Mitsubishi Electric Mr.SLIM SUZ-KA09NA User manual

SERVICE MANUAL
No.OCH467
REVISED EDITION-A
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
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................ 8
7. DATA.................................................................11
8. ACTUATOR CONTROL....................................13
9. SERVICE FUNCTION.......................................14
10. TROUBLESHOOTING......................................14
11. FUNCTION SETTING....................................... 30
12. DISASSEMBLY INSTRUCTIONS.....................33
HFC
utilized
R410A
July 2011
R410A
Outdoor unit
[Model names] [Service Ref.]
SUZ-KA09NA SUZ-KA09NA.TH
SUZ-KA12NA SUZ-KA12NA.TH
SUZ-KA15NA SUZ-KA15NA.TH
SUZ-KA18NA SUZ-KA18NA.TH
Note:
This service manual describes serv-
ice data of the outdoor units.
• RoHS compliant products have
<G> mark on the spec name plate.
PARTS CATALOG (OCB467)
SUZ-KA18NA.TH
Revision:
• SLZ-KA·NA models have been
added as connectable indoor units.
• Some descriptions have been mod-
ified.
• Please void OCH467.

2
3
Air outlet
Drain outlet
Piping
Drain hose
Air inlet
(back and side)
1COMBINATION OF INDOOR AND OUTDOOR UNITS
OUTDOOR UNIT
Piping
Air outlet
Drain hose
Drain outlet
Air inlet
(back and side)
SUZ-KA18NA
PART NAMES AND FUNCTIONS
2
SUZ-KA09NA SUZ-KA12NA SUZ-KA15NA
Heat pump type
Outdoor unit
SUZ-
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Indoor unit
Service
Manual No.
Service Ref.
Heat pump without
electric heater
KA18NA.THKA15NA.TH
HWE08020
KA12NA.THKA09NA.TH
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—
SEZ-KD09NA4.TH
SEZ-KD12NA4.TH
SEZ-KD15NA4.TH
SEZ-KD18NA4.TH
SLZ-KA09NA.TH
SLZ-KA12NA.TH
SLZ-KA15NA.TH
OCH487
OCB487
OUTDOOR UNIT

2
3
Outdoor unit model SUZ-KA09NA SUZ-KA12NA SUZ-KA15NA SUZ-KA15NA
Power supply V , phase , Hz 208/230 , 1 , 60
Max. fuse size (time delay) A 15
Min. circuit ampacity A 12 12 12 14
Fan motor F.L.A 0.50 0.93
Compressor
Model KNB073FQDHC KNB092FQAHC SNB130FQBH
R.L.A 6.6 6.6 7.4 10.0
L.R.A 8.2 8.2 9.3 12.5
Refrigeration oil oz. (Model) 10.8 (NEO22) 15.2 (NEO22)
Refrigerant control Linear expansion valve
Sound level 1Cooling dB(A) 46 49 49 54
Heating dB(A) 50 51 51 56
Defrost method Reverse cycle
Dimensions W in. 31-1/2 33-1/16
D in. 11-1/4 13
H in. 21-5/8 33-7/16
Weight Ib. 66 77 80 119
External nish 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 (0.0315)
Gas in. 3/8 (0.0315) 1/2 (0.0315)
Connection method Indoor Flared
Outdoor Flared
Between the indoor &
outdoor units Height difference ft. 40 50
Piping length ft. 65 100
Refrigerant charge (R410A) 1 lb. 16 oz. 2 lb. 9 oz. 3 lb. 16 oz.
NOTE: Test conditions are based on AHRI 210/240.
1: Rating conditions (Cooling) — Indoor: 80˚FDB, 67˚FWB, Outdoor: 95˚FDB, (75˚FWB)
(Heating) — Indoor: 70˚FDB, 60˚FWB, Outdoor: 47˚FDB, 43˚FWB
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
5
Unit: inch
SUZ-KA09NA SUZ-KA12NA SUZ-KA15NA
Liquid pipe :1/4 (flared)
Gas pipe :3/8 (flared) (KA09/12)
1/2 (flared) (KA15)
6-23/32
2
5-7/8
2-23/32
1-3/4
15-3/4
12 ~ 12-3/4
13-9/16
11/16
1-9/16
7/8
21-5/8
11-1/32
13/32
31-1/2
19-11/16 5-15/16
11-29/32
17/3229/32 11-1/4
Air in
handle
Air in
Air out
2- 3/8 13/16 Oval hole
Drain hole 1-5/8
REQUIRED SPACE Basically open 4 inch or more
without any obstruction in front
and on both sides of the unit.
14 in. or more
8 in. or more
4 in. or more
4 in. or more
Open two sides of left,
right, or rear side.
SUZ-KA18NA
20-9/32
14-3/16
Air in
11-25/32
2-19/32
Air in
Air out
19-11/16
33-1/16
13
2
4-25/32
33-7/16
16-15/16
3-3/16
4-3/8 × 13/16 slot
1-11/32
1-9/16
Drain 3 holes
(ø1 -5/16)
30°
35°
2-9/16
Liquid:1/4(flared)
Gas :1/2(flared)
3-9/16
8-11/32
Open as a rule 20 inch or more
if the front and both sides are open
4 inch or more/8 inch
or more if there are
obstacles to both sides
Open as a rule
20 inch or more if the back,
both sides and top are open
REQUIRED SPACE
14 in. or more
4 in. or more
4OUTLINES AND DIMENSIONS

4
5
SUZ-KA09NA SUZ-KA12NA
5WIRING DIAGRAM
SUZ-KA09NA, SUZ-KA12NA WIRING DIAGRAM
LEDLED
H
26H
IC802
IPM,IC932
L61
DB61,DB65
C62,C63
SYMBOL NAME SYMBOL SYMBOLNAME NAME
T801 21S4
X63,X64,X66
TB1,TB2
TR821
LEV
RT65 RT64
PTC64,PTC65
MC
RT62 RT61
MF
F701,F801,F901
RT68
NOTES:
1. About the indoor side electric wiring refer to the indoor unit electric wiring diagram for servicing. 2. Use copper conductors only. (For field wiring).
LED
2
RED 26H
BLKBLK
2
IC932
3
L1
L2
1
CN931
5
5
GROUND
From INDOOR UNIT CONNECTING WIRE
POWER SUPPLY 208/230V 1 phase 60Hz
TO INDOOR UNIT CONNECTING WIRES 208/230V 1 phase 60Hz
From INDOOR UNIT CONNECTING WIRES DC12-24V
LD63
F701 X64
PTC64
BLK
LD-E1
PTC65
LD-S
LD62
LD61
6
INVERTER P.C. BOARD
3
F901
BLU
CN721
X63
21
1
RT65
CN643
RT62
RT61
CN641
4
1
CIRCUIT BREAKER
BRN
BLU
BRN
RED
12
S3
S2
S1
TB2 TB1
RT64 RT68
CN642 CN644
2
1
CN932
L61
C62C63
LD70 LD66
DB61
DB65
+++
–
–
~ ~~ ~ +
TR821
F801 T801
1
3
P N
W
U V
IC802
3
1
V
W
MS 3~
MS
MF
3~ M
LEV
MC IPM
U
WHT
RED
BLK
3
1
RED
WHT
BLK
BLU YLW
ORN
LDW
LDV
LDU
CN61
6
CN724
1
21S4
11
2 2 1
(OPTION PARTS)
YLW
BLK BLK
BLK BLK
1H
BLK
CN722
3
1
X66
4
t° t° t° t° t°
SMOOTHING CAPACITOR DIODE MODULE FUSE (T3.15AL250V) DEFROST HEATER(OPTION PARTS) INTELLIGENT POWER DEVICE INTELLIGENT POWER MODULE REACTOR
EXPANSION VALVE COIL COMPRESSOR FAN MOTOR CIRCUIT PROTECTION DEFROST THERMISTOR DISCHARGE TEMP.THERMISTOR FIN TEMP.THERMISTOR AMBIENT TEMP.THERMISTOR
OUTDOOR HEAT EXCHANGER TEMP. THERMISTOR. TERMINAL BLOCK SWITCHING POWER TRANSISTOR TRANSFORMER RELAY REVERSING VALVE COIL HEATER PROTECTOR(OPTION PARTS)

6
7
SUZ-KA15NA
SUZ-KA15NA WIRING DIAGRAM
RT68
TB1,TB2
TR821
T801
21S4
X63,X64,X66
26H
F701,F801,F901
MF
RT61 RT62
MC
PTC64,PTC65
RT64
LEVC61,C62,C63
SYMBOL SYMBOL SYMBOLNAME NAME NAME
DB61,DB65
IC802
IPM,IC932
L61 RT65
H
LED LED
LED
2
RED
26H
BLKBLK
2
C61
INVERTER P.C. BOARD
F901
CN932
C62C63
LD70 LD66
DB61
DB65
––
~
~
~ ~
+
++ + +
TR821
F801
3
P N
W
U V
3
1
V
W
U
MS 3~
MS M 3~
MC
MF LEV
IPM
WHT
RED
BLK
3
1
RED
WHT
BLK
LDW
LDV
LDU
CN61
3
L1
L2
IC932
1
CN931
5
5
GROUND
From INDOOR UNIT CONNECTING WIRE
POWER SUPPLY 208/230V 1 phase 60Hz
TO INDOOR UNIT CONNECTING WIRES 208/230V 1 phase 60Hz
From INDOOR UNIT CONNECTING WIRES DC12-24V
LD63
F701 X64
PTC64
BLK
LD-E1
PTC65
LD-S
LD62
LD61
6
3
BLU
CN721
21
1
RT65
CN643
RT62
RT61
CN641
4
1
CIRCUIT BREAKER
BRN
BLU
BRN
RED
12
S3
S2
S1
TB2 TB1
RT64 RT68
CN642 CN644
2
1
L61
T801
1
IC802
BLU YLW
ORN
6
CN724
1
21S4
11
2 2 1
(OPTION PARTS)
YLW
BLK BLK
BLK BLK
1
H
BLK
CN722
3
1
X63
X66
4
t° t° t° t° t°
SMOOTHING CAPACITOR DIODE MODULE FUSE (T3.15AL250V) DEFROST HEATER(OPTION PARTS) INTELLIGENT POWER DEVICE INTELLIGENT POWER MODULE REACTOR
EXPANSION VALVE COIL
COMPRESSOR FAN MOTOR CIRCUIT PROTECTION DEFROST THERMISTOR DISCHARGE TEMP.THERMISTOR FIN TEMP.THERMISTOR AMBIENT TEMP.THERMISTOR
OUTDOOR HEAT EXCHANGER TEMP. THERMISTOR. TERMINAL BLOCK SWITCHING POWER TRANSISTOR TRANSFORMER RELAY REVERSING VALVE COIL HEATER PROTECTOR(OPTION PARTS)
NOTES:
1. About the indoor side electric wiring refer to the indoor unit electric wiring diagram for servicing. 2. Use copper conductors only. (For field wiring).

6
7
SUZ-KA18NA
RT68
TR821
TB1,TB2
X63,X64,X66
21S4
T801
HEATER PROTECTOR(OPTION PARTS)
26H
DB61,DB65
C61,C62,C63
SYMBOL NAME SYMBOL NAME SYMBOL NAME
DEFROST HEATER(OPTION PARTS)
L61
IC802
IPM, HC930
H
F701,F801,F901
LED
LED RT65
RT64
RT62
RT61
PTC64,PTC65
MF
MC
LEV
LED
11
2 2 1 2
(OPTION PARTS)
YLW
RED
BLK BLK
BLK BLK
26H
BLKBLK
2 1
H
BLK
CN722
3
1
X66
TO INDOOR UNIT CONNECTING WIRES 208/230V 1 phase 60Hz
GROUND
FROM INDOOR UNIT CONNECTING WIRE
BLU
FROM INDOOR UNIT CONNECTING WIRES DC12-24V
POWER SUPPLY 208/230V 1 phase 60Hz
11 1 1 1
52 3 2 4 1
INVERTER P.C. BOARD
CN931
5
21S4
CN724
6
CN61
LDU
LDV
LDW
ORN YLW
BLU
BLK
WHT
RED
1
3
BLK
RED
WHT
U
W
MC
MF LEV
MS
3~
MS M
3~
V
1
3
IC802
V U
IPM
WN
P
31
HC930
T801
F801
TR821
DB65 DB61
LD66
LD70
C63 C62 C61
L61
CN932 CN644CN642
RT68
RT64
L2
L1
TB1 TB2
S1
S2
S3
BRN
2
1
RED
BRN
BLU
CIRCUIT BREAKER
CN641
RT61 RT62
CN643
RT65
3
X63
CN721
F901
6
LD61 LD62 LD-S
PTC65 LD-E1
BLK
PTC64
X64
F701
LD63
NOTES: 1. About the indoor side electric wiring refer to the indoor unit electric
wiring diagram for servicing.
2. Use copper conductors only. (For field wiring).
~
–
+++ + +
–
~ ~
~
t° t° t° t° t°
4
REACTOR DIODE MODULE
EXPANSION VALVE COIL COMPRESSOR
SMOOTHING CAPACITOR FUSE (T3.15AL250V) INTELLIGENT POWER DEVICE INTELLIGENT POWER MODULE
FAN MOTOR
CIRCUIT PROTECTION DEFROST THERMISTOR
DISCHARGE TEMP.THERMISTOR
FIN TEMP.THERMISTOR AMBIENT TEMP.THERMISTOR
OUTDOOR HEAT EXCHANGER
TEMP. THERMISTOR.
TERMINAL BLOCK
SWITCHING POWER TRANSISTOR
TRANSFORMER
RELAY
REVERSING VALVE COIL
SUZ-KA18NA WIRING DIAGRAM

8 9
Unit: inch (mm)
SUZ-KA09NA
Outdoor
heat
exchanger
Flared connection
Defrost
thermistor
RT61
Discharge
temperature
thermistor
RT62
Flared connection
Stop valve
(with strainar)
Stop valve
(with service port)
Refrigerant flow in cooling
Compressor
4-way valve
Refrigerant flow in heating
Refrigerant pipe ø3/8
(with heat insulator)
Refrigerant pipe ø1/4
(with heat insulator)
R.V. coil
heating ON
cooling OFF
Strainer
#100
LEV
Ambient
temperature
thermistor
RT65
Muffler
Capillary tube
O.D. 0.118 ×I.D. 0.079
×9-7/16
(ø3.0 × ø2.0 ×240)
Outdoor heat
exchanger
temperature
thermistor
RT68
Service port
Service port
Muffler
SUZ-KA12NA SUZ-KA15NA
Outdoor
heat
exchanger
Flared connection
Defrost
thermistor
RT61
Discharge
temperature
thermistor
RT62
Flared connection
Stop valve
(with strainar)
Stop valve
(with service port)
Refrigerant flow in cooling
Compressor
4-way valve
Refrigerant flow in heating
Refrigerant pipe ø3/8 (KA12)
Refrigerant pipe ø1/2 (KA15)
(with heat insulator)
Refrigerant pipe ø1/4
(with heat insulator)
R.V. coil
heating ON
cooling OFF
Strainer
#100
Capillary tube
O.D. 0.118 × I.D. 0.071
× 23-5/8
(ø 3.0 × ø 1.8 × 600 ) (×2)
LEV
Ambient
temperature
thermistor
RT65
Muffler
Capillary tube
O.D. 0.118 ×I.D. 0.079
×9-7/16
(ø3.0 × ø2.0 ×240)
Outdoor heat
exchanger
temperature
thermistor
RT68
Muffler
Service port
Service port
6REFRIGERANT SYSTEM DIAGRAM
Unit: inch (mm)

8 9
SUZ-KA18NA
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 1/2
(with heat insulator)
Refrigerant pipe ø 1/4
(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
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-KA09/12/15NA 65 40 3/8 (KA09/12)
1/2 (KA15) 1/4
SUZ-KA18NA 100 50 1/2
Unit: inch (mm)

10 11
ADDITIONAL REFRIGERANT CHARGE (R410A: oz.)
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 65
SUZ-KA09NA 1 lb. 16 oz. 0 1.62 4.86 8.10 11.34 12.96SUZ-KA12NA 2 lb. 9 oz.
SUZ-KA15NA Calculation: X oz. = 1.62/5 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-KA18NA 3 lb. 16 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)
NOTE: Refrigerant piping exceeding 25 ft. requires additional refrigerant charge according to the calculation.

10 11
7 DATA
STANDARD OPERATION DATA
Representative matching SEZ-KD09NA4 SEZ-KD12NA4 SEZ-KD15NA4 SEZ-KD18NA4
Item Unit Cooling Heating Cooling Heating Cooling Heating Cooling Heating
Total
Capacity Btu/h 8100 10900 11500 13600 14100 18000 17200 21600
SHF - 0.80 — 0.76 — 0.80 — 0.79 —
Input kW 0.670 1.020 0.920 1.140 1.170 1.500 1.380 1.700
Electrical circuit
Indoor unit SEZ-KD09NA4 SEZ-KD12NA4 SEZ-KD15NA4 SEZ-KD18NA4
Power supply (V, Phase, Hz) 230, 1, 60
Input kW 0.06 0.04 0.07 0.05 0.09 0.07 0.09 0.07
Current A 0.51 0.39 0.57 0.46 0.74 0.63 0.74 0.63
Outdoor unit SUZ-KA09NA SUZ-KA12NA SUZ-KA15NA SUZ-KA18NA
Power supply (V, phase, Hz) 230, 1, 60
Input kW 0.61 0.98 0.85 1.09 1.08 1.43 1.39 1.63
Current A 2.80 4.33 3.64 4.65 4.45 5.96 5.38 6.91
Refrigerant circuit
Condensing pressure PSIG
398 448 387 386 399 389 373 397
Suction pressure
PSIG 135 97 135 104 133 96 142 100
Discharge temperature °F 148 170 162 165 159 182 150 172
Condensing temperature °F 116 125 114 114 116 115 112 116
Suction temperature °F 49 33 55 35 46 41 52 33
Ref. pipe length ft. 25
Refrigerant charge (R410A) - 1 lb. 16 oz. 2 lb. 9 oz. 3 lb. 16 oz.
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 61 102 58 103 60 102 60 101
Outdoor
unit
Intake air temperature DB °F 95 47 95 47 95 47 95 47
WB °F — 43 — 43 — 43 — 43

12 13
Representative matching SLZ-KA09NA SLZ-KA12NA SLZ-KA15NA
Item Unit Cooling Heating Cooling Heating Cooling Heating
Total
Capacity Btu/h 8400 10900 11100 13600 15000 18000
SHF - 0.84 — 0.77 — 0.67 —
Input kW 0.700 0.930 0.920 1.180 1.460 1.950
Electrical circuit
Indoor unit SLZ-KA09NA SLZ-KA12NA SLZ-KA15NA
Power supply (V, Phase, Hz) 230, 1, 60
Input kW 0.08 0.08 0.09 0.09 0.09 0.09
Current A 0.35 0.35 0.40 0.40 0.65 0.65
Outdoor unit SUZ-KA09NA SUZ-KA12NA SUZ-KA15NA
Power supply (V, phase, Hz) 230, 1, 60
Input kW 0.63 0.86 0.84 1.10 1.38 1.87
Current A 3.12 4.02 3.82 4.93 5.98 8.10
Refrigerant circuit
Condensing pressure PSIG 401 406 379 418 422 475
Suction pressure
PSIG 147 104 139 106 128 98
Discharge temperature °F 154 169 152 173 174 188
Condensing temperature °F 116 117 111 118 118 128
Suction temperature °F 52 34 51 36 51 31
Ref. pipe length ft. 25
Refrigerant charge (R410A) - 1 lb. 16 oz. 2 lb. 9 oz.
Indoor
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 62 97 60 101 57 111
Outdoor
unit
Intake air temperature DB °F 95 47 95 47 95 47
WB °F — 43 — 43 — 43

