Mitsubishi Electric Mr. Slim PKA-A24KA4 User manual

SERVICE MANUAL
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
SPLIT-TYPE, AIR CONDITIONERS
Note:
•This manual describes only
service data of the indoor
units.
•RoHS compliant products
have <G> mark on the spec
name plate.
CONTENTS
1. REFERENCE MANUAL................................... 2
2. SAFETY PRECAUTION................................... 3
3. PART NAMES AND FUNCTIONS................... 4
4. SPECIFICATIONS............................................ 7
5. NOISE CRITERION CURVES.......................... 8
6. OUTLINES AND DIMENSIONS....................... 9
7. WIRING DIAGRAM......................................... 10
8. REFRIGERANT SYSTEM DIAGRAM............ 11
9. TROUBLESHOOTING....................................12
10. SPECIAL FUNCTION..................................... 26
11. DISASSEMBLY PROCEDURE....................... 29
PARTS CATALOG (OCB488)
No. OCH488
REVISED EDITION-A
May 2011
ON/OFF
TEMP.
9700058
WIRED REMOTE
CONTROLLER
(Option)
INDOOR UNIT
Indoor unit
[Model names] [Service Ref.]
PKA-A24KA4
PKA-A24KA4.TH
PKA-A30KA4
PKA-A30KA4.TH
PKA-A36KA4
PKA-A36KA4.TH
IR WIRELESS REMOTE
CONTROLLER
(Option)
ON/OFF TEMP
Revision:
•6. OUTLINES AND
DIMENSIONS has been modi-
fied in REVISED EDITION-A.
•Some descriptions have been
modified.
•Please void OCH488.

2
1REFERENCE MANUAL
OUTDOOR UNIT SERVICE MANUAL
Service Ref. Service Manual No.
PUZ-A24/30/36NHA4
PUZ-A24/30/36NHA4-BS
PUY-A24/30/36NHA4
PUY-A24/30/36NHA4-BS
OCH481
OCB481
Radio frequency interface Wired remote controller IR wireless remote controller
ON/OFF
TEMP.
COOL
DRY
AUTO
FAN
HEAT
RF thermostat
Remote controller (Optional parts)

3
SAFETY PRECAUTION
2
Cautions for units utilising refrigerant R410A
2-2. CAUTIONS RELATED TO NEW REFRIGERANT
Use new refrigerant pipes.
Store the piping to be used indoors during
installation, and keep both ends of the piping
sealed until just before brazing. (Leave elbow
joints, etc. in their packaging.)
Charge refrigerant from liquid phase of gas
cylinder.
If the refrigerant is charged from gas phase, composition
change may occur in refrigerant and the efficiency will be
lowered.
Use a vacuum pump with a reverse flow check
valve.
Vacuum pump oil may flow back into refrigerant cycle and
that can cause deterioration of refrigerant oil etc.
Use the following tools specifically designed for
use with R410A refrigerant.
The following tools are necessary to use R410A refrigerant.
Handle tools with care.
If dirt, dust or moisture enters into refrigerant cycle, that can
cause deterioration of refrigerant oil or malfunction of com-
pressor.
Do not use a charging cylinder.
If a charging cylinder is used, the composition of refrigera-
nt will change and the efficiency will be lowered.
Flare tool
Electronic refrigerant
charging scale
Vacuum pump adaptor
Size adjustment gauge
Gauge manifold
Torque wrench
Gas leak detector
Charge hose
Tools for R410A
Contamination inside refrigerant piping can cause deterio-
ration of refrigerant oil etc.
If dirt, dust or moisture enters into refrigerant cycle, that can
cause deterioration of refrigerant oil or malfunction of com-
pressor.
If large amount of mineral oil enters, that can cause deterio-
ration of refrigerant oil etc.
The refrigerant oil applied to flare and flange
connections must be ester oil, ether oil or
alkylbenzene oil in a small amount.
Make sure that the inside and outside of refrige-
rant piping is clean and it has no contaminants
such as sulfur, oxides, dirt, shaving particles, etc,
which are hazards to refrigerant cycle.
In addition, use pipes with specified thickness.
Do not use refrigerant other than R410A.
If other refrigerant (R22 etc.) is used, chlorine in refrige-
rant can cause deterioration of refrigerant oil etc.
Ventilate the room if refrigerant leaks during
operation. If refrigerant comes into contact with
a flame, poisonous gases will be released.
Use the specified refrigerant only.
Never use any refrigerant other than that specified.
Doing so may cause a burst, an explosion, or fire when the
unit is being used, serviced, or disposed of.
Correct refrigerant is specified in the manuals and on the
spec labels provided with our products.
We will not be held responsible for mechanical failure,
system malfunction, unit breakdown or accidents caused
by failure to follow the instructions.
2-1. ALWAYS OBSERVE FOR SAFETY
Before obtaining access to terminal, all supply
circuits must be disconnected.

4
Gravimeter
Unit
[3] Service tools
Use the below service tools as exclusive tools for R410A refrigerant.
3PART NAMES AND FUNCTIONS
Indoor unit
Emergency operation
switch
Front grille
Air inlet
Filter
Air outlet
Louver
Vane
No. Tool name Specifications
1Gauge manifold · Only for R410A
· Use the existing fitting specifications. (UNF1/2)
· Use high-tension side pressure of 5.3MPa·G or over.
2Charge hose · Only for R410A
· Use pressure performance of 5.09MPa·G or over.
3Electronic scale —
4Gas leak detector · Use the detector for R134a, R407C or R410A.
5Adaptor for reverse flow check · Attach on vacuum pump.
6Refrigerant charge base —
7Refrigerant cylinder · Only for R410A · Top of cylinder (Pink)
· Cylinder with syphon
8Refrigerant recovery equipment —
[1] Cautions for service
(1) Perform service after recovering the refrigerant left in unit completely.
(2) Do not release refrigerant in the air.
(3) After completing service, charge the cycle with specified amount of refrigerant.
(4) When performing service, install a filter drier simultaneously.
Be sure to use a filter drier for new refrigerant.
[2] Additional refrigerant charge
When charging directly from cylinder
· Check that cylinder for R410A on the market is syphon type.
· Charging should be performed with the cylinder of syphon stood vertically. (Refrigerant is charged from liquid phase.)

5
Wired remote controller (Option)
°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
PAR-21MAA
ON/OFF
FILTER
CHECK
OPERATION
CLEAR
TEST
TEMP.
MENU
BACK DAY
MONITOR/SET
CLOCK
ON/OFF
•
•
Display Section
For purposes of this explanation,
all parts of the display are shown.
During actual operation, only
the relevant items will be lit.
Identifies the current operation
Shows the operating mode, etc.
*Multilanguage display is available.
“Centrally Controlled” indicator
Indicates that operation from the
remote controller has been prohib-
ited 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, the time to be
switched off is shown.
“Sensor” indication
Displays when the remote controller
sensor is used.
“Locked” indicator
Indicates that remote controller but-
tons have been locked.
“Clean The Filter” indicator
To be displayed on when it is time to
clean the filter.
Timer indicators
The indicator comes on if the corre-
sponding timer is set.
Up/Down Air Direction indica-
tor
The indicator shows the direc-
tion of the outcoming airflow.
“One Hour Only” indicator
Room Temperature display
Shows the room temperature. The room
temperature display range is 46–102˚F.
The display blinks if the temperature
is less than 46˚F or 102˚F or more.
Louver display
Indicates the action of the swing louver.
Does not appear if the louver is not
running.
(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.
Operation Section
Temperature setting 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
cover
ON/OFF button
Fan Speed button
Filter button
(<Enter> button)
Test Run button
Check button (Clear button)
Airflow Up/Down button
Louver button
( Operation button)
To return operation
number
Ventilation button
( Operation button)
To go to next operation
number
Note:
“PLEASE WAIT” message
This message is displayed for approximately 3 minutes when power is supplied to the indoor unit or when the unit is recovering from a power failure.
“NOT AVAILABLE” message
This message is displayed if an invalid button is pressed (to operate a function that the indoor unit does not have).
If a single remote controller is used to operate multiple indoor units simultaneously that are different types, this message will not be displayed as
far as any of the indoor units is equipped with the function.
Built-in temperature sensor
Displays if the airflow is set to
low or downward during COOL
or DRY mode. (Operation varies
according to model.)
The indicator goes off in 1 hour,
when the airflow direction
also changes.

6
IR wireless remote controller (Option)
ON/OFF TEMP
FAN
VANE
TEST RUN
AUTO STOP
AUTO START
h
min
LOUVER
MODE
CHECK
RESETSET CLOCK
MODEL
SELECT
NOT AVAILABLE
SWING
CHECK
FAN
TEST
RUN
°F
°C
AMPMSTOP
START
AMPM
COOL
DRY
AUTO
FAN
HEAT
VANE CONTROL button
Changes the air flow direction.
CLOCK button
RESET button
SET button
ON/OFF button
The unit is turned ON and OFF alternately
each time the button is pressed.
LOUVER button
Changes left / right airflow direction.
(Not available for this model.)
MODE SELECT button
Switches the operation mode between
COOLING/DRY/FAN/HEATING and AUTO
mode.
+In case the outdoor unit is cooling only
type, the heating and auto mode are not
available.
CHECK-TEST RUN button
Performs an inspection check or test
operation. Do not use it for normal operation.
FAN SPEED SELECT button
Changes the fan speed.
TIMER display
Displays when in timer operation or when
setting timer.
button
Sets any desired room temperature.
CLOCK display
Displays the current time.
“” “ ” display
Displays the order of timer operation.
“ ” “ ” display
Displays whether timer is on or off.
Buttons used to set the “hour and minute” of
the current time and timer settings.
"h" and "min" buttons
Temperature setting display
Indicates the desired temperature setting
which is set.
display
Displays selected fan speed.
display
The vertical direction of airflow is indicated.
display
Blinks when model is selected.
display
Lights up while the signal is transmitted to
the indoor unit when the button is pressed.
display
Indicate that the unit is being checked or
test-run.
OPERATION MODE display
Indicates which operation mode is in effect.
TIMER CONTROL buttons
AUTO STOP (OFF timer): when this switch
is set, the air conditioner will be
automatically stopped at the preset time.
AUTO START (ON timer): when this switch
is set, the air conditioner will be automatically
started at the preset time.
MODEL SELECT
CHECK TEST RUN

7
SPECIFICATIONS
4
A
A
kW
F.L.A
m3/min(CFM)
Pa(mmAq)
dB
mm(in.)
mm(in.)
mm(in.)
mm(in.)
kg(lbs)
Service Ref.
Power supply(phase, cycle, voltage)
Max. Fuse Size
Min.Circuit Ampacity
External finish
Heat exchanger
Fan Fan(drive) %No.
Fan motor output
Fan motor
Airflow(Low-Middle-High)
External static pressure
Operation control & Thermostat
Noise level(Low-Middle-High)
Field drain pipe I.D.
Dimensions
Weight
W
D
H
INDOOR UNIT
PKA-A24KA4.TH
1 phase, 60Hz, 208/230V
15
1
White Munsell 1.0Y 9.2/0.2
Plate fin coil
Line flow fan (direct) × 1
0.056
0.36
Dry: 18-20-22 (635-705-775)
Wet: 16-18-20 (570-635-700)
0(direct blow)
Remote controller & built-in
39-42-45
16(5/8)
1170 (46-1/16)
295 (11-5/8)
365 (14-3/8)
21 (46)
1 phase, 60Hz, 208/230V
15
1
Plate fin coil
0(direct blow)
Remote controller & built-in
A
A
kW
F.L.A
*/min(CFM)
Pa(mmAq)
dB
mm(in.)
mm(in.)
mm(in.)
mm(in.)
kg(lbs)
Service Ref.
Power supply(phase, cycle, voltage)
Max. Fuse Size
Min.Circuit Ampacity
External finish
Heat exchanger
Fan Fan(drive) %No.
Fan motor output
Fan motor
Airflow(Low-Middle-High)
External static pressure
Operation control & Thermostat
Noise level(Low-Middle-High)
Field drain pipe I.D.
Dimensions
Weight
W
D
H
INDOOR UNIT
PKA-A30KA4.TH
White Munsell 1.0Y 9.2/0.2
0.056
0.36
16(5/8)
Line flow fan (direct) × 1
Dry: 18-20-22 (635-705-775)
Wet: 16-18-20 (570-635-700)
39-42-45
1170 (46-1/16)
295 (11-5/8)
365 (14-3/8)
21 (46)
A
A
kW
F.L.A
m3/min(CFM)
Pa(mmAq)
dB
mm(in.)
mm(in.)
mm(in.)
mm(in.)
kg(lbs)
Service Ref.
Power supply(phase, cycle, voltage)
Max. Fuse Size
Min.Circuit Ampacity
External finish
Heat exchanger
Fan Fan(drive) %No.
Fan motor output
Fan motor
Airflow(Low-Middle-High)
External static pressure
Operation control & Thermostat
Noise level(Low-Middle-High)
Field drain pipe I.D.
Dimensions
Weight
W
D
H
INDOOR UNIT
PKA-A36KA4.TH
1 phase, 60Hz, 208/230V
15
1
White Munsell 1.0Y 9.2/0.2
Plate fin coil
Line flow fan (direct) × 1
0.056
0.57
Dry: 20-23-26 (705-810-920)
Wet: 18-21-23 (635-730-830)
0(direct blow)
Remote controller & built-in
43-46-49
16(5/8)
1170 (46-1/16)
295 (11-5/8)
365 (14-3/8)
21 (46)

8
5NOISE CRITERION CURVES
UNIT
WALL
3.3ft
3.3ft
MICROPHONE
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 (0dB= 0.0002 μ
bar
)
BAND CENTER FREQUENCIES, Hz
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
High
NOTCH
Low
49
SPL(dB)
43
LINE
90
80
70
60
50
40
30
20
10
63 125 250 500 1000 2000 4000 8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCTAVE BAND SOUND PRESSURE LEVEL, dB(0dB=0.0002 μbar)
BAND CENTER FREQUENCIES, Hz
PKA-A24KA
PKA-A30KA
PKA-A24KAL
PKA-A30KAL
High
Low
45
SPL(dB)
39
LINE
NOTCH PKA-A36KA4.THPKA-A24KA4.TH
PKA-A30KA4.TH

9
OUTLINES AND DIMENSIONS
6
Front side
46-1/16(1170)
9-1/2(241)
33-21/32(855)2-29/32(74)
14-3/8(365)
Emergency operation switch
(cooling/heating)
Terminal block for Outdoor unit
Terminal block for
MA-remote controller
Front side(Grille open)
Terminal block for power supply (option)
Filter hook
6-1/16(154)
4-27/32(123)
18-31/32(482)Liquid pipe
17-15/32(444)Gas pipe
23-1/32(585)Drain hose 5-9/32(134)
Min.9/32(7)
Center measurement hole
:3/32(:2.5)
Knockout hole for
rear piping
2-15/16×18-29/32(75×480)
75- : 3/16( : 5.1)
Tapping
screw hole
Mount board
Wall hole for
right rear piping
Indoor unit outline
4- : 11/32( : 9) Bolt hole
Wall hole for
left rear piping
1/8(3)
R1-15/32(R37.5)
2-1/8(54)
0
5/8(15.5)
0
17-9/32(439) 0
17-9/32(439)
15-1/8(384)
13/32(10) 20-3/8(517.4) 17-7/8(454) 16-3/32(408.5) 15-1/8(384) 14-11/32(364) 12-3/8(314) 4-11/32(110) 2-3/8(60) 13/32(10) 18-5/16(465.5) 17-7/8(454)
16-3/32(408.5)
15-1/8(384.5) 14-11/32(364) 12-3/8(314) 4-11/32(110) 2-3/8(60)
1-1/4(32)
12-5/32(308.5)
31/32(25)
11-1/2(292)
11(279.5)
9-17/32(242)
7-9/16(192)
5-19/32(142)
4-29/32(125)
4-19/32(117)
3-15/16(100)
2-15/16(75)
1-31/32(50)
15-1/8(384)
0
13-3/4(349.2)
16-15/16(430.5)
1/2(12.5)
11-1/2(292)
10-13/32(264)
9-1/32(229.5)
8-17/32(217)
6-9/16(167)
5-3/32(129.5)
4-1/8(104.5)
3-7/16(87.5)
2-15/32(62.5)
1-15/32(37.5)
1/2(12.5)
2-1/8(54)
31/32(25)
0
12-1/4(311)
8-17/32(216.5)
13-11/32(339)
20-7/8(530.5)
7-7/16(189)
13-11/32(339)
17-11/16(449.2)
23-1/32(585)
23-1/32(585)
A
5/16(7.8)
3-1/32(77)
2-5/8(67)
2-9/16(65)
B
Knockout hole for piping
13/32(10.7)
2-9/16(65)
3-1/32(77)
3-7/16(87)
C
5/16(7.8)
2-9/16(65)
3-1/32(77)
2-5/8(67)
Louver(manual)
Vane(auto)
Knockout hole
for lower piping
Under side
BB
Receiver
DEFROST/STAND BY lamp
Operation lamp
2-19/32(66)
23/32(18)
1-1/4(32)
2-3/32(53)
1-3/16(30)
1-3/8(35)
Mount board
C
Knockout hole
for right piping
Right side
11-5/8(295) 3/16(5)
Left side
A
Knockout hole
for left piping
Top side
2-9/16(65.2)
5-17/32(140.3)
7/16(11)
17(431.7)
16-11/16(423.7)
Air outlet
Air inlet
Min.1-7/8(48)
Min.9-27/32(250)
Required space(Indoor unit)
Min.3-31/32(100.5)
Min.8-21/32(220)
Min.2-1/16(52.3)



