AY XP12GR N Service Manual 1
AY XP12GR N Service Manual 1
AY XP12GR N Service Manual 1
SERVICE MANUAL
SPLIT TYPE
ROOM AIR CONDITIONER
MODELS INDOOR UNIT
AY-XP12GR-N
OUTDOOR UNIT
AE-X12GR-N
In the interests of user-safety (Required by safety regulations in some
countries) the set should be restored to its original condition and only
parts identical to those specified should be used.
CONTENTS
CHAPTER 1. SPECIFICATION
[1] SPECIFICATION............................................ 1-1
[2] EXTERNAL DIMENSION............................... 1-2
[3] WIRING DIAGRM .......................................... 1-3
[4] ELECTRICAL PARTS .................................... 1-3
CHAPTER 2. EXPLAMATION OF CIRCUIT AND OPERATION
[1] BLOCK DIAGRAMS....................................... 2-1
[2] MICROCOMPUTER CONTROL SYSTEM
........ 2-3
[3] FUNCTION..................................................... 2-8
CHAPTER 3. FUNCTION AND OPERATION OF PROTECTIVE PROCEDURES
[1] PROTECTION DEVICE FUNCTIONS AND
OPERATIONS................................................ 3-1
[2] AIR CONDITIONER OPERATION IN
THERMISTOR ERROR ................................. 3-3
[3] THERMISTOR TEMPERATURE CHARACTERISTICS ............................................... 3-5
[4] HOW TO OPERATE THE OUTDOOR
UNIT INDEPENDENTLY................................ 3-5
[5] GENERAL TROUBLESHOOTING CHART
........ 3-6
[6]
[7]
[8]
AEX12GRN
CHAPTER 1. SPECIFICATION
AEX12GRN
Service Manual
[1] SPECIFICATION
1. AY-XP12GR-N AE-X12GR-N
MODEL
ITEMS
Cooling capacity(Min.Max.)
Heating capacity(Min. Max.)
Moisture removal(at cooling)
kW
kW
Liters/h
INDOOR UNIT
AY-XP12GR-N
3.5 (0.9 - 4.0)
4.6 (0.9 - 6.5)
1.1
OUTDOOR UNIT
AE-X12GR-N
Electrical data
Phase
Rated frequency
Rated voltage
Rated current
(Min - Max.)
Rated input
(Min - Max.)
Power factor
Compressor
Refrigerant system
Noise level
(at cooling/heating)
Hz
V
A
A
W
W
%
%
Cool
Heat
Cool
Heat
Cool
Heat
Type
Model
Oil charge
Evaporator
Condenser
Control
Refrigerant (R410A)
De-lce system
High
dB(A)
Low
dB(A)
Soft
dB(A)
Single
50
220240
4.2 ( 0.8 5.7 )
5.3 ( 0.8 7.8 )
875 (1501250 )
1150 ( 1601700 )
9587
9990
Hermetically sealed rotary type
DA111A1F22F
450mL Ester oil VG74
Louver Fin and Grooved tube type
Corrugate Fin and Grooved tube type
Expansion valve
1050g
Micro computer controled reversed systems
40/44
47/49
38/38
27/34
Fan system
Drive
Air flow quantity
(at cooling/heating)
High
Low
Soft
m3/min.
m3/min.
m3/min.
Fan
Direct drive
10.5/12.9
9.5/10.3
5.9/8.7
Cross flow fan
32/30
Propeller fan
Connections
Refrigerant coupling
Refrigerant tube size Gas, Liquid
Drain piping mm
Flare type
1/2", 1/4"
O.D 18
Others
Safety device
Air filters
Net dimensions
Net weight
Width
Height
Depth
mm
mm
mm
kg
NOTE: The condition of star marked item are ISO5151 : 1994(E), contition T1.
11
AEX12GRN
198
278
790
18.5
58
175
22.0
2. Outdoor unit
540
72
299
324
135
12
37.5
4.
58
14
265
165
12
136
81
540
780
AEX12GRN
2. Outdoor unit
MODEL
MLB084
REMARKS
DC Motor
MODEL
DA111A1F22F
ML-A902
REMARKS
D.C. brush-less motor
DC Motor
QFS-GA064JBZZ(250V, 1A)
QFS-GA051JBZZ(250V, 2A)
QFS-GA052JBZZ(250V, 3.15A)
QFS-CA001JBZZ(250V, 20A)
QFS-CA002JBZZ(250V, 15A)
2. Outdoor Unit
DESCRIPTION
Compressor
Outdoor fan motor
Outdoor fan motor capacitor
Fu4
Fu3
Fu2
Fu1
Fu5, 6
13
AEX12GRN
Manual
CHAPTER 2. EXPLAMATION OF CIRCUITService
AND OPERATION
AEX12GRN
2A
Fuse
AC power
3.15A
Fuse
AC clock circuit
EEPROM
Select circuit
Auxiliary mode
Power on circuit
Cluster generator
Serial signals
Sub
CPU
LED display
21
Unit-unit wiring
(AC power and
serial signals)
AEX12GRN
2. Outdoor unit
AC clock circuit
15A
protection
IGBT
Power factor
converter circuit
Smoothing
circuit
Filter
circuit
20A
protection
Outdoor fan
4-way valve
15A
protection
Compressor
Current transformer
Compressor thermistor
EEPROM
LED
Expansion valve
22
VSS
MQ
RESET
OE
SDA
SCL
VCC
VPP
BUSY
5V
CN4
JPT
IC9
PJ431CT
50V
0.1
C4
5V
R9
1K
C44
10V
220
R95
4.7K
R6
100K
L1
10H
R81
1K
R59
10K
R58
10K
R54
10K
PC7
4
CN90
5V
JPO
JPH
R52
10K
R53
10K
ZD5
15V
5V
R92
R91
HAJP
C40
50V
1000p
5V
R87
10K
R86
10K
C52
25V
0.1
JPW
JPP
R7
15KF
C5
50V
1500p
R5
30KF
D2
D1FL20U
C
50V
0.1
WIRELESS
PREHEAT
POWER ON
(HA CIRCUIT)
C39
16V
0.01
C36
16V
0.01
PC817XP3
AUTO RESTART
PC6
C49
PC817XP3
C48
250V
10000p
12
11
10
CN80
5V
R65
IC2
RESET
0V
IC3
MR1712
4 3
EEPROM
IC10
C37
25V
0.1
C26
25V
4.7
5V
C2
50V
100
D21
D1FL20U
C35
2KV
33p
TEST
(TEST RUN)
C57
50V
1000p
5V
AUX.
