Service
Manual
"W" SERIES
18K - 24K
INVERTER-DRIVEN AIR
CONDITIONING UNITS
PLEASE READ AND
UNDERSTAND THIS MANUAL
BEFORE USING THIS
INVERTER-DRIVEN AIR
CONDITIONING UNIT
. KEEP
THIS MANUAL FOR FUTURE
REFERENCE.
OUTDOOR UNITS
DHW18CMB21S
DHW24CMB21S
Type
,03257$17
Model
2
P5415467
Important Notice
● Johnson Controls, Inc. pursues a policy of continuing improvement in design and performance in its
products. As such, Johnson Controls, Inc. reserves the right to make changes at any time without
prior notice.
● Johnson Controls, Inc. cannot anticipate every possible circumstance that might involve a potential hazard.
● This inverter air conditioning unit is designed for standard air conditioning applications only. Do not use
this unit for anything other than the purposes for which it was intended for.
● The installer and system specialist shall safeguard against leakage in accordance with local pipetter
and electrical codes. The following standards may be applicable, if local regulations are not available.
International Organization for Standardization: (ISO 5149 or European Standard, EN 378). No part of
this manual may be reproduced in any way without the expressed written consent of Johnson Controls,
Inc.
● This inverter-driven (cooling or heat pump) air conditioning unit will be operated and serviced in the
United States of America and comes with all required Safety, Danger, and Caution, warnings.
● If you have questions, please contact your distributor or dealer.
● This manual provides common descriptions, basic and advanced information to maintain and service
this inverter-driven (cooling or heat pump) air conditioning unit which you operate, as well for other
models.
● This inverter-driven (cooling or heat pump) air conditioning unit has been designed for a specic
temperature range. For optimum performance and long life, operate this unit within range limits.
● This manual should be considered as a permanent part of the air conditioning equipment and should
remain with the air conditioning equipment.
Product Inspection upon Arrival
1. Upon receiving this product, inspect it for any damages incurred in transit. Claims for damage, either
apparent or concealed, should be led immediately with the shipping company.
2. Check the model number, electrical characteristics (power supply, voltage, and frequency rating), and
any accessories to determine if they agree with the purchase order.
3. The standard utilization for this unit is explained in these instructions. Use of this equipment for
purposes other than what it designed for is not recommended.
4. Please contact your local agent or contractor as any issues involving installation, performance, or
maintenance arise. Liability does not cover defects originating from unauthorized modications
performed by a customer without the written consent of Johnson Controls, Inc. Performing any
mechanical alterations on this product without the consent of the manufacturer will render your
warranty null and void.
Service Manual
Table of Contents
Table of Contents
Safety Summary
...................................................................................................................i
1.
Features and Summary
...........................................................................................1
6SHFL¿FDWLRQV
..................................................................................................................2
3. Outline Dimension Diagram
................................................................................6
4. Refrigerant System Diagram
..............................................................................7
5.
Electrical Parts
................................................................................................................8
5.1 Wiring Diagram........................................................................................................................8
5.2 PCB Printed Diagram............................................................................................................10
6. Function and Control
..............................................................................................12
7.
Troubleshooting
..........................................................................................................15
7.1 Flashing LED of Indoor/Outdoor Unit and Primary Judgment..............................................15
7.2 Malfunction Checking and Elimination ..................................................................................16
7.3 Maintenance Method for Normal Malfunction........................................................................29
8.
Removal Procedures
...............................................................................................31
Appendix
...................................................................................................................................44
Appendix 1: Reference Sheet of Celsius and Fahrenheit ............................................................44
$SSHQGL[&RQ¿JXUDWLRQRI&RQQHFWLRQ3LSH.............................................................................44
Appendix 3: Pipe Expanding Method ...........................................................................................45
Appendix 4: List of Resistance for Ambient Temperature Sensor ................................................46
Support Contact Information
.................................................................................49
31
P5415467
1. Introduction
This manual should be considered as a permanent part of the air conditioning equipment and should
remain with the air conditioning equipment.
This manual concentrates on inverter-driven cooling or heat pump air conditioning units. Read this manual
carefully before installation.
2. Important Safety Instructions
Safety Messages
Indicates a hazardous situation that, if not avoided, could result in death or
serious injury.
