Mitsubishi SUZ-KA18NA2 User manual

SERVICE MANUAL R410A
Outdoor unit
[Model Name]
SUZ-KA18NA2
SUZ-KA18NAH2
SUZ-KA24NA
SUZ-KA24NAH2
SUZ-KA30NA
SUZ-KA30NAH2
SUZ-KA36NA
SUZ-KA36NAH2
[Service Ref.]
SUZ-KA18NA(H)2.TH
SUZ-KA24NA(H)2.TH
SUZ-KA30NA(H)2.TH
SUZ-KA36NA(H)2.TH
PARTS CATALOG (OCB688)
CONTENTS
1. COMBINATION OF INDOOR AND OUTDOOR UNITS
...
2
2. PART NAMES AND FUNCTIONS......................2
3. SPECIFICATION.................................................3
4. OUTLINES AND DIMENSIONS.......................... 4
5. WIRING DIAGRAM............................................ 5
6. REFRIGERANT SYSTEM DIAGRAM................ 9
7. DATA..................................................................11
8. ACTUATOR CONTROL.....................................14
9. SERVICE FUNCTIONS......................................15
10. TROUBLESHOOTING.......................................15
11. FUNCTION SETTING........................................ 32
12. DISASSEMBLY INSTRUCTIONS......................35
Note:
•This manual describes service
data of the outdoor units only.
No. OCH688
REVISED EDITION-A
May 2019
SPLIT-TYPE, AIR CONDITIONERS
SUZ-KA18NA(H)2.TH
Revision:
•Some descriptions
have been modified in
REVISED EDITION-A.
OCH688 is void.

2
OCH688A
1COMBINATION OF INDOOR AND OUTDOOR UNITS
OUTDOOR UNIT
Piping
Air outlet
Drain outlet
Air inlet
(back and side)
Drain hose
PART NAMES AND FUNCTIONS
2
SUZ-KA18NA(H)2.TH SUZ-KA24NA(H)2.TH SUZ-KA30NA(H)2.TH SUZ-KA36NA(H)2.TH
Heat pump type
Outdoor unit
SUZ-
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Indoor unit
Service
Manual No.
Service Ref.
Heat pump without
electric heater
OCH669
OCB669
KA18NA(H)2.TH
—
—
—
—
—
—
—
—
—
—
—
—
—
PEAD-A18AA7.MX
PEAD-A24AA7.MX
PEAD-A30AA7.MX
PEAD-A36AA7.MX
SVZ-KP18NA.MX
SVZ-KP24NA.MX
SVZ-KP30NA.MX
SVZ-KP36NA.MX
MLZ-KP18NA
MD-1404-K019
MD-1404-K018
KA24NA(H)2.TH KA30NA(H)2.TH KA36NA(H)2.TH
HWE08020
BWE10180
OBH802
OBB802
HWE16080
BWE016290
—
—
—
—
—
—
SEZ-KD18NA4.TH
SLZ-KF18NA.TH

3
OCH688A
Outdoor unit model SUZ-KA18
NA(H)2 SUZ-KA24 NA(H)2 SUZ-KA30 NA(H)2 SUZ-KA36 NA(H)2
Power supply V , phase , Hz 208/230 , 1 , 60
Max. fuse size (time delay) A 15 20
Min. circuit ampacity A 14 17
Fan motor F.L.A 0.67 1.00
Compressor
Model SNB130FQBMT SNB220FQGM1T
R.L.A 10.0 13.0
L.R.A 12.5 16.0
Refrigeration oil oz. (Model) 11.8(FV50S) 15.6(FV50S)
Refrigerant control Linear expansion valve
Sound level*1Cooling dB(A) 54 55
Heating dB(A) 55
Defrost method Reverse cycle
Dimensions Win 34-5/8 D in 33-1/16
Hin 13
Weight Ib 127 129
([WHUQDO¿QLVK Munsell 3Y 7.8/1.1
Control voltage
(by built-in transformer) VDC 12 - 24
Refrigerant piping Not supplied
Refrigerant pipe size
(Min. wall thickness) Liquid in 1/4 (0.0265) 3/8(0.0285)
Gas in 1/2 (0.0285) 5/8(0.0315)
Connection method Indoor Flared
Outdoor Flared
Between the indoor &
outdoor units Height difference ft 50 100
Piping length ft 100
Refrigerant charge (R410A) 3 lb. 9 oz. 4 lb. 14 oz.
Note: Test conditions are based on AHRI 210/240.
5DWLQJFRQGLWLRQV&RROLQJ²,QGRRUÛ)'%Û):%2XWGRRUÛ)'%Û):%
 +HDWLQJ²,QGRRUÛ)'%Û):%2XWGRRUÛ)'%Û):%
3SPECIFICATION
OPERATING RANGE
(1) POWER SUPPLY
Rated voltage Guaranteed voltage (V)
Outdoor unit 208/230 V 1 phase
60 Hz
Min. 187 208 230 Max. 253

