Midea MEHSU-09CHD2 User manual

CONTENTS
1. Precaution ..................................................................................................................................................... 1
1.1 Safety Precaution .......................................................................................................................... 1
1.2 Warning .......................................................................................................................................... 1
2. Part Names and Features ............................................................................................................................ 4
2.1 Model Names of Indoor/Outdoor units .......................................................................................... 4
2.2 Part names of Indoor/Outdoor units .............................................................................................. 5
2.3 Features ......................................................................................................................................... 9
3. Dimension ................................................................................................................................................... 18
3.1 Indoor Unit ................................................................................................................................... 18
3.2 Outdoor Unit ................................................................................................................................ 23
4. Service Space ............................................................................................................................................. 25
4.1 Indoor Unit ................................................................................................................................... 25
4.2 Outdoor Unit ................................................................................................................................ 27
5. Refrigerant Cycle Diagram ........................................................................................................................ 28
6. Wiring Diagram ........................................................................................................................................... 29
6.1 Indoor Unit ................................................................................................................................... 29
6.2 Outdoor Unit ................................................................................................................................ 34
7. Fan Curves .................................................................................................................................................. 41
8 Electric Characteristics .............................................................................................................................. 48
9 Sound Level ................................................................................................................................................. 49
9.1 Indoor unit .................................................................................................................................... 49
9.2 Outdoor unit ................................................................................................................................. 52
10 Accessories ............................................................................................................................................... 53
11 The Specification of Power ...................................................................................................................... 55
12 Installation Details .................................................................................................................................... 57
12.1 Location selection ................................................................................................................... 57
12.2 Indoor unit installation ............................................................................................................. 57
12.3 Outdoor unit installation .......................................................................................................... 64
12.4 Refrigerant pipe installation .................................................................................................... 65
12.5 Drainage pipe installation ....................................................................................................... 69
12.6 Vacuum Drying and Leakage Checking ................................................................................. 72
12.7 Additional refrigerant charge .................................................................................................. 73
12.8 Engineering of insulation ........................................................................................................ 74
12.9 Engineering of electrical wiring ............................................................................................... 75
12.10 Test operation ...................................................................................................................... 75
13. Operation Characteristics ....................................................................................................................... 77
14. Electronic Function .................................................................................................................................. 78
14.1 Abbreviation ............................................................................................................................... 78

14.2 Display function ......................................................................................................................... 78
14.3 Main Protection .......................................................................................................................... 78
14.4 Operation Modes and Functions ............................................................................................... 79
16. Troubleshooting ....................................................................................................................................... 85
16.1 Indoor Unit Error Display ........................................................................................................... 86
16.2 Outdoor unit error display .......................................................................................................... 87
For 9K-24K outdoor unit: ................................................................................................................... 87
For 36K-48K Outdoor Unit ................................................................................................................. 88
Outdoor check function ...................................................................................................................... 88
16.3 Diagnosis and Solution .............................................................................................................. 91
16.4 Main parts check ...................................................................................................................... 107
17. Disassembly Instructions ..................................................................................................................... 114
17.1 Indoor unit ................................................................................................................................ 114
17.2 Outdoor unit ............................................................................................................................. 131

1
1. Precaution
1.1 Safety Precaution
 To prevent injury to the user or other
people and property damage, the following
instructions must be followed.
 Incorrect operation due to ignoring
instruction will cause harm or damage.
 Before service the unit, be sure to
read this service manual at first.
1.2 Warning
 Installation
 Do not use a defective or underrated
circuit breaker. Use this appliance on a
dedicated circuit.
There is risk of fire or electric shock.
 For electrical work, contact the dealer,
seller, a qualified electrician, or an
authorized service center.
Do not disassemble or repair the product,
there is risk of fire or electric shock.
 Always ground the product.
There is risk of fire or electric shock.
 Install the panel and the cover of
control box securely.
There is risk of fire of electric shock.
 Always install a dedicated circuit and
breaker.
Improper wiring or installation may cause
electric shock.
 Use the correctly rated breaker of
fuse.
There is risk of fire or electric shock.
 Do not modify or extend the power
cable.
There is risk of fire or electric shock.
 Do not install, remove, or reinstall the
unit by yourself (customer).
There is risk of fire, electric shock, explosion,
or injury.
 Be caution when unpacking and
installing the product.
Sharp edges could cause injury, be especially
careful of the case edges and the fins on the
condenser and evaporator.
 For installation, always contact the
dealer or an authorized service center.
 Do not install the product on a
defective installation stand.
 Be sure the installation area does not
deteriorate with age.
If the base collapses, the air conditioner could
fall with it, causing property damage, product
failure, and personal injury.
 Do not let the air conditioner run for a
long time when the humidity is very high
and a door or a window is left open.
 Take care to ensure that power cable
could not be pulled out or damaged during
operation.
There is risk of fire or electric shock.
 Do not place anything on the power
cable.
There is risk of fire or electric shock.
 Do not plug or unplug the power
supply plug during operation.
There is risk of fire or electric shock.
 Do not touch (operation) the product
with wet hands.
 Do not place a heater or other
appliance near the power cable.
There is risk of fire and electric shock.
 Do not allow water to run into
electrical parts.
It may cause fire, failure of the product, or
electric shock.
 Do not store or use flammable gas or
combustible near the product.
There is risk of fire or failure of product.
 Do not use the product in a tightly
closed space for a long time.
Oxygen deficiency could occur.
 When flammable gas leaks, turn off
the gas and open a window for ventilation
before turn the product on.

2
 If strange sounds or smoke comes
from product, turn the breaker off or
disconnect the power supply cable.
There is risk of electric shock or fire.
 Stop operation and close the window
in storm or hurricane. If possible, remove
the product from the window before the
hurricane arrives.
There is risk of property damage, failure of
product, or electric shock.
 Do not open the inlet grill of the
product during operation. (Do not touch the
electrostatic filter, if the unit is so equipped.)
There is risk of physical injury, electric shock,
or product failure.
 When the product is soaked, contact
an authorized service center.
There is risk of fire or electric shock.
 Be caution that water could not enter
the product.
There is risk of fire, electric shock, or product
damage.
 Ventilate the product from time to
time when operating it together with a stove
etc.
There is risk of fire or electric shock.
 Turn the main power off when
cleaning or maintaining the product.
There is risk of electric shock.
 When the product is not be used for a
long time, disconnect the power supply plug
or turn off the breaker.
There is risk of product damage or failure, or
unintended operation.
 Take care to ensure that nobody
could step on or fall onto the outdoor unit.
This could result in personal injury and
product damage.
 CAUTION
 Always check for gas (refrigerant)
leakage after installation or repair of
product.
Low refrigerant levels may cause failure of
product.
 Install the drain hose to ensure that
water is drained away properly.
A bad connection may cause water leakage.
 Keep level even when installing the
product.
It can avoid vibration of water leakage.
 Do not install the product where the
noise or hot air from the outdoor unit could
damage the neighborhoods.
It may cause a problem for your neighbors.
 Use two or more people to lift and
transport the product.
 Do not install the product where it will
be exposed to sea wind (salt spray) directly.
It may cause corrosion on the product.
Corrosion, particularly on the condenser and
evaporator fins, could cause product
malfunction or inefficient operation.
 Operational
 Do not expose the skin directly to
cool air for long time. (Do not sit in the
draft).
 Do not use the product for special
purposes, such as preserving foods, works
of art etc. It is a consumer air conditioner,
not a precision refrigerant system.
There is risk of damage or loss of property.
 Do not block the inlet or outlet of air
flow.
 Use a soft cloth to clean. Do not use
harsh detergents, solvents, etc.
There is risk of fire, electric shock, or damage
to the plastic parts of the product.
 Do not touch the metal parts of the
product when removing the air filter. They
are very sharp.
 Do not step on or put anything on the
product. (outdoor units)
 Always insert the filter securely.
Clean the filter every two weeks or more
often if necessary.
A dirty filter reduces the efficiency of the air
conditioner and could cause product
malfunction or damage.

3
 Do not insert hands or other objects
through air inlet or outlet while the product
is operated.
 Do not drink the water drained from
the product.
 Use a firm stool or ladder when
cleaning or maintaining the product.
Be careful and avoid personal injury.
 Replace the all batteries in the remote
control with new ones of the same type. Do
not mix old and new batteries or different
types of batteries.
There is risk of fire or explosion.
 Do not recharge or disassemble the
batteries. Do not dispose of batteries in a
fire.
They may burn of explode.
 If the liquid from the batteries gets
onto your skin or clothes, wash it well with
clean water. Do not use the remote of the
batteries have leaked.

