Mitsubishi Electric MLZ-KP25VF Service Manual Download Page 28

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Start

Indoor unit
operates.
Outdoor unit
does not
operate.

Indoor unit
does not receive
the signal from
remote controller.

OPERATION INDICATOR
lamp on the indoor unit is
flashing on and off.

Outdoor unit
operates only
in Test Run
operation.
1

Outdoor unit
does not
operate
even in
Test Run
operation.
1

Indoor unit
operates, when
EMERGENCY
OPERATION
switch is pressed.

Indoor unit
does not operate,
when
EMERGENCY
OPERATION
switch is pressed.

Check room
temperature
thermistor.
Refer to 11-7.
"TEST POINT
DIAGRAM AND
VOLTAGE".

Refer to
"How to check
inverter/
compressor".

1. Check indoor/outdoor
connecting wire.
(Check if the power
is supplied to the
indoor unit.)
2. Refer to 11-6.
"Check of indoor
electronic control
P.C. board and indoor
fan motor".

Unit does not
operate
normal
operation in
COOL or
HEAT mode.

Refer to
"Check of
R.V. coil".

Left lamp
Flash on and off
at 0.5-second
intervals
Cause:
Indoor/
Outdoor unit

0LVZLULQJ

or trouble
of serial signal

Left lamp
2-time flash
Cause:
Indoor unit

7URXEOHRI

room temp-
erature/
indoor coil
thermistor

Left lamp
3-time flash
Cause:
Indoor unit

7URXEOHRI

indoor fan
motor

Left lamp
5-time flash
Cause:
Outdoor unit

2XWGRRU

power
system
abnormality

Left lamp
6-time flash
Cause:
Outdoor unit

7URXEOHRI

thermistor
in outdoor
unit

Left lamp
7-time flash
Cause:
Outdoor unit

7URXEOHRI

outdoor
control
system

Refer to 11-6.
"How to
check
miswiring
and serial
signal error
(when
outdoor unit
does not work)".

Check room
temperature
thermistor
and indoor
coil thermis-
tor.
Refer to 11-7.
"Test point
diagram and
voltage".

Refer to 11-6.
"Check of
indoor fan
motor".

Refer to
"How to check
the inverter/
compressor".

Refer to
"Check of
outdoor
thermistors".

Replace the
inverter P.C.
board or
the outdoor
electronic
control P.C.
board.

Left lamp
9-time flash
Cause:
Indoor unit

7URXEOHRI

float sensor
or drain
pump

Refer to 11-6.
"Check of
float sensor".

Check the
drain pump.

Left lamp
14-time flash
or more
Cause:
Outdoor unit

2WKHU

abnormality

&KHFNWKH

stop valve.

Check
"Flow chart of
the detailed
outdoor unit
failure mode
recall function."

Left lamp
4-time flash
Cause:
Indoor unit

7URXEOHRI

indoor unit
control
system

Replace the
indoor
electronic
control
P.C. board.

Refer to outdoor unit service manual.

Indoor unit operates.
Outdoor unit does not
operate normally.

If blinking of OPERATION
INDICATOR lamp cannot be
checked, it can be checked with
failure mode recall function.

1
"Test Run operation" means the
operation within 30 minutes after
EMERGENCY OPERATION switch
is pressed.

Refer to 11-6.
"Check of
remote controller,
receiver P.C.
board and
indoor electronic
control P.C.
board".

11-3. INSTRUCTION OF TROUBLESHOOTING

OBH801

Summary of Contents for MLZ-KP25VF

Page 1: ...vice manual MXZ D VA Series OBH626 MXZ E VA Series OBH723 MXZ F VF Series OBH790 PARTS CATALOG OBB801 CONTENTS 1 TECHNICAL CHANGES 2 2 SAFETY PRECAUTION 3 3 PART NAMES AND FUNCTIONS 7 4 SPECIFICATION 8 5 NOISE CRITERIA CURVES 9 6 OUTLINES AND DIMENSIONS 10 7 WIRING DIAGRAM 11 8 REFRIGERANT SYSTEM DIAGRAM 12 9 SERVICE FUNCTIONS 13 10 MICROPROCESSOR CONTROL 16 11 TROUBLESHOOTING 24 12 DISASSEMBLY IN...

Page 2: ...instructions Preparation before the repair service Prepare the proper tools Prepare the proper protectors Provide adequate ventilation After stopping the operation of the air conditioner turn off the power supply breaker and remove the power plug Discharge the capacitor before the work involving the electric parts Precautions during the repair service Do not perform the work involving the electric...

Page 3: ...work on the systems 1 2 Work Procedure Work shall be undertaken under a controlled procedure so as to minimize the risk of a flammable gas or vapor being present while the work is being performed 1 3 General Work Area All maintenance staff and others working in the local area shall be instructed on the nature of work being carried out Work in confined spaces shall be avoided The area around the wo...

Page 4: ...ve number of connections terminals not made to original specification damage to seals incorrect fitting of glands etc Ensure that the apparatus is mounted securely Ensure that seals or sealing materials have not degraded to the point that they no longer serve the purpose of prevent ing the ingress of flammable atmospheres Replacement parts shall be in accordance with the manufacturer s specificati...

Page 5: ...ystem when charging is complete if not already Extreme care shall be taken not to overfill the refrigeration system Prior to recharging the system it shall be pressure tested with the appropriate purging gas The system shall be leak tested on completion of charging but prior to commissioning A follow up leak test shall be carried out prior to leaving the site 9 Decommissioning Before carrying out ...

Page 6: ...et of instructions concerning the equipment that is at hand and shall be suitable for the recovery of all appropriate refrigerants including when applicable flammable refriger ants In addition a set of calibrated weighing scales shall be available and in good working order Hoses shall be com plete with leak free disconnect couplings and in good condition Before using the recovery machine check tha...

Page 7: ...screw for 4 х 16 mm 2 Remote controller 1 Remote controller holder 1 Fixing screw for 3 5 x 16 mm Black 2 INDOOR UNIT MLZ KP25VF MLZ KP35VF MLZ KP50VF Display section Horizontal vane Vertical vane Air outlet LU OWHU LU SXULI LQJ OWHU Air inlet LU FOHDQLQJ OWHU Silver ionized air SXUL HU OWHU RSWLRQ Intake grille Safety strings Spec name plate Open the display cover Remote control receiving section...

Page 8: ...W Power factor 1 58 58 58 Fan motor current 1 A 0 3 0 3 0 3 Fan motor Model RC0J30 CZ RC0J30 CZ RC0J30 CZ Dimensions W x H x D mm 1102 x 185 x 360 1102 x 185 x 360 1102 x 185 x 360 Weight kg 15 5 15 5 15 5 Special remarks Air direction 5 5 5 Sound level High Med Low SLow dB A 38 34 31 27 37 34 29 26 40 36 32 27 40 36 32 26 47 41 36 29 48 42 37 26 Fan speed High Med Low SLow rpm 1110 1020 930 800 1...

Page 9: ...HEARING FOR CONTINUOUS NOISE COOLING FUNCTION 38 37 SPL dB A LINE High FAN SPEED HEATING Heating Dry bulb temperature 20ºC 90 80 70 60 50 40 30 20 10 63 125 250 500 1000 2000 4000 8000 NC 60 NC 50 NC 40 NC 30 NC 20 NC 70 OCTAVE BAND SOUND PRESSURE LEVEL dB re 0 0002 MICRO BAR BAND CENTER FREQUENCIES Hz Test conditions Cooling Dry bulb temperature 27ºC Wet bulb temperature 19ºC APPROXIMATE THRESHOL...

Page 10: ...10 OUTLINES AND DIMENSIONS 6 Unit mm INDOOR UNIT MLZ KP25VF MLZ KP35VF MLZ KP50VF OBH801 ...

Page 11: ...11 7 WIRING DIAGRAM INDOOR UNIT MLZ KP25VF E1 ER1 MLZ KP35VF E1 ER1 MLZ KP50VF E1 ER1 OBH801 ...

Page 12: ... with heat insulator Indoor coil thermistor RT12 main Indoor heat exchanger Flared connection Room temperature thermistor RT11 Indoor coil thermistor RT13 sub Flared connection Refrigerant flow in cooling Refrigerant flow in heating Refrigerant pipe Ø12 7 with heat insulator Refrigerant pipe Ø6 35 with heat insulator Indoor coil thermistor RT12 RT14 RT15 main INDOOR UNIT Unit mm MLZ KP25VF MLZ KP3...

Page 13: ...to set the remote controller 1 Hold down button on the remote controller for 2 seconds to enter the pairing mode 2 Press button again and assign a number to each remote controller Each press of button advances the number in the following order 1 2 3 4 3 Press button to complete the pairing setting After the setting turn ON the power supply and with the remote controller headed towards the indoor u...

Page 14: ...usly at restart Therefore the special counter measures are required to prevent the main voltage drop or the rush of the starting current by adding to the system that allows the units to start one by one C111 JR77 IC101 How to disable AUTO RESTART FUNCTION Turn off the main power for the unit Cut the jumper wire to JR77 on the indoor electronic control P C board Refer to 11 7 Operation If the main ...

Page 15: ...lectronic control P C board Slide switch SW3 Normal Up Increase airflow volume 9 4 P C BOARD MODIFICATION FOR CHANGING AIRFLOW VOLUME How to change Dip switch SWV1 setting Factory setting is up 1 Make sure that the breaker for air conditioner is turned OFF 2 Remove the electrical cover 1 and 2 of the indoor unit 3 Slide out the electronic control P C board and change the slide switch SWV1 to norma...

Page 16: ...m set temperature The room temperature is approaching the set tem perature About 1 to 2 C from set temperature Standby mode Refer to multi system operation Lit Blinking Not lit Signal transmitting section Battery replacement indicator Operation display section Temperature buttons STOP OPERATE OFF ON button Indication of remote controller model is on back FAN SPEED CONTROL button OPERATION SELECT b...

Page 17: ...tton 3 Press TEMPERATURE buttons TEMP or button to select the desired temperature The setting range is 10 C and 16 31 C 1 Cold air prevention control When the compressor is not operating or is starting and the temperature of indoor heat exchanger and or the room tem perature is low or when defrosting is being done the indoor fan will stop or rotate in Very Low speed 2 Defrosting Defrosting starts ...

Page 18: ...ssor 2 The horizontal vane angle and mode change as follows by pressing VANE CONTROL button NOTE The setting when the lower airflow is preferred in the Airflow direction 1 The angle of airflow direction 1 can be slightly lowered by changing SWV1 to normal when the lower airflow is preferred or the airflow causes the dirt on the ceiling Refer to 9 5 P C BOARD MODIFICATION FOR CHANGING AIRFLOW DIREC...

Page 19: ...ects water level above fixed point during a HEAT operation b emergency HEAT operation c standby when during multi system operation d standby when ON timer is set e operation STOP Drain pump operates in conditions 1 or 2 Operation stop condition Condition other than 1 or 2 indicated above 2 Float sensor Float moves with the up and down of water surface inside the drain pan and judges water level Fi...

Page 20: ...F timer setting a Press OFF TIMER button during operation b Set the time of the timer using TIME SET buttons and Each time FORWARD button is pressed the set time increases by 10 minutes each time BACKWARD but ton is pressed the set time decreases by 10 minutes 2 To release the timer To release ON timer press ON TIMER button To release OFF timer press OFF TIMER button TIMER is cancelled and the dis...

Page 21: ...The simple ON OFF timer setting is available while the weekly timer is on In this case the ON OFF timer has priority over the weekly timer the weekly timer operation will start again after the simple ON OFF timer is complete When the weekly timer is set temperature cannot be set to 10 C The weekly timer operation and i save operation cannot be used together 1 How to set the weekly timer E g ON 6 0...

Page 22: ...cking weekly timer setting 1 Press button to enter the weekly timer setting mode blinks 2 Press or buttons to view the setting of the particular day or number 3 Press button to exit the weekly timer setting 4 Press button to complete and transmit the weekly timer setting which was blink ing goes out and the current time will be displayed 10 10 i save OPERATION 1 How to set i save operation 1 Press...