4
OCH688A
Unit: inch
SUZ-KA18NA(H)2.TH SUZ-KA24NA(H)2.TH SUZ-KA30NA(H)2.TH SUZ-KA36NA(H)2.TH
4OUTLINES AND DIMENSIONS
16-7/16
1-9/16
1-5/8
Drain hole
6-7/8 19-11/16
13
2
Air in
Air in
Air out 2-holes 13/32 13/16
14-3/16
33-1/16
4-5/16 3-3/16
34-5/8
17-25/32
Service panel
3-29/32
6-1/2
7-11/16
35
44
Liquid refrigerant pipe joint
Refrigerant pipe (flared) Ø 1/4 (KA18)
Refrigerant pipe (flared) Ø 3/8 (KA24/30/36)
Gas refrigerant pipe joint
Refrigerant pipe (flared) Ø 1/2 (KA18)
Refrigerant pipe (flared) Ø 5/8 (KA24/30/36)
*1 20 in. (500 mm) or more when front
and sides of the unit are clear
14 in. (350 mm)
or more
4 in. (100 mm)
or more
REQUIRED SPACE
Clear *1
4 in. (100 mm)
or more
20 in. (500 mm)
or more *2
*2 When any 2 sides of left, right
and rear of the unit are clear

5
OCH688A
SUZ-KA18NA2.TH
5WIRING DIAGRAM

:

:
:
 


6
OCH688A
SUZ-KA18NAH2.TH

:

:
:
 


7
OCH688A
SUZ-KA24NA2.TH SUZ-KA30NA2.TH  SUZ-KA36NA2.TH
/

ᨈ

ᨉᨏ
ᨉᨏ
᧯ᨺ
%1
7$%
7$%
7$%6
/('
<(
%8


/


37&
'%$ '%%
;
7$%% 7$%$
37&
:+5'
)
4%
%8
&,5&8,7
%5($.(5
*1<(
4$
'% '$
9

$& 
+]
7%
ᨉᨂ
%.
:+
5'


ᨉ᧿
8
:
9
%. 5'
:+
&%
1
3
:
9
8
,&
7$% 7$% 7$%
᧧᧧
&%
᧧
&%
7$%$
7$%%
32:(5
 6833/<
᧮᧭ᨏ᧰
ᨏ᧭ ᨏ᧯ ᨏ᧮
ᨉᨏ
᧯ᨺ
+
+
57

&1 ;

ᨉ
ᨈᨁᨒ

&1

57
&1

/' %.
5'
7$%6
/('
,19(57(5

3&

%2$5'
7

&1
/'( /'(
%.
%.
; )
57
Wr
5757

&1

&1

&1
*1<(
72  ,1'225 
81,7
9

$&
9

'&
7%
ᨉᨂ

) )
7$%
,&
&1

:+
%8
 5'



<(
%. %.
%. %.
%.%.
%. WrWrWrWr
1$0(
6:,7&+,1*

32:(5

75$16,6725
'()5267

7+(50,6725
',6&+$5*(

7(037+(50,6725
$0%,(17

7(037+(50,6725
),1

7(037+(50,6725
287'225

+($7

(;&+$1*(5
7(037+(50,6725
6<0%2/
4$4%
57 57 57 57 57
7(50,1$/

%/2&.
75$16)250(5
7%7%
7
;
5(/$<
;;
5(/$<
6 +
+($7(5

3527(&725
᧤
237,21

3$576
᧥
5(9(56,1*

9$/9(

&2,/
6<0%2/
1$0(
) ) )
)86(
᧤
7$/9
᧥
)86(
᧤
7$/9
᧥
+
'()5267

+($7(5
᧤
237,21

3$576
᧥
,&,&
/
5($&725 32:(5

02'8/(
37&37&
&,5&8,7

3527(&7,21
0) 0& /(9
/('
/('
(;3$16,21

9$/9(

&2,/
&2035(6625
)$1

02725
',2'(
᧤
237,21

3$576
᧥
6<0%2/
1$0(1$0(
',2'(

02'8/(
60227+,1*

&$3$&,725
)86(
᧤
7$/9
᧥
6<0%2/
'%$'%%
'$'%
&%&%&%
127(6
$ERXW

WKH

LQGRRU

VLGH

HOHFWULF

ZLULQJ

UHIHU

WR

WKH

LQGRRU

XQLW HOHFWULF

ZLULQJ

GLDJUDP

IRU

VHUYLFLQJ
8VH

FRSSHU

VXSSO\

ZLUHV 6\PEROV

LQGLFDWH 7HUPLQDO

EORFN &RQQHFWRU

8
OCH688A
SUZ-KA24NAH2.TH SUZ-KA30NAH2.TH SUZ-KA36NAH2.TH
5(/$<
;;
'()5267

+($7(5
%8
:+
32:(5

6833/<

&1
,&
7$%% 7$%$
&%
᧧
&%
᧧᧧
7$%7$%7$%
,&
8
9
:
3
1
&%
:+
5' %. 9
:
8
ᨉ᧿


5'
:+
%.
)) 
ᨉᨂ
7%
  9

'&
9

$&
7%
9  $&  +]
72

,1'225
 81,7
'$ '%
4$
*1<(
&,5&8,7
%5($.(5
%8
4%
&1

&1

&1

57 57
WrWrWrWrWr
57
)
;
%.
%.
/'( /'(
&1

7
,19(57(5

3&

%2$5'
5' :+
37&
7$%$
7$%%
;
'%% '%$
37&


/


%8 <(
/('
7$%6
5'
7$% 7$%
%.
/'

