Mitsubishi Electric MJ-E21BG-S1-IT User manual

2013
DEHUMIDIFIER
SERVICE MANUAL
Model MJ-E21BG-S1-IT
No.MJW-E-1207A
Sold from 2013
CONTENTS
1. Precautions 2
2. Names and Functions of Parts 3
3. Specifications 5
4. Outer Dimensions 5
5. Wiring Diagram 6
6. Function 8
7. Technical Points 9
8. Precautions for failure diagnosis 10
9. Troubleshooting Procedure 11
10. Troubleshooting 18
11. Maintenance 19
12. Service Checklist 21
13. Precautions for Disassembly and Reassembly 22
14. Disassembly and Reassembly Hints 24
15. Parts Catalog 32

1. Precautions Note) This page is extracted from the instruction manual.
2

Note) This page is extracted from the instruction manual. 2. Names and Functions of Parts
3

Note) This page is extracted from the instruction manual.
4

3. Specifications
4. Outer Dimensions
Note) This page is extracted from the instruction manual.
5

5. Wiring Diagram
1) Wiring Diagram
(1) Current fuse....................Overcurrent flow caused by deterioration in electrical parts or other problems
turns the power source to OFF.
<Current setting: 2A>
(2) Motor protector................The compressor stops operating if the room temperature exceeds 35°C.
(Overload relay) The compressor will also shut down when malfunctions or other problems
cause the current flow to exceed 5.3A.
(3) Control circuitry...............The room temperature thermister senses temperature below about 0°C, and
shuts down the compressor.
(4) Thermal fuse...................When blower motor temperature exceeds 133°C due to blower locking or other
malfunctions, blower operation shuts down.
(5) Current fuse for compressor protection
................... If the protection by motor protector and control circuitry is not effective,
the compressor shuts down when the current to it exceeds approximately 10A.
<Setting current: 10A>
Safety Devices
P1 P11
P20
P100
P2 P3P5
P4
FM
S
C
R
CM
P200
P10
P13
SV
P201
P
101
SM
White
White
Orange Orange
Red Red
Thermistor (Tube
temperature sensing)
1℃(defrost)/12℃(end)
Sensors
(Humidity and room
temperature sensing)
Power control board
Blue
Yellow/Green
Brown
Gray
Gray
Gray
Gray
Blue Blue Blue
Black
Gray
White
Red
Yellow
Operation
control board
Float switch
Power plug
Stepping motor
Run capacitor
Compressor
Solenoid valve Blower fan motor
6

2) Board Diagram
[Power control board]
[Operation control board]
7

6. Function
■Function List
Compressor
Blower fan
Solenoid valve
Swing louvre
Power
Lamps
Air Purifier
Full
Drying inside
Humidity (set/current)
Operation mode
Swing area
Swing monitor
Off/on timer
Mildew guard
Defrost
Low temp
Child lock
Power
Selection
Mode
Humidity Selection
Air purfier
Swing louvre
Off/on timer
Drying inside
Child lock
LCD indicator LED indicator
Button
Child lock Operation off Auto Mildew guard Low Temp Intelligent Laundry
Easy dehumidifying
Full Air purifier
Drying inside
Defrost Off timer on On timer being set On timer counting
Low
Operation mode
Dehumidifying operation
High
Note : Display lamp/Operable
: Timer - flashes when on
: Off/stopped/inoperable
: Operable only when swing on/lit
: Operable only when swing on and blower fan rotates
: LCD/LED lights at each operation mode
: LCD/LED flashes at each operation mode
: Lights at room temperatures of 14℃or under
: Varies by conditions.
: ON LED lit or flashing
: OFF LED lit
ON
OFF
Intelligent
HIGH
8

7. Technical Points
Dehumidifying
Defrosting
Coolant flow
Blow
Fan
Heat exchanger (heat radiation)
φ5
φ6.35
φ5
φ6.35
Compressor
Heat exchanger (cooling)
Intake
φ6.35
Tube temperature
sensing thermistor
φ6.35
Capillary tube
Capillary tube
φ2.0×φ0.8×φ340
φ5.0×φ4.0
φ6.35
Humidity
sensor
Room
temperature
sensing thermistor
Solenoid
valve
(closed when
dehumidifying
and open
when
defrosting)
Note) This page is extracted from the instruction manual.
■Coolant Circuit
■Performance curve
9