Page 23: ...works even in the test run or the emergency operation In the test run or emergency operation the horizontal vane operates in VANE AUTO mode Emergency operation continues until EMERGENCY OPERATION switch is pressed once or twice or the unit receives any signal from the remote controller In the latter case normal operation will start NOTE Do not press EMERGENCY OPERATION switch during normal operati...

Page 24: ... the power supply before removing the front panel the cabinet the top panel and the electronic control P C board 3 When removing the electronic control P C board hold the edge of the board with care NOT to apply stress on the components 4 When connecting or disconnecting the connectors hold the connector housing DO NOT pull the lead wires MLZ KP25VF MLZ KP35VF MLZ KP50VF 3 Troubleshooting procedur...

Page 25: ...he set temperature is displayed with the remote controller headed towards the indoor unit Press EMERGENCY OPERATION switch so that the memorized abnormal condition is deleted 4 Release the failure mode recall function according to Releasing the failure mode recall function men tioned above Yes Blinks No OFF NOTE 1 Make sure to release the failure mode recall function after it is set up otherwise t...

Page 26: ...n Press STOP OPERATE OFF ON button of the remote controller the set temperature is displayed with the remote controller headed towards the indoor unit Press EMERGENCY OPERATION switch so that the memorized abnormal condition is deleted Release the failure mode recall function according to Releasing the failure mode recall function Repair the failure parts With the remote controller headed towards ...

Page 27: ...When the serial signal from the out door unit is not received for a maxi mum of 6 minutes Refer to 11 6 How to check miswir ing and serial signal error 5 time flash 2 5 second OFF Not lit Drain pump Float sensor Float sensor is open Float sensor detects abnormal water level Check the float sensor and the drain pump Check the connectors of float sensor and the drain pump Refer to 11 6 Check of floa...

Page 28: ...door unit 7URXEOH RI thermistor in outdoor unit Left lamp 7 time flash Cause Outdoor unit 7URXEOH RI outdoor control system Refer to 11 6 How to check miswiring and serial signal error when outdoor unit does not work Check room temperature thermistor and indoor coil thermis tor Refer to 11 7 Test point diagram and voltage Refer to 11 6 Check of indoor fan motor Refer to How to check the inverter c...

Page 29: ...cuit 5HIHU WR WKH FKDUDFWHULVWLFV RI indoor coil thermistor and the room temperature thermistor on 11 7 Left lamp flashes 3 time flash 2 5 second OFF KHQ WKH URWDWLRQDO IUHTXHQF IHHGEDFN signal is not emitted during the indoor fan operation 5HIHU WR KHFN RI LQGRRU IDQ PRWRU Indoor unit and outdoor unit do not operate Indoor unit and outdoor unit do not operate Left lamp flashes 5 time flash 2 5 se...

Page 30: ... left hand side lamp is lighted 11 5 TROUBLE JUDGEMENT CRITERIA OF MAIN PARTS MLZ KP25VF MLZ KP35VF MLZ KP50VF Part name Figure Check method and criteria Indoor fan motor Measure the resistance with a tester Part temperature 10 C 30 C Normal N a N Room temperature thermistor RT11 Indoor coil thermistor 57 57 57 0 1 RT13 SUB Horizontal vane motor MV1 Measure the resistance between the terminals wit...

Page 31: ...Y OPERATION switch is pressed If more than 12 seconds passes by turn OFF the power supply and turn ON it again then measure the voltage 1 Measure the voltage between CN211 and 2 Measure the voltage between CN211 and Is there 325 V DC between CN211 and Yes Yes Replace the indoor fan motor Replace the indoor electronic control P C board The indoor fan motor error has occurred and the indoor fan repe...

Page 32: ...er on receiving part Replace the receiver P C board Assign a number of remote controller Refer to 9 2 Check if the unit operates with the remote controller Does the unit operate with the remote controller Yes No OK Measure the voltage between the receiver P C board connector CN301 and when the remote controller button is pressed Is the voltage approximately 4 V DC 5 V DC No Yes Replace the indoor ...