Indicates a hazardous situation that, if not avoided, could result in minor or
moderate injury.
Indicates information considered important, but not hazard-related (for
example, messages relating to property damage).
General Precautions
To reduce the risk of serious injury or death, read these instructions
thoroughly and follow all warnings or cautions included in all manuals that
accompanied the product and are attached to the unit. Refer back to these
safety instructions as needed.
● This system should be installed by personnel certied by Johnson Controls, Inc. Personnel must be
qualied according to local, state and national building and safety codes and regulations. Incorrect
installation could cause leaks, electric shock, re or explosion. In areas where Seismic ‘’Performance
requirements are specied, the appropriate measures should be taken during installation to guard against
possible damage or injury that might occur in an earthquake if the unit is not installed correctly, injuries may
occur due to a falling unit.
● Use appropriate Personal Protective Equipment (PPE), such as gloves and protective goggles and,
where appropriate, have a gas mask nearby. Also use electrical protection equipment and tools suited
for electrical operation purposes. Keep a quenching cloth and a re extinguisher nearby during brazing.
Use care in handling, rigging, and setting of bulky equipment.
● When transporting, be careful when picking up, moving and mounting these units. Although the unit may
be packed using plastic straps, do not use them for transporting the unit from one location to another. Do
not stand on or put any material on the unit. Get a partner to help, and bend with your knees when lifting
to reduce strain on your back. Sharp edges or thin aluminum ns on the air conditioner can cut ngers,
so wear protective gloves.
● Do not touch or adjust any safety devices inside the indoor or outdoor units. All safety features,
disengagement, and interlocks must be in place and functioning correctly before the equipment is put
into operation. If these devices are improperly adjusted or tampered with in any way, a serious accident
can occur. Never bypass or jump-out any safety device or switch.
● Johnson Controls, Inc. will not assume any liability for injuries or damage caused by not following steps
outlined or described in this manual. Unauthorized modications to Johnson Controls products are
prohibited as they…
◦ May create hazards which could result in death, serious injury or equipment damage.
◦ Will void product warranties.
◦ May invalidate product regulatory certications.
◦ May violate OSHA standards.
i
4
P5415467
Take the following precautions to reduce the risk of property damage.
● Be careful that moisture, dust, or variant refrigerant compounds not enter the refrigerant cycle during
installation work. Foreign matter could damage internal components or cause blockages.
● If air lters are required on this unit, do not operate the unit without the air lter set in place. If the air
lter is not installed, dust may accumulate and breakdown may result.
● Do not install this unit in any place where silicon gases can coalesce. If the silicon gas molecules
attach themselves to the surface of the heat exchanger, the nned surfaces will repel water. As a
result, any amount of condensate can overow from the condensate pan and could run inside of the
electrical box, possibly causing electrical failures.
● When installing the unit in a hospital or other facility where electromagnetic waves are generated
from nearby medical and/or electronic devices, be prepared for noise and electronic interference
Electromagnetic Interference (EMI). Do not install where the waves can directly radiate into the
electrical box, controller cable, or controller. Inverters, appliances, high-frequency medical equipment,
and radio communications equipment may cause the unit to malfunction. The operation of the unit
may also adversely affect these same devices. Install the unit at least 10 ft. (approximately 3m) away
from such devices.
● When a wireless zone controller is used, locate at a distance of at least 3.3 ft. (approximately 1 meter)
between the indoor unit and electric lighting. If not, the receiver part of the unit may have difculty
receiving operation commands.
● Do not install the unit in any location where animals and plants can come into direct contact with the
outlet air stream. Exposure could adversely affect the animals and plants.
● Do not install the unit with any downward slope to the side of the drain boss. If you do, you may have
water owing back which may cause leaks.
● Be sure the condensate hose discharges water properly. If connected incorrectly, it may cause leaks.
● Do not install the unit in any place where oil can seep onto the units, such as table or seating areas in
restaurants, and so forth. For these locations or social venues, use specialized units with oil-resistant
features built into them. In addition, use a specialized ceiling fan designed for restaurant use. These
specialized oil-resistant units can be ordered for such applications. However, in places where large
quantities of oil can splash onto the unit, such as a factory, even the specialized units cannot be used.
These products should not be installed in such locations.
Installation Precautions
To reduce the risk of serious injury or death, the following installation
precautions must be followed.
● When installing the unit into…
▫ A wall: Make sure the wall is strong enough to hold the unit’s weight. It may be necessary to
construct a strong wood or metal frame to provide added support.
▫ A room: Properly insulate any refrigerant tubing run inside a room to prevent “sweating” that can
cause dripping and water damage to wall and oors.
▫ Damp or uneven areas: Use a raised concrete pad or concrete blocks to provide a solid, level
foundation for the unit to prevent water damage and abnormal vibration.
▫ An area with high winds: Securely anchor the outdoor unit down with bolts and a metal frame.
Provide a suitable air bafe.
▫ A snowy area (only for heat pump model): Install the outdoor unit on a raised platform that is
higher than drifting snow. Provide snow vents.
● Do not install the unit in the following places. Doing so can result in an explosion, re, deformation,
corrosion, or product failure.
▫ Explosive or ammable atmosphere
▫ Where re, oil, steam, or powder can directly enter the unit, such as in close proximity or directly
above a kitchen stove.
▫ Where oil (including machinery oil) may be present.
▫ Where corrosive gases such as chlorine, bromine, or sulde can accumulate, such as near a hot
tub or hot spring.
▫ Where dense, salt-laden airow is heavy, such as in coastal regions.
▫ Where the air quality is of high acidity.
▫ Where harmful gases can be generated from decomposition.
ii
5
P5415467
● Do not position the condensate pipe for the indoor unit near any sanitary sewers where corrosive
gases may be present. If you do, toxic gases can seep into breathable air spaces and can cause
respiratory injuries. If the condensate pipe is installed incorrectly, water leakage and damage to the
ceiling, oor, furniture, or other possessions may result. If condensate piping becomes clogged,
moisture can back up and can drip from the indoor unit. Do not install the indoor unit where such
dripping can cause moisture damage or uneven locations: Use a raised concrete pad or concrete
blocks to provide a solid, level foundation for the unit to prevent water damage and abnormal
vibration.
● Before performing any brazing work, be sure that there are no ammable materials or open
ames nearby.
● Perform a run test to ensure normal operation. Safety guards, shields, barriers, covers, and protective
devices must be in place while the compressor/unit is operating. During the test run, keep ngers and
clothing away from any moving parts.
● Clean up the site when nished, remembering to check that no metal scraps or bits of wiring have
been left inside the unit being installed.
● During transportation, do not allow the backrest of the forklift to make contact with the unit,
otherwise, it may cause damage to the heat exchanger and also may cause injury when
stopped or started suddenly.
● Remove gas inside the closing pipe when the brazing work is performed. If the brazing ller metal is
melted with remaining gas inside, the pipes will be blown off and it may cause injury.
● Be sure to use nitrogen gas for an airtight test. If other gases such as oxygen gas, acetylene gas or
uorocarbon gas are accidentally used, it may cause explosion or gas intoxication.
After installation work for the system has been completed, explain the “Safety Precautions,” the proper use
and maintenance of the unit to the customer according to the information in all manuals that came with the
system. All manuals and warranty information must be given to the user or left near the Indoor Unit.
Refrigerant Precautions
To reduce the risk of serious injury or death, the following refrigerant
precautions must be followed.
● As originally manufactured, this unit contains refrigerant installed by Johnson Controls. Johnson
Controls uses only refrigerants that have been approved for use in the unit’s intended home country
or market. Johnson Controls distributors similarly are only authorized to provide refrigerants that
have been approved for use in the countries or markets they serve. The refrigerant used in this unit
is identied on the unit’s faceplate and/or in the associated manuals. Any additions of refrigerant into
this unit must comply with the country’s requirements with regard to refrigerant use and should be
obtained from Johnson Controls distributors. Use of any non-approved refrigerant substitutes will void
the warranty and will increase the potential risk of injury or death.
● If installed in a small room, take measures to prevent the refrigerant from exceeding the maximum
allowable concentration in the event that refrigerant gases should escape. Refrigerant gases can
cause asphyxiation (0.42 kg/m3 based on ISO 5149 for R410A). Consult with your distributor for
countermeasures (ventilation system and so on). If refrigerant gas has leaked during the installation
work, ventilate the room immediately.
● The design pressure for this product is 601 psi (4.15MPa). The pressure of R410A refrigerant is 1.4
times higher than that of the refrigerant R22. Therefore, the refrigerant piping for R410A shall be
thicker than that for R22. Make sure to use the specified refrigerant piping. If not, the refrigerant piping
may rupture due to an excessive refrigerant pressure. Besides, pay attention to the piping thickness
when using copper refrigerant piping. The thickness of copper refrigerant piping differs depending on
its material.
● The refrigerant R410A is adopted. The refrigerant oil tends to be affected by foreign matters such
as moisture, oxide lm, (or fat). Perform the installation work with care to prevent moisture, dust, or
different refrigerant from entering the refrigerant cycle. Foreign matter can be introduced into the
cycle from such parts as expansion valve and the operation may be unavailable.
● To avoid the possibility of different refrigerant or refrigerant oil being introduced into the cycle, the
sizes of the charging connections have been changed from R407C type and R22 type. It is necessary
to prepare the appropriate tools before performing the installation work.
● Use refrigerant pipes and joints which are approved for use with R410A.
● A compressor/unit comprises a pressurized system. Never loosen threaded joints while the system is
iii
6
P5415467
under pressure and never open pressurized system parts.
● Before installation is complete, make sure that the refrigerant leak test has been performed. If
refrigerant gases escape into the air, turn OFF the main switch, extinguish any open ames and
contact your service contractor. Refrigerant (Fluorocarbon) for this unit is odorless. If the refrigerant
should leak and come into contact with open ames, toxic gas could be generated. Also, because the
uorocarbons are heavier than air, they settle to the oor, which could cause asphyxiation.
● When installing the unit, and connecting refrigerant piping, keep all piping runs as short as
possible, and make sure to securely connect the refrigerant piping before the compressor starts
operating. If the refrigerant piping is not connected and the compressor activates with the stop
valve opened, the refrigerant cycle will become subjected to extremely high pressure, which can
cause an explosion or re.
● Tighten the are nut with a torque wrench in the specied manner. Do not apply excessive force to the
are nut when tightening. If you do, the are nut can crack and refrigerant leakage may occur.
● When maintaining, relocating, and disposing of the unit, dismantle the refrigerant piping after the
compressor stops.
● When pipes are removed out from under the piping cover, after the insulation work is completed,
cover the gap between the piping cover and pipes by a packing (eld-supplied). If the gap is not
covered, the unit may be damaged if snow, rain water or small animals enter the unit.
● Do not apply an excessive force to the spindle valve at the end of opening. Otherwise, the spindle
valve ies out due to refrigerant pressure. At the run test, fully open the gas and liquid valves,
otherwise, these devices will be damaged. (It is closed before shipment.)
● If the arrangement for outdoor units is incorrect, it may cause owback of the refrigerant and result in
failure of the outdoor unit.
● The refrigerant system may be damaged if the slope of the piping connection kit exceeds +15
o
.
Electrical Precautions
Take the following precautions to reduce the risk of electric shock, re or
explosion resulting in serious injury or death.
● Highly dangerous electrical voltages are used in this system. Carefully refer to the wiring diagram
and these instructions when wiring. Improper connections and inadequate grounding can cause
serious injury or death.
● Perform all electrical work in strict accordance with this installation and maintenance manual and all
the relevant regulatory standards.
● Before servicing, open and tag all disconnect switches. Never assume electrical power is
disconnected. Check with meter and equipment.
● Only use electrical protection equipment and tools suited for this installation.
● Use specied cables between units.
● The new air conditioner may not function normally in the following instances:
▫ If electrical power for the new air conditioner is supplied from the same transformer as the device*
referred to below.
▫ If the power source cables for this device* and the new air conditioner unit are located in close
proximity to each other.
Device*: (Example): A lift, container crane, rectier for electric railway, inverter power
device, arc furnace, electric furnace, large-sized induction motor and large-sized switch.
Regarding the cases mentioned above, surge voltage may be inducted into the power supply
cables for the packaged air conditioner due to a rapid change in power consumption of the
device and an activation of a switch.
Check eld regulations and standards before performing electrical work in order to protect the
power supply for the new air conditioner unit.
iv
7
P5415467
● Communication cabling shall be a minimum of 18-Gauge, 2-Conductor, Stranded Copper. Shielded
cable must be considered for applications and routing in areas of high EMI and other sources of
potentially excessive electrical noise to reduce the potential for communication errors. When shielded
cabling is applied, proper bonding and termination of the cable shield is required as per Johnson
Controls guidelines. Plenum and riser ratings for communication cables must be considered per
application and local code requirements.
● Use an exclusive power supply for the air conditioner at the unit’s rated voltage.
● Be sure to install circuit breakers (ground fault interrupter, isolating switch, molded case circuit
breaker and so on), with the specied capacity. Ensure that the wiring terminals are tightened securely
to recommended torque specications.
● Clamp electrical wires securely with a cable clamp after all wiring is connected to the terminal block.
In addition, run wires securely through the wiring access channel.
● When installing the power lines, do not apply tension to the cables. Secure the suspended cables at
regular intervals, but not too tightly.
● Make sure that the terminals do not come into contact with the surface of the electrical box. If the
terminals are too close to the surface, it may lead to failures at the terminal connection.
● Turn OFF and disconnect the unit from the power source when handling the service connector. Do not
open the service cover or access panel to the indoor or outdoor units without turning OFF the main
power supply.
● After ceasing operation, be sure to wait at least ve minutes before turning off the main power
switch. Otherwise, water leakage or electrical breakdown may result. Disconnect the power source
completely before attempting any maintenance for electrical parts. Check to ensure that no residual
voltage is present after disconnecting the power source.
● Do not clean with, or pour water into, the controller as it could cause electric shock and/or damage the
unit. Do not use strong detergent such as a solvent. Clean with a soft cloth.
● Check that the ground wire is securely connected. Do not connect ground wiring to gas piping, water
piping, lighting conductor, or telephone ground wiring.
● If a circuit breaker or fuse is frequently activated, shut down the system and contact your
service contractor.
● Perform all electrical work in accordance with this manual and in compliance with all regulations and
safety standards.
● Do not open a service access cover or panel of an indoor or outdoor unit without rst turning OFF the
power at the main power supply.
● Residual voltage can cause electric shock. At all times, check for residual voltage after disconnecting
from the power source before starting work on the unit.
● This equipment can be installed with a Ground Fault Circuit Breaker (GFCI), which is a recognized
measure for added protection to a properly grounded unit. Install appropriate sized breakers/fuses/
overcurrent protection switches, and wiring in accordance with local, state and NEC codes and
requirements. The equipment installer is responsible for understanding and abiding by applicable
codes and requirements.
v
1
Technical Information
Service Manual
1. Summary
1. Features and Summary
Outdoor Unit
DHW18CMB21S
DHW24CMB21S
2
Technical Information
Service Manual