12 13
SUZ-KA09NA SUZ-KA12NA SUZ-KA15NA SUZ-KA18NA
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 ○ ○
Indoor coil temperature
thermistor
Cooling: Coil frost prevention ○
Heating: High pressure protec-
tion ○ ○
Defrost thermistor Heating: Defrosting ○○○○○
Fin temperature thermistor Protection ○ ○
Ambient temperature
thermistor Cooling: Low ambient tempera- ture operation ○ ○ ○
Outdoor heat exchanger tem-
perature thermistor
Cooling: Low ambient tempera-
ture operation ○ ○ ○
Cooling: High pressure protec-
tion ○ ○ ○
8ACTUATOR CONTROL

14 15
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 10-6-1.)
Jumper Defrost nish temperature
SUZ-KA09/12/15 SUZ-KA18
JS
Soldered
(Initial setting) 41°F (5°C) 48°F (9°C)
None
(Cut) 50°F (10°C) 64°F (18°C)
SUZ-KA09NA SUZ-KA12NA SUZ-KA15NA SUZ-KA18NA
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 10-6.1)
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. and 10-3.
Lead wiring Housing point
SUZ-KA09NA SUZ-KA12NA SUZ-KA15NA SUZ-KA18NA
9SERVICE FUNCTIONS

14 15
10-2. FAILURE MODE RECALL FUNCTION
As this air conditioner has a function to memorize all the failures that had happened, the latest failure detail can be
recalled by following the procedures below.
10-2-1. Wired remote controller
Turn on the power.
Press the [CHECK] button twice.
Set refrigerant address with [TEMP] button
if system control is used.
Press the [ON/OFF] button to stop the self-check.
°C
°C SIMPLE
PAR-21MAA
ON/OFF
FILTER
CHECK
OPERATION
CLEAR
TEST
TEMP.
MENU
BACK DAY MONITOR/SET
CLOCK
ON/OFF



 
CHECK button
Refrigerant address
TEMP. button
IC: Indoor unit
OC: Outdoor unit
Check code
10-2-2. Failure mode table (Wired remote controller)
[Output pattern A]Errors detected by indoor unit
Check code
Wired remote controller
Symptom Remark
P1 Intake sensor error
P2
P9 Pipe (TH2) sensor error
Pipe (TH5) sensor error
E6,E7 Indoor/outdoor unit communication error
P4 Drain sensor error/Float switch connector open
P5 Drain pump error
P6 Freezing/Overheating protection operation
EE Communication error between indoor and outdoor units
P8 Pipe temperature error
E4, E5 Remote controller signal receiving error
Fb Indoor unit control system error (memory error, etc.)
E1, E2 Remote controller control board error
E0, E3 Remote controller transmission error
[Output pattern B]Errors detected by unit other than indoor unit (outdoor unit, etc.)
Check code Symptom Remark
E9 Indoor/outdoor unit communication error (Transmitting error) (Outdoor unit)
UP Compressor overcurrent interruption
U3,U4 Open/short of outdoor unit thermistors
UF Compressor overcurrent interruption (When compressor locked)
U2 Abnormal high discharging temperature/insufficient refrigerant
U1,Ud Abnormal high pressure/Overheating protection operation
U5 Abnormal temperature of heat sink
U8 Outdoor unit fan protection stop
U6 Compressor overcurrent interruption/Abnormal of power module
U7 Abnormality of super heat due to low discharge temperature
U9,UH Abnormality such as overvoltage or voltage shortage and abnormal
synchronous signal to main circuit/Current sensor error
Others Other errors
For details, check the LED display
of the outdoor controller board.
• On wired remote controller
Check code displayed in the LCD.
Wired remote controller

16
17
10-2-3. Outdoor unit failure mode table
Abnormal point
(Failure mode / protection) LED indication (Outdoor P.C. board) Condition Remedy Indoor/
outdoor unit
failure mode
recall function
Outdoor unit
failure mode
recall function
None (Normal) — — — — —
Outdoor power system
—
Overcurrent protection stop is continuously
performed 3 times within 1 minute after the
compressor gets started.
Reconnect connectors.
Refer to 10-5. "How to
check inverter/compressor".
Check stop valve.
•
•
•○ ○
Discharge temperature
thermistor 1-time ash every 2.5 seconds Thermistor shorts or opens during compressor
running. Refer to 10-5. "Check of outdoor thermistors".
Defective outdoor thermistors
can be identied by checking
the blinking pattern of LED.
•
○ ○
Defrost thermistor
Fin temperature thermistor 3-time ash
2.5 seconds OFF
P.C. board temperature
thermistor 4-time ash 2.5 seconds OFF
Ambient temperature
thermistor 2-time ash 2.5 seconds OFF
Overcurrent 11-time ash
2.5 seconds OFF Large current ows into intelligent power
module. Reconnect compressor connector.
Refer to 10-5. "How to check
inverter/compressor".
Check stop valve.
•
•
•
—○
Compressor synchronous
abnormality (Compressor start-
up failure protection)
12-time ash
2.5 seconds OFF Waveform of compressor current is distorted. Reconnect compressor
connector.
Refer to 10-5. "How to check
inverter/compressor".
•
•—○
Discharge temperature
—
Temperature of discharge temperature
thermistor exceeds 241°F (116°C), compressor
stops.
Compressor can restart if discharge temperature
thermistor reads 212°F (100°C) or less 3
minutes later.
Check refrigerant circuit and
refrigerant amount.
Refer to 10-5. "Check of
LEV".
•
•—○
High pressure
—
Temperature of indoor coil thermistor exceeds
158°F (70°C) in HEAT mode. Temperature of
outdoor heat exchanger temperature thermistor
exceeds 158°F (70°C) in COOL mode.
Check refrigerant circuit and
refrigerant amount.
Check stop valve.
•
•—○
Fin temperature/ P.C. board
temperature 7-time ash 2.5 seconds OFF Temperature of n temperature thermistor on the
inverter P.C. board exceeds 167 ~ 176°F (75 ~
80°C), or temperature of P.C. board temperature
thermistor on the inverter P.C. board exceeds
158 ~ 167°F (70 ~ 75°C).
Check around outdoor unit.
Check outdoor unit air
passage.
Refer to 10-5. "Check of
outdoor fan motor".
•
•
•—○
Outdoor fan motor
—
Outdoor fan has stopped 3 times in a row within
30 seconds after outdoor fan start-up. Refer to 10-5. "Check of
outdoor fan motor". Refer to
10-5. "Check of inverter P.C.
board".
•
—○
Nonvolatile memory data 5-time ash
2.5 seconds OFF Nonvolatile memory data cannot be read
properly. Replace the inverter P.C. board.
•○ ○
Discharge temperature
—
Temperature of discharge temperature
thermistor has been 122°F (50°C) or less for 20
minutes.
Refer to 10-5. "Check of
LEV".
Check refrigerant circuit and
refrigerant amount.
•
•—○
DC voltage 8-time ash
2.5 seconds OFF DC voltage of inverter cannot be detected
normally. Refer to 10-5. "How to check inverter/compressor".
•
—○
Each phase current of
compressor 9-time ash 2.5 seconds OFF Each phase current of compressor cannot be
detected normally.
Overcurrent Compressor open-
phase 10-time ash 2.5 seconds OFF Large current ows into intelligent power module
(IPM).
The open-phase operation of compressor is
detected.
The interphase short out occurs in the output of
the intelligent power module (IPM).
The compressor winding shorts out.
Reconnect compressor
connector.
Refer to 10-5. "How to
check inverter/compressor".
•
•—○
Stop valve (Closed valve) 14-time ash
2.5 seconds OFF Closed valve is detected by compressor current. Check stop valve• ○ ○
NOTE: Blinking patterns of this mode differ from the ones of Troubleshooting check table (10-3.).

16
17
10-3. TROUBLESHOOTING CHECK TABLE
No. Symptom LED indication Abnormal point/
Condition Condition Remedy
1Outdoor
unit does
not oper-
ate.
1-time ash every
2.5 seconds Outdoor power sys- tem Overcurrent protection stop is continuously performed 3 times within 1 minute after the compressor gets started, or failure of re-
start of compressor has repeated 24 times.
Reconnect connector of compressor.
Refer to 10-5. "How to check inverter/
compressor".
Check stop valve.
•
•
•
2Outdoor thermistors Discharge temperature thermistor, n temperature thermistor, de-
frost thermistor, outdoor heat exchanger temperature thermistor,
P.C. board temperature thermistor or ambient temperature therm-
istor shorts or opens during compressor running.
Refer to 10-5. "Check of outdoor
thermistors".
•
3Outdoor control sys-
tem Nonvolatile memory data cannot be read properly. Replace inverter P.C. board.•
46-time ash
2.5 seconds OFF Serial signal The communication fails between the indoor and outdoor unit for 3 minutes. Refer to 10-5. "How to check miswir- ing and serial signal error.
•
511-time ash
2.5 seconds OFF Stop valve/ Closed valve Closed valve is detected by compressor current. Check stop valve.•
614-time ash 2.5 seconds OFF Outdoor unit (Other abnormality) Outdoor unit is defective. Refer to 10-2.2. "Flow chart of the de- tailed outdoor unit failure mode recall
function".
•
7'Outdoor
unit stops
and re-
starts 3
minutes
later' is
repeated.
2-time ash
2.5 seconds OFF Overcurrent protec- tion Large current ows into intelligent power module. When overcurrent protection occurs within 10 seconds after
compressor starts, compressor restarts after 15 seconds.
Reconnect connector of compressor.
Refer to 10-5. "How to check inverter/
compressor".
Check stop valve.
•
•
•
8
3-time ash
2.5 seconds OFF Discharge tempera- ture overheat protec-
tion
Temperature of discharge temperature thermistor exceeds 241°F
(116°C), compressor stops. Compressor can restart if discharge
temperature thermistor reads 212°F (100°C) or less 3 minutes
later.
Check refrigerant circuit and refrigerant
amount.
Refer to 10-5. "Check of LEV".
•
•
9
4-time ash
2.5 seconds OFF Fin temperature /P.C. board temperature
thermistor overheat
protection
Temperature of n temperature thermistor on the heat sink ex-
ceeds 167 ~ 176°F (75 ~ 80°C) or temperature of P.C. board tem-
perature thermistor on the inverter P.C. board exceeds 158 ~ 167
°F (70 ~ 75°C).
Check around outdoor unit.
Check outdoor unit air passage.
Refer to 10-5. "Check of outdoor fan
motor".
•
•
•
10 5-time ash 2.5 seconds OFF High pressure pro- tection Temperature of indoor coil thermistor exceeds 158°F (70°C) in HEAT mode. Temperature of outdoor heat exchanger temperature
thermistor exceeds 158°F (70°C) in COOL mode.
Check refrigerant circuit and refrigerant
amount.
Check stop valve.
•
•
11 8-time ash 2.5 seconds OFF Compressor syn- chronous abnormal-
ity
The waveform of compressor current is distorted. Reconnect connector of compressor.
Refer to 10-5. "How to check inverter/
compressor".
•
•
12
10-time ash
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. "Check of outdoor fan motor.
Refer to 10-5. "Check of inverter P.C.
board.
•
•
13 12-time ash
2.5 seconds OFF Each phase current of compressor Each phase current of compressor cannot be detected normally. Refer to 10-5. "How to check inverter/ compressor".
•
14 13-time ash
2.5 seconds OFF DC voltage DC voltage of inverter cannot be detected normally. Refer to 10-5. "How to check inverter/ compressor".
•
15 Outdoor
unit oper-
ates.
1-time ash
2.5 seconds OFF Frequency drop by current protection Current from power outlet is nearing Max. fuse size. The unit is normal, but check the follow- ing.
Check if indoor lters are clogged.
Check if refrigerant is short.
Check if indoor/outdoor unit air circula-
tion is short cycled.
•
•
•
16
3-time ash
2.5 seconds OFF Frequency drop by high pressure protec-
tion
Temperature of indoor coil thermistor exceeds 131°F (55°C) in
HEAT mode, compressor frequency lowers.
Frequency drop by
defrosting in COOL
mode
Indoor coil thermistor reads 46°F (8°C) or less in COOL mode,
compressor frequency lowers.
17
4-time ash
2.5 seconds OFF Frequency drop by discharge tempera-
ture protection
Temperature of discharge temperature thermistor exceeds 232°F
(111°C), compressor frequency lowers. Check refrigerant circuit and refrigerant amount.
Refer to 10-5. "Check of LEV".
Refer to 10-5. "Check of outdoor
thermistors".
•
•
•
18 Outdoor unit oper-
ates.
7-time ash
2.5 seconds OFF Low discharge tem- perature protection Temperature of discharge temperature thermistor has been 122°F (50°C) or less for 20 minutes. Refer to 10-5. "Check of LEV". Check refrigerant circuit and refrigerant
amount.
•
•
19
8-time ash
2.5 seconds OFF PAM protection PAM: Pulse Amplitude
Modulation
The overcurrent ows into IGBT (Insulated Gate Bipolar transis-
tor: 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.
20
9-time ash
2.5 seconds OFF Inverter check mode The connector of compressor is disconnected, inverter check mode starts. Check if the connector of the compres- sor is correctly connected. Refer to
10-5. "How to check inverter/compres-
sor".
•
NOTE: 1. The location of LED is illustrated at the right gure. Refer to 10-6.1.
2. LED is lighted during normal operation.
The ashing frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the ashing frequency is “2”.
ON
OFF 2.5-second OFF 2.5-second OFF
0.5-second ON 0.5-second ON
LED
Flashing →
Inverter P.C. board (Parts side)