&1
57

&1

ᨈᨁᨒ
ᨉ

;
&1

57
%1
᧯ᨺ
ᨉᨏ
᧯ᨺ
ᨉᨏ
ᨏ᧮ ᨏ᧯
ᨏ᧭
ᨈ

/

᧮᧭ᨏ᧰
6\PEROV

LQGLFDWH

7HUPLQDO

EORFN

&RQQHFWRU8VH

FRSSHU

VXSSO\

ZLUHV
$ERXW

WKH

LQGRRU

VLGH

HOHFWULF

ZLULQJ

UHIHU

WR

WKH

LQGRRU

XQLW

HOHFWULF

ZLULQJ

GLDJUDP

IRU

VHUYLFLQJ
127(6
5(/$<
1$0(
) ) )
&%&%&%
'$'%
'%$'%%
6<0%2/
)86(
᧤
7$/9
᧥
)86(
᧤
7$/9
᧥
)86(
᧤
7$/9
᧥
60227+,1*

&$3$&,725
5($&725
&,5&8,7

3527(&7,21
)$1

02725
0)
&2035(6625
0&
(;3$16,21

9$/9(

&2,/
/(9
/('
/('
',6&+$5*(

7(037+(50,6725
57
75$16)250(5
7
7(50,1$/

%/2&.
57
7(037+(50,6725
287'225

+($7

(;&+$1*(5
7%7%
6:,7&+,1*

32:(5

75$16,6725
4$4%
',2'(

02'8/(
1$0( 1$0( 1$0(
6<0%2/ 6<0%2/
',2'(
57
),1

7(037+(50,6725
32:(5

02'8/(
37&37&
;
,&,&
/
+
57
'()5267

7+(50,6725
57
$0%,(17

7(037+(50,6725
6 +
+($7(5

3527(&725
5(9(56,1*

9$/9(

&2,/
6<0%2/
<(
5'
%.%.%.
%. %.
%. %.




+
+

9
OCH688A
Unit: inch (mm)
SUZ-KA18NA(H)2.TH
Outdoor
heat
exchanger
Flared connection
Defrost
thermistor
RT61
Discharge
temperature
thermistor
RT62
Flared connection
Stop valve
Capillary tube
O.D. 0.157×
I.D. 0.094×
3-15/16
(ø 4.0 × ø 2.4 × 100)
Capillary tube
O.D. 0.157×
I.D. 0.094×7-7/8
(ø 4.0 × ø 2.4 × 200) Refrigerant flow in cooling
Compressor
4-way
valve
Refrigerant flow in heating
Refrigerant pipe
ø1/2 ( ø 12.7)
(with heat insulator)
Refrigerant pipe ø1/4 ( ø 6.35)
(with heat insulator)
LEV R.V. coil
heating ON
cooling OFF
Strainer
#100
Outdoor heat
exchanger
temperature
thermistor
RT68
Strainer
#100
Muffler
Capillary tube
O.D. 0.118×
I.D. 0.079× 7-7/8
(ø3.0×ø2.0×200(×4))
Stop valve
(with service port)
Service
port
Service port
Muffler
Strainer
#100
6REFRIGERANT SYSTEM DIAGRAM
SUZ-KA24NA(H)2.TH SUZ-KA30NA(H)2.TH SUZ-KA36NA(H)2.TH
Outdoor
heat
exchanger
Flared connection
Defrost
thermistor
RT61
Discharge
temperature
thermistor
RT62
Flared connection
Stop valve
(with strainar)
Stop valve
(with service port)
Capillary tube
O.D. 0.142 × I.D. 0.094
× 1-31/32
(ø 3.6 × ø 2.4 × 50) Refrigerant flow in cooling
Compressor
4-way valve
Refrigerant flow in heating
Refrigerant pipe
ø 5/8
(with heat insulator)
Refrigerant pipe ø 3/8
(with heat insulator)
LEV R.V. coil
heating ON
cooling OFF
Muffler
#100
Receiver
Outdoor heat
exchanger
temperature
thermistor
RT68
Ambient
temperature
thermistor
RT65
Strainer
#100
Service port
Service port
Unit: inch (mm)

10
OCH688A
Max. Length
A
Max. Height
difference
B
Indoor
unit
Outdoor unit
MAX. REFRIGERANT PIPING LENGTH and MAX. HEIGHT DIFFERENCE
Model Refrigerant piping: ft. Piping size O.D: in.
Max. Length
A Max. Height difference BGas Liquid
SUZ-KA18/NA(H)2100 50 1/2 1/4
SUZ-KA24/30/36
NA(H)2100 5/8 3/8
ADDITIONAL REFRIGERANT CHARGE (R410A: oz.)
NOTE: Refrigerant piping exceeding 25 ft. requires additional refrigerant charge according to the calculation.
Model Outdoor unit
precharged Refrigerant piping length (one way): ft.
25 30 40 50 60 70 80 90 100
SUZ-KA18NA2
SUZ-KA18NAH2 3 lb. 9 oz. 0 1.08 3.24 5.40 7.56 9.72 11.88 14.04 16.20
Calculation: X oz. = 1.08/5 oz./ft. × (Refrigerant piping length (ft.) - 25)
Model Outdoor unit
precharged Refrigerant piping length (one way): ft.
25 30 40 50 60 70 80 90 100
SUZ-KA24/30/36
NA(H)2 4 lb. 14 oz. 0 2.69 8.07 13.45 18.83 24.21 29.59 34.97 40.35
Calculation: X oz. = 2.65/5 oz./ft. × (Refrigerant piping length (ft.) - 25)

11
OCH688A
7DATA
STANDARD OPERATION DATA
Representative matching SEZ-KD18NA4 SLZ-KF18NA PEAD-A18AA7 PEAD-A24AA7
Item Unit Cooling Heating Cooling Heating Cooling Heating Cooling Heating
Total
Capacity BTU/h 18000 21600 17700 19700 18000 21600 24000 25000
SHF – 0.82 – 0.71 – 0.80 – 0.77 –
Input kW 1.31 1.58 1.41 1.85 1.27 1.6 1.92 1.99
Electrical circuit
Indoor unit SEZ-KD18NA4 SLZ-KF18NA PEAD-A18AA7 PEAD-A24AA7
Power supply (V, phase, Hz) 230, 1, 60 230, 1, 60 230, 1, 60
Input kW 0.09 0.07 0.04 0.04 0.11 0.09 0.12 0.1
Current A 0.74 0.63 0.43 0.38 0.95 0.84 1.03 0.92
Outdoor unit SUZ-KA18
NA(H)2 SUZ-KA18 NA(H)2 SUZ-KA18 NA(H)2 SUZ-KA24 NA(H)2
Power supply (V, phase, Hz) 230, 1, 60 230, 1, 60 230, 1, 60
Input kW 1.22 1.51 1.37 1.81 1.16 1.51 1.8 1.89
Current A 4.96 6.24 5.70 7.66 4.57 6.12 7.32 7.73
Refrigerant circuit
Condensing pressure PSIG 369 366 372 492 371 365 411 418
Suction pressure
PSIG 141 100 125 105 135 100 140 108
Discharge temperature °F 158 167 155 174 158 167 161 162
Condensing temperature °F 111 110 111 128 111 110 119 120
Suction temperature °F 56 41 46 34 57 41 51 35
Ref. pipe length ft. 25 25 25
Refrigerant charge (R410A) – 1.6 1.6 1.6 2.2
Indoor
unit
Intake air temperature DB °F 80 70 80 70 80 70 80 70
WB °F 67 60 67 60 67 60 67 60
Discharge air temperature DB °F 57 101 56 108 56 103 56 101
Outdoor
unit
Intake air temperature DB °F 95 47 95 47 95 47 95 47
WB °F 75 43 75 43 75 43 75 43

12
OCH688A
Representative matching PEAD-A30AA7 PEAD-A36AA7 SVZ-KP18NA SVZ-KP24NA
Item Unit Cooling Heating Cooling Heating Cooling Heating Cooling Heating
Total
Capacity BTU/h 27000 30000 33000 33500 18000 21600 24000 25000
SHF – 0.84 – 0.84 – 0.85 – 0.81 –
Input kW 2.16 2.41 3.51 3.17 1.36 1.6 1.92 1.91
Electrical circuit
Indoor unit PEAD-A30AA7 PEAD-A36AA7 SVZ-KP18NA SVZ-KP24NA
Power supply (V, phase, Hz) 230, 1, 60 230, 1, 60
Input kW 0.17 0.15 0.25 0.23 0.16 0.18
Current A 1.31 1.2 1.71 1.6 1.44 1.6
Outdoor unit SUZ-KA30
NA(H)2 SUZ-KA36 NA(H)2 SUZ-KA18 NA(H)2 SUZ-KA24 NA(H)2
Power supply (V, phase, Hz) 230, 1, 60 230, 1, 60
Input kW 1.99 2.26 3.26 2.94 1.2 1.44 1.74 1.73
Current A 8.08 9.28 13.55 12.18 4.47 5.52 6.75 6.70
Refrigerant circuit
Condensing pressure PSIG 419 417 456 356 369 349 411 415
Suction pressure
PSIG 147 105 142 97 144 100 145 108
Discharge temperature °F 164 162 176 176 158 158 156 167
Condensing temperature °F 120 120 127 108 111 108 116 119
Suction temperature °F 53 34 50 30 58 37 59 35
Ref. pipe length ft. 25 25
Refrigerant charge (R410A) – 2.2 1.6 2.2
Indoor
unit
Intake air temperature DB °F 80 70 80 70 80 70 80 70
WB °F 67 60 67 60 67 60 67 60
Discharge air temperature DB °F 58 98 57 95 58 100 59 96
Outdoor
unit
Intake air temperature DB °F 95 47 95 47 95 47 95 47
WB °F 75 43 75 43 75 43 75 43

13
OCH688A
Representative matching SVZ-KP30NA SVZ-KP36NA MLZ-KP18NA
Item Unit Cooling Heating Cooling Heating Cooling Heating
Total
Capacity BTU/h 27000 30000 33000 33500 18000 20000
SHF – 0.9 – 0.84 – 0.67 –
Input kW 2.16 2.06 3.72 3.03 1.44 1.77
Electrical circuit
Indoor unit SVZ-KP30NA SVZ-KP36NA MLZ-KP18NA
Power supply (V, phase, Hz) 230, 1, 60 230, 1, 60
Input kW 0.21 0.34 0.04
Current A 2.0 3.0 0.4
Outdoor unit SUZ-KA30
NA(H)2 SUZ-KA36 NA(H)2 SUZ-KA18 NA(H)2
Power supply (V, phase, Hz) 230, 1, 60 230, 1, 60
Input kW 1.95 1.85 3.38 2.69 1.4 1.73
Current A 7.39 6.96 13.17 10.17 5.86 7.30
Refrigerant circuit
Condensing pressure PSIG 414 322 453 336 368 453
Suction pressure
PSIG 155 87 139 95 123 105
Discharge temperature °F 160 159 174 175 164 175
Condensing temperature °F 116 102 124 109 110 118
Suction temperature °F 61 39 55 36 56 34
Ref. pipe length ft. 25 25
Refrigerant charge (R410A) – 2.2 1.6
11Indoor
unit
Intake air temperature DB °F 80 70 80 70 80 70
WB °F 67 60 67 60 67 60
Discharge air temperature DB °F 60 93 59 99 52 117
Outdoor
unit
Intake air temperature DB °F 95 47 95 47 95 47
WB °F 75 43 75 43 75 43

14
OCH688A
8-2. R.V. COIL CONTROL
Heating .................ON
Cooling .................OFF
Dry ....................OFF
NOTE: The 4-way valve reverses for 5 seconds right before start-up of the compressor.
ON
OFF
ON
OFF
Outdoor fan
motor
Compressor
5 seconds 15 seconds
8-1. OUTDOOR FAN MOTOR CONTROL
The fan motor turns ON/OFF, interlocking with the compressor.
[ON] The fan motor turns ON 5 seconds before the compressor starts up.
[OFF] The fan motor turns OFF 15 seconds after the compressor has stopped running.
ON
OFF
Compressor
Outdoor fan
motor
R.V.coil ON
OFF
ON
OFF
<COOL>
5 seconds
<HEAT>
5 seconds
8-3. RELATION BETWEEN MAIN SENSOR AND ACTUATOR
Sensor Purpose Actuator
Compressor LEV Outdoor fan
motor R.V.coil Indoor fan motor
Discharge temperature
thermistor Protection żż
Indoor coil temperature
thermistor
Cooling: Coil frost prevention ż
Heating: High pressure protec-
tion żż
Defrost thermistor Heating: Defrosting żżżżż
Fin temperature thermistor Protection żż
Ambient temperature
thermistor Cooling: Low ambient tempera- ture operation żżż
Outdoor heat exchanger tem-
perature thermistor
Cooling: Low ambient tempera-
ture operation żżż
Cooling: High pressure protec-
tion żżż
8ACTUATOR CONTROL

15
OCH688A
9-1. CHANGE IN DEFROST SETTING
Changing defrost finish temperature
<JS> To change the defrost finish temperature, cut/solder the JS wire of the outdoor inverter P.C. board.
(Refer to "10-6. TEST POINT DIAGRAM AND VOLTAGE".)
Jumper 'HIURVW¿QLVKWHPSHUDWXUH
SUZ-KA18NA(H)2SUZ-KA24/30/36NA(H)2
JS
Soldered
(Initial setting) 48°F (9°C) 50°F (10°C)
None
(Cut) 64°F (18°C) 64°F (18°C)
9-2. PRE-HEAT CONTROL SETTING
PRE-HEAT CONTROL
When moisture gets into the refrigerant cycle, it may interfere the start-up of the compressor at low outside temperature.
The pre-heat control prevents this interference. The pre-heat control turns ON when outside temperature is 68°F (20°C)
or below. When pre-heat control is turned ON, compressor is energized. (About 50 W)
<JK> To activate the pre-heat control, cut the JK wire of the inverter P.C. board. (Refer to "10-6. TEST POINT
DIAGRAM AND VOLTAGE".)
NOTE: When the inverter P.C. board is replaced, check the Jumper wires, and cut/solder them if necessary.
10 TROUBLESHOOTING
10-1. CAUTIONS ON TROUBLESHOOTING
1. Before troubleshooting, check the following
1) Check the power supply voltage.
2) Check the indoor/outdoor connecting wire for miswiring.
2. Take care of the following during servicing
1) Before servicing the air conditioner, be sure to turn OFF the main unit first with the remote controller, and turn off the
breaker.
2) Be sure to turn OFF the power supply before removing the front panel, the cabinet, the top panel, and the electronic
control P.C. board.
3) When removing the electrical parts, be careful of the residual voltage of smoothing capacitor.
4) When removing the electronic control P.C. board, hold the edge of the board with care NOT to apply stress on the
components.
5) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires.
3. Troubleshooting procedure
1) First, check if the OPERATION INDICATOR lamp is blinking ON and OFF to indicate an abnormality.
2) Before servicing check that the connector and terminal are connected properly.
3) When the electronic control P.C. board seems to be defective, check the copper foil pattern for disconnection and the
components for bursting and discoloration.
4) Refer to "10-2. TROUBLESHOOTING CHECK TABLE" and "10-3. HOW TO PROCEED "SELF-DIAGNOSIS"".
Lead wiring Housing point
9SERVICE FUNCTIONS

16
OCH688A
NOTE: 1. The location of LED is illustrated at the right figure. Refer to "10-6.TESTPOINTDIAGRAM".
2. LED is lighted during normal operation.
The blinking frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the blinking frequency is “2”.
ON
OFF 2.5-second OFF 2.5-second OFF
0.5-second ON 0.5-second ON LED
Blinking ĺ
Inverter P.C. board
10-2. TROUBLE SHOOTING CHECK TABLE
No. Symptoms LED
indication check code Abnormal point/ Condition Condition Remedy
1
Outdoor
unit does
not
operate.
1-time blink
every
2.5 seconds
UP Outdoor power system Overcurrent protection cut-out operates 3 consecutive times within 1
minute after the compressor gets started. • Reconnect connector of compressor. • Refer to “10-5.AHow to check
inverter/compressor".
• Check stop valve.
2U3 Outdoor thermistors Discharge temperature thermistor shorts, or opens duringcompressor
running. • Refer to “10-5.FCheck of outdoor thermistors".
U4 Fin temperature thermistor, defrost thermistor, P.C. board temperature
thermistor, outdoor heat exchanger temperature thermistor or ambient
temperature thermistor shorts, or opens during compressor running.
36-time blink
2.5 seconds
OFF
FC Outdoor control system Nonvolatile memory data cannot be read properly. • Replace inverter P.C. board.
4E8 /
E9
Serial signal The communication fails between the indoor and outdoor unit for 3
minutes. • Check indoor/outdoor connecting wire.
• Replace indoor or outdoor P.C.board
if abnormality is displayed again.
511-time blink
2.5 seconds
OFF UE Stop valve/
Closed valve Closed valve is detected by compressor current. • Check stop valve.
6WLPHÀDVK
2.5 seconds
OFF PL
Outdoor refrigerant
system abnormality A closed valve and air trapped in the refrigerant circuit are detected based on the temperature sensed by the indoor and outdoor
thermistors and the current of the compressor.
• Check for a gas leak in a connecting
piping, etc.
• Check stop valve.
• Refer to “10-5. OCheck of outdoor
fan motor".
7
'Outdoor
unit stops
and
restarts 3
minutes
later' is
repeated.
2-time blink
2.5 seconds OFF
Overcurrent protection /DUJHFXUUHQWÀRZVLQWRLQWHOOLJHQWSRZHUPRGXOH • Reconnect connector of compressor.
• Refer to “10-5.AHow to check
inverter/compressor".
• Check stop valve.
83-time blink
2.5 seconds OFF Discharge temperature
overheat protection Temperature of discharge temperature thermistor exceeds 116°C, compressor stops. Compressor can restart if discharge temperature
thermistor reads 100°C or less 3 minutes later.
• Check refrigerant circuit and refriger-
ant amount.
• Refer to “10-5. kCheck of LEV".
94-time blink
2.5 seconds OFF
Fin temperature/P.C.
board temperature
thermistor overheat
protection
7HPSHUDWXUHRI¿QWHPSHUDWXUHWKHUPLVWRURQWKHKHDWVLQNH[FHHGV
72 to 86°C or temperature of P.C. board temperature thermistor on the
inverter P.C.board exceeds 72 to 85°C.
• Check around outdoor unit.
• Check outdoor unit air passage.
• Refer to “10-5. ICheck of outdoor
fan motor".
10 5-time blink
2.5 seconds OFF High pressure protec-
tion Indoor coil thermistor exceeds 70°C in HEAT mode. Defrost thermistor exceeds 70°C in COOL mode. • Check refrigerant circuit and refriger- ant amount.
• Check stop valve.
11 8-time blink
2.5 seconds OFF Compressor synchro-
nous abnormality The waveform of compressor current is distorted. • Reconnect connector of compressor. • Refer to “10-5.AHow to check
inverter/compressor".
12 10-time blink
2.5 seconds OFF
Outdoor fan motor Outdoor fan has stopped 3 times in a row within 30 seconds after
outdoor fan start-up. • Refer to “10-5.ICheck of outdoor fan motor.
• Refer to “10-5.LCheck of inverter
P.C. board.
13 12-time blink
2.5 seconds OFF Each phase current of
compressor Each phase current of compressor cannot be detected normally. • Refer to “10-5.LHow to check inverter/compressor".
14 13-time blink
2.5 seconds OFF DC voltage DC voltage of inverter cannot be detected normally. • Refer to “10-5.AHow to check
inverter/compressor".
15
Outdoor
unit
operates.
1-time blink
2.5 seconds OFF Frequency drop by cur-
rent protection When the input current exceeds approximately 12A(KA18)/16A(KA24) /16A(KA30)/16A(KA36), compressor frequency lowers. • The unit is normal, but check the fol- lowing.
&KHFNLILQGRRU¿OWHUVDUHFORJJHG
• Check if refrigerant is short.
• Check if indoor/outdoor unit air circu-
lation is short cycled.
16 3-time blink
2.5 seconds OFF
Frequency drop by high
pressure protection Temperature of indoor coil thermistor exceeds 131 °F [55 °C] in HEAT mode, compressor frequency lowers.
Frequency drop by de-
frosting in COOL mode Indoor coil thermistor reads 46 °F [8 °C] or less in COOL mode, com- pressor frequency lowers.
17 4-time blink
2.5 seconds OFF
Frequency drop by
discharge temperature
protection
Temperature of discharge temperature thermistor exceeds 232 °F [111
°C], compressor frequency lowers. • Check refrigerant circuit and refriger- ant amount.
• Refer to “10-5.kCheck of LEV".
• Refer to “10-5.GCheck of outdoor
thermistors".
18 7-time blink
2.5 seconds OFF Low discharge tempera-
ture protection Temperature of discharge temperature thermistor has been 122 °F [50 °C] or less for 20 minutes. • Refer to “10-5.kCheck of LEV". • Check refrigerant circuit and refriger-
ant amount.
19 8-time blink
2.5 seconds OFF
PAM protection
PAM: Pulse Amplitude
Modulation
7KHRYHUFXUUHQWÀRZVLQWR,*%7,QVXODWHG*DWH%LRSRODUWUDQVLVWRU
TR821) or the bus-bar voltage reaches 320 V or more, PAM stops and
restarts.
This is not malfunction. PAM protection
will be activated in the following cases:
1. Instantaneous power voltage drop.
(Short time power failure)
2. When the power supply voltage is
high.
Zero cross detecting
circuit Zero cross signal for PAM control cannot be detected.
20 9-time blink
2.5 seconds OFF
Inverter check mode The connector of compressor is disconnected, inverter check mode
starts. • Check if the connector of the com- pressor is correctly connected.
• Refer to “10-5.AHow to check
inverter/compressor".

17
OCH688A
10-3. HOW TO PROCEED "SELF-DIAGNOSIS"
As this air conditioner has a function to memorize all the failures that had occurred, the latest failure detail can be recalled by
following the procedure below. Use this function when the check code is not displayed with wired remote controller or the re-
mote controller at use is wireless type.
F1 F2 F3 F4
unemecivreS
rosruC :unemniaM
Test run
Input maintenance info.
Function setting
Check
Self check
kcehcfleS
:tceleS
Ref. address
sserddA
kcehcfleS
Ref. address
Return: teseR
Error Unt # CI.prG
Self check
Return: Reset
Ref. address
Error
-- Unt # Grp.
-- --
When there is no error history
Self check
Delete error history?
Ref. address
Cancel OK
Self check
Return:
Ref. address
Error history deleted
2
With the F1 or F2 button, enter the refrigerant address, and press the button.
Select "Self check" with the F1 or F2 button, and press the button.
1Select "Service" from the Main menu, and press the button.
3Check code, unit number, attribute will appear.
"-" will appear if no error history is available.
4Resetting the error history.
Press the F4 button (Reset) on the screen that shows the error history.
$FRQ¿UPDWLRQVFUHHQZLOODSSHDUDVNLQJLI\RXZDQWWRGHOHWHWKHHUURUKLVWRU\
Press the F4 button (OK) to delete the error history.
If deletion fails, "Request rejected" will appear.
"Unit not exist" will appear if no indoor units that are correspond to the entered
address are found.
Navigating through the screens
• To go back to the Service menu .......... button
• To return to the previous screen ....... button
10-3-1. Self-diagnosis <PAR-3xMAA ("x" represents 0 or later)>

18
OCH688A
If operations cannot be completed with the remote controller, diagnose the remote controller with this function.
F1 F2 F3 F4
unemecivreS
rosruC :unemniaM
Maintenance password
Remote controller check
F1 F2 F3 F4
Remote controller check
:nigeB
Start checking?
Remote controller check
:nigeB
Start checking?
1Select "Service" from the Main menu, and press the button.
Select "Remote controller check" with the F1 or F2 button, and press
the button.
2
Select "Remote controller check" from the Service menu, and press the but-
ton to start the remote controller check and see the check results.
To cancel the remote controller check and exit the Remote controller check
menu screen, press the or the button.
The remote controller will not reboot itself.
Check the remote controller display and see if anything is displayed
(including lines). Nothing will appear on the remote controller display if
the correct voltage (8.5–2 V DC) is not supplied to the remote controller.
If this is the case, check the remote controller wiring and indoor units.
OK: No problems are found with the remote controller. Check other
parts for problems.
E3, 6832: There is noise on the transmission line, or the indoor unit or another
remote controller is faulty. Check the transmission line and the
other remote controllers.
NG (ALL0, ALL1):
Send-receive circuit fault. Remote controller needs replacing.
ERC: The number of data errors is the discrepancy between the number of
bits in the data transmitted from the remote controller and that of the
data that was actually transmitted over the transmission line. If data
errors are found, check the transmission line for external noise inter-
ference.
Remote controller check results screen
If the button is pressed after the remote controller check results are dis-
played, remote controller check will end, and the remote controller will automati-
cally reboot itself.
10-3-2. Remote controller check <PAR-3xMAA ("x" represents 0 or later)>
3