6SHFL¿FDWLRQV
Model
Power
supply
Rated Voltage V~
DHW18CMB21S
208/230
Rated Frequency Hz 60
Phases 1
Cooling capacity(max~min) W 5280(2051~6155)
Heating capacity(max~min) W 5570(2500~6624)
Cooling Power Input(max~min) W 1650
Heating Power Input(max~min) W 1640
Cooling Current Input A 10.67/10.56
Heating Current Input A 6.78/6.10
Rated Power Input W 2800
Rated Current A 12.48
EER W/W 3.2
COP W/W 3.4
Outdoor
Unit
ZHUHAI LANDA COMPRESSOR CO.,LTD
QXA-B141zF030A
RB68EP
Inverter Rotary
A /
A 7.2
W 1440
1NT11L-6233
Electron expansion valve
O
F -0.4~118.4
O
F -4~75.2
Aluminum Fin-copper Tube
inch ĭ
inch 2-1/18
inch 33 1/2X1 /12X26
rpm 630
W 60
A /
ȝ) /
CFM 1883
$[LDOÀRZ
inch ĭ
Automatic Defrosting
T1
I
IP24
Compressor Trademark
Compressor Model
Compressor Refrigerant Oil Type
Compressor Type
L.R.A
Compressor Rated Load Amp (RLA)
Compressor Power Input
Compressor Thermal Protector
Metering Method
Cooling Operation Ambient Temperature Range
Heating Operation Ambient Temperature Range
Condenser Material
Condenser Pipe Diameter
Rows-Fin Gap(mm)
Coil length (l) X height (H) X coil width (L)
Fan Motor Speed (rpm) (H/M/L)
Output of Fan Motor
Fan Motor RLA
Fan Motor Capacitor
Air Flow Volume of Outdoor Unit
Fan Type-Piece
Fan Diameter
Defrosting Method
Climate Type
Isolation
Moisture Protection
Permissible Excessive Operating Press
ure for the
Discharge Side
MPa 4.3
Permissible Excessive Operating Pressure for the
MPa 2.5
inch 38X27 5/9X15 3/5
inch 40 2/5X18X29
inch 40 1/2X18X29 1/2
lb 114.7
lb 124.6
R410A
Suction Side
Dimension (W/H/D)
Dimension of Package (L/W/H)
Dimension of Package(L/W/H)
Net Weight
Gross Weight
Refrigerant Charge
Refrigerant Charge
oz 77.6
3
Technical Information
Service Manual
Outdoor
Unit
sq in 0.0032
N 3
- Flare Connection
ft 16.4
oz/ft. 0.2
Cross-sectional Area of Power Cable Conductor
Recommended Power Cable(Core)
Connection Pipe Connection Method
Not Additional Gas Connection Pipe Length
Connection Pipe Gas Additional Charge
Outer Diameter of Liquid Pipe1
inch 1/4
(Metric)
Outer Diameter of Liquid Pipe2
inch 1/4
(Metric)
Outer Diameter of Gas Pipe1
inch 3/8
(Metric)
Outer Diameter of Gas Pipe2
(Metric)
inch 3/8
Connection Pipe Max. Height Distance(indoor and
indoor)
ft 32.8
Connection Pipe Max. Height Distance(indoor and
outdoor and indoor up)
ft 32.8
Connection Pipe Max. Height Distance(indoor and
outdoor and outdoor up)
ft 32.8
Max. equivalent connection pipe length(outdoor to
last indoor)
ft 32.8
Connection Pipe Max. Length Distance(total lenght) ft 65.6
The above data is subject to change without notice; please refer to the nameplate of the unit.
4
Technical Information
Service Manual
Model
Power
supply
Rated Voltage V~
DHW24CMB21S
208/230
Rated Frequency Hz 60
Phases 1
Cooling capacity(max~min) W 7620(2198~9672)
Heating capacity(max~min) W 8500(2198~7500)
Cooling Power Input(max~min) W 2400
Heating Power Input(max~min) W 2350
Cooling Current Input A 10.65
Heating Current Input A 10.43
Rated Power Input W 4550
Rated Current A 20.19
EER W/W 3.0
COP W/W 3.5
Outdoor
Unit
ZHUHAI LANDA COMPRESSOR CO.,LTD
QXAS-D23zX090B
RB68EP
Inverter Rotary
A /
A 11.5
W 2550
1NT11L-6233
Electron expansion valve
O
F -0.4~118.4
O
F -4~75.2
Aluminum Fin-copper Tube
inch ĭ
inch 2-1/18
inch 38 2/3X1 1/2X29 4/9
rpm 800
W 90
A /
ȝ) /
CFM 2354
$[LDOÀRZ
inch ĭ
Automatic Defrosting
T1
I
IP24
Compressor Trademark
Compressor Model
Compressor Refrigerant Oil Type
Compressor Type
L.R.A
Compressor Rated Load Amp (RLA)
Compressor Power Input
Compressor Thermal Protector