4
2. Part Names and Features
2.1 Model Names of Indoor/Outdoor units
Series Capacity
Indoor units Outdoor units
Cassette
9K
MEHSU-09CHC2
MCHSU-09PHH2
Duct MEHSU-09CHD2
Console MEHSU-09CHN2
Cassette
12K
MEHSU-12CHC2
MCHSU-12PHH2
Duct MEHSU-12CHD2
Console MEHSU-12CHN2
Cassette
18K
MEHSU-18CHC2
MCHSU-18PHH2
Duct MEHSU-18CHD2
Floor Ceiling
MEHSU-18CHF2
Cassette
24K
MEHSU-24CHC2
MCHSU-24PHH2
Duct MEHSU-24CHD2
Floor Ceiling
MEHSU-24CHF2
Cassette
36K
MEHSU-36CSC2
MCHSU-36CSH2
Duct MEHSU-36CSD2
Floor Ceiling
MEHSU-36CSF2
Cassette
48K
MEHSU-48CSC2
MCHSU-48CSH2;
Duct MEHSU-48CSD2
Floor Ceiling
MEHSU-48CSF2

5
2.2 Part names of Indoor/Outdoor units
Cassette Unit

6
Duct Units

7
Console

8
Ceiling-floor Units

9
2.3 Features
2.3.1 Duct Units
2.3.1.1 Installation Accessories: (Optional)
 Front Board, Canvas Air Passage, Filter, Panel, for easy installation
2.3.1.2 Easy Installation: Two air Inlet Styles (Bottom side or Rear side)
 Air inlet from rear is standard for all capacity; air inlet from bottom is optional.
 The size of air inlet frame from rear and bottom is same, it’s very easy to move the cover from
bottom to rear side, or from rear to the bottom, in order to matching the installation condition.
2.3.1.3 Fresh Air Intake Function
 Install one duct from the reserved fresh-air intake to outdoor.
Continually inhale the fresh air to improve the quality of the indoor air, fulfills air quality more
healthy and comfortable.
Panel
Air intake from rear (Standard) Air intake from bottom (Optional)
6.30in
4.92in
3.15in
3.54in

10
2.3.1.4 Easy Maintenance
 Clean the filter (Optional, standard product without filter)
It is easy to draw out the filter from the indoor unit for cleaning, even the filter is installed in rear
side or bottom side.
 Replace the motor or centrifugal fan
Remove the ventilated panel firstly. Remove a half of blower housing and take out the motor with
centrifugal fan. Directly remove two bolts, and then replace the motor or centrifugal fan easily.
2.3.1.5 Reserved Remote On-off and Central Control Ports
 Reserved remote on-off ports and central control ports, can connect the cable of an on-off
controller or a central controller to realize remote on-off control function or group control function.
2.3.1.6 Built-in Drain Pump (Optional):
 Built-in drain pump can lift the water to 750mm(29.53in) upmost. It’s convenient to install drainage
piping under most space condition.
Motor
Blower Housing
Ventilated Panel
Remote on-off ports Central control ports

11
2.3.1.7 Built-in Display Board
 The standard indoor unit can be controlled by wired controller.
 There is a display board with a receiver in the E-box. Move out the display, and fix it in other place,
even in the distance of 2m(6.56ft). The unit will realized remoter control.
 The wired controller and the display board can display the error code or production code when the
chips detect some failure.
Display
750mm(29.53in) upmost
Wired Controller (Standard) Remote Controller (Optional)

12
2.3.2 Cassette Unit
2.3.2.1 Lower Noise
 Optimize air channel system design to ensure the maximum quietness and comfort.
 Noise max down 6dB.
2.3.2.2 Turbo Mode (Optional)
 Turbo function can boost cooling or heating speed in a short period, and makes the room cool
down or heat up rapidly.
2.3.2.3 Fire-proof Controller Box
 Electrical control box adopts new design, which can meet higher fire safety requirements.
2.3.2.4 Fresh Air
 Fresh air intake function bring you fresh and comfortable air feeling.
2.3.2.5 Wired Controller (Optional)
 Compared with infrared remote controller, wired controller can be fixed on the wall and avoid
mislaying. It's mainly used for commercial zone and makes air conditioner control more
convenient.
Old New
Turbo Mode (After 30 min)
Cold
Hot
Common vs. Turbo
Old
New

13
2.3.2.6 Build-in Drain Pump
 The drain pump can lift the condensing water up to 750mm(29.53in) upmost.
 It’s convenient to install drainage piping under most space condition.
2.3.2.7Terminals For Alarm Lamp and Long-distance On-off Controller Connection Are
Standard
 Reserve terminals for the connection of alarm lamp and long-distance on-off controller, more
human control.

