pipes more than three times.
4. Do not bend the pipe while insulated. First, cut the insulation with a sharp cutting tool and
expose it to the appropriate bend radius, as shown below. After bending the pipe, replace the
insulation and seal it with pipe wrap tape.
Refrigerant Piping at the Indoor Units
Reference the Indoor Unit Installation Guide
Refrigerant Piping at the Outdoor Unit
Tighten the are nut of the connection pipe at the outdoor unit valve connector. Follow the are
nut guidelines in this manual.
Table 7: Torque Reference Table
Pipe Diameter in. (mm) Tube Thickness in. (mm) Tightening Torque
1/4" (6.35) ≥ 0.03 (0.8) 11.25 - 14.75 lb•ft (15 ~ 20 N•m)
3/8" (9.52) ≥ 0.03 (0.8) 22.25 - 29.50 lb•ft (30 ~ 40 N•m)
1/2" (12.7) ≥ 0.03 (0.8) 33.25 - 40.50 lb•ft (45 ~ 55 N•m)
5/8" (15.9) ≥ 0.04 (1.0) 44.25 - 47.75 lb•ft (60 ~ 65 N•m)
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NOTICE
1. To prevent distortion and breaking of the pipe, bend the pipe with a radius of curvature of 6
in. (150 mm) or more. Use a tubing bender when forming the copper tubing into a bend.
2. If the pipe is bent repeatedly at the same place, it will break.
CAUTION
Connect the gas pipe after connecting the liquid pipe completely.
Insulating the Refrigerant Piping and Connections
1. The refrigerant pipes should be insulated and wrapped with appropriate insulating
material and wrapping tape. This will prevent condensation, water leakage and
damage to the insulating material.
2. The connections at the indoor unit should be wrapped with insulating material. No
gap is allowed on the joint of the indoor unit, as shown below.
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Vacuum and Refrigerant Leakage Detection
NOTICE
Do not purge the air with refrigerant. Use a vacuum pump to vacuum the installation!
1. When connecting refrigerant pipe to the unit or removing it from the unit, please use both a
back-up wrench and the torque wrench.
2. When connecting, place the equipment specied oil type on the backside of the copper
tube are prior to tightening. Do not place oil on the are face, as this will promote system
contamination, tighten it by hand and then tighten it with the spanner or adjustable wrench.
3. Refer to the torque reference table within this document before tightening to determine the
appropriate torque (over-tightening will damage the nut and lead to leakage).
4. Use dry Nitrogen to pressurize the piping circuit with 150 PSIG and allow it to hold while
performing other installation processes. It is recommended to apply a soap bubble solution and
observe the connection.
5. Evacuate each individual refrigeration circuit to 350 microns or below, and close o󰀨 the valve to
the vacuum pump. If the pressure rises above 500 microns within one minute, but not above
1500 microns within 5 minutes, moisture is present. If the pressure continues to rise above
1500 microns, a leak exists in the circuit being tested.
a) If moisture is present, use triple evacuation process to eliminate the moisture.
b) If a leak is present, leak check all joints and piping.
Evacuation is not completed until the micron gauge does not rise above 500 microns within
one minute after achieving 350 micron pressure vacuum.
6. After evacuation is complete, additional charge is to be added.
a) If no additional charge is required, break the vacuum with refrigerant, then remove the
gauge connectors.
b) slightly open the liquid valve at the outdoor unit, allow system to equalize, then fully
open the liquid valve and then open the vapor service valve.
7. After leak checking is complete, apply thermal insulation around the are connections and all
exposed refrigeration pipes.
a) Seal the insulation
b) Inspect the insulation to ensure no breakages are present.
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21 Series Multi-Split
NOTE: The wiring diagrams in this guide are included as a reference. The manufacturer has a policy of continuous product and
product data improvement and reserves the right to change design and specications without notice. Always check the unit
nameplate and wiring diagram for the actual unit requirements.

MS-SVN085A-EN
Electrical Notes:
1. EACH unit should be installed with its own dedicated power supply source. The power source
needs to be sized correctly for the unit capacity.
2. The rated voltage of the unit is as shown in this manual.
3. Before turning on, verify that the voltage is within the 187~252 V range (for 208/230 V, single
phase units).
4. Always use a grounded terminal and install a separate receptacle to supply power to the
air conditioner. For high voltage connections, exible electrical conduit is recommended
whenever vibration transmission may create a noise problem within the structure.
5. Use a dedicated breaker and receptacle matched to the capacity of the air conditioner.
1. Remove the wire clip and connect the power connection wire and signal control wire terminals
according to the color coding.
2. Attach the wires to the terminals and make sure they are securely fastened. Refer to wiring
diagrams in this manual. An example is provided in the gure below:
Outdoor Wiring Connections
Wiring Precautions
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18K:
30/36K:
black
(brown)
To the power supply
To unit BTo unit A
connecting
To unit C
connecting
cable
connecting
cable cable
white
(blue)
whitered
(blue)
green
(yellow-green)
green
(yellow-green)
black
(brown)
whitered
(blue)
green
(yellow-green)
black
(brown)
whitered
(blue)
green
(yellow-green)
(brown)
black
Power cord
L1 L2
To the power supply
B
N(1)
23
black
black red
(brown)
red
(brown)(brown)
INDOOR UNIT B
white
(yellow
whiteblack
-green)
green
(yellow
-green)
green
(yellow
-green)
green
A
L1(1) L2(3)
2
INDOOR UNIT A
POWER
L1 L2
(blue)
white
(blue)(blue)
To unit B
To unit A
connecting
cable
L1 2L2 3
Power cord connecting
cable
24K:
18K:
30/36K:
black
(brown)
To the power supply
To unit BTo unit A
connecting
To unit C
connecting
cable
connecting
cable cable
white
(blue)
whitered
(blue)
green
(yellow-green)
green
(yellow-green)
black
(brown)
whitered
(blue)
green
(yellow-green)
black
(brown)
whitered
(blue)
green
(yellow-green)
(brown)
black
Power cord
L1 L2
To the power supply
B
N(1)
23
black
black red
(brown)
red
(brown)(brown)
INDOOR UNIT B
white
(yellow
whiteblack
-green)
green
(yellow
-green)
green
(yellow
-green)
green
A
L1(1) L2(3)
2
INDOOR UNIT A
POWER
L1 L2
(blue)
white
(blue)(blue)
To unit B
To unit A
connecting
cable
L1 2L2 3
Power cord connecting
cable
24K: