Mitsubishi MLZ-KA25VA-E1, MLZ-KA35VA-E1, MLZ-KA50VA-E1 Service Manual

CEILING CASSETTE TYPE, HEAT PUMP AIR CONDITIONERS

INDOOR UNIT

SERVICE MANUAL

Ceiling cassette type Models

No. OBH483

MLZ-KA25VA MLZ-KA35VA MLZ-KA50VA -

MLZ-KA25VA MLZ-KA35VA MLZ-KA50VA

Outdoor unit service manual MXZ-A•VA Series (OB377)

CONTENTS

1. PART NAMES AND FUNCTIONS······················2

2. SPECIFICATION·················································3

3. NOISE CRITERIA CURVES·······························4

4. OUTLINES AND DIMENSIONS·························5

5. WIRING DIAGRAM ············································6

6. REFRIGERANT SYSTEM DIAGRAM················7

7. SERVICE FUNCTIONS ······································8

8. MICROPROCESSOR CONTROL ····················10

9. TROUBLESHOOTING······································15

10. DISASSEMBLY INSTRUCTIONS·····················30

PARTS CATALOG (OBB483)

NOTE:

• RoHS compliant products have <G> mark on the spec name plate.

1 2 3 4 5 6 7 8 9

Alkaline battery (AAA) for remote controller Drain hose (with insulation) Special washer (with cushion, 4pcs) Installation template Fixing screw for 4 M5 o 30 Band Fixing screw for 6 4 o 16 Remote controller Remote controller holder Fixing screw for 9

MLZ-KA25VA MLZ-KA35VA

2 1 8 1 4 1 2 1 1 2

MLZ-KA50VA

Vertical vane

Air outlet

Horizontal vane

Air filter (Catechin air filter, option)

Air cleaning filter (Anti-Allergy Enzyme Filter, option)

Safety string

Intake grille

Remote control receiving section

Display and operation section (When the intake grille is opened)

Operation indicator lamp

Emergency operation switch

Air inlet

PART NAMES AND FUNCTIONS

INDOOR UNIT

MLZ-KA25VA MLZ-KA35VA MLZ-KA50VA

ACCESSORIES

T3.15AL 250V

12V 300" 12V 300"

ERZV14D471

230V 6.4W

DC 12V

Item

Model

Fuse Horizontal vane motor Vertical vane motor Varistor DRAIN PUMP FLOAT SENSOR

MLZ-KA25VA

MLZ-KA35VA

MLZ-KA50VA

(F11) (MV1) (MV2)

(NR11)

(DP)

(FS)

Cooling

528/ 480/ 432

35/ 32/ 29

1,120/1,030/950

MLZ-KA35VAMLZ-KA25VA MLZ-KA50VA

Indoor model

Function

Power supply

Single phase

230V,50Hz

0.3 40

—

0.3

RC0J30-KC

1,102O175O360

KM07E

Heating

552/ 492/ 420

36/ 32/ 28

1,160/ 1,060/ 930

Air flow(High/Med./Low) Running current ✽1 Power input ✽1 Auxiliary heater Power factor ✽1 Fan motor current ✽1 Model Dimensions WOHOD Weight Air direction Sound level(High/Med./Low) Fan speed(High/Med./Low)

Fan speed regulator Remote controller model

K /h

A(kW)

dB(A)

rpm

Electrical

data

Capacity

Fan motor

Special

remarks

Cooling

564/ 504/ 438

37/ 34/ 31

1,180/ 1,080/ 960

Single phase

230V,50Hz

0.3 40

—

0.3

RC0J30-KC

1,102O175O360

KM07E

Heating

594/ 528/ 462

38/ 35/ 31

1,230/ 1,120/ 1,000

Cooling

684/ 588/ 498

43/ 38/ 34

1,380/1,220/1,070

Single phase

230V,50Hz

0.3 40

—

0.3

RC0J30-KC

1,102O175O360

KM07E

Heating

708/ 618/ 528

43/ 39/ 34

1,420/ 1,270/ 1,120

SPECIFICATION

NOTE : Test conditions are based on ISO 5151.

Specifications and rating conditions of main electric parts

Cooling : Indoor Dry-bulb temperature 27:Wet-bulb temperature 19: Heating : Indoor Dry-bulb temperature 20: Refrigerant piping length (one way): 5m

✽1 Measured under rated operating frequency.