Metering Method
Cooling Operation Ambient Temperature Range
Heating Operation Ambient Temperature Range
Condenser Material
Condenser Pipe Diameter
Rows-Fin Gap(mm)
Coil length (l) X height (H) X coil width (L)
Fan Motor Speed (rpm) (H/M/L)
Output of Fan Motor
Fan Motor RLA
Fan Motor Capacitor
Air Flow Volume of Outdoor Unit
Fan Type-Piece
Fan Diameter
Defrosting Method
Climate Type
Isolation
Moisture Protection
Permissible
Excessive Operating Pressure for the
Discharge Side
MPa 4.3
Permissible Excessive Operating Pressure for the
MPa 2.5
inch 38 4/7X31 1/9X17 1/3
inch 42 1/2X19X33
inch 42 2/3X19 1/5X33 2/3
lb 153.2
lb 164.3
R410A
Suction Side
Dimension (W/H/D)
Dimension of Package (L/W/H)
Dimension of Package(L/W/H)
Net Weight
Gross Weight
Refrigerant Charge
Refrigerant Charge
oz 77.6
5
Technical Information
Service Manual
Outdoor
Unit
sq in 0.0051
N 3
- Flare Connection
ft 16.4
oz/ft. 0.2
Cross-sectional Area of Power Cable Conductor
Recommended Power Cable(Core)
Connection Pipe Connection Method
Not Additional Gas Connection Pipe Length
Connection Pipe Gas Additional Charge
Outer Diameter of Liquid Pipe1
inch 1/4
(Metric)
Outer Diameter of Liquid Pipe2
inch 1/4
(Metric)
Outer Diameter of Liquid Pipe2
inch 1/4
(Metric)
Outer Diameter of Gas Pipe1
inch 3/8
(Metric)
Outer Diameter of Gas Pipe2
inch 3/8
(Metric)
Outer Diameter of Gas Pipe2
(Metric)
inch 3/8
Connection Pipe Max. Height Distance(indoor and
indoor)
ft 32.8
Connection Pipe Max. Height Distance(indoor and
outdoor and indoor up)
ft 32.8
Connection Pipe Max. Height Distance(indoor and
outdoor and outdoor up)
ft 32.8
Max. equivalent connection pipe length(outdoor to
last indoor)
ft 65.6
Connection Pipe Max. Length Distance(total lenght) ft 196.8
The above data is subject to change without notice; please refer to the nameplate of the unit.
6
Technical Information
Service Manual
3. Outline Dimension Diagram
35 1/8
38
27 5/9
15 3/5
13 3/7
22
14 1/2
Unit:inch
Unit:inch
DHW18CMB21S
DHW24CMB21S
38 4/7
35 1/8
13 3/7
17 1/3
31 1/9
22
14 1/2
7
Technical Information
Service Manual
4. Refrigerant System Diagram
outdoor
indoor
D1
C
1
B1
A1
filter
A heat exchanger
gas -liquid separator
inverter compressor
discharge silencer
discharge temperature
sensor
SP
4-way valve
outdoor heat exchanger
fan
high pressure switch
B heat exchanger
C heat exchanger
D heat exchanger
filter
filter
filter
filter
Note: Not available for 14K/18K
model
C2
C3
D3
D2
B3
B2
A2
A3
A1:Aunit electronic expansion valve B1:B-unit electronic expansion valve
C1:C-unit electronic expansion valve D1:D-unit electronic expansion valve
A2:A-unit gas pipe temperature sensor B2:B-unit gas pipe temperature sensor
C2:C-unit gas pipe temperature sensor D2:D-unit gas pipe temperature sensor
A3:Aunit liquid pipe temperature sensor B3:B-unit liquid pipe temperature sensor
C3:C-unit liquid pipe temperature sensor D3:D-unit liquid pipe temperature sensor
Note: Not available for 14K/18K model
8
Technical Information
Service Manual
5.
Electrical Parts
5.1 Wiring Diagram
Symbol Symbol Color Symbol Symbol Color Symbol Name
WH White GN GREEN COMP Compressor
YE Yellow BN Brown Grouding wire
RD Red BU Blue
YEGN Yellow/Green BK Black
VT Violet OG Orange
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ƔDescription
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Technical Information
Service Manual
DHW24CMB21S
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These circuit diagrams are subject to change without notice, please refer to the one supplied with the unit.