L2
D20
D1FL20U
R27
10K
P62
P61
P60
P57
P56
P55
P54
P53
P52
P51
P50
P47
P46
P45
P44
P43
SW1
5V
5V
R57
680
PC9
PC817XP3
Q9
KRA106S
1SR139
FU2
2A - 250V
AC CLOCK
R85
10K
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
R46
1k
R71
1k
C3
50V
100
HOT KEEP
5V
C7
10V
470
D1
D1FS4
D14
D2S6M
1 5
5V
IC1
3
2
C33
50V
1000p
8MHz
OSC1
R35
Q19
KRC102S
C32
50V
1000p
R17 1K
R30
680
5V
R94
10K
R48
10k
C27
16V
0.01
IC7
KIA7815API
5V
P00
P01
P02
P03
P04
P05
P06
P07
P10
P11
P12
P13
P14
P15
P16
P17
DC15V
DB1
D2SBA60
R1
3.3
5W
3
PC817XP3
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
R89
1K
R45
4.7k
5V
10k
PC4
PC817XP3
PC5
R32
8.2k
R31
56k
R34
6.8k
C56
C54
NF1
KRC108S
Q1
C98, C99
1KV 1000p
KRC108S
Q3
KRC102S
R4
4.7K
C16
50V
0.01
Q15
C99
C98
Vs
Vcc
PG
GND
3
2
PC3
5V
2
PC81716P
12V
1
5V
C42
3 25V
0.1
CONNECTOR OF JOINT
(FAN MOTOR)
BCN1
7
Vm
R24
39K
R26
200K
1/2W
R25
200K
1/2W
D3
D1N60
C53~C56
250V4700p
NR1
C55
C53
R75
3.3K
Q11
KRA101S
DC
FAN
MOTOR
R23
1/4W
910
SSR
5V
SERIAL SIGNALS
GND for
12V LINE
GND for
5V LINE
12V
POWER SUPPLY OF
SUB MICRO COMPUTER
ERROR SIGNAL
OF SERIAL
RM
4.7K
12V
BCN7
3W
11K
3W
11K
R44
1/4W
1.8k
RH
RE
KID65004AF
12V
C23
275V
0.01
REMOTE CONTROLLER
SIGNAL
R20
1/4W
910
R76
100
1W
1
3
5
7
9
11
2
4
6
8
10
12
RG
680
2W
CLUSTER
GENERATOR
CNA
D8
D1N60
OUT
RB
680
2W
IN
9 10 11 12
9 10 11 12
RA
680
2W
R40
680
2W
LOUVER MOTOR
TOP
9 10
LOUVER MOTOR
BOTTOM
CIRCUIT DIAGRAM
3
PC2 PC853HXP
2
PC1 PC817XP3
DISPLAY PWB
12V
RC
680
2W
RY1
CONNECTOR OF JOINT
(DRAIN PAN)
R70
2.7K
CONNECTOR OF JOINT
(CLUSTER)
BCN5
1
FU1
3.15A - 250V
FLASH
TH2
PIPE THERMO
TH1
TEMP THERMO
R11
2.4KF
PC817XP3
2
R80
1.2K
1 PC6
R56
1/4W
100
R8
2.4KF
C43
25V
470
R97
4.7k
C12
100V
100pF
C47
50V
0.1
R66
3.3K
R2
1/2W
1M
RF
1/2W
1M
C22
16V
0.01
D15
D1FL20U
R3
10KF
RN
4.7K
C1
450V 120
R29
3.3k
R22
11KF
R37
RD
D7
D1N60
11K
2W
11K
2W
ZD1
ST03D - 200
ZD2 HZ24 - 2
JPS
C90
C18 35V100
R10
1.5K
R51
1/4W
100
R69
100K
R38 100k
TR1
R93
100k
R47
4.7k
8
7
6
5
1
2
3
4
C19 50V0.047
R13
100K
R96
10.0KF
C30
16V10
R55
2.4K
R60
10.0KF
R61
10.0KF
C31
16V10
C20 250V0.01
C50
25V
0.1
C46
35V
100
R36
4.7K
R73
100K
R28
10k
C24
25V
0.1
BZ
R39
4.7k
12V
R68
4.7K
R90
R50
10k
R67
47k
C17
16V
0.01
C25
10V
100
JPF
R98
4.7K
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
P63
P64
P65
P66
P67
VSS
VR
VCC
P30
P31
P32
P33
P34
P35
P36
P37
23
P42
VSS
RST
P41
P40
XIN
XOU
VSS
P27
P26
P25
P24
P23
P22
P21
P20
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
5V
5V
9 10 11
9 10 11
AEX12GRN
1. Indoor unit
R41 56k
IC6
B
L
U
E
E1
F1
LED
102
LED
104
DISPLAY PWB
LED
103
LED
105
D1
G1
A1
RECEIVER CIRCUIT
IC201
GP1U261RK
C1
H1
B1
SG201
+ C201
16V
47
C202
25V
0.1
R201
47
E2
F2
A2
LED
106
G2
D2
LED
101
2 (H1)
C2
H2
B2
LED
107
LED
108
LED
109
12
CN104A
10
12
9
10
CN104B
11
5V
11
GND for
5V LINE
REMOTE CONTROLLER
SIGNALS
a
b
c
d
e
f
g
CN105A
10
CN105C
GND for
12V LINE
C103
25V
0.1
GND for
12V LINE
IC102
C102
25V
4.7
C105
50V
0.22
Q104
KRC106S
Q102
KRA106S
JP1
C101
25V
0.1
KID65783AF
JP2
RESET
IC103
12V
12V
8MHz
OSC101
3
C104
16V
47
M5V
R107
R106
R105
R104
R103
R102
1W180 * 7
R101
1/4W
1.2K * 4
Q103
KRC106S
Q101
KRA106S
R109
CN105B
11
LED
110
c
d
e
3
f
4
g
R113
R110
2 (H2)
R114
LED
111B
PC
7 (A1)
6 (B1)
4 (C1)
(COM) 10
1 (D1)
3 (E1)
8 (F1)
9 (G1)
7 (A2)
6 (B2)
b
4 (C2)
c
(COM) 5
1 (D2)
24
3 (E2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
P12
P13
P14
P20
P21
P22
P23
P24
P25
P26
P27
Vref
RESET
CNVss
Vcc
Xin
Xout
Vss
M5V
GND for
5V LINE
GND for
12V LINE
IC104
12V
KID65004AF
IC101
M37542
P11
P10
P07
P06
P05
P04
P03
P02
P01
P00
P37
P36
P35
P34
P33
P32
P31
P30
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
R118
10K
M5V
R116
100K
Q105
KRC106S
5V
GND for
12V LINE
IC106
12V
KID65004AF
GND for
12V LINE
IC105
12V
KID65004AF
R119
1K
12V
LOUVER MOTOR
BOTTOM
CN101
LOUVER MOTOR
TOP
CIRCUIT DAIGRAM
POWER SUPPLY OF
SUB MICRO COMPUTER
M5V
ERROR SIGNAL
OF SERIAL
REMOTE CONTROLLER
SIGNALS
SERIAL SIGNALS
5V
R108
4.7K
GND for
5V LINE
GND for
12V LINE
CN102
10
CN103
8 (F2)
9 (G2)
FLASH
1
R115
4.7K
(
2
AEX12GRN
AEX12GRN
1.3. Printed wiring board
25
AEX12GRN
2. Outdoor unit
2.1. Electronic control circuit diagram
26
AEX12GRN
2.2. Printed wiring board
27
AEX12GRN
[3] FUNCTION
1. Function
1.1. Startup control
The main relay remains off during the first 45 seconds (first safety
time) immediately after the power cord is plugged into an AC outlet in