Electric shock
No wet hands
Don’t touch
Check Returntoasitwas
Keep awayWear gloves
WARNING
CAUTION
WARNING
CAUTION
Mishandling may result in minor or damage to your home or property ,etc.
Mishandling may result in fatal or serious injury, or fire.
Remove the power plug
from the socket.
Forbidden Always follow the
instructions Alert
Meanings of graphic symbols are explained below.
Failure to do so may cause electric shock or injuries.
Do not touch a rotating object
until it completely stops.
The rotating object may catch your hand etc,
and result in injuries.
Check the wiring diagram
before wiring processing.
Failure to do so may cause combustion,
generation of smoke, and/or malfunction.
When performing work with
the power on, be careful
not to touch the live part.
This may cause electric shock.
Do not work with wet hands.
This may cause electric shock.
After the work,
laythewireout asitwasbefore.
Failure to do so may cause combustion,
generation of smoke, and/or malfunction.
Wear protective gloves.
Failure to do so may result in injuries
by the edge of metal, electric shock,
and/or burns caused by contact with hot section.
Keep children away.
Failure to do so may result in
electric shock and/or injuries when moving
the unit or using a measuring device.
The following precautions should be observed in order to perform troubleshooting safely and correctly.
The following diagrams indicate circumstances where danger can result from mishandling the unit.
Unplug
8. Precautions for failure diagnosis
10

NO
YES
NO
NO
OK
OK
YES
YES
NO
NO
NG
YES
NO
YES
OK
NG
NG
NG
NG
OK
NG
NG NG
OK
OK
OK
OK
OK
OK
NG
OK
OK
OK
OK
OK
NG
NG
YES
NO
YES
NG
NG
NG
NG
OK
NG
NG
OK
OK
A B
Check if there is no
disconnection or contact
failure of the connectors
and connector pins of
powercontrol board.
Are error codes
displayed?
“E0” “E1” “E7” “E8”
“A1” “A2” “A3” “A6” “P4”
Refer to“ErrorIndicationsand
CorrectiveActions,” and follow
the procedures.
Does the power lamp light
by turning the power on?
Check the continuity of power cord.
Replace the power cord.
Replace the power control board.
Check the current fuse of
power control board (2A/250V).
Does the detective buzzer beep
by turning the power on?
Check if the lamps and LCD
of control panel light.
*How to put out all lighting(Press
the mode switch and the humidity
selection switch together 4 times
when the power is off. Turn on
the power within 2 seconds.)
*Check if LED on the operation
control board is down.
(When LED is down, correct it.)
Insert the connector
and connector pins
securely.
Replace the operation control board.
Replace the power control board.
Is “Full lamp” lighting? Is the tank filled with water? Drain water from the tank.
Check the float.
Check the float.
,VWKHIORDWVZLWFKFRPLQJRII
or attached upside-down?
 Is the float movement smooth?
 Is a magnet attached to the float?
Check the float switch.
 Check if there is no disconnection or
contact failure of the connector (P13)and
connector pins of power control board.
 Check the continuity between connecter (P13)
terminals when the water tank is equipped.
Normal…Tank full:open
Empty:short
Replace the float switch.
Replace the power control board.
Replace the operation control board.
Does it dehumidify?
Does the blower fan motor rotate?
Insert the connector
and connector pins
securely.
Check the resistance of the
blower fan motor.
Normal:Between yelORZDQGEOXHȍ
%HWZHHQEODFNDQGEOXHȍ
Abnormal: Open or short
Check if there is no disconnection
or contact failure of the connector
(P2)and connector pins of power
control board.
Replacethe blower fan motor.
Replacethe power control board.
Replacethe operation control board.
9. Troubleshooting procedure
1) Failure diagnosis flowchart
11

YES
NO
OK
OK
NO YES
YES
NO
YES
NO
NO
YES
NG
OK
NG
NG
NG
NG
NO
NG
NG
NG
NG
OK
OK
OK
OK
OK
OK
OK
NG
OK
OK
OK
NG
NG
OK
YES
A B
C D
OK
NG
NG
OK
Does the compressor operate?
Is the operating environment
low temperature?
(less than 2°C)
Dehumidification may not be
possible in low temperature
environments. (The compressor
does not operate by detecting
abnormal low temperature)
Check if there is no disconnection
or contactfailure of the connector
(P5)and connector pins of power
control board.
Insert the connector
and connector pins
securely.
Check the current fuse of
motor protector (2A/250V).
Replace the current fuse.
Check the continuity of the
motor protector.
Nornal:Open
Abnormal:Short
*
Check it at room temperature
when the power is off.
Replacethe motor protector.
Check the resistance of
the compressor.
Nornal:Terminal C-R 17ȍ
7HUPLQDO&6ȍ
Abnormal:Open or short
Replacethe compressor.
Is there an overcurrent?
(The surface of the compressor is hot.)
Replacethe compressor.
Replacethe power control board.
Replacethe operation control board.
Is the heat exchanger
(evaporator) cold?
Check the coolant circuit.
(If the coolant leaks.
If the tube clogs.)
Ɣ
The part of the cooler near
the tube temperature sensor
should be at least 10°C lower
than room temperature when
normal.
Ɣ The bottom of the heat
exchanger has frost when the
quantity of coolant is little by
coolant leaking.
Are the power consumption
and current normal?
Replace the parts that
coolant is leaking or the
tube is clogged.
Check the resistance of the
tube temperature sensing thermistor.
Nornal:%HWZHHQ3SLQVNȍ
WRNȍ
Abnormal:Open or short
Replace the tube temperature
sensing thermistor
Replacethe power control board.
Replacethe operation control board.
*Note: Do not replace the compressor easily excpet when the overcurrent(Lock),
the abnormal noise or the abnormal vibration is occured.
(includes the oil leak in the compressor)
12

YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
YES
YES
NO
OK
OK
NO
NG
NG NG
NG
YES
OK
OK
NG
OK
OK
OK
OK
C
E
D
Are there any clogs or dust on
the filter. Clean filter.
Is the operating environment
low humidity and low temperature?
It is normal.
Dehumidication may not be
possible in low humidity and
low temperature environments.
Explain the performance
curve on P9.
The unit is normal.
The unit stop working in the
middle of operation.
Is the defrost mode selected?
Does the defrost indicator light?
It is normal.
Defrost mode is operating.
Airflow stops in a few minutes.
Is automatic operation
selected?
Easy dehumidifying /
Intelligent laundry /
Mildew guard / Auto / Off timer
Is the operating
environment low humidity
and low temperature?
Dehumidication may
not be possible in low
humidity and low
temperature environments.
Explain the performance
curve on P9.
1) Easy dehumidifying:It stops according to the humidity level.
2) Intelligent laundry:It stops in a minimum of about 60 minutes and a maximum of about
12 hours.
3) Mildew guard:It operates intermittently 2-4 hours (24 hours).The operating time varies
depending on the humidity.
4) Auto:Compressor and blower fan stop when current humidity is -1% of set humidity or less.
5) Off timer:It stops at the set time.
6) All operation mode:Is the off timer operation selected with other operation mode?
Off timer operation has priority over other modes.
1-6 indicate that the unit is operating normally. Explain that to the customer.
Stepping motor (louvre)
does not operate. Is the swing louvre switch
“OFF”?
Does the swing direction of
the louvre change to “Wide”,
“Upward”,or ”Rear”?
Check if there is no disconnection or
contact failure of the connector (P20)and
connector pins of power control board.
Insert the connector and
connector pins securely.
Check the resistance between
connector pins of the stepping
motor (P20 connector).
Normal:
Terminal1-2
Terminal1-3
Terminal1-4
Terminal1-5
Abnormal:Each interval is
open or short
342-418ȍ
Replace the stepping motor.
Replace the power control board.
Replace the operation control board.
The unit is normal.
OK
NG
NG
OK NG
NG
NG
OK
OK
OK
NO
YES
Does the solenoid valve operate?
(Shorten J301 and J302)
Check if there is no disconnection
or contact failure of the connector
(P3)and connector pins of power
control board.
Insert the connector
and connector pins
securely.
Check the resistance of the
solenoid valve coil.(P3 connector)
Nornal:Between the pin1 and
pin2 2.0kȍ-2.2kȍ
Abnormal:Open or short
Replace the solenoid valve coil.
Replace the power control board.
Replace the operation control board.
13

YES
YES
NO
NO
NO
YES
NG
OK
OK
OK
NG
OK
E
OK
OK
Only a small quantity of
water is dehumidified. Is the operating environment low humidity and low
temperature?
Dehumidication may not be
possible in low humidity and
low temperature environments.
Explain the performance
curve on P9.
Is there any dust on the room
temperature and humidity sensor?
Remove the dust from the room
temperature and humidity sensor.
Check if there is no disconnection or
contact failure of the connector (P10)and
connector pins of power control board.
Insert the connector and
connector pins securely.
Check the resistance of the room
temperature and humidity sensor.
(P10 connector)
Normal:Between the pin3 and pin4
NȍNȍ
Abnormal:Open or short
Replace the room temperature
and humidity sensor.
The unit is normal.
14