Outdoor Dry-bulb temperature 35:Wet-bulb temperature 24: Outdoor Dry-bulb temperature 7:Wet-bulb temperature 6:

OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR

BAND CENTER FREQUENCIES, Hz

Test conditions, Cooling : Dry-bulb temperature 27: Wet-bulb temperature 19:

COOLING

FUNCTION

43 43

SPL(dB(A))

LINE

High

FAN SPEED

HEATING

Heating : Dry-bulb temperature 20:

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 27: Wet-bulb temperature 19:

APPROXIMATE THRESHOLD OF HEARING FOR CONTINUOUS NOISE

COOLING

FUNCTION

35 36

SPL(dB(A))

LINE

High

FAN SPEED

HEATING

Heating : Dry-bulb temperature 20:

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 27: Wet-bulb temperature 19:

APPROXIMATE THRESHOLD OF HEARING FOR CONTINUOUS NOISE

COOLING

FUNCTION

37 38

SPL(dB(A))

LINE

High

FAN SPEED

HEATING

Heating : Dry-bulb temperature 20:

63 125 250 500 1000 2000 4000 8000

NC-60

NC-50

NC-40

NC-30

NC-20

NC-70

APPROXIMATE THRESHOLD OF HEARING FOR CONTINUOUS NOISE

INDOOR UNIT

CEILING

GRILLE

MICROPHONE

1.4m

NOISE CRITERIA CURVES

MLZ-KA25VA

MLZ-KA35VA

MLZ-KA50VA

Center of ceiling opening, suspension bolt pitch and grille are located in one position.

Air outlet

(Top)

(Front)

Refrigerant

Pipe

Length of drain hose 540 Drain pipe

NOTE : Drain hose can be used by cutting it.

VP20

Liquid

[6.35

[9.52(MLZ-KA25/35) [12.7(MLZ-KA50)

Gas

Ceiling surface

Drain hose

500mm or less

Hole position for the installation of grille

Decline 1/100

Drain pipe VP20

How to connect drain pipe on indoor unit by lifting drain hose. w Drain hose can be used by cutting it.

Ceiling surface

Suspension bolt M10

Grille

414 Outer side of grille

384 Ceiling opening

308 Suspension bolt pitch

Electrical box

1051 Suspension bolt pitch

Air outlet

(Top)

Wireless remote controller

(Front)

(Right side)

Grille (MLP-440W)

Electrical box

Receiving section

Drain pipe VP20

Display and receiving section

Ceiling surface

Liquid pipe [6.35 (Flared)

Gas pipe MLZ-KA25/35 : [9.52 MLZ-KA50 : [12.7 (Flared)

Drain hose connecting part (drain pipe VP20)

Pipe cover

Drain pan

Outlet opening area

Drain hose connecting part

Pipe cover

308

Suspension bolt pitch

Drain hose

No gaps between the ceiling surface and grille

0.04m

13.549.7

230

2 2

960

360

110

170

244

175

112

116

110

175

180 or more

[58

54.5

1051 Suspension bolt pitch

1160 Ceiling opening

1200 Outer side of grille

Outlet

2020

54.5

(51.6)

180

1102

1200

414

58 18

158

466.5

166.5

172.4

81.8

173

166.5

OUTLINES AND DIMENSIONS

MLZ-KA25VA MLZ-KA35VA MLZ-KA50VA

INDOOR UNIT

Unit : mm

INDOOR UNIT

MLZ-KA25VA MLZ-KA35VA

WIRING DIAGRAM

MLZ-KA50VA

Indoor heat exchanger

Flared connection

Room temperature thermistor RT11

Indoor coil thermistor RT13 (sub)

Flared connection

Refrigerant pipe [9.52 (with heat insulator)

Refrigerant pipe [6.35 (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 [12.7 (with heat insulator)

Refrigerant pipe [6.35 (with heat insulator)

Indoor coil thermistor RT12,RT14, RT15 (main)

REFRIGERANT SYSTEM DIAGRAM

INDOOR UNIT

MLZ-KA25VA MLZ-KA35VA

MLZ-KA50VA

Unit : mm

No. 1 unit No. 2 unit No. 3 unit No. 4 unit

1 unit operation No modification

– – –

2 units operation

Same as at left

Solder J1

– –

3 units operation

Same as at left Same as at left

Solder J2

–

4 units operation

Same as at left Same as at left Same as at left

Solder both J1 and J2

CN211

Fuse (F11)

IC101

T11

VARISTOR (NR11)

Indoor electronic control P.C. Board

CN151

C111

R111

No. 1 unit No. 2 unit No. 3 unit No. 4 unit

JR05

No modification

Cut off JR05

No modification

Cut off JR05

JR06 No modification No modification

Cut off JR06 Cut off JR06

JR06

JR05

SERVICE FUNCTIONS

MLZ-KA25VA MLZ-KA35VA MLZ-KA50VA

7-1. TIMER SHORT MODE

For service, set time can be shortened by short circuit of JPG and JPS on the electronic control P.C. board. The time will be shortened as follows. (Refer to 9-7.) Set time : 1-minute ➔ 1-second Set time : 3-minute ➔ 3-second (It takes 3 minutes for the compressor to start operation. However, the starting time is

7-2. P.C. BOARD MODIFICATION FOR INDIVIDUAL OPERATION

A maximum of 4 indoor units with wireless remote controllers can be used in a room. In this case, to operate each indoor unit individually by each remote controller, both the P.C. boards of remote controller and the electronic control P.C. boards must be modified according to the number of the indoor unit.