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2.3.3 Console
2.3.3.1. Modern and Elegant Appearance
 The simple and stylish designs can nicely harmonies with your living space.
3.2.3.2. Four Panels optional
2.3.3.3. Two Air-outlet Ways
Cooling mode
Quick Cooling To maintain room temp
 Air outlet from top and bottom to make quick cooling ------When the A/C is just switched on, or
room temp. is still high, cold air will be blown out from top and bottom air outlet to cool down the
room quickly
 Air outlet from top to maintain room temp. ----When the room has been cooled down, or the A/C
has been opened over 1 hour, cold air only from the top outlet to keep constant room temp

15
Heating mode
 Anti-cold air ------When the AC is just turn on, temperature of evaporator is very low, in this case,
in order to prevent cold air direct blowing, only the upper louver is opened in a high position, the
lower louver closed.
2.3.3.4. Four Air Inlets
2.3.3.5. Low Noise
 DC indoor fan motor, which has five speeds.
 Low noise and energy saving.
 Advanced centrifugal fan technology makes a fast airflow and reduces the indoor noise.
2.3.3.6. Golden fin is optional.
2.3.3.7. Active carbon filter is standard

16
2.3.1 Ceiling-floor Units
2.3.1.1 Two-way Installation
 The rounded design of the ceiling and floor type air conditioner allows either ceiling or floor-level
installation. Ceiling installation saves room space, while floor installation helps prevent the loss of
warm air.
2.3.1.2 Brief Design
 Brief design that is suitable for any interior will not only give you cooling and heating performance
but also upgrade your lifestyle.
2.3.1.3 3D Airflow
Vertical air flow and horizontal airflow can be adjusted by remote controller, the cooperation of the two
airflow ways help to spread air comfortably throughout even a large room. With these functions, the
whole room can be evenly air-conditioned for both floor-level and ceiling installation.

17
2.3.1.4 Optional Drainage Pipe Connection
Both right side and left side drainage holes are available to avoid the space limitation for drainage
pipe installation. Make you more convenient during installation.
C Panel (LED display) D Panel
2.3.1.5 Convenience Operating and Easy Maintenance
Remote controller as standard, wired controller for optional.
The filter without screw fixed, can be took out easily.
2.3.1.6 Easy Installation, Save Working Time
The pipes can be connected from bottom, back and right side, makes the installation more easily.
The wiring works can be finished before installation.
2.3.1.7 Outside Water Pump for Ceiling Installation Only. Floor Mount will require an
External Pump or Gravity Drain

18
3. Dimension
3.1 Indoor Unit
Duct Units
A
C
B
D
J
I
K
Air filter ( optional ) air inlet from rear side
air inlet from bottom side
FE
GH
Electric control box
Air filter ( optional )
L
4-install hanger
Gas side
Liquid side
M
W1
W2
H1
H2
25 Drain connecting pipe
( for pump )
Test mouth & Test cover
Fresh air intake
25 Drain pipe
25 Drain pipe
Capacity (KBtu) Outline dimension(mm) Air outlet opening size Air return opening size
Size of install
hanger Size of refrigerant pipe
A B C D E
F G
H
I J K L M H1
H2
W1
W2
9 mm
700 210 635 570 65 493 35 119
595 200 80 740 350 120
143
95 150
in 27.56
8.27 25 22.44
2.56
19.41
1.38
4.69
23.43 7.87 3.15 29.13 13.78 4.72
5.63
3.74
5.91
12 mm
700 210 635 570 65 493 35 119
595 200 80 740 350 120
143
95 150
in 27.56
8.27 25 22.44
2.56
19.41
1.38
4.69
23.43 7.87 3.15 29.13 13.78 4.72
5.63
3.74
5.91
18 mm
920 210 635 570 65 713 35 119
815 200 80 960 350 120
143
95 150
in 36.22
8.27 25.00
22.44
2.56
28.07
1.38
4.69
32.09 7.87 3.15 37.80 13.78 4.72
5.63
3.74
5.91
24 mm
920 270 635 570 65 713 35 179
815 260 20 960 350 120
143
95 150
in 36.22
10.63
25.00
22.44
2.56
28.07
1.38
7.05
32.09 10.24 0.78 37.80 13.78 4.72
5.63
3.74
5.91
36 mm
1140
270 775 710 65 933 35 179
1035 260 20 1180 490 120
143
95 150
in 44.88
10.63
30.51
27.95
2.56
36.73
1.38
7.05
40.75 10.24 0.78 46.46 19.29 4.72
5.63
3.74
5.91
48 mm
1200
300 865 800 80 968 40 204
1094 288 45 1240 500 175
198
155
210
in 47.24
11.81
34.06
31.50
3.15
38.11
1.57
8.03
43.07 11.34 1.77 48.82 19.69 6.89
7.80
6.10
8.27
1 in