2) Simple Check Table for Main Parts
Component name Testing procedure
Tube temperature
sensing thermistor
Room
temperature and
humidity sensor
board
Compressor
Blower fan motor
Solenoid valve coil
Detach the connector and measure the resistance using a multimeter
(component temperature: 10℃to 30℃).
Detach the connector and measure the resistance using a multimeter
(component temperature: 10℃to 30℃).
With the connector detached, measure the resistance across the terminals using a multimeter
(winding temperature: 10℃to 30℃).
Normal Abnormal
Between P11 pins: 8.0kΩto 20.8kΩ
Normal: 47 to 51kΩ(between P10 pins 3 and 4)
Abnormal: Open or shorted
Open or shorted
Normal Abnormal
Open or shorted
Measure the resistance between terminals using a multimeter
(component temperature: 10℃to 30℃).
Measure the resistance between terminals using a multimeter
(winding temperature: 10℃to 30℃).
2.0kΩ~ 2.2kΩ
Open or shorted
Normal Abnormal
17Ω~ 19Ω
32Ω~ 36Ω
C-R side
C-S side
Open or shorted
Normal Abnormal
217Ω~ 236Ω
219Ω~ 237Ω
Yellow-Blue
Black-Blue
Stepping motor
Measure the resistance across terminals with a multimeter.
(Part temperature: approx 25℃)
Open or shorted
Normal Abnormal
342Ω~ 418Ω
Terminals 1-2
Terminals 1-3
Terminals 1-4
Terminals 1-5
15

3) Error Indications and Corrective Actions
4) Self-Test Program and Execution Procedure
Error (failure)
P10 connector out of position
Room temperature thermistor blowout Check the P10 connection.
Check the room temperature and humidity sensor
board.
Corrective action
Room temperature thermistor short
Room temperature and humidity
sensor board failure
P11 connector out of position
Tube temperature thermistor blowout Check the P11 connection.
Check the tube temperature thermistor.
Tube temperature thermistor short
Tube temperature sensor failure
Microprocessor failure
RAM error Replace the main board.
Frequency determination error
(When power is on) Outlet/power check
(Replace the main and power supply boards.)
Watchdog timer error Replace the main board.
Compressor
Indication
(Timer display)
E0
E1
E7
E8
A1
A2
A3
A6
P4
Frequency determination error
(During operation)
Follow the “Does it dehumidify?” in the “Failure
diagnosis flowchart” of P11.
(1) Deactivating 3-minute restart prevent lock
①Start: Press the MODE and HUMIDITY SELECTION buttons together 3 times when the power
is off. Press the POWER button within 2 seconds.
②Functions:
①Deactivates 3-minute restart prevention lock (immediate operation)
②Fan: Fix at rank 6 (max. airflow)
③Activates compressor
④Operating mode: Low Temp
⑤Low temperature is indicated on LCD.
⑥When E2PROM error is detected, FULL, DRYING INSIDE andAIR PURIFIER LEDs are lit.
③To end: Turn power off. The solenoid valve functions for 3 seconds.
16

LCD and
LED all lit Current
humidity Room
temperature
indicator
Tube
temperature
indicator Current fan
rank Determined
frequency
For current humidity
(all displays in decimal)
Mode displayed
Examples
(2) LED, LCD and fan tests
①Start: Press the MODE and HUMIDITY SELECTION buttons simultaneously 4 times when the
power is off. Press the POWER button within 2 seconds.
②Mode select: Use the OFF/ON TIMER button to change the diagnosis mode (0 - 5).
(3) Operation/Error history mode
①Start: Press the MODE and HUMIDITY SELECTION buttons simultaneously 5 times when the
power is off. Press the POWER button within 2 seconds.
②Mode select: Use the OFF/ON TIMER button to select indicator mode (0-F).
(4) Demo program
①Start: With the power OFF, hold down the MODE and HUMIDITY SELECTION buttons,
and press the POWER button. The demo program starts in 3 seconds.
②Operations (all buttons are disabled):
①Fan: Fixed at rank 3
②Compressor/solenoid valve: Stopped
③LCD/LED: Lights in random sequence
④Swing louvre: Wide
③End: Remove power plug.
0: Latest error
7: Oldest error
Compressor
malfunction detected
Error history display
Example: Latest error display
Tube temperature
Thermistor short-circuit
detected
Watchdog error
Tube temperature
Thermistor open-circuit
detected Frequency determination
error at power ON
Room temperature
Thermistor short-circuit
detected Frequency error
when fan operated
Room temperature
Thermistor open-circuit
detected
Latest error Display mode
A6 error
A2 error
A3 error
P4 error
E8 error
E7 error
E1 error
E0 error
When “display mode” is 8 to F, the number of error
generations is displayed in hexadecimal.
17

Note) This page is extracted from the instruction manual.
10. Troubleshooting
18

11. Maintenance Note) This page is extracted from the instruction manual.
19

Note) This page is extracted from the instruction manual.
20