Midea MDT1-08DMN3-QA3 User manual

YDT1/T2101221 (0)
SERVICE MANUAL
MIDEA DEHUMIDIFIER
T1 SERIES
Factory Model Sale Model
EU-CF0.3BD/N3-T1(A3) MDT1-08DMN3-QA3
EU-CFK0.3BD/N3-T1(A3) MDT1-08DKN3-QA3
EU-CFZ0.3BD/N3-T1(A3) MDT1-08DEN3-QA3
EU-CF0.4BD/N3-T1(A3) MDT1-10DMN3-QA3
EU-CFK0.4BD/N3-T1(A3) MDT1-10DKN3-QA3
EU-CFZ0.4BD/N3-T1(A3) MDT1-10DEN3-QA3
EU-CFK0.6BD/N3-T1(A3) MDT1-16DKN3-QA3
EU-CFZ0.6BD/N3-T1(A3) MDT1-16DEN3-QA3
EU-CF0.6BD/N3-T1(A3) MDT1-16DMN3-QA3
EU-CF0.8BD/N3-T1(A3) MDT1-20DMN3-QA3
EU-CFK0.8BD/N3-T1(A3) MDT1-20DKN3-QA3
EU-CFZ0.8BD/N3-T1(A3) MDT1-20DEN3-QA3
T2 SERIES
EU-CFZ0.4BD/N3-T2(A3) MDT2-10DEN3

CONTENTS
1. Precaution .................................................................................................................................................... 1
1.1 Safety Precaution.......................................................................................................................... 1
1.2 Warning............................................................................. Ошибка! Закладка не определена.
2. Display. ......................................................................................................................................................... 5
3. Dimension .................................................................................................................................................... 6
4. Refrigerant Cycle Diagram ......................................................................................................................... 6
5. Wiring Diagram ............................................................................................................................................ 7
6. Features........................................................................................................................................................ 9
7. Electronic function...................................................................................................................................... 9
7.1 Terms and definitions....................................................................................................................9
7.2 Electric part assembly condition that use ..................................................................................... 9
7.3 PCB working environment ............................................................................................................ 9
7.4 Protection function...................................................................................................................... 10
7.5 Set humidity operation.................................................................................................................11
7.6 Continually dehumidify operation.................................................................................................11
8. Basic test procedure..................................................................................................................................11
8.1 Defective compressor.........................................................................................................................11
8.2 Sealed refrigeration system repairs................................................................................................... 14
8.3 Fan motor........................................................................................................................................... 16
8.4 Capacitor............................................................................................................................................ 17
9. Characteristic of temperature sensor...................................................................................................... 18
10. Troubleshooting....................................................................................................................................... 18
11. Exploding view ........................................................................................................................................ 21

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 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 fore or 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.
There is risk of fire, electric shock, explosion, or injury.
Do not install the product on a defective installation stand.
It may cause injury, accident, or damage to the product.

2
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.
Moisture may condense and wet or damage furniture.
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.
There is risk of fire or electric shock.
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 electric 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.
Do not use the telephone or turn switches on or off. There is risk of explosion or fire.
If strange sounds, or small 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.

3
When the product is soaked (flooded or submerged), 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.
To 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.
Avoid personal injury.
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 periods of time. (Do not sit in the draft).
This could harm to your health.
Do not use the product for special purposes, such as preserving foods, works of art, etc. It is a

4
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.
It may cause product failure.
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.
There is risk of personal injury.
Do not step on pr put anything on the product. (outdoor units)
There is risk of personal injury and failure of product.
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.
Do not insert hands or other object through air inlet or outlet while the product is operated.
There are sharp and moving parts that could cause personal injury.
Do not drink the water drained from the product.
It is not sanitary could cause serious health issues.
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.
The chemical in batteries could cause burns or other health hazards.