19
OCH688A
[Procedure]
1. Press the CHECK button twice.
• "CHECK" lights, and refrigerant address "00" blinks.
• Check that the remote controller's display has stopped before continuing.
2. Press the temperature buttons.
• Select the refrigerant address of the indoor unit for the self-diagnosis.
Note: Set refrigerant address using the outdoor unit’s DIP switch (SW1).
(For more information, see the outdoor unit installation manual.)
3. Point the remote controller at the sensor on the indoor unit and press the
HOUR button.
• If an air conditioner error occurs, the indoor unit's sensor emits an intermittent
buzzer sound, the operation light blinks, and the check code is output.
(It takes 3 seconds at most for check code to appear.)
4. Point the remote controller at the sensor on the indoor unit and press the ON/
OFF button.
• The check mode is cancelled.
<Malfunction-diagnosis method at maintenance service>
10-3-3. Self-diagnosis <Wireless remote controller>
<In case of trouble during operation>
When a malfunction occurs to air conditioner, both indoor unit and outdoor unit will stop and operation lamp blinks to inform
unusual stop.
ON/OFF TEMP
FAN
VANE
MODE
CHECK
LOUVER
TEST RUN
AUTO STOP
AUTO START
h
min
RESET
SET CLOCK
CHECK
CHECK
display
Temperature
button
CHECK
button
Refrigerant
address
display
HOUR
button
ON/OFF
button

20
OCH688A
[Output pattern A] Errors detected by indoor unit
[Output pattern B]
E9
1. If the beeper does not sound again after the initial
2 beeps to confirm the self-check start signal was received and
the OPERATION INDICATOR lamp does not come on,
there are no error records.
2. If the beeper sounds 3 times continuously “beep, beep, beep (0.4 + 0.4 + 0.4 sec.)” after the initial 2 beeps to confirm
the self-check start signal was received, the specified refrigerant address is incorrect.
OPERATION
INDICATOR
lamp
blink
pattern
Beep Beep Beep Beep Beep Beep Beep
Off
Approx. 2.5 sec. On Approx. 3 sec. On 0.5 sec. On 0.5 sec. On 0.5 sec. On 0.5 sec. Off Approx. 2.5 sec. On Approx. 3 sec. On 0.5 sec. On 0.5 sec.
· · · Repeated
Number of blinks/beeps in pattern indicates the check
code in the following table (i.e., n=5 for “U2”) Number of blinks/beeps in pattern indicates the check code in the following table
nth
1st 2nd 3rd 1st 2nd
Self-check
starts
(Start signal
received)
Beeper sounds
[Output pattern B]
OPERATION
INDICATOR
lamp
blink
pattern
Beep Beep Beep Beep Beep Beep Beep
Off
Approx. 2.5 sec. On 0.5 sec. On 0.5 sec. On 0.5 sec. On
0.5 sec. Off
Approx. 2.5 sec. On 0.5 sec. On 0.5 sec.
· · ·Repeated
Number of blinks/beeps in pattern indicates the check
code in the following table (i.e., n=5 for “P5”) Number of blinks/beeps in pattern indicates the check code in the following table
nth
1st 2nd 3rd 1st 2nd
Self-check
starts
(Start signal
received)
Beeper sounds
• Refer to the following tables for details on the check codes.
[Output pattern A]
Notes:
*The check code in the parenthesis indicates PAR-30MAAmodel.
Beeper sounds/OPERATION
INDICATOR lamp blinks Check code Symptom Remark
(Number of times)
Wireless remote controller
Wired remote controller
Beeper sounds/OPERATION
INDICATOR lamp blinks Check code
(Number of times)
Wireless remote controller
Wired remote controller
1P1
Intake sensor error
P9 Pipe (TH5) sensor error
2P2 Pipe (TH2) sensor error
3E6,E7
Indoor/outdoor unit communication error
4 P4 Drain sensor error/Float switch connector (CN4F) open
5P5 Drain pump error
PA Forced compressor stop (due to water leakage abnormality)
6 P6 Freezing/Overheating protection operation
7 EE Communication error between indoor and outdoor units
9 E4, E5 Remote controller signal receiving error
Errors detected by unit other than indoor unit (outdoor unit, etc.)
Symptom
1Indoor/outdoor unit communication error
2(Transmitting error) (Outdoor unit)
3Open/short of outdoor unit thermistors
UP
U3,U4
Others
14 Other errors (Refer to the technical manual for the outdoor unit.)
12
14 Fb (FB)* PL Indoor unit control system error (memory error, etc.)
–E0, E3
– E1, E2 Remote controller control board error
Remote controller transmission error
Abnormality of refrigerant circuit
Compressor overcurrent interruption
As for indoor
unit, refer to
indoor unit's
service manual.