order to disable outdoor unit operation and protect outdoor unit electric
components.
When the temperature of the 2-way valve rises to 10C or higher after
about 180 seconds, the compressor restarts and resumes normal
operation.
Once the compressor stops operating, it will not restart for 180 seconds to protect the compressor.
(The indoor unit will restart operation immediately after the ON switch
is operated on the remote control.)
Compressor operation
Compressor ON
Compressor remains OFF
for 180 seconds
OFF operation on
remote control
ON operation on
remote control
Compressor can
turn ON
Once the temperature of the indoor unit heat exchanger drops below
the overheat protection temperature, the operating frequency is
increased by about 4 to 10 Hz every 60 seconds until the normal operation condition resumes.
Compressor ON
If the temperature of the indoor unit heat exchanger exceeds the overheat protection temperature for 60 seconds at minimum operating frequency, the compressor stops operating and then restarts after about
180 seconds, and the abovementioned control is repeated.
When the air conditioner starts up in heating mode, the indoor unit fan
will not operate until the temperature of the indoor unit heat exchanger
reaches about 23C in order to prevent cold air from blowing into the
room.
Also, the indoor unit fan operates at low speed until the temperature of
the indoor unit heat exchanger reaches about 38C so that people in
the room will not feel chilly air flow.
If the temperature of the outdoor unit heat exchanger exceeds the outdoor unit heat exchanger overheat protection temperature for (120 sec
: outdoor temperature 40C 60 sec : outdoor temperature < 40C)
at minimum operating frequency, the compressor stops operating and
then restarts after about 180 seconds, and the abovementioned control is repeated.
35
When the air conditioner starts up in cooling mode, the discharged air
temperature is lowered slightly, and for the reduction of unpleasant
odors the operation of the indoor unit fan is delayed 60 seconds if the
automatic fan speed mode in cooling mode is set.
If the temperature of the compressor exceeds the compressor overheat prevention temperature (110C), the operation frequency is
decreased by about 4 to 10 Hz. Then, this operation is repeated every
60 seconds until the temperature of the compressor drops below the
overheat protection temperature (100C).
28
AEX12GRN
1.10. Startup control
When the air conditioner starts in the cooling or heating mode, if the
room temperature is 2C higher than the set temperature (in cooling
operation) or 3.5C lower (in heating operation), the air conditioner
operates with the operating frequency at maximum. Then, when the
set temperature is reached, the air conditioner operates at the operating frequency determined by fuzzy logic calculation, then enters the
normal control mode after a while.
If the current flowing in the air conditioner exceeds the peak control
current (see the table below), the operation frequency is decreased
until the current value drops below the peak control current regardless
of the frequency control demand issued from the indoor unit based on
the room temperature.
Model
AY-XP12GR-N
1.13. Defrosting
2) The self-diagnostic memory can be recalled and shown on the display by stopping the operation and holding down AUX button for
more than 5 seconds.
Start of
heating
operation
20 min or more
20 min or more
If a malfunction occurs, LED1 on the outdoor unit flashes in 0.2-second intervals as shown below.
Defrosting
Max. 10 min
Defrosting
Max. 10 min
ON
1.14. ON timer
OFF
1 sec 1 sec 0.6 sec
When this timer is set, the compressor operating frequency lowers for
quieter operation, and the room temperature is gradually varied after
one hour (reduced 1C three times (max. 3C) in heating, or increased
0.3C three times (max. 1C) in cooling or dehumidifying operation) so
that the room temperature remains suitable for comfortable sleeping.
the figures in ( ) are temperature settings
Heating operation
Set temperature
Activation of
OFF timer
-1 C
1 hour
later
Activation of
OFF timer
0.3 C
0.3 C
1 hour
later
-1 C
-1 C
Max.
Max.
Timer setting
1.5 hours 2 hours reached
later
later
Cooling/dehumidifying operation
Set temperature
0.3 C
Max.
Max.
Timer setting
1.5 hours 2 hours reached
later
later
29
AEX12GRN
1.19. Airflow control
The airflow control holds the two upper and lower louvers at special
positions during operation to prevent discharged air from directly blowing onto people in the room.
1.19.2 Heating
When the airflow button is pressed the lower louver is set at a downward angle to send the air directly toward the floor.
Manual mode
Auto mode
1.3 C
O
0.6 C
Set temperature
2) If the room temperature remains in the hot keep zone, the compressor is turned OFF and ON in 3-minute intervals.
If the room temperature is 26C or higher when dehumidifying operation starts, the dehumidifying operation provides a low cooling effect in
accordance with the room temperature setting automatically determined based on the outside air operation. (The setting value is the
same as the set temperature for cooling operation in the auto mode.)
3) The indoor unit fan turns OFF and ON with a delay of 30 seconds
from the compressor OFF/ON.
4) After the above operation in 3-minute intervals is repeated four
times, the interval extends to 6 minutes.
If the room temperature is lower than 26C when dehumidifying operation starts, the dehumidifying operation minimizes the lowering of the
room temperature.
The operation stops after 40 minutes. (The air conditioner shows the
remaining minutes: 40 39 38 ... 3 2 1)
Heating operation
3) While the compressor is completely OFF in 2), the louvers are set
horizontally to prevent cold air from blowing.
The zone transition and the end of hot keep operation (room temperature lower than the set temperature) are judged when the compressor
ON period ends.
Fan operation
O
24 C
2 10
AEX12GRN
1.26. Auto restart
When power failure occures, after power is recovered, the unit will
automatically restart in the same setting which were active before the
power failure.
Swing louvre
Plasmacluster mode
Timer setting
Internal cleaning
Temperature setting
Fan setting
Power ON/OFF
12V
AC230V
IC6
R76
R75
R23
SSR
Microcomputer output
C23
RE RH
Cluster unit
R20
3
5
6
Reactor L5
DB1
AC
230V
Noise
filter
IPM
Reactor L6
Compressor
DB2
IGBT
drive
circuit
AC clock
detection
circuit
IGBT
[PAM drive circuit]
Microcomputer (IC1)
PAM drive circuit block diagram
2 11
Overvoltage
detection
circuit
Compressor
position
detector
AEX12GRN
When the IGBT is ON, an electric current flows to the IGBT via the reactor (L5), (L6) and diode bridge (DB2).
When the IGBT turns OFF, the energy stored while the IGBT was ON is charged to the voltage doubler capacitor via the diode bridge (DB1).
As such, by varying the ON/OFF duty of the IGBT, the output voltage is varied.
DB1
Reactor
Stored energy
L5
L6
DB2
IGBT ON
IGBT OFF
IGBT
AC voltage waveform
AC voltage waveform
AC current waveform
AC current waveform
Zero-cross detection
IGBT ON period
AC voltage waveform
Clock
50Hz
A
1.2mS
B
1.2mS
C 0.25 2.3mS
IGBT ON
B
The clock circuit determines the time from one rising point of the clock waveform to the next rising point.
The zero-cross of the AC voltage is judged as the rising of the clock waveform, as shown in the diagram above.
The detected clock waveform is used to judge the power source frequency (50Hz).
Based on the zero-cross of the AC voltage, the IGBT turns ON after a delay time set according to the power source frequency.
After the above delay time, the IGBT turns ON to supply a current to the reactor.
The ON time of the IGBT determines the amount of energy (level of DC voltage rise) supplied to the reactor.
DC voltage level in each operation mode (varies depending on external load conditions)
Cooling operation --- 220 to 240 V
Heating operation --- 220 to 280 V
2 12
AEX12GRN
3.3. PAM protection circuit
To prevent excessive voltage of PAM output from
damaging the IPM and electrolytic capacitor as well
as the control printed circuit board (PCB), this circuit
monitors the PAM output voltage and turns off the
PAM control signal and PAM drive immediately
when an abnormal voltage output is generated. At
the same time, it shuts off the compressor operation.
(Overvoltage detection)
15V
5V
420V
750uF
C9
C10
R2
255K
R114
1M
R112
15K
R5
300K
R115
1.8K
R116
1K
IC1
38
R7
23.7K
R8
23.7K
0V
R113
19.1KF
IC8
0V
0V
All units shut down completely when the error occurs four times.
2) When the outdoor unit clock waveform differs from the specified value immediately before the PAM IGBT turns ON
When there is no clock waveform input
When a clock signal of other than specified power source frequency (50/60 Hz) is input
When an error is detected
Malfunction No. 14-0 is indicated when the error code is called out by the indoor unit's self-diagnosis function.
The LED on the outdoor unit flashes 14 times when an error is generated.
The LED continues flashing in the 14-time cycle even after the compressor stops operating.
The LED turns off (data is deleted from the memory) when the outdoor unit power is turned off.
In case of error 2)
An error signal is sent to the indoor unit as soon as an error is judged.
Malfunction No. 14-1 is indicated when the error code is called out by the indoor unit's self-diagnosis function.
The LED on the outdoor unit flashes 14 times when an error is judged.
The LED on the outdoor unit flashes in normal pattern when the compressor stops operating.
(Compressor OFF or Thermostat OFF from remote control)
When a user complains that the air conditioner does not provide sufficient cool air or warm air
In addition to conventional error-generating reasons, there is a possibility that the PAM IGBT does not turn ON even if the compressor is operating.
In that case, the DC voltage does not rise even though the compressor is operating, and lowers to the 180-VDC level.
Check items
2 13
AEX12GRN
4. Explanation of IPM drive circuit
The IPM for compressor drive is made by Mitsubishi Electric.
The power supply for the IPM drive, the shunt resistance for overcurrent detection, etc., are provided outside the IPM (control PCB).
P(Vcc)
Bootstrap capacitor
(HU,HV,HW)
HVIC
VDB
U,V,W,
High-voltage-withstanding,
high-speed recovery diode
VD
(LU,LV,LW)
N-side
IGBT
LVIC
VCIN(n)
N(GND
Bootstrap circuit
2 14
AEX12GRN
4.1.2 DC overcurrent detection circuit
When a current of about 25 A or higher flows through the shunt resistance (R49) on the control printed circuit board (PCB), the voltage at this resistance is input to IPM CIN pin (26). Then, the gate voltage of the lower-phase IGBT (LU, LV, LW) inside the IPM turns OFF to cut off the overcurrent. At
the same time, an L output of about 1.8 ms is generated from IPM Fo pin (24), and this results in an L input to overcurrent detection input pin (34) of
the microcomputer (IC1) and turns OFF the PWM signal output (IC1 pins (51) through (56)) to the IGBT gate.
SET
RESET
(Lower phase)
Internal IGBT gate
(About 22 A)
SC
a1
About 1.8 ms
Error output Fo
Shunt resistance
Overcurrent
R49
5V
IC1
34
IPM overcurrent
detection circuit
CiN
26
FO
0V
24
2 15
AEX12GRN
5. 120 energizing control (digital position detection control)
This control system detects the digital position detection signal and adjusts the rate of acceleration/deceleration accordingly.
The motor's induced voltage waveform is input to the comparator in the form of PWM-switched pulse waveform, and a position detection signal is
generated as a reference voltage equaling 1/2 of 280 VDC. However, since there is no induced voltage waveform when the PWM waveform is OFF,
the microcomputer performs internal processing so that detection is enabled only when it is ON. Based on the detected position signal, actual PWM
waveform output timing is determined. Since it does not use a filter circuit, the detection accuracy is high.
The microcomputer performs internal processing to cancel spike voltage during the regenerative process.
Furthermore, even if the induced voltage is low, position detection is still possible, thus allowing sensor-less operation at low rotation speed in the initial stage of operation. This reduces the starting current and improves the IPM reliability.
Reference voltage
(1/2 of DC voltage)
Spike voltage
(cancelled)
2 16
AEX12GRN
Service
Manual
CHAPTER 3. FUNCTION AND OPERATION
OF PROTECTIVE
PROCEDURES
AEX12GRN
DC overcurrent
error
Operation
Description
Detection period
Reset condition
Self-diagnosis
result display
Indoor
Outdoor
unit
unit
Operation OFF or ON
Indoor
unit error
display
2
Yes
None
Operation OFF or ON
Yes
None
When in cooling or
dehumidifying operation
None
None
None
Yes
Yes
When in heating
operation
None
Yes
Yes
When in cooling or
dehumidifying operation
None
Yes
Yes
When compressor is
in operation
None
Yes
Yes
None
Yes
Yes
Yes 1
Yes
Yes
When in cooling or
dehumidifying operation
When compressor is
in operation
31
AEX12GRN
Function
AC overcurrent
error
10
AC overcurrent
error in compressor
OFF status
11
12
13
14
Compressor high
temperature error
15
16
17
18
19
20
21
22
23
24
Operation
Description
Detection period
Reset condition
When compressor is
in operation
Operation OFF or ON
When compressor is
in non-operation
When compressor is
in operation
When compressor is
in operation
Self-diagnosis
result display
Indoor
Outdoor
unit
unit
Indoor
unit error
display
Yes 1
Yes
Yes
Replacement of
defective parts such
as IPM
Yes 2
Yes
Yes
Operation OFF or ON
Yes 1
Yes
Yes
Operation OFF or ON
Yes 1
Yes
Yes
Operation OFF or ON
Yes 1
Yes
Yes
When in operation
Operation OFF or ON
Yes 1
Yes
Yes
At compressor startup
Operation OFF or ON
Yes 1
Yes
Yes
At compressor startup
Operation OFF or ON
Yes 1
Yes
Yes
At compressor startup
Operation OFF or ON
Yes 1
Yes
Yes
At compressor startup
Operation OFF or ON
Yes 1
Yes
Yes
At compressor startup
Operation OFF or ON
Yes 1
Yes
Yes
At compressor startup
Operation OFF or ON
Yes 1
Yes
Yes
At compressor startup
Operation OFF or ON
Yes 1
Yes
Yes
At compressor startup
Operation OFF or ON
Yes 1
Yes
Yes
At compressor startup
Operation OFF or ON
Yes 1
Yes
Yes
When in operation
Yes
None
When in operation
Operation OFF or ON
(Automatic reset
when less than 8 minutes)
Reset after reception
of serial signal
None
None
32
None
AEX12GRN
Function
25
26
Operation
27
28
29
PAM overvoltage
error
PAM clock error
30
Description
Detection period
Reset condition
At compressor startup
Compressor operating at 120 energizing
Self-diagnosis
result display
Indoor
Outdoor
unit
unit
Operation OFF or ON
Indoor
unit error
display
Yes 3
Yes
Yes
Operation OFF or ON
Yes 3
Yes
Yes
Operation OFF or ON
Yes 1
Yes
Yes
When in operation
Operation OFF or ON
Yes 1
Yes
Yes
None
Yes
Yes
At compressor startup
Operation OFF or ON
Yes 1
Yes
Yes
1The outdoor unit restarts four times before the indoor unit error is displayed (complete shutdown).
2A single error judgment results in the display of the indoor unit error (complete shutdown).
3The outdoor unit restarts eight times before the indoor unit error is displayed (complete shutdown).
Heat exchanger
thermistor (TH2)
Mode
Control operation
When resistance is
low (temperature
judged higher than
actual)
Cooling mode is activated even if room
temperature is low.
Auto
Operation mode
judgment
Cooling
Frequency control
Dehumidifying
Normal operation.
Heating
Frequency control
Cooling
Dehumidifying
Heating
Freeze prevention
Cold air prevention
33
Short-circuit
When resistance
is high (temperature judged lower
than actual)
Heating mode is
activated even if
room temperature is
high.
Room does not
become cool.
Normal operation.
Compressor stops
occasionally.
Cold air prevention
deactivates too
slow.
Open-circuit
Heating mode is
always activated.
Compressor does
not operate.
AEX12GRN
2. Outdoor unit
Item
Control operation
Compressor
chamber thermistor (TH1)
Cooling
Dehumidifying
Heating
Expansion valve
control and compressor protection
Heat exchanger
thermistor (TH2)
Cooling
Dehumidifying
Heating
Expansion valve
control
Defrosting
Defrosting operation
is not activated as
needed, and frost
accumulates on outdoor unit (expansion
valve is closed).
Auto
Operation mode
judgment
Cooling
Dehumidifying
Operation not
affected
Normal operation.
Heating
Rating control
Defrosting
Defrosting operation
is activated unnecessarily.
Cooling
Dehumidifying
Expansion valve
control
Heating
Expansion valve
control
Cooling
Dehumidifying
Expansion valve
control
Heating
Operation not
affected
Frost accumulates on
indoor unit evaporator and room does
not become cool
(expansion valve is
closed).
Normal operation.
When resistance is
low (temperature
judged higher than
actual)
Compressor operates, but room does
not become cool or
warm (expansion
valve is open).
Compressor operates
at low speed or stops.
Short-circuit
Mode
34
Compressor high
temperature error
indication.
When resistance
is high (temperature judged lower
than actual)
Layer short-circuit
or open-circuit may
result in compressor in normal operation.
Normal operation.
Open-circuit
AEX12GRN
TH2
K
100
CN4
1 CN4
80
Resistance
(K )
60
Tester
40
Tester
20
Symbol
Thermistor
Color
Room temperature
TH1
(CN4)
Yellow
Heat exchanger
TH2
(CN4)
Orange
0
-10
10
20
30
Temperature(
40
Connector
CN8
10
10
500K
40K
Tester
Resistance 400K
(K )
Resistance at 0
14.57 k
Resistance
(K ) 30K
300K
Resistance at 25
52.76 k
5.8K
3.06K
4.17K 2.28K
100K
Resistance at 25
4.431 k
TH2 TH5
20K
200K
Tester
(In case of TH2 heat exchanger thermistor)
10K
1.72K
0
-20
20
60
80
Temperature(
100
120
-20
20
40
60
Temperature(
No.
Thermistor
Connector
Color
Compressor thermistor
Red
Orange
Green
Suction thermistor
Black
Yellow
C10
C9
(L2)
35
AEX12GRN
Inspection method
Check visually.
Check melting of FU1, FU2.
Normal value/condition
There should be no cracking in PWB
or pattern.
There should be no open-circuit.
Remedy
Replace PWB.
Normal value/condition
Refer to THERMISTOR TEMPERATURE CHARACTERISTICS 1
There should be no open-circuit or
faulty contact.
Thermistor should not be disconnected.
Remedy
Replace thermistor.
Normal value/condition
Fan speed should change except during dehumidifying operation, ventilation, light dehumidifying operation,
internally normal operation
Remedy
Explain to user.
Normal value/condition
2.5 V or higher (two batteries in series
connection)
As indicated on battery compartment.
Remedy
Install new batteries.
Replace PWB.
Inspection method
Measure thermistor resistance (dismount for check).
Replace thermistor.
Install correctly.
Inspection method
Check operation mode.
Inspection method
Measure battery voltage.
Normal value/condition
Louvers should operate smoothly.
Remedy
Remove or correct catching section.
Install correctly.
Inspection method
Operate to see if louvers are
caught in place.
Inspect connectors.
Check visually.
36
AEX12GRN
6. There is noise in TV/radio
Main cause
Grounding wires not connected
properly.
TV/radio is placed too close to
outdoor unit.
Other than above.
Inspection method
Check grounding wire connections.
Check distance between TV/radio
and outdoor unit.
Check for radio wave interference. (See page )
Normal value/condition
Grounding wires should be connected
properly.
If TV/radio is placed too close, it may
become affected by noise.
Remedy
Connect grounding wires properly.
Move TV/radio away from outdoor
unit.
Normal value/condition
Remedy
7. Malfunction occurs
Main cause
Malfunction caused by noise.
Inspection method
Check for radio wave interference. (See page )
Inspection method
Check wiring between indoor and
outdoor units.
Check IPM continuity.
Check electrolytic capacitor.
Compressor lock.
Normal value/condition
Terminal board 1-N: 230 VAC, 50 Hz
Terminal board 2: serial signal
Refer to IPM check method 3
Refer to Inverter electrolytic capacitor
(C9, C10) check method 2
Fuse should not be blown.
23010 VAC, 50 Hz
Compressor should start normally.
Remedy
Correct wiring.
Replace IPM.
Replace electrolytic capacitor.
Replace fuse/diode bridge.
Replace fuse.
Replace outdoor unit PWB
assembly.
Make sure that power supply voltage is 180 V or higher.
Apply external impact to compressor.
Replace compressor.
9. Operation stops after a few minutes and restarts, and this process repeats
Main cause
Dried-up electrolytic capacitor.
Layer short-circuit in expansion
valve coil.
Inspection method
Measure 320-VDC line voltage.
Measure resistance.
Normal value/condition
250 V or higher.
463 in each phase (at 20C)
Remedy
Replace electrolytic capacitor.
Replace coil.
CAUTION: If fuse FU1/FU4/FU5 (outdoor unit control circuit board) is blown, be careful of charging voltage in inverter electrolytic capacitor C9, C10.
To discharge stored electricity, unplug the power cord and connect the plug of a soldering iron (100VAC, 50W) between the positive and
negative terminals of inverter electrolytic capacitor C9, C10.
37
AEX12GRN
NO
YES
Is LED1 on outdoor
unit flashing?
NO
YES
No
(unlit)
Immediately
after startup
YES
NO
NO
Normal
YES
NO
Disconnect expansion
valve connector.
YES
NO
YES
YES
YES
NO
Replace compressor.
38
YES
OK
NO
+13 V on PWB.
End.
AEX12GRN
2. Procedure for determining defective expansion valve
Measure resistance in expansion valve coil.
NO
YES
Checker
NO
Connector
J.S.T. XAP-06V-1
Terminal
SXA-001T-P0.6
YES
6JGTOKUVQTUKP
PQTOCNEQPFKVKQP
&GHGEVKXGVJGTOKUVQT
4GRNCEGVJGTOKUVQTCUUGODN[
4GRNCEGGZRCPUKQP
XCNXGCUUGODN[
45
(several M )
Value in ( ) is for digital tester.
39
AEX12GRN
5. IPM check method
Turn off the power, let the large capacity electrolytic capacitor (C10) discharge completely, and dismount the IPM. Then, using a tester, check leak
current between C and E.
When using a digital tester, the (+) and (-) tester lead wires in the table must be reversed.
Needle-type tester
(-)
(+)
P
N
U
V
W
Needle-type tester
(-)
(+)
U
N
V
W
(several M)
(several M)
9
8
7
%+0
%(1
%(1
%+0
801
9176
)0&
80%
(1
90
(Q
90
80
80
70
70
80
92
82
8176
8%%
85
%1/
.8+%
*1
+0
8$
*8+%
8%%
89(5
85
%1/
82
89($
*1
+0
8$
*8+%
8%%
82
88($
88(5
85
%1/
72
*1
+0
8%%
82
87(5
87($
*8+%
8$
7176
&+2+2/
80
1. Checking procedures
No
.
1
Item
Preparation
Check method
Normal value/condition
320 VDC
3 10
Remedy
AEX12GRN
No
.
4
Item
Compressor check
Final check
Check method
Normal value/condition
Remedy
NO
Does LED light?
YES
Is voltage between NO
IPM pins (31) and
(35) 320 V or
higher?
YES
NO
Check indoor
unit.
Is switching power NO
supply output of
13 VDC, 15 VDC
produced?
YES
Is 5 VDC output
produced?
NO
Malfunction of 3-terminal regulator IC4, IC1
YES
Microcomputer oscillator error
Malfunction of microcomputer reset IC
Malfunction of microcomputer
NO
Normal
3 11
AEX12GRN
3. Caution in checking printed circuit boards (PWB)
3.1. Non-insulated control circuit
The GND terminals of the low-voltage circuits (control circuits for microcomputer and thermistors and drive circuits for expansion valve and relays) on
the control printed circuit board (PWB) are connected to the compressor drive power supply (320-VDC negative terminal). Therefore, exercise utmost
caution to prevent electric shock.
If a measuring instrument used for the test is grounded, its chassis (ground) has the same electric potential as the 0-V probe. Since non-insulated circuits have the following voltage potential difference from the ground, connection of the grounding wire results in a short-circuit between the 0-V line
and the ground, thus allowing an excessive current to flow to the tester to cause damage.
If the sheaths of the thermistor lead wires or expansion valve lead wires inside the outdoor unit become damaged due to pinching by the front panel
or other metal parts or contacting a pipe, a high voltage can flow and destroy the circuits. To prevent these problems, carefully conduct assembly
work.
Reactor
2
+
-
AC230V
IPM
1
Compressor motor
Ground
0-V line
Point (F)
Danger!!
Do not connect
the grounding
wire.
Reason
The oscilloscope (chassis ground) has the same electric potential as the 0-V probe. The
entire electronic control section of the outdoor unit has a voltage potential difference from
the ground as shown in the above diagram. When the oscilloscope is set up, the 0-V line
and the ground voltage (ground) will be short-circuited, resulting in an excessive current
flow to cause damage to the oscilloscope or indoor electric circuits.
3 12
AEX12GRN
The number of indications displayed by the LEDs on the outdoor unit differs from that for the 2001 cooling unit models (for detailed display of malfunction information).
The display of malfunction No. differs from that of the 2001 cooling unit models. To show detailed malfunction information, two types of numbers
flash alternately. (example: "21" "-0")
1) The content of the self-diagnosis memory can be called out and displayed on the seven-segment display section on the indoor unit. (The error
data cannot be called out for display by the LED on the outdoor unit.)
2) If the power cord is unplugged from the AC outlet or the circuit breaker is turned off, the self-diagnosis memory loses the stored data.
a) The self-diagnosis display function of the indoor unit indicates the content of diagnosis by showing the error main category (number) and the
error sub-category (-number) alternately in 1-second intervals on the seven-segment display section of the indoor unit.
Example of self-diagnosis display on indoor unit: Compressor high-temperature error
'TTQTOCKPECVGIQT[
'TTQTUWDECVGIQT[
b) The self-diagnosis display function of the outdoor unit indicates the error information by flashing LED1 on the outdoor unit according to the content of self-diagnosis.
The self-diagnosis display function of the outdoor unit is active only for about 3 to 10 minutes after self-diagnosis is performed during operation,
and the display returns to normal condition after this display period.
The content of self-diagnosis cannot be called out by the self-diagnosis display function of the outdoor unit.
Example of self-diagnosis display on outdoor unit: Compressor high-temperature error
ON
OFF
1 sec 1 sec 0.6 sec 1 sec 0.6 sec 1 sec 1 sec 1 sec 0.6 sec 1 sec 0.6 sec 1 sec 1 sec
c) The content of diagnosis is transferred to the indoor unit via serial communication, but it does not trigger a complete shutdown operation.
: Flashes in 2-sec intervals (normal), : On,
intervals, the outdoor unit is in normal condition.)
Status of
indoor/
outdoor
units
Indoor/
outdoor
units in
operation
Indoor/
outdoor
units in
complete
shutdown
Indication
by LED1
on outdoor unit
*2
Normal
flashing
1 time
Malfunction
No. displayed on
main unit
display section *1
Main Subcate- category gory
0
0
: Off,
: Flashes 3 times in 0.2-sec intervals (When LED1 on the outdoor unit flashes in 2-sec
Content of diagnosis
Main category
Inspection location/method
Remedy
Sub-category
Normal
Heat exchanger
thermistor short-circuit error
(1)
-1
(2)
-2
Suction thermistor
short-circuit error
2-way valve thermistor short-circuit
error
(3)
-0
-3
Outdoor unit
thermistor
short-circuit
3 13
(1)
(2)
(3)
AEX12GRN
Status of
indoor/
outdoor
units
Indoor/
outdoor
units in
complete
shutdown
Indication
by LED1
on outdoor unit
*2
2 times
Malfunction
No. displayed on
main unit
display section *1
Main Subcate- category gory
2
-0
Content of diagnosis
Main category
Sub-category
Cycle temperature
Inspection location/method
(1)
(1)
(2)
(2)
(3)
(4)
(5)
-1
Indoor
unit in
operation
Outdoor
unit in
temporary stop
-2
-3
-4
Indoor
unit in
operation
Outdoor
unit in
temporary stop
Indoor/
outdoor
units in
complete
shutdown
3 times
-0
Dry operation
5 times
-0
Outdoor unit
thermistor
open-circuit
-1
-2
-3
-4
Heat exchanger
thermistor open-circuit error
(1)
(2)
3 14
Remedy
(3)
(4)
(5)
Ensure unobstructed
air flow from the outdoor unit air outlet.
Connect power supply of proper voltage.
Charge the specified
amount of refrigerant.
Replace the outdoor
unit compressor thermistor assembly.
(3)
(4)
(1)
(2)
(3)
(5)
AEX12GRN
Status of
indoor/
outdoor
units
Indoor/
outdoor
units in
complete
shutdown
Indication
by LED1
on outdoor unit
*2
6 times
Malfunction
No. displayed on
main unit
display section *1
Main Subcate- category gory
6
-0
Content of diagnosis
Main category
Sub-category
Outdoor unit DC
DC overcurrent error
Inspection location/method
(1)
(1)
(2)
(2)
(2)
(3)
(4)
(5)
-1
Indoor/
outdoor
units in
complete
shutdown
7 times
-0
Outdoor unit AC
AC overcurrent error
Remedy
(1)
(2)
(3)
(4)
(5)
(1)
-1
AC overcurrent error
in OFF status
(1)
-2
(1)
(1)
(2)
(1)
-3
(1)
(2)
(3)
3 15
(1)
(1)
(2)
(3)
AEX12GRN
Status of
indoor/
outdoor
units
Indoor/
outdoor
units in
complete
shutdown
Indication
by LED1
on outdoor unit
*2
9 times
Malfunction
No. displayed on
main unit
display section *1
Main Subcate- category gory
9
-0
Content of diagnosis
Main category
Outdoor unit
cooling/heating
switchover
Inspection location/method
Sub-category
(1)
(2)
(1)
(3)
(4)
(4)
Compressor startup
error
(1)
(1)
(2)
(1)
(2)
(3)
(4)
-3
(1)
(2)
(3)
-4
(1)
(2)
Indoor/
outdoor
units in
complete
shutdown
Indoor/
outdoor
units in
complete
shutdown
11
times
11
-0
Outdoor unit DC
fan
(1)
(2)
13
times
13
-0
DC compressor
-1
(3)
(4)
Indoor/
outdoor
units in
complete
shutdown
Indoor/
outdoor
units in
operation
14
times
14
-0
-1
Outdoor unit
PAM
Remedy
(1)
(1)
3 16
(2)
(3)
(4)
(1)
(2)
(3)
(2)
(1)
(2)
(3)
(2)
(3)
(4)
(1)
(2)
(1)
AEX12GRN
Status of
indoor/
outdoor
units
Malfunction
No. displayed on
main unit
display section *1
Main Subcate- category gory
17
-0
Indication
by LED1
on outdoor unit
*2
Indoor
unit in
operation
Outdoor
unit in
complete
shutdown
Content of diagnosis
Main category
Wires between
units
Inspection location/method
Sub-category
Serial open-circuit
(1)
(2)
(1)
(2)
(3)
(4)
(5)
18
19
Indoor/
outdoor
units in
complete
shutdown
-0
Serial short-circuit
(1)
-1
(1)
-0
(1)
(2)
(3)
(4)
20
Indoor/
outdoor
units in
operation
Indoor/
outdoor
units in
operation
88
-0
Communication
error
(1)
(2)
(1)
(3)
3 17
(1)
(2)
(4)
(5)
(1)
(1)
(1)
(2)
(3)
(1)
(2)
Symptom
Turns On momentarily, then turns Off.
"18-1"
Outdoor
unit
(2)
Remedy
(4)
AEX12GRN
Inter-unit wiring error mode
2
1
Indoor
unit N
Indoor
unit N
Indoor
unit N
Indoor
unit N
1
Outdoor
unit
Outdoor
unit
Symptom
Relays turns Off after about 30 minutes.
None
(Displays "18-0" when malfunction code is called out.)
Outdoor
unit
5
Outdoor
unit
3 18
AEX12GRN
Service Manual
Indoor unit
Evaporator
Flare coupling
3
Flare coupling
3-way
2-way
valve
valve
Heating
Cooling
Strainer
Muffler
Outdoor unit
Accumulator
4
1
Expansion
valve
Compressor
Coil
Condenser
C
Reverse valve
Cooling
Heating
*
Indoor side
Dry-bulb Temp. (C)
Relative Humidity (%)
27
47
20
Outdoor side
Dry-bulb Temp. (C)
Relative Humidity (%)
35
40
7
87
No.
Hz
(rpm)
1
2
3
4
3-way valve pressure (MPaG)
AY-XP12GR-N
MAX.
Cool
69
(4150)
75C
40C
12C
10C
0.87
Heat
90
(5400)
87C
2C
36C
3C
3.29
TEST RUN
Cool
Heat
42
42
(2500)
(2500)
61C
60C
38C
3C
13C
30C
13C
5C
1.04
2.34
41
AEX12GRN
1. AY-XP12GR-N
1.1. At Cooling
1.2. At Heating
1200
Input(W)
Input(W)
1000
900
800
1000
900
Heating capacity(kW)
Cooling capacity(kW)
700
1100
4.0
3.8
3.6
3.4
3.2
25
30
35
Outside air temp.(C)
5.0
4.5
4.0
3.5
3.0
2.5
40
-5
42
0
5
7
Outside air temp.(C)
10