10
Technical Information
Service Manual
1
1
23 4 5 6 7 8 9 10
11
12
13
14
15
16
5.2 PCB Printed Diagram
Ɣ
TOP VIEW
Ɣ
BOTTOM VIEW
DHW18CMB21S
1 Terminal of compressor
2
Terminal of low-temperature
cooling temperature sensor
3
Overload protection terminal of
compressor
4
Temperature sensor terminal of
outdoor unit
5
High pressure protection
terminal
6
Low pressure protection
terminal
7 Terminal of outdoor unit
8
Electric heating belt terminal of
chassis
9 Terminal of 4-way valve
10
Electric heating belt terminal of
compressor
11
Terminal of temperature sensor
wire for liquid valve and gas
valve
12
Terminal of electronic
expansion valve
13
Terminal of communication wire
for indoor unit and outdoor unit
14
Neutral wire terminal for
communication
15 Live wire terminal
16 Neutral wire terminal
11
Technical Information
Service Manual
123456 879
10
11
12
13
14
15
16
17
18
19
20
21
22
23
DHW24CMB21S
Ɣ
TOP VIEW
Ɣ
BOTTOM VIEW
1
Terminal of compressor
2
Low pressure protection
terminal
3
High pressure protection
terminal
4
Overload protection terminal of
compressor
5
Temperature sensor terminal of
outdoor unit
6
Electric heating terminal of
chassis
7
Electric heating terminal of
compressor
8
Terminal of outdoor unit
9
Terminal of 4-way valve
10
Temperature sensor for liquid
valve and gas valve for unit A
11
Temperature sensor for liquid
valve and gas valve for unit B
12
Temperature sensor for liquid
valve and gas valve for unit C
13
Temperature sensor for liquid
valve and gas valve for unit D
14
Electronic expansion vale for
unit A
15
Electronic expansion vale for
unit C
16
Electronic expansion vale for
unit B
17
Electronic expansion vale for
unit D
18
Communication wire with indoor
unit
19
Neutral wire for counication
20
Live wire
21
Neutral wire
22
Reactor wire 1
23
Reactor wire 2
12
Technical Information
Service Manual
6. Function and Control
1 Basic functions of the system
1.1 Cooling Mode
1.1.1 Cooling conditions and process:
When turning on the unit for cooling operation, if any of the indoor units calls for cooling the system will start in cooling mode. In
this case, the electronic expansion valve, the outdoor fan and the compressor start operation.
1.1.2 Stop in cooling operation
1.1.2.1 Compressor stops
The compressor stops immediately; the outdoor fan stops after 1min.
1.1.2.2 If any of the indoor units needs cooling, the outdoor unit will still be operating in the cool mode (the compressor does not
stop)
The compressor operates immediately according to the required frequency. For the indoor unit with no requirement, the
corresponding electronic expansion valve is closed.
1.1.3 Cooling mode switches to heating mode
When the unit switches to heating mode, the 4-way valve is energized after the compressor stops for 2min.
1.1.4 4-way valve: In this mode, the 4-way valve is de-energized.
1.1.5 Outdoor fan control in cooling mode
The outdoor fan starts 5s before the starting of compressor. The outdoor fan will run in high speed for 3min after starting and
then it will run in the set speed. The fan shall run at every speed for at least 80s. (When the quantity of running indoor
units is changed, the unit will enter the control described in 1.3.5.1 and 1.3.5.2).
When the compressor stops, the outdoor fan runs at present speed and stops after 1min.
1.2 Dry Mode (also called dehumidification mode)
1.2.1 The dry conditions and process are the same as those in cooling mode.
1.2.2 The status of 4-way valve: De-energized.
1.2.3 The temperature setting range: 60.8°F - 86°F (16 - 30ć) .
1.2.4 Protection function: The same as those in cooling mode.
1.2.5 In dry mode, the maximum value A of the capacity requirement percentage of single unit is 90% of that in cooling mode.
The open condition of the electronic expansion valve, outdoor fan and compressor is the same as those in cooling mode.
1.3 Heating Mode
1.3.1 Cooling conditions and process:
When one of the indoor units reaches the heating operation condition, the unit starts heating operation.
1.3.2 Stop in heating operation:
1.3.2.1 When all the indoor units reach the stop condition, the compressor stops and the outdoor fan stops after 1min.
1.3.2.2 Some of the indoor units reach the stop condition
The compressor reduces the frequency immediately and operates according to the required frequency.
1.3.2.3 Heating mode transfers to cooling mode (dry mode), fan mode
a. The compressor stops;
b. The power of 4-way valve is cut off after 2min;
c. T
he outdoor fan stops after 1min;
d.
The status
of
4-way valve: De-energized.
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