Page 33: ... resistance between CN211 and of the indoor fan motor connector Short open circuit Replace the indoor fan motor Short open circuit Replace the horizontal vane motor the vertical vane motor coil and the indoor electronic control P C board Turn OFF the power supply Check both parts side and pattern side of the indoor electronic control P C board visually Replace the varistor NR11 and fuse F11 Are th...

Page 34: ...ower supply Is there 230 V AC between outdoor terminal block S1 and S2 Does the left lamp of OPERATION INDICATOR lamp light up Confirmation of the power supply to the indoor unit Press EMERGENCY OPERATION switch once Check the power supply Is the serial signal error indicated 6 minutes later Turn OFF the power supply Check once again if the indoor outdoor connecting wire is not wrongly connected S...

Page 35: ...No No Is there 230 V AC between CN1N1 and Is there large amount of water in drain pan 1 Refer to 11 5 when float sensor can be checked Yes Replace the indoor electronic control P C board Replace the indoor electronic control P C board Replace the indoor electronic control P C board Check power supply voltage No Replace the float sensor Yes Remove clog from drain hose No Replace the drain pump No N...

Page 36: ...he installation condition combination of specific conditions such as antennas or wiring Check the following before asking for service 1 Devices affected by the electromagnetic noise TV sets radios FM AM broadcast shortwave 2 Channel frequency broadcast station affected by the electromagnetic noise 3 Channel frequency broadcast station unaffected by the electromagnetic noise 4 Layout of indoor outd...

Page 37: ...to 9 3 CN211 Indoor fan motor 325 V DC 3 6 V DC 15 V DC GND High voltage DC 0 or 15 V DC 5 V DC SW301 Emergency operation switch GND Timer short mode point 2 points Refer to 9 1 CN151 Vane motor connector Receiver P C board Factory setting Do not change the setting ON OFF 1 2 3 4 5 6 SW101 CN105 Connector to optional interface Modifica tion point for individual operation Refer to 9 2 Indoor coil t...

Page 38: ...pull out the terminal slowly The terminal which has the locking mechanism can be detached as shown below There are following 2 types of the terminal with locking mechanism The terminal without locking mechanism can be detached by pulling it out Check the shape of the terminal before detaching Detaching method of the terminal with locking mechanism Connector Sleeve Locking lever MLZ KP25VF MLZ KP35...

Page 39: ...it fits closely with the ceiling surface Loosely fasten with the provided fixing screws at 4 places on the left and right side Figure 6 5 Tighten the fixing screws at 2 places in the middle and the fixing screw in the center Figure 6 6 Tighten the fixing screws at 4 places on the left and right sides NOTE Make sure there are no gaps between the indoor unit and the grille or between the grille and ...

Page 40: ...d right sides Check after installing 1 Check that there are no gaps between the indoor unit and the grille or between the grille and the ceiling surface NOTE If there are any gaps the wind may come in and it may cause water to drip 2 Check that the screw cap is installed 3 Check that the left and right side panels are installed securely 4 Check that the emergency operation switch is installed secu...

Page 41: ...nd 5 Disconnect the connectors of the horizontal and vertical vane motors 6 Remove the indoor coil thermistors main and sub 7 Remove the drain cover 3 fixing screws 8 Remove the pipe band 9 Remove the heat exchanger 6 fixing screws 10 Remove the stabilizer 2 fixing screws 5 Removing the horizontal and vertical vane motors 1 Remove the grille 2 Remove the drain pan 3 Remove the horizontal vane 4 Re...

Page 42: ...crews and slide it downward 10 Remove the stabilizer 2 fixing screws 11 Partially slide the indoor electric control P C board out 12 Disconnect the connector CN211 of indoor fan motor 13 Remove the motor band 2 fixing screws Figure 6 14 Remove the indoor fan motor and line flow fan No need to remove the indoor heat exchanger to remove these 2 items 42 Drain pump Drain hose Float sensor Fixing scre...

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Mitsubishi Electric MLZ-KP25VF, Service Manual

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