18
19
10-4. TROUBLE CRITERION OF MAIN PARTS
SUZ-KA09NA SUZ-KA12NA SUZ-KA15NA SUZ-KA18NA
Part name Check method and criterion Figure
Defrost thermistor (RT61)
Fin temperature
thermistor (RT64)
Ambient temperature
thermistor (RT65)
Outdoor heat exchanger
temperature thermistor
(RT68)
Measure the resistance with a tester.
Refer to 10-6. “Test point diagram and voltage”, 1. “Inverter P.C.
board”, for the chart of thermistor.
Discharge temperature
thermistor (RT62)
Measure the resistance with a tester. Before measurement, hold the
thermistor with your hands to warm it up.
Refer to 10-6. “Test point diagram and voltage”, 1. “Inverter P.C.
board”, for the chart of thermistor.
Compressor
Measure the resistance between terminals with a tester.
(Temperature: 14 ~ 104 °F (-10 ~ 40 °C))
Normal (Ω)
KA09 KA12 KA15/18
U-V
U-W
V-W 1.36 ~ 1.93 1.52 ~ 2.17 0.78 ~ 1.11
Outdoor fan motor
Measure the resistance between lead wires with a tester.
(Temperature: 14 ~ 104 °F (-10 ~ 40 °C))
Color of lead wire Normal (Ω)
KA09/12/15 KA18
RED – BLK
BLK – WHT
WHT – RED 28 ~ 40 11 ~ 16
R. V. coil (21S4)
Measure the resistance with a tester.
(Temperature: 14 ~ 104 °F (-10 ~ 40°C))
Normal (kΩ)
0.97 ~ 1.38
Expansion valve coil
(LEV)
Measure the resistance with a tester.
(Temperature: 14 ~ 104 °F (-10 ~ 40 °C))
Color of lead wire Normal (Ω)
WHT – RED
37 ~ 54
RED – ORN
YLW – BRN
BRN – BLU
W
U
V
WHT RED BLK
WHT RED BLK
LEV
WHT
RED
ORN
YLW
BRN
BLU

18
19
10-5. TROUBLESHOOTING FLOW
Are the voltages balanced?
Disconnect the connector (CN61) between
compressor and the intelligent power module
(IPM).
Replace the inverter P.C. board.
Check the voltage between terminals.
Check the compressor. See 10-5. “Check of compressor”.
No
Yes
See 10-5. “Check of open phase”.
● With the connector between the compressor and the intelligent power module disconnected, activate the inverter and check if
the inverter is normal by measuring the voltage balance between the terminals.
Output voltage is 50 - 130 V. (The voltage may differ according to the tester.)
<< Operation method (Test run operation)>>
1. Press the TEST (RUN) button twice.
2. Press the MODE button and switch to the COOL (or HEAT) mode.
3. Compressor starts at rated frequency in COOL mode or 58 Hz in HEAT mode.
4. Indoor fan operates at High speed.
5. To cancel test run operation, press the ON/OFF button on remote controller.
<<Measurement point>>
at 3 points
BLK (U) - WHT (V)
BLK (U) - RED (W)
WHT(V) - RED (W)
NOTE: 1. Output voltage varies according to power supply voltage.
2. Measure the voltage by analog type tester.
3. During this check, LED of the inverter P.C. board ashes 9 times. (Refer to 10-6.1.)
Measure AC voltage between the lead wires at 3 points.
Refer to 10-5. “Check of compressor
operation time”.
Does the compressor operate continuously? Refer to 10-5. “Check of compressor start failure”.
OK.
No
Yes
Refer to 10-5. “Check of compressor
winding”.
Is the compressor normal? Replace the compressor.
No
Yes
B Check of open phase
A How to check inverter/compressor
C Check of compressor

20
21
F Check of compressor start failure
D Check of compressor winding
E Check of compressor operation time
● Disconnect the connector (CN61) between the compressor and intelligent power module, and measure the resistance be-
tween the compressor terminals.
<<Measurement point>>
at 3 points
BLK - WHT
BLK - RED
WHT - RED
<<Judgement>>
Refer to 10-4.
0[Ω] ················· Abnormal [short]
Infinite [Ω]········ Abnormal [open]
NOTE: Be sure to zero the ohmmeter before measurement.
Measure the resistance between the lead wires at 3 points.
After the compressor is heated with a drier,
does the compressor start? 1 Replace the compressor.
Compressor start failure. Activate pre-heat control.
(Refer to 9-2. "PRE-HEAT CONTROL SETTING")
No
Yes
Does the compressor run for 10 seconds or
more after it starts? Check the refrigerant circuit.
Check the stop valve.
Yes
No
Conrm that 1~4 is normal.
• Electrical circuit check
Contact of the compressor connector (including CN61)
Output voltage of inverter P.C. board and balance of them (See 10-5. )
Direct current voltage between DB61(+) and (-) on the inverter P.C. board
Voltage between outdoor terminal block S1-S2
1.
2.
3.
4.
1
Heat the compressor with
a drier for about 20 minutes.
Do not recover refrigerant
gas while heating.
Heating part
●Connect the compressor and activate the inverter. Then measure
the time until the inverter stops due to over current.
<<Operation method>>
Start heating or cooling operation by pressing the TEST button
twice on the remote controller. (Test run mode)
(TEST RUN OPERATION: Refer to 10-5 B.)
<<Measurement>>
Measure the time from the start of compressor to the stop of
compressor due to overcurrent.
Compressor starts
Abnormal
(IPM failure)
(Compressor winding short)
Abnormal
(Compressor lock out)
(Starting defect)
Abnormal
(Poor contact,)
(Outdoor P.C. board defect)
(Disconnected connector)
Abnormal
(Refrigerant circuit defect)
(Closed valve)
Normal
0 second
1 second
2 seconds
10 seconds
10 minutes
<<Judgement>>