Refrigerant pipe: 3/8 O.D(:9.52)
Refrigerant pipe: 5/8 O.D(:15.88)
5/8(:16) O.D
Drain hose
Piping connection
Liquid pipe
Gas pipe
Through hole
:2-15/16
(:75) :2-15/16~:3-5/32
(:75~:80)
Sleeve
(purchased locally) Flared connection: 5/8F
Flared connection: 3/8F
PKA-A24KA4.TH PKA-A30KA4.TH PKA-A36KA4.TH
Unit: inch (mm)

10
WIRING DIAGRAM
7
PKA-A24KA4.TH PKA-A30KA4.TH PKA-A36KA4.TH
Symbol Name Symbol Name
I.B Indoor controller board
FUSE FUSE (T3.15AL250V)
CN2L Connector (LOSSNAY)
CN30 Connector (LLC)
CN105 Connector (Radio frequency interface)
CN152 Connector (Back-up heating)
CN90 Connector (Remote operation adapter)
Connector (Emergency operation)
CN32 Connector ( Remote switch)
CN41 Connector (HA terminal-A)
CN51 Connector (Centrally control)
LED1 Power supply (I.B)
LED2 Power supply (R.B)
LED3 Transmission (Indoor-outdoor)
SW1 Switch (Model selection) +See table 1
SW2
SWE
Switch (Capacity code) +See table 2
[Explanation of symbols]
MS Fan motor
W.B Pcb for IR wireless remote controller
Switch board
SWE2 Emergency operation
M Vane motor
LED1 LED (Operation indication : Green)
REC1 Receiving unit
LED2 LED (Preparation for heating: Orange)
TB2 Terminal block(Indoor unit Power (option))
TB4 Terminal block (Indoor/outdoor connecting line)
TB5 Terminal block (Remote controller transmission line)
RFI Radio frequency interface for RF thermostat
TH1 Room temp. Thermistor
Pipe temp. Thermistor/liquid
Cond./eva. temp. Thermistor
(32°F/15kΩ, 77°F/5.4kΩDetect)
(32°F/15kΩ, 77°F/5.4kΩDetect)
(32°F/15kΩ, 77°F/5.4kΩDetect)
TH2
TH5
S.W
Notes:
1. SymboIs used in wiring diagram above are, : Connector, : Terminal (block).
2. Indoor and outdoor connecting wires have poIarities, make sure to match terminal
numbers (S1, S2, S3) for correct wirings.
3. Since the outdoor side electric wiring may change, be sure to check the outdoor unit
electric wiring diagram for servicing.
4. This diagram shows the wiring of indoor and outdoor connecting wires.(specification of 230V),
adopting superimposed system of power and signal.
+ 1: Use copper supply wires.
R.B Wired remote controller board
TB6 Terminal block (Remote controller transmission line)
Refer to
tables
1and 2
CN90
(WHT)
CN2L
(RED)
CN151
(WHT)
CN20
(RED)
CN44
(WHT)
CN4F
(WHT)
CN22
(BLU)
CN301
(GRN)
CN41
(WHT)
CN51
(WHT)
CN32
(WHT)
CNMF
(WHT)
S.W
W.B
SWE
R.B
CNP (BLU)
CN3C
(BLU)
CNRU
(WHT)
LDSWE (A)
(BLU)
LDSWE(B)
REC1
LED1
LED2
SWE2
CN01
(BLK)
DB1
X1
FUSE
I.B
1
1
11 1 5 1
6
1
6
4
11
1
2
141425
TH1 TH2 TH5
2
1139
CN152
(WHT)
CN30
(BLK)
11310
3
3
3
2
2
1
2
1
1
1
5
6
Mt° t° t°
MS
3~
TB4
TB5
S1
S2
S3
RU
ORN
ORN ORN
BRN
LED1
LED3
LED2
TB6
ON
OFF
TO
OUTDOOR
UNIT
YLW YLW
BLK
<Table 1>
SW1
(MODEL SELECTION)
SETTING SETTING
ON
OFF
12345
<Table 2>
SW2 (CAPACITY CODE)
MODELS
PKA-A24KA4
ON
OFF
12345
SETTING
MODELS
ON
OFF
12345
PKA-A30KA4
SETTING
MODELS
ON
OFF
12345
PKA-A36KA4
OPTION PART
The black square ( ■) indicates a switch position.
CN105
( RED )
RFI
5
2
<+1>