5
2. Display
EU-CF0.3BD/N3-T1(A3)(MDT1-08DMN3-QA3)
EU-CF0.4BD/N3-T1(A3)(MDT1-10DMN3-QA3)
EU-CF0.8BD/N3-T1(A3)(MDT1-20DMN3-QA3)
EU-CFZ0.3BD/N3-T1(A3)(MDT1-08DEN3-QA3)
EU-CFZ0.4BD/N3-T1(A3)(MDT1-10DEN3-QA3)
EU-CFZ0.6BD/N3-T1(A3)(MDT1-16DEN3-QA3)
EU-CFZ0.8BD/N3-T1(A3)(MDT1-20DEN3-QA3)
EU-CFZ0.4BD/N3-T2(A3) (MDT2-10DEN3)

6
Description:
① Power on indicator light(green)
② Bucket full indicator light(red)
③ Power Pad
④ Continuous operation on indicator light(green)
⑤ Display
⑥ Continue pad
⑦ Humidity set control pads
3. Dimension
T1 Series T2 Series
Dimension
Mode
W(mm)
H(mm)
D(mm)
T1: 8L,10L
350
452
275
T1: 16L,20L
397
502
297
T2: 10L
350
395
350
4. Refrigerant Cycle Diagram
The figure below is a brief description of the important components and their function in what is
called the refrigeration system.

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5. Wiring Diagram
(1)EU-CF0.3BD/N3-T1 (A3) (MDT1-08DMN3-QA3)
EU-CF0.4BD/N3-T1 (A3) (MDT1-10DMN3-QA3)
EU-CF0.6BD/N3-T1 (A3) (MDT1-16DMN3-QA3)
EU-CF0.8BD/N3-T1 (A3) (MDT1-20DMN3-QA3)
(2)EU-CFK0.3BD/N3-T1 (A3) (MDT1-08DKN3-QA3)
EU-CFK0.4BD/N3-T1 (A3) (MDT1-10DKN3-QA3)
EU-CFK0.6BD/N3-T1 (A3) (MDT1-16DKN3-QA3)
EU-CFK0.8BD/N3-T1 (A3) (MDT1-20DKN3-QA3)

8
(3) EU-CFZ0.3BD/N3-T1 (A3) (MDT1-08DEN3-QA3)
EU-CFZ0.4BD/N3-T1 (A3) (MDT1-10DEN3-QA3)
EU-CFZ0.6BD/N3-T1 (A3) (MDT1-16DEN3-QA3)
EU-CFZ0.8BD/N3-T1 (A3) (MDT1-20DEN3-QA3)
EU-CFZ0.4BD/N3-T2 (A3) (MDT2-10DEN3)

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6. Features
※LED display
※Auto Shut off
※Continuous dehumidification mode
※1.5L or 2.7L water bucket and water full protection
※Auto defrost, Anti-freezing control
※Turbo key function and normal key function(Optional)
※Self-diagnosis and auto-protection function.
※Wait 3 minutes before resuming operation
※Auto-restart, When the power supply is interrupted and then restore, the unit automatically restore
the previous function setting.
7 .Electronic function
7.1 Terms and definitions
TE: Temperature of evaporator.
TH: Humidity of ambient.
TS: The set humidity.
S1: Switch 1
7.2 Electric part assembly condition that use
(1).Scope of application of voltage of the power: 220-240VAC, 50Hz, 1phase;
(2).Working environment: 5’C~+35’C;
(3).The humidity of electric part working environment:≤RH95%;
(4).The electric storage working temperature:-20’C~+70’C.
7.3 PCB working environment
(1).Tolerance of measure indoor side humidity: ±5%RH, the scope of application: 35%RH~80%RH;
(2).Tolerance of measure evaporator temperature: ±1’C, the scope of application: 5’C~+35’C;
(3).EMC, EMI accord with CE authentication demand;
(4).The electric apparatus accords with CE, GB4706.32-1996, GB/T7725-1996 demand safely.