How to modify the remote controller P.C. board

Remove batteries before modification. The board has a print as shown below :

shortened by short circuit of JPG and JPS.)

NOTE : For modification, take out the bat-

teries and press the OPERATE/STOP(ON/OFF) button 2 or 3 times at first. After modification, put back the batteries then press the RESET button.

The P.C. board has the print “J1” and “J2”. Solder “J1” and “J2” according to the number of indoor unit as shown in Table 1. After modification, press the RESET button.

Table 1

How to modify the electronic control P.C. board

Turn OFF the power supply before modification. Cut off “JR05” and “JR06” on the electronic control P.C. board according to the number of indoor unit as shown in Table 2. (Refer to 9-7.)

Table 2

NOTE : After modification, turn ON the power supply and with the remote controller headed towards the indoor unit, press the

OPERATE/STOP(ON/OFF) button. If one or two beeps is heard from the indoor unit, modification is completed correctly.

JR07

CN106

CN111

CN112 CN113

C111

T11

CN211

CN151

IC101

F11

R111

NR11

7-3. AUTO RESTART FUNCTION

Change dip switch SW3 setting according to the height of ceiling.

Dip switch SW3 Ceiling height

Normal

2.4 m or below

Increase airflow volume above 2.4 m and 2.7 m or below

How to change Dip switch (SW3) setting (Default setting is Normal)

1. Turn OFF the power supply for the air conditioner.

2. Remove electrical cover A and B.

3. Slide out electronic control P.C. board, and switch up or down Dip switch (SW3).

4. Put electronic control P.C. board back to the original position, and install electrical cover A and B.

NOTE:

To prevent damage of P.C. board due to static electricity, make sure to perform static elimination before setting.

Normal

Increase airflow volume

Dip switch SW3

Electronic control P.C. board

Electrical cover B

Electrical cover A

NOTE: When the ceiling is above 2.7 m, airflow volume may be insufficient even with the Dip switch (SW3) set to "increase airflow.

When the indoor unit is controlled with the remote controller, the operation mode, the set temperature, and the fan speed are memorized by the indoor electronic control P.C. board. The “AUTO RESTART FUNCTION” sets to work the moment power has restored after power failure. Then, the unit will restart automatically.

Operation

If the main power has been cut, the operation settings remain.

1 2 After the power is restored, the unit restarts automatically according to the memory.

(However, it takes at least 3 minutes for the compressor to start running.)

How to release “AUTO RESTART FUNCTION”

1Turn off the main power for the unit. 2Solder the Jumper wire to JR07 on the indoor electronic control P.C. board. (Refer to 9-7.)

NOTE:

• The operation settings are memorized when 10 seconds have passed

after the indoor unit was operated with the remote controller.

• If main power is turned OFF or a power failure occurs while AUTO

START/STOP timer is active, the timer setting is cancelled.

• If the unit has been off with the remote controller before power failure, the

auto restart function does not work as the power button of the remote controller is off.

• To prevent breaker tripping due to the rush of starting current, systematize

other home appliance not to turn on at the same time.

• When some air conditioners are connected to the same supply system, if

they are operated before power failure, the starting current of all the compressors may flow simultaneously 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.

7-4. P.C. BOARD MODIFICATION FOR CHANGING AIRFLOW VOLUME

(This diagram shows an overall view.)

ra verall view.)

Open the front lid.

ON-TIMER button

CLOCK SET button

TIME SET buttons FORWARD button BACKWARD button

OFF-TIMER button

WIDE VANE button

RESET button

VANE CONTROL button

Signal transmitting section

Operation display section

Temperature buttons

OPERATE/STOP (ON/OFF) button

FAN SPEED CONTROL button

OPERATION SELECT button

ECONO COOL button

Indication of remote controller model is on back

MICROPROCESSOR CONTROL

MLZ-KA25VA MLZ-KA35VA MLZ-KA50VA

WIRELESS REMOTE CONTROLLER

Once the operation mode is set, the same operation mode can be repeated by simply turning OPERATE/STOP (ON/OFF) button ON. Indoor unit receives the signal with a beep tone. When the system turns off, 3-minute time delay will operate to protect system from overload and compressor will not restart for 3 minutes.

+ 22 hidden pages

Mitsubishi MLZ-KA25VA-E1, MLZ-KA35VA-E1, MLZ-KA50VA-E1 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual