Mitsubishi SEZ-KC25VA.W Service Manual

TECHNICAL & SERVICE MANUAL

CONTENTS

1. PART NAMES AND FUNCTIONS········2

2. SPECIFICATIONS·································4

3. OUTLINES AND DIMENSIONS············6

4.WIRING DIAGRAM ·······························7

5.

REFRIGERANT SYSTEM DIAGRAM

·········8

6.TROUBLESHOOTING···························9

7. DISASSEMBLY PROCEDURE···········13

8. PARTS LIST········································18

9. OPTIONAL PARTS·····························21

INDOOR UNIT

Indoor unit
[Model names] [Service Ref.]

SEZ-KC25VA SEZ-KC25VA.W

SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS

WIRED REMOTE

CONTROLLER

ON/OFF

TEMP.

Ceiling Concealed

Series SEZ

R410A

Model name
indication

Note :

•This manual does not cover
outdoor units.When ser vicing
outdoor units, please refer
to the service manual
No.OC322 together with this
manual.

2

1

PART NAMES AND FUNCTIONS

Indoor Unit
SEZ-KC25VA.W

Air outlet duct flange

Air outlet

Air inlet

● Operation buttons

PAR-21MAA

ON/OFF

FILTER

CHECK

OPERATION

CLEAR

TEST

TEMP.

MENU

BACK DAY

MONITOR/SET

CLOCK

ON/OFF

Set Temperature buttons

Down

Up

Timer Menu button
(Monitor/Set button)

Mode button (Return button)

Set Time buttons

Back

Ahead

Timer On/Off button
(Set Day button)

Opening the
door.

Start/Stop button

Fan Speed button

Filter button
(<return sign> button)

Test Run button

Service button (Clear button)

Airflow Up/Down button

Louver button
(

Operation button)

To preceding operation
number.

Ventilation button
(

Operation button)

To next operation number.

On the controls are set, the same operation mode can be repeated by simply pressing the ON/OFF button.

Wired remote controller

3

● Display

For purposes of this explanation,
all parts of the display are shown
as lit. During actual operation, only
the relevant items will be lit.

˚F˚C

˚F˚C

ERROR CODE

AFTER

TIMER

TIME SUN MON TUE WED THU FRI SAT

ON
OFF

Hr
AFTER

FILTER

FUNCTION

ONLY1Hr.

WEEKLY

SIMPLE

AUTO OFF

Identifies the current operation

Shows the operating mode, etc.
* Multilanguage display is sup-

ported.

“Centrally Controlled” indicator

Indicates that operation of the re­mote controller has been prohib­ited by a master controller.

“Timer Is Off” indicator

Indicates that the timer is off.

Temperature Setting

Shows the target temperature.

Day-of-Week

Shows the current day of the week.

Time/Timer Display

Shows the current time, unless the simple or Auto Off
timer is set.
If the simple or Auto Off timer is set, shows the time
remaining.

“Sensor” indication

Displayed when the remote controller
sensor is used.

“Locked” indicator

Indicates that remote controller but­tons have been locked.

“Clean The Filter” indicator

Comes on when it is time to clean the
filter.

Timer indicators

The indicator comes on if the corre­sponding timer is set.

Up/Down Air Direction indica­tor

The indicator shows the direc­tion of the outcoming airflow.

“One Hour Only” indicator

Displayed if the airflow is set to
weak and downward during COOL
or DRY mode. (Operation varies
according to model.)
The indicator goes off after one
hour, at which time the airflow di­rection also changes.

Room Temperature display

Shows the room temperature.

Louver display

Indicates the action of the swing
louver. Does not appear if the
louver is stationary.

(Power On indicator)

Indicates that the power is on.

Fan Speed indicator

Shows the selected fan speed.

Ventilation indicator

Appears when the unit is running in
Ventilation mode.

Caution

● Only the Power display lights when the unit is stopped and power supplied to the unit.

● When power is turned ON for the first time the (Centrally controlled) display appears to go off momentarily but this is not a

malfunction.

● “NOT AVAILABLE” is displayed when the Air speed button are pressed.This indicates that this room unit is not equipped with
the fan direction adjustment function and the louver function.

● When power is turned ON for the first time, it is normal that “PLEASE WAIT” is displayed on the room temperature indication
(For max. 2minutes). Please wait until this “PLEASE W AIT”indication disappear then start the operation.

4

2

SPECIFICATIONS

SEZ-KC25VA.W

Indoor model

Function

Power supply

Single phase

230V , 50Hz

474/288

10

0.45
60
—
97

0.28

CRC4417BB

WHT-BLK : 261 BLK-BLU : 475

YLW-BRN : 294

790✕225✕550

19

1

36/25

2
10
10
10

Cooling

Heating

Air flow (High/Low)
Power outlet
Running current ✽1
Power input Rated frequency
Auxiliary heater
Power factor ✽1
Fan motor current ✽1
Model

Winding
resistance (at20:)

Dimensions W✕H✕D
Weight
Air direction
Sound level (High/Low)
Fan speed regulator
Thermistor RT11 (at 25:)
Thermistor RT12 (at 25:)
Thermistor RT13 (at 25:)

K /h

A
A

W

A(kW)

%

A

Ω

mm

kg

dB(A)

kΩ
kΩ
kΩ

Electrical

data

Fan

motor

Special remarks

Capacity

NOTE :Test conditions are based on ISO 5151

Cooling : Indoor D.B. 27

: W.B. 19:

Outdoor D.B. 35: W.B. 24:

Heating : Indoor D.B. 20: W.B. 5:

Outdoor D.B. 7: W.B. 6:
Refrigerant piping length (one way): 5m
✽1 Measured under rated operating frequency.

1.5+ 440V
250V 6.3A

ERZV10D471

TO OUTDOOR UNIT : 3P TO WIRED REMOTE CONTROLLER : 2P

135:i5:

INDOOR UNIT

Item

Model

Indoor fan capacitor
Fuse
Varistor
Terminal block
Indoor fan motor thermal fuse

SEZ-KC25VA.W

(C)

(FUSE)

(ZNR)

(TB)

Specifications and rating conditions of main electric parts

5

NOISE CRITERION CURVES

2m

Aux.duct

1m

1.5m

Measurement location

NOTE:The sound level is measured in an anechoic room where echoes are few, when compressor stops. The sound

may be bigger than displayed level under actual installation condition by surrounding echoes.The sound level
can be higher by about 2 dB than the displayed level during cooling and heating operation.

SEZ-KC25VA.W

NOTCH

Hi
Lo

<50Hz>

SPL(dB)

36
25

70

60

50

40

30

20

10

OCTAVE BAND PRESSURE LEVEL (dB) 0dB = 20µPa

Appro
Approximate minimum

audible limit on continuous noise

0

63 125 250 500 1000 2000 4000 8000

OCTAVE BAND CENTER FREQUENCIES (Hz)

High speed
Low speed

NC60

NC50

NC40

NC30

NC20

Make the access door at the appointed position properly

for service maintenance.

Ceiling surfaceAccess door

Required space for service and maintenance

Lifting plate

(4-14x30)

Air filter

80

Control box

T erminal bed

(Power source)

Bottom plate

23 664(Lifting bolt pitch)

710

The part air intake duct is attached.(✻3)

(When the air intake duct is used)

610

50

150

790

582

204.5

42.5

30

225(✻2)

15

148

13.55050

510

14127

56.5

(52)

(57)

129

55301 301

189

Detailed chart around the air intake duct frange(✻3)

(Duct and frange should be supplied in the field)

550(✻1)

More than 20mm

More than 20mm

6- ø 3hole

55

50X11=550

16

2X12- ø 3hole

14

459(Lifting bolt pitch)

15

113

Air outlet

Air inlet

450

50~150

300

450

2X3- ø 3hole

25

500

50~150

1

2

3

Note 1. Use M10 screw for the lifting bolt (field supply).

2. Keep the service space for the maintenance from the bottom

when the heat exchanger is cleaned.

3. The direction of air intake can be changed from the bottom to

the rear by attaching the bottom plate to the air intake side.

4. Drain Pan is changeable from right and left.

5. The dimension is changed, in case the optional long-life filter

is attached.

Rear Air-Intake spec. :Depth is increased by 30mm(✻1)

Bottom Air-Intake spec. :Height is increased by 30mm(✻2)

Refrigerant piping flare connection

(gas ø 9.52 copper tube):LP ········1

Refrigerant piping flare connection

(liquid ø 6.35 copper tube):HP ········2

Drain piping connection R1 (External thread) ········3

6

OUTLINES AND DIMENSIONS

3

SEZ-KC25VA.W

7

4

WIRING DIAGRAM

SEZ-KC25VA.W

12

213

131313

1

2

312 4567

1234675

2121

2121

6457321

6457321

TO OUTDOOR UNIT

TH2

TRANS

AC220-240V

CNSK(RED)

DC13.1V

CN2S(WHT)

P.B.

BLU

(CONTROL)

CN3C

ORN

(POWER)

CND

RED

(POWER BOARD)

CNDK

S1S2S3

I.B.

TB4

FUSE

ZNR

X6 X5 X4

WHT

(POWER

BOARD)

CN2D

WHT

(FAN)

FAN

LED1

LED2

LED3

CN32

CN2L

CN51 CN41

CN90

BLK

(2 PHASE)

CN29

RED

(INTAKE)

CN20

WHT

(LIQUID)

CN21

BLU

(REMOCON)

CN22

X6 X5 X4

TH1TH5

1

2

SW2

12345

ON

OFF

5432

OFF

ON

1

SW3

OFF

ON

1

SWE

TB15

TO MA-REMOTE

CONTROLLER

DC8.7-13V

LED1

FUSE

CN90

ZNR

X6

X5

X4

VARISTOR

RELAY (FAN MOTOR HI)

RELAY (FAN MOTOR Lo)

SWE

SW3

RELAY (FAN MOTOR LL)

SWITCH (EMERGENCY OPERATION)

SWITCH (MODE SELECTION)

SW2

LED3

LED2

SWITCH (CAPACITY CODE)

TRANSMISSION (INDOOR-OUTDOOR)

POWER SUPPLY (I.B.)

POWER SUPPLY (I.B.)

FUSE (6.3A)

CN51

CN41

CN32

CN2L

CONNECTOR (WIRELESS)

CENTRALLY CONTROL

CONNECTOR (HA TERMINAL-A)

CONNECTOR (REMOTE SWITCH)

CONNECTOR (LOSSNAY)

I.B.

P.B.

SYMBOL

INDOOR CONTROLLER BOARD

NAME

INDOOR POWER BOARD

SYMBOL

C

MF FAN MOTOR

CAPACITOR (FAN MOTOR)

NAME

TB4

TERMINAL BLOCK (INDOOR/OUTDOOR CONNECTING LINE)

TB15

TERMINAL BLOCK (REMOTE CONTROLLER

TRANSMISSION LINE)

TH1

INT AKE AIR TEMP. THERMIST OR

(0˚C/15kΩ. 25˚C/5.2kΩ DETECT)

TH2

PIPE TEMP. THERMIST OR/LIQUID

(0

˚C/15kΩ. 25˚C/5.2kΩ DETECT)

TH5

COND./EVA. TEMP. THERMISTOR

(0

˚C/15kΩ. 25˚C/5.2kΩ DETECT)

C

MF

INSERT

BLU

The motor connector is

connected with 230V,240V

power at factory shipment.

If 220V power is used,

Insert the attachment.

Color/Power source

WHT/230,240V

BLU/220V

NOTES:1.Since the outdoor side electric wiring may change be sure to

check the outdoor unit electric wiring for servicing.

2.Indoor and outdoor connecting wires are made with polarities, make

wiring matching terminal numbers (S1,S2,S3).

3.Symbols used in wiring diagram above are,

: Connector, : Terminal.

4.The wiring between MA-REMOTE CONTROLLER and TB15 is

included in the package.