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7.4 Protection function
(1).Time delay safety control (3 minutes).
When the compressor is stopped in operation, it needs 3 minutes delay to restart.
When the setting humidity is reached in operation, the compressor will stop, and it will not start
again within 3 minutes.
If the auto-restart is available, the compressor also needs 3 minutes delay to start.
(2).Anti-freezing protect control (P1)
If the temperature of the evaporator falls below 1℃for 15minutes or more, the compressor turn off
to protect the evaporator from freezing. Compressor will restart again after 9 minutes.
See the below graph:
(3).Water full protection
There is one switch on the top of water tank, S1.
(a)At running status, if the water level of water exceeds the safety water level and the S1 closed, the
unit will protect by itself. It will shut-down all of load and back to work provided the water tank is
empty by manual.
(b)At wake status, if the water level of water exceeds the safety water level and the S1 closed, the unit
will protect by itself. It will back to work provided the water is empty by manual.
Note: If it has P2 protect, the unit will under lock status, the button of control plane could not
operated, until the P2 protect have been delete.
(4).Sensor malfunction
If the A/D of sensor is not at the range of 0.05~4.95V, the sensor is broken. If the TH sensor has this
malfunction, the display will show E1, if it is TC, the display will show E2.
TE
≤
-1℃
Comp
ressor
Fan
Add up15mins
Add up9mins
On
On
Off
On

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(5).Malfunction display
When the malfunction happened at the same time, the priority is P1>T2>T1
7.5 Set humidity operation
(1).In this operation, the range of work is 35%RH-85%RH.
(2).The fan keeps the same speed as last mode.
(3).The action of compressor in this operation is like the below graph show:
7.6 Continually dehumidify operation
In this operation, the compressor and fan will be working continually unless there is a water full
protection or sensor fault protection. The Setting humidity operation is unapplied.
8 Basic test procedure
8.1 Defective compressor
Compressors are single phase, 220-240volt, depending on the model unit. All compressor motors
are permanent split capacitor type using only a running capacitor across the start and run terminal.
All compressors are internally spring mounted and externally mounted on rubber isolators.
8.1.1 Compressor wiring test
LCD or LED display
Stand for
E1
TH sensor malfunction
E2
TC sensor malfunction
P1
Unit is defrosting
P2
Water full protection

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Remove compressor terminal box cover and disconnect wires from terminals. Using an
ohmmeter, check continuity across the following:
Terminal "C" and "S" - no continuity
- Open winding - replace compressor.
Terminal "C" and "R" - no continuity
- Open winding - replace compressor.
Terminal "R" and "S" - no continuity
- Open winding - replace compressor.
8.1.2 Ground test
Use an ohmmeter to set on its highest scale. Touch one lead to the compressor body (clean point of
contact as a good connection is a must) and the other probe in turn to each compressor terminal.
If a reading is obtained, the compressor is grounded and must be replaced.
8.1.3 Checking the compressor efficiency
The reason for compressor inefficiency is normally due to broken or damaged suction and/or
discharge valves, reducing the ability of the compressor to pump refrigerant gas.
This condition can be checked as follows:
1. Install a piercing valve on the suction and discharge or liquid process tube.
2. Attach gauges to the high and low sides of the system.
3. Start the system and run a “cooling or heating performance test.”
If test shows:
A. Below normal high side pressure.
B. Above normal low side pressure.

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C. Low temperature difference across coil.
The compressor valves are faulty - replace the compressor
8.1.4 Terminal overload (external)
Some compressors are equipped with an external overload which is located in the compressor
terminal box adjacent to the compressor body .The overload is wired in series with the common
motor terminal. The overload senses both major amperage and compressor temperature. High
motor temperature or amperage heats the disc causing it to open and break the circuit to the
common motor terminal.
Heat generated within the compressor shell is usually due to:
1. High amperage.
2. Low refrigerant charge.
3. Frequent recycling.
4. Dirty condenser.
8.1.5 Terminal overload – Test (compressor external type)
1. Remove overload.
2. Allow time for overload to reset before attempting to test.
3. Apply ohmmeter probes to terminals on overload wires. There should be continuity through
the overload.
8.1.6 Terminal overload (internal)
Some model compressors are equipped with an internal overload. The overload is embedded
in the motor windings to sense the winding temperature and/or current draw. The overload is
connected in series with the common motor terminal.
Should the internal temperature and/or current draw become excessive; the contacts in the
overload will open, turning off the compressor? The overload will automatically reset, but may
require several hours before the heat is dissipated.
8.1.7 Checking the internal overload
1. No power to unit, remove the leads from the compressor terminals.
2. Using an ohmmeter, test continuity between terminals C-S and C-R. If not continuous, the
compressor overload is open and the compressor must be replaced.

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8.2 Sealed refrigeration system repairs
8.2.1 Equipment require
1. Voltmeter
2. Ammeter
3. Ohmmeter
4. E.P.A. Approved Refrigerant Recovery System.
5. Vacuum Pump (capable of 200 microns or less vacuum.)
6. Acetylene Welder
7. Electronic Halogen Leak Detector (G.E. Type H-6 or equivalent.)
8. Accurate refrigerant charge measuring device such as:
a. Balance Scales - 1/2 oz. accuracy
b. Charging Board - 1/2 oz. accuracy
9. High Pressure Gauge - (0 - 400 lbs.)
10. Low Pressure Gauge - (30 - 150 lbs.)
11. Vacuum Gauge - (0 - 1000 microns)
8.2.2 Equipment must be capable of:
1. Recovery CFC's as low as 5%.
2. Evacuation from both the high side and low side of the system simultaneously.
3. Introducing refrigerant charge into high side of the system.
4. Accurately weighing the refrigerant charge actually introduced into the system.
5. Facilities for flowing nitrogen through refrigeration tubing during all brazing processes.
8.2.3 Hermetic compressor replacement.
The following procedure applies when replacing components in the sealed refrigeration
circuit or repairing refrigerant leaks. (Include Compressor, condenser, evaporator, capillary
tube, refrigerant leaks, etc.)
1. Recover the refrigerant from the system at the process tube located on the high side of the
system by installing a line tap on the process tube. Apply gauge from process tube to EPA
approved gauges from process tube to EPA approved recovery system. Recover CFCs in
system to at least 5%.
2. Cut the process tube below pinch off on the suction side of the compressor.
3. Connect the line from the nitrogen tank to the suction process tube.

15
4. Drift dry nitrogen through the system and unsolder the more distant connection first.
(Filter drier, high side process tube, etc.)
5. Replace inoperative component, and always install a new filter drier. Drift dry nitrogen
through the system when making these connections.
6. Pressurize system to 30 PSIG with proper refrigerant and boost refrigerant pressure to 150
PSIG with dry nitrogen.
7. Leak test complete system with electric halogen leak detector, correcting any leaks found.
8. Reduce the system to zero gauge pressure.
9. Connect vacuum pump to high side and low side of system with deep vacuum hose or
copper tubing. (Do not use regular hoses.)
10. Evacuate system to maximum absolute holding pressure of 200 microns or less. NOTE:
This process can be speeded up by use of heat lamps, or by breaking the vacuum with
refrigerant or dry nitrogen at 5,000 microns. Pressure system to 5 PSIG and leave in
system a minimum of 10 minutes. Recover refrigerant, and proceed with evacuation of a
pressure of 200 microns or a minimum of 10%.
11. Break vacuum by charging system from the high side with the correct amount of refrigerant
specified. This will prevent boiling the oil out of the crankcase.
NOTE: If the entire charge will not enter the high side, allow the remainder to enter the low
side in small increments while operating the unit.
12. Restart unit several times after allowing pressures to stabilize. Pinch off process tubes, cut
and solder the ends. Remove pinch off tool, and leak check the process tube ends
8.2.4 Special procedure in the case of compressor motor burnout
1. Recover all refrigerant and oil from the system.
2. Remove compressor, capillary tube and filter drier from the system.
3. Flush evaporator condenser and all connecting tubing with dry nitrogen or equivalent, to
remove all contamination from system. Inspect suction and discharge line for carbon
deposits. Remove and clean if necessary.
4. Reassemble the system, including new drier strainer and capillary tube.
5. Proceed with processing as outlined under hermetic component replacement.
8.2.5 Rotary compressor special troubleshooting and service
Basically, troubleshooting and servicing rotary compressors is the same as on the
reciprocating compressor with only a few exceptions.

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1. Because of the spinning motion of the rotary, the mounts are critical. If vibration is present,
check the mounts carefully.
2. The electrical terminals on the rotary are in a different order than the reciprocating
compressors. The terminal markings are on the cover gasket. Use your wiring diagram to
insure correct connections.
8.2.6 Refrigerant charge
1. The refrigerant charge is extremely critical. It must be measured charge carefully - as exact
as possible to the nameplate charge.
2. The correct method for charging the rotary is to introduce liquid refrigerant into the high
side of the system with the unit off. Then start compressor and enter the balance of the
charge, gas only, into the low side.
The introduction of liquid into the low side, without the use of a capillary tube, will cause
damage to the discharge valve of the rotary compressor.
NOTE: All inoperative compressors returned to Friedrich must have all lines properly plugged
with the plugs from the replacement compressor.
8.3 Fan motor
A single phase permanent split capacitor motor is used to drive the evaporator blower and
condenser fan. A self-resetting overload is located inside the motor to protect against high
temperature and high amperage conditions.
Fan motor test
1. Determine that capacitor is serviceable.
2. Disconnect fan motor wires from fan speed switch or system switch.
3. Apply "live" test cord probes on black wire and common terminal of capacitor. Motor should
run at high speed.
4. Apply "live" test cord probes on red wire and common terminal of capacitor. Motor should
run at low speed.
5. Apply "live" test cord probes on each of the remaining wires from the speed switch or
system switch to test intermediate speeds.

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8.4 Capacitor
A run capacitor is wired across the auxiliary and main winding of a single phase permanent split
capacitor motor such as the compressor. A single capacitor can be used for each motor or a dual
rated capacitor can be used for both.
The capacitor's primary function is to reduce the line current while greatly improving the torque
characteristics of a motor. The capacitor also reduces the line current to the motor by improving the
power factor of the load. Run capacitor hook-up line side of the capacitor is marked with a red dot
and is wired to the line side of the circuit
Capacitor test:
1. Remove capacitor from unit.
2. Check for visual damage such as bulges, cracks, or leaks
3. For dual rated, apply an ohmmeter lead to common (C) terminal and the other probe to the
compressor (HERM) terminal. A satisfactory capacitor will cause a deflection on the pointer,
and then gradually move back to infinity.
4. Reverse the leads of the probe and momentarily touch the capacitor terminals. The
deflection of the pointer should be two times that of the first check if the capacitor is good.
5. Repeat steps 3 and 4 to check fan motor capacitor.
NOTE: A shorted capacitor will indicate a low resistance and the pointer will move to the "0"
end of the scale and remain there as long as the probes are connected.
An open capacitor will show no movement of the pointer when placed across the terminals of
the capacitor

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9 Characteristic of temperature sensor
10 Troubleshooting
In general, possible trouble is classified in three kinds. One is called Starting Failure which is caused
from an electrical defect, another is ineffective Air Conditioning caused by a defect in the refrigeration
circuit and improper application, and the other is called the Structure Damage.
Temp.℃
Resistance
KΩ
Temp.℃
Resistance
KΩ
Temp.℃
Resistance
KΩ
-10
62.2756
17
14.6181
44
4.3874
-9
58.7079
18
13.918
45
4.2126
-8
56.3694
19
13.2631
46
4.0459
-7
52.2438
20
12.6431
47
3.8867
-6
49.3161
21
12.0561
48
3.7348
-5
46.5725
22
11.5
49
3.5896
-4
44
23
10.9731
50
3.451
-3
41.5878
24
10.4736
51
3.3185
-2
39.8239
25
10
52
3.1918
-1
37.1988
26
9.5507
53
3.0707
0
35.2024
27
9.1245
54
2.959
1
33.3269
28
8.7198
55
2.8442
2
31.5635
29
8.3357
56
2.7382
3
29.9058
30
7.9708
57
2.6368
4
28.3459
31
7.6241
58
2.5397
5
26.8778
32
7.2946
59
2.4468
6
25.4954
33
6.9814
60
2.3577
7
24.1932
34
6.6835
61
2.2725
8
22.5662
35
6.4002
62
2.1907
9
21.8094
36
6.1306
63
2.1124
10
20.7184
37
5.8736
64
2.0373
11
19.6891
38
5.6296
65
1.9653
12
18.7177
39
5.3969
66
1.8963
13
17.8005
40
5.1752
67
1.83
14
16.9341
41
4.9639
68
1.7665
15
16.1156
42
4.7625
69
1.7055