Mitsubishi Electric CITY MULTI PUHY-P200M-B1-BM How to use

Models PUHY-P200M-B1-BM/PUHY-P250M-B1-BM
Service Handbook
AIR CONDITIONERS CITY MULTI

CONTENTS
- 1 -
I Electrical Wiring Diagram
[1] Electrical Wiring Diagram ....................................................................................................... 2
II Refrigerant Circuit
[1] Refrigerant Circuit Figure........................................................................................................ 3
III Control
[1] Functions and Factory Settings of the Dipswitches ................................................................ 4
IV Test Run Mode
[1] Standard Operation Data (Reference Data) ........................................................................... 5
V Troubleshooting
[1] Check Code Lists.................................................................................................................... 7
[2] Preliminary error Code Lists (Outdoor unit only) .................................................................... 9
[3] Responding to Error Display on the Remote Controller........................................................ 10

- 2 -
[ I Electrical Wiring Diagram ]
I Electrical Wiring Diagram
[1] Electrical Wiring Diagram
4
ONOFF
10
1
SW4
SW1
Detection
circuit
*1
L2
ON
4
1
OFF
CNVCC4
(2P)
CNVCC5
(2P)
1
2
1
2
*For more contents displayed on LD1 with other switch settings, see LED monitor display on the outdoor board.
1
2
3
4
5
6
7
1
2
3
4
5
6
7
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
3
2
1
3
2
1
6
5
4
3
2
1
6
5
4
3
2
1
3
2
1
3
2
1
3
2
1
U
U
W
W
V
V
MC
SLEV
LEV1
Abnormal output
Compressor ON/OFF output
Demand input
Night mode input
Snow sensor input
52
C
CH1
CH2
CH3
63H
SSR
X05
X04
X02
X01
CN20
(7P)
CN32
(3P)
CN33
(6P)
CN35
(3P)
Red
Red
Red
Black
Green
Black
White White
Black
Red Red
Red
Blue
Red Red
Red Red Red
Red
CN34
(6P)
CN38
(3P)
Green Green
CN05
(4P)
CN03
(3P)
CN02
(8P)
CN01
(2P)
CNL
(3P)
TH4 TH3 TH6 TH5 TH8 TH7 TH2 TH1
63LS
CNRS3
(7P)
CNVCC3
(6P)
CNAC3
(5P)
CNLV1
(5P)
CNLV2
(5P)
CN51
(5P)
CN3D
(3P)
CN3S
(3P)
CNRS2
(7P)
CNVCC2
(6P)
CNAC2
(5P)
CN52C
(3P)
CNCT
(4P)
CNDC2
(3P)
CNDR2
(9P)
CN15V2
(14P)
CN15V1
(14P)
CNDR1
(9P)
Yellow
Yellow
CNDC1
(3P)
CNTH
(2P)
CNL2
(2P)
CN30V
(2P)
CNFAN
(3P)
ON
OFF
Factory default
Display of Relay
output 1 (Light ON)
Display of Check 1
(Blink)
Flag 1
Flag 1 Flag 2 Flag 3 Flag 4 Flag 5 Flag 6 Flag 7 Flag 8
Flag 2 Flag 3 Flag 4 Flag 5 Flag 6 Flag 7 Flag 8
Displayed contents when LD1 is lit (blink) Remarks
Operation of SW1
Contents
Compressor
in operation
Crank case
heater 21S4 SV1 SV2 Always
Light ON
Error code display
The error address and the error code are displayed alternately.
Example: Error address 51, Discharge temp. error (Error code 1102)
LD1
<Display of LD1>
LD1
SW1
SWU2
Tens digit Ones digit
SWU1
Unit address setting switch
SV
1
21
S4
SV
2
CNS1
(2P)
CNS2
(3P)
TB3 TB7
Shield
A
ABB
<Operation of SW1 (Self-diagnose switch) on Control Board and Displayed Contents on LD1>
*1 part might not exist.
MF
1
THHS L2 R2
DCCT
MF
5
4
3
2
1
CNFAN1
(5P)
Gate amp board
(G/A PKG)
IPM
Control board
(MAIN PKG) INV board
(INV PKG)
Red
Red White
White
Green
Blue
Red
Red
Blue
Blue
Blue
12V
DSA ZNR1~4
Centralized power supply
CN41
(4P)
CN40
(4P)
1
F1
6A
F2
6A
F01
2A
1
2
3
RSTE
E
T
R
E
T
R
R1
52C
POWER-BOARD
FN1 FN3
FN2
FN6
FN4
DCL
C1
+
P
N
F01
3A
LED1
LED2
LED3
SW2SW3
1
10
1
10
1
10
OFF ONOFF ONOFF ON
63HS
CNH
(3P)
TH9
CN06
(2P)
TH10
CN09
(2P)
63HS High pressure sensor
LEV1
SLEV
THHS
63LS
Choke coil (Transmission)
Electronic expansion valve (SC coil)
Electronic expansion valve (Oil return)
Low pressure sensor
Thermistor (Radiator plate)
Thermistor (Liquid outlet temp. detection at Sub-Cool coil bypass)
TH8
Thermistor (Shell temp. detection at compressor)
Thermistor (Liquid temp. detection at CS circuit)
DC Current Sensor (Direct Current)
Resistance of rush current prevention
Bleeder resistance
Main capacitor (smooth)
Electro-magnetic contactor (Inverter main circuit)
Motor for compressor
Motor Fan (Radiator plate)
Crank case heater (Compressor)
Four-way valve
Solenoid valve (Discharge-suction bypass)
High pressure switch
Thermistor (Discharge piping temp. detection)
Thermistor (Saturation evaporation temp. detection)
Thermistor (Liquid level detection of accumulator, lower)
Thermistor (Liquid level detection of accumulator, upper)
Thermistor (OA temp. detection)
Thermistor (Piping temp. detection)
Thermistor (Liquid outlet temp. detection at Sub-Cool coil)
Terminal block for power supply
Terminal block for transmission line (For indoor series)
Terminal block for transmission line (For centralized administration)
Earth terminal
Code heater (Liquid level detection of accumulator)
DCCT
R1
R2
C1
52C
MC
MF1
CH1
SV1,SV2
21S4
63H
TH1
TH2
TH3
TH4
TH5
TH6
TH7
TB1
TB3
TB7
CH2,CH3
Symbol Symbol Symbol Symbol Name Name Name Name
E
MF Motor Fan (Heat exchanger)
TH10
TH9
Note: Refer to the list shown above for switch settings.
Unit plate
Controller
box plate
E
Connecting to the
indoor unit, remote
controller
TB1
R
S
T
DS (Diode stack)
+
-
Power source
200V 3 phase
50/60Hz
5
4
3
2
1
2
12
3
123
4
1234
1
1
2
12
1212
0
3
123
123
123
4675891234 67589
1234 67589
11
11111111
1
22
22222222
33
33333
3
4467
7
5
5
8
111210 1314
12 3 4 67589111210 1314
1234
1234
ON
OFF
SW3-10
Model
P200
P250
Flag 8 stays lit while power supply
of the microcomputer is turned on.
1234 6758910
Operation
Error
Charge

- 3 -
[ II Refrigerant Circuit ]
II Refrigerant Circuit
[1] Refrigerant Circuit Figure
1. Outdoor unit
SCC
LEV1
HEX f HEX b
TH6
CS circuit
SV2
CP
CJ1
CJ2
63HS
SV1
ST6
CV1
CP3
O/S
63H
63LS
MA SA
ST8
ST4
TH4
TH3
TH7
ST7
LEV1
ST2 BV2
Indoor unit
ST1 BV1
ST3
Comp
Dryer
TH9
TH10
CP
TH2
TH8
TH5
SLEV
ST5

- 4 -
[ III Control ]
III Control
[1] Functions and Factory Settings of the Dipswitches
1. Outdoor unit
(1) Main board
Switch Function Function according to switch setting Switch setting timing
OFF ON ON OFF
SWU 1-2 Unit address setting Set to 00 or 51-100 with the dial switch
(Note 2)
SW1 1-8 For self diagnosis/
operation monitoring Refer to the LED monitor display on the outdoor unit board.
9-10 - - - * Set the switch to OFF
SW2
1Centralized control
switch
Without connec-
tion to the central-
ized controller
With connection to
the centralized
controller
Before power on
2Deletion of connec-
tion information Normal control Deletion Before power on
3Deletion of error his-
tory SW
Storage of IC/OC
error history
Deletion of IC/OC
error history
Anytime after power on (When
switched from OFF to ON)
4Refrigerant amount
adjustment Normal control Refrigerantamount adjustment mode
Anytime after power
on (When switched
from OFF to ON)
10 minutes after
compressor startup
5Heating refrigerant
pay-back time 15 sec. 30 sec. Anytime after power on
6
OA sensor failure/
Liquid level over flow
abnormality enabled
Failure enabled Failure disabled Anytime after power on
7 Forced defrost Normal control Forced defrost
starts
Anytime after power
on (When switched
from OFF to ON)
10 minutes after
compressor startup
8 Defrost timer setting 39 minutes 90 minutes Anytime after power on
(Except during defrost operation)
9- - -
Anytime after power on (Only when
switched from OFF to ON)
10 - - - -
SW3
1SW 3-2 enabled/dis-
abled SW3-2 disabled SW3-2 enabled Anytime after power on
2Test run mode: ON/
OFF Stops all ICs Sends a test-run signal to all ICs
After power on and when SW3-1 is
on.
3
Defrost start temperature -10°C [14°F] -7°C [19°F] Anytime after power on
4
Defrost end temperature 8°C [46°F] 15°C [59°F]
Anytime after power on (Except dur-
ing defrost operation)
LEV opening of IC without
heating thrmo-ON system
during defrost operation
Normal control 2000
5- - - -
6 Pump down operation Normal control Pump down opera-
tion
Anytime after power on (When
switched from OFF to ON)
7
Target condensing
temperature on the
heating mode Tcm
49°C [120°F] 53°C [127°F] Anytime after power on
8- - - -
9Unit model selection
SW 3-10 and 4-4
enabled
SW 3-10 and 4-4
for model P355 dis-
abled
Before power on
10 Model P200 Model P250 Before power on
SW4
1SW4-2 enabled/dis-
abled Disabled Enabled Anytime after power on
2Composition correc-
tion value
Value will be changed as follows when
the switch turns ON to OFF or OFF to ON
±0%→+3%→+6%→+9%→+12%→
-6%→-3%→±0%
SW4-1 is on.
3- - - -
4- - - OFF
5- - - -
6- - - -
7- - - -
8- - - OFF
9- - - -
10 - - - -
Note 1: SWU 1-2 is set to 00 and SWU 3-10 is set in every model, and other SWUs are set to OFF at factory shipment.
Note 2: When the outdoor unit address is set to 100, set the address setting switch to any one of 01-50.

- 5 -
[ IV Test Run Mode ]
IV Test Run Mode
[1] Standard Operation Data (Reference Data)
1. PUHY
(1) Cooling operation
Operation
Outdoor unit model
PUHY-P200 PUHY-P250
Operat-
ing condi-
tions
Ambient
tempera-
ture
Indoor DB/
WB
°C
27/19
Outdoor 35/24
Indoor
unit
No. of connected
units
Unit
4
No. of units in opera-
tion 4
Model - 80 71 56 22 112 80 71 22
Piping
Main pipe
m
5
Branch pipe 10
Total pipe length 45 45
Fan speed - Hi
Amount of refrigerant kg 11.7 13.7
Outdoor
unit
Electric current A 27.7 34.7
Voltage V 200
LEV
opening
Indoor unit
Pulse
270 420 360 250 360 270 420 250
SC (LEV1) 116 132
Oil return section (SLEV) 200 272
Pressure High pressure (after O/S)/low
pressure (before accumulator) MPa 2.15/0.5 (21.9/5.1) 2.15/0.46 (21.9/4.7)
Temp. of
each sec-
tion
Outdoor
unit
Discharge (TH1)
°C
87 97
Heat exchanger out-
let (TH5) 40 42
Accumu-
lator
Inlet 9 7
Outlet 11 9
Compressor inlet 9 12
Low pressure two-
phase temp. (TH2) 42
Liquid level detec-
tion, upper (TH4) 30
Liquid level detec-
tion, lower (TH3) 87
Compressor shell
bottom 75
SC heat exchanger
outlet (TH7)* 27
Bypass outlet (TH8)* 10 8
Indoor
unit
LEV inlet 26
Heat exchanger out-
let 12
Composition detection value
(αOC) 0.23

- 6 -
[ IV Test Run Mode ]
(2) Heating operation
Operation
Outdoor unit model
PUHY-P200 PUHY-P250
Operat-
ing condi-
tions
Ambient
tempera-
ture
Indoor DB/
WB
°C
20/-
Outdoor 7.0/6.0
Indoor
unit
No. of connected
units
Unit
4
No. of units in opera-
tion 4
Model - 80 71 56 22 112 80 71 22
Piping
Main pipe
m
5
Branch pipe 10
Total pipe length 45
Fan speed - Hi
Amount of refrigerant kg 11.7 13.7
Outdoor
unit
Electric current A 27.0 33.5
Voltage V 200
LEV
opening
Indoor unit
Pulse
290 470 410 250 330 290 470 250
SC (LEV1) 0
Oil return section (SLEV) 123 200
Pressure High pressure/low pressure MPa 2.10/0.36 (21.4/3.7) 2.10/0.36 (21.4/3.7)
Temp. of
each sec-
tion
Outdoor
unit
Discharge (TH11/
TH12)
°C
83 88
Heat exchanger out-
let (TH5) -3 -2
Accumu-
lator
Inlet -3 -4
Outlet -3 -4
Compressor inlet -3 -4
Low pressure two-
phase temp. (TH2) -8
Liquid level detec-
tion, upper (TH4) 35 38
Liquid level detec-
tion, lower (TH3) -3
Compressor shell
bottom 35 44
Indoor
unit
LEV inlet 30
Heat exchanger out-
let 74
Composition detection value
(αOC) 0.28

- 7 -
[ V Troubleshooting ]
V Troubleshooting
[1] Check Code Lists
Error Code Error code definition
Searched unit
Notes
0403 Serial communication error O
0900 Test run mode O
1102 Abnormal discharge air temperature O
1111 Low pressure saturation temp. sensor (TH2) O
1112 Abnormal low pressure
saturation temp.
Liquid level detection temper-
ature sensor (TH3) O
1113 Liquid level detection temp.
sensor (TH4) O
1143 Abnormal shell temp. at compressor O
1301 Abnormal low pressure O
1302 Abnormal high pressure O
1500 Excessive or insufficient refrigerant O
2500 Water leakage O
2502 Drain pump failure/Float switch trip O
2503 Drain pump failure/Float switch trip O O
2600 Water leakage O
2601 Water supply cut-off O
4102 Open phase O
4103 Reverse phase/open phase O
4115 Power supply sync signal abnormality O
4116 RPM error/Motor malfunction O O
4121 Harmonics action device error O
4200 Vdc sensor/circuit failure O
4220 Bus voltage drop protection O
4230 Heatsink overheat protection O
4240 Overload protection O
4250 IPM/Bus voltage abnormality O
4260 Cooling fan abnormality O
Temperature sensor
failure
Suction air temperature
(TH21) O
5101 Return of OA processing unit
(TH4) O
Discharge air temperature
(TH1, TH11, TH12) O
5102
Indoor piping (TH22) O
Pipes on the OA processing
unit (TH2) O
Outdoor low pressure satura-
tion (TH2) O
Outdoor unit
Indoor unit
Outdoor temp. processing unit
Remote controller

- 8 -
[ V Troubleshooting ]
5103
Temperature sensor
failure
Gas side pipe (TH23) O
Pipes on the OA processing
unit (gas side) (TH3) O
Outdoor liquid level detection
(TH3) O
5104
Pipes on the OA processing
unit (TH1) O
Liquid level detection (TH4) O
5105 Pipe (TH5) O
5106 Outside air temperature (TH6) O
5107 Liquid temp. (TH7) O
5108 SC coil bypass outlet (TH8) O
5109 Liquid temp. sensor at CS circuit failure (TH9, TH9b) O
5110 Radiator plate at INV temp. sensor failure (THHS) O
5112 Shell temp. sensor at compressor (TH10) O
5201 High pressure sensor failure (HPS) O
5301 IDC sensor/circuit failure O
6600 Address overlaps O O O O
6602 Transmission processor hardware error O O O O
6603 Transmission circuit bus-busy O O O O
6606 Communication error with the transmission processor O O O O
6607 No ACK O O O
6608 No response O O O
6810 UR communication error (UR: unit remote controller) O O O In case of using UR.
7100 Total capacity error O
7101 Capacity code error O O O
7102 Error in the number of connected units O
7105 Address setting error O
7106 Attribute setting error O
7109 Connection settings error O
7110 Unset unit connection information error O
7111 Remote controller sensor failure O O
7130 Incompatible units O
Error Code Error code definition
Searched unit
Notes
Outdoor unit
Indoor unit
Outdoor temp. processing unit
Remote controller

- 9 -
[ V Troubleshooting ]
[2] Preliminary error Code Lists (Outdoor unit only)
Preliminary error code Contents of preliminary error
1202 Abnormal discharge air temp. or discharge air temp. sensor preliminary failure (TH1)
1205 Piping temp. sensor preliminary failure (TH5)
1211 Low pressure saturation temp. or low pressure saturation temp. sensor preliminary failure (TH2)
1212 Low pressure saturation temp. or temp. sensor on liquid level detection preliminary failure (TH4)
1213 Low pressure saturation temp. or temp. sensor under liquid level detection preliminary failure (TH3)
1214 THH sensor/circuit preliminary failure
1216 Liquid outlet temp. sensor at Sub-Cool coil preliminary failure (TH7)
1217 Bypass outlet temp. sensor at Sub-Cool coil preliminary failure (TH8)
1219 Liquid temp. at composition detection or liquid temp. sensor at composition detection preliminary failure
1221 OA temp. sensor preliminary failure (TH6)
1243 Oil temp. at compressor or oil temp. sensor at compressor preliminary failure
1402 High pressure error or pressure sensor preliminary failure
1600 Overfilling refrigerant preliminary error
1605 Preliminary vacuum operation protection
1607 Preliminary CS circuit choking malfunction
4171 Harmonics action device preliminary error
4300
Idc sensor/circuit preliminary failure
Vdc sensor/circuit preliminary failure
Serial communication preliminary error
4320 Preliminary bus voltage drop abnormality
4330 Preliminary heat sink overheat malfunction
4340 Overload protection
4350 Preliminary IPM/Bus voltage abnormality
4360 Cooling fan preliminary failure

- 10 -
[ V Troubleshooting ]
[3] Responding to Error Display on the Remote Controller
1. Mechanical system
Error Code Error definition and error
detection method Cause Check method and remedy
0403 Serial commu-
nication error
Serial communication er-
ror between the main
board and the INV board.
(1) Faulty wiring Check for wiring between the con-
nector (CNRS3B) on the main board
and the connector (CNRS2) on the
INV board. Check for contact of the
connectors.
(2) Inverter board switch set-
ting error
Confirm that the SW1-4 on the INV
board is set to OFF.
(3) INV board failure Replace the compressor INV board
when the power turns on automati-
cally, even if the power source is re-
set.
1102 Abnormal dis-
charge air tem-
perature
1.If the discharge tem-
perature of 140°C
[284°F] or more is de-
tected during the
above operation (the
first detection), the
outdoor unit stops
once, turns to anti-re-
start mode for 3 min-
utes, and restarts after
3 minutes automati-
cally.
2.If the discharge tem-
perature of 140°C
[284°F] or more is de-
tected again (the sec-
ond detection) within
30 minutes after the
second stop of the
outdoor unit described
above, the mode will
be changed to 3-
minute restart mode,
then the outdoor unit
will restart in 3 min-
utes.
3.If the discharge tem-
perature of 140°C
[284°F] or more is de-
tected (the third detec-
tion) within 30 minutes
after the stop of the
outdoor unit described
above (regardless of
the first or the second
stop), the outdoor unit
will make an error
stop, and the error
code "1102" will be
displayed.
4.If the discharge tem-
perature of 140°C
[284°F] or more is de-
tected more than 30
minutes after the pre-
vious stop of the out-
door unit, the
detection is regarded
as the first detection,
and the operation de-
scribed in step 1
above will start.
5.For 30 minutes after
the stop (the first stop
or the second stop) of
the outdoor unit, pre-
liminary errors will be
displayed on the LED
display.
(1) Gas leak, gas shortage Check the refrigerant amount.
(2) Overload operation Check operating conditions and op-
eration status of indoor/outdoor
units.
(3) LEV failure on the indoor
unit
(4) LEV1 failure on the out-
door unit
Perform a cooling or heating opera-
tion and check the operation.
Cooling : LEV on the indoor unit
LEV1
Heating : LEV on the indoor unit
Check the LEV.
(5) Closed ball valve Confirm that the ball valve is fully
open.
(6) Outdoor fan (including fan
parts) failure, motor failure,
or fan controller malfunc-
tion
Rise in discharge temp. by
low pressure drawing for
(3) - (6).
Check the fan on the outdoor unit.
Refer to the section on troubleshoot-
ing the outdoor unit fan.
(7) Gas leak between low and
high pressures
(4-way valve failure, Com-
pressor failure, Solenoid
valve (SV1, SV2) failure)
Perform a cooling or heating opera-
tion and check the operation.
(8) Solenoid valve (SV2) fail-
ure (The by-pass valve
(SV2) can not control rise
in high pressure.)
Check the solenoid valve
(9) Thermistor failure
(TH1,TH11,TH12)
Check the thermistor resistor.
(10) Input circuit failure on the
controller board thermistor
Check the inlet air temperature on
the LED monitor.

- 11 -
[ V Troubleshooting ]
1111 Saturation
temp. sensor
(TH2)
1.If the saturation temp.
sensor TH2 or temp.
sensor for liquid level
detection TH3/TH4
detects -40°C [-40°F]
or lower during the
above operation (the
first detection), the
outdoor unit stops
once, turns to anti-re-
start mode for 3 min-
utes, and restarts after
3 minutes automati-
cally.
2.If the discharge tem-
perature of -40°C
[-40°F] or lower is de-
tected again (the sec-
ond detection) within
30 minutes after the
second stop of the
outdoor unit described
above, the mode will
be changed to 3-
minute restart mode,
then the outdoor unit
will restart in 3 min-
utes.
3.If the discharge tem-
perature of -40°C
[-40°F] or lower is de-
tected (the third detec-
tion) within 30 minutes
after the stop of the
outdoor unit described
above (regardless of
the first or the second
stop), the outdoor unit
will make an error
stop, and the error
code "1111", "1112" or
"1113" will be dis-
played.
4.If the discharge tem-
perature of -40°C
[-40°F] or lower is de-
tected more than 30
minutes after the pre-
vious stop of the out-
door unit, the
detection is regarded
as the first detection,
and the operation de-
scribed in step 1
above will start.
5.For 30 minutes after
the stop (the first stop
or the second stop) of
the outdoor unit, pre-
liminary errors will be
displayed on the LED
display.
Note 1: The Saturation temp.
error. is not detected
for 3minutes after the
compressor starts,
during the defrost op-
eration and for 3 min-
utes after the defrost
operation stops.
Note 2: When short/open is
detected by the sen-
sor TH2-TH4 in ten
minutes before and
after the compressor
runs, "1111", "1112"
or "1113" will be dis-
played.
(1) Gas leak, gas shortage Check the refrigerant amount.
(2) Light-load operation Check operating conditions and op-
eration status of indoor/outdoor
units.
(3) LEV failure on the indoor
unit
(4) LEV1 failure on the out-
door unit
→Cooling
Perform a cooling or heating opera-
tion and check the operation.
Cooling : LEV on the indoor unit
LEV1
Heating : LEV on the indoor unit.
Check the solenoid valve
(5) Ball valve failure Confirm that the ball valve is fully
open.
1112 Liquid level de-
tection temp.
sensor
(TH4)
(6) Short cycle on the indoor
unit side
Check the indoor units for problems
and correct them, if any.
(7) Clogged filter on the indoor
unit
(8) Reduced air flow due to
dirty fan on the indoor unit
(9) Dirty heat exchanger of the
indoor unit
(10) Fan block of the indoor
unit and the motor failure
Lowered in low pressure
caused by lowered evapo-
ration capacity in cooling
operation for (5) - (10).
(11) Short cycle on the out-
door unit side
Check the outdoor units for prob-
lems and correct them, if any.
(12) Dirty heat exchanger of
the outdoor unit
1113 Liquid level de-
tection temp.
sensor
(TH3)
(13) Fan block of the indoor
unit, the motor, the fan
condenser and the mag-
netic contactor 52F failure
Lowered in low pressure
caused by lowered capaci-
ty in heating operation for
(11) - (12), or evaporation
capacity excess in cooling
operation.
Check the outdoor fan.
(14) Solenoid calve SV2 fail-
ure
The by-pass valve (SV2)
can not control drop in low
pressure.
Check the solenoid valve
(15) Thermistor failure (TH2-
TH6)
Check the resistance value of the
thermistor
(16) Pressure sensor failure Check the pressure sensor
(17) Thermistor on the control
board/input circuit of the
pressure sensor failure
Check the inlet temperature of the
sensor/pressure on the LED moni-
tor.
(18) Thermistor settings error
(TH2-6)
Error Code Error definition and error
detection method Cause Check method and remedy

- 12 -
[ V Troubleshooting ]
1143 Shell tempera-
ture sensor of
compressor
(TH10)
1.If the shell tempera-
ture sensor of com-
pressor (TH10)
detects 85°C [185°F]
and more for 60-min-
utes stretch (the first
detection), the out-
door unit stops at once
turns to anti-restart-
mode for 3 minutes,
and restarts after 3
minutes automatically.
2.If the shell tempera-
ture sensor of com-
pressor detects 85°C
[185°F] and more for
60-minutes stretch
(the second detec-
tion), the outdoor unit
will make an error stop
and the error code
"1143" will be dis-
played.
3.If the shell tempera-
ture sensor of com-
pressor detects 85°C
[185°F] and more for
60-minutes stretch
(the third detection) af-
ter the previous stop
of the outdoor unit, the
detection is regarded
as the first detection,
and the operation de-
scribed in step 1
above will start.
4.For 2 hours after the
stop (the first stop or
the second stop) of
the outdoor unit, pre-
liminary errors will be
displayed on the LED
display.
(1) Gas leak, gas shortage Check the refrigerant amount.
(2) Heavy-load operation Check operation conditions and op-
eration status of indoor/outdoor
units.
(3) LEV failure on the indoor
unit
(4) LEV1 failure on the out-
door unit
(5) SLEV failure on the indoor
unit
Perform a cooling or heating opera-
tion and check the operation status.
Cooling : LEV on the indoor unit
LEV1
SLEV
Heating : LEV on the indoor unit
SLEV
Check LEV and the solenoid valve.
(6) Ball valve failure Confirm that the ball valve is fully
open.
(7) Thermistor failure Check the resistance value of the
thermistor.
(8) Thermistor input circuit
failure
Check the inlet temperature of the
sensor on the LED monitor
1301 Abnormal low
pressure
When starting the com-
pressor from Stop Mode
for the first time if low-
pressure reads
0.098MPa [14psi] imme-
diately before start-up,
the operation immediate-
ly stops.
(1) Inner pressure drop due to
a leakage.
(2) Low pressure sensor fail-
ure
(3) Short-circuited pressure
sensor cable due to torn
outer rubber
(4) A pin on the male connec-
tor is missing.
(5) Disconnected wire
(6) Failure of the low pressure
input circuit on the control-
ler board
Check the low pressure sensor.
Error Code Error definition and error
detection method Cause Check method and remedy

- 13 -
[ V Troubleshooting ]
1302 Abnormal high
pressure 1
(outdoor unit)
1.If the pressure of
2.74MPa [397psi] or
higher is detected by
the pressure sensor
during operation (the
first detection), the
outdoor stops once,
turns to anti-restart
mode for 3 minutes,
and restarts after 3
minutes automatically.
2.If the pressure of
2.74MPa [397psi] or
higher is detected by
the pressure sensor
again (the second de-
tection) within 30 min-
utes after the first stop
of the outdoor unit, the
outdoor unit stops
once, turns to anti-re-
start mode for 3 min-
utes, and restarts after
3 minutes automati-
cally.
3.If the pressure of
2.94MPa [426 psi] or
higher is detected by
the pressure sensor
(the third detection)
within 30 minutes of
the second stop of the
outdoor unit, the out-
door unit will make an
error stop, and the er-
ror code "1302" will be
displayed.
4.If the pressure of
2.74MPa [397 psi] or
higher is detected
more than 30 minutes
after the stop of the
outdoor unit, the de-
tection is regarded as
the first detection, and
the operation de-
scribed in step 1
above will start.
5.For 30 minutes after
the stop of the outdoor
unit, preliminary errors
will be displayed on
the LED display.
6.The outdoor unit
makes an error stop
immediately when not
only the pressure sen-
sor but also the pres-
sure switch detects
2.94+0,-1.5 MPa
[426+0,-218 psi]
(1) LEV failure on the indoor
unit
→Heating
Perform a heating operation and
check the operation.
Heating : LEV
Check the LEV.
(2) Closed ball valve Confirm that the ball valve is fully
open.
(3) Short cycle on the indoor
unit side
(4) Clogged filter on the indoor
unit
(5) Reduced air flow due to
dirty fan on the indoor unit
fan
(6) Dirty heat exchanger of the
indoor unit
(7) Indoor fan (including fan
parts) failure or motor fail-
ure
Rise in high pressure
caused by lowered con-
densing capacity in heat-
ing operation for (2) - (6).
Check the indoor units for problems
and correct them, if any.
(8) Short cycle on the outdoor
unit
(9) Dirty heat exchanger of the
outdoor unit
Check the outdoor units for prob-
lems and correct them, if any.
(10) Outdoor fan (including
fan parts) failure, motor
failure, or fan controller
malfunction
Rise in discharge temp. by
low pressure drawing for
(8) - (10).
Check the fan on the outdoor unit.
Refer to the section on troubleshoot-
ing the outdoor unit fan.
(11) Solenoid valve (SV1,
SV2) malfunction (The by-
pass valve (SV1,2) can not
control rise in high pres-
sure).
Check the solenoid valve.
(12) Thermistor failure
(TH2, TH5, TH6).
Check the thermistor resistor.
(13) Pressure sensor failure Check the high pressure sensor.
(14) Failure of the thermistor
input circuit and pressure
sensor input circuit on the
controller board
Check the temperature and the pres-
sure of the sensor with LED monitor.
(15) Faulty mounting of ther-
mistor (TH2, TH5, TH6)
(16) Disconnected male con-
nector on the pressure
switch (63H) or discon-
nected wire
Check the temperature and the pres-
sure of the sensor with LED monitor.
Error Code Error definition and error
detection method Cause Check method and remedy

- 14 -
[ V Troubleshooting ]
1302 Abnormal high
pressure 2
(outdoor unit)
If the pressure of
0.098MPa [14psi] or low-
er is registered on the
pressure sensor immedi-
ately before start-up, it
will trigger an abnormal
stop, and error code
"1302" will be displayed.
(1) Inner pressure drop due to
a leakage.
(2) Pressure sensor failure
(3) Shorted-circuited pressure
sensor cable due to torn
outer rubber
(4) A pin on the male connec-
tor on the pressure sensor
is missing or contact fail-
ure
(5) Disconnected pressure
sensor cable
(6) Failure of the pressure
sensor input circuit on the
controller board
Check the high pressure sensor.
1500 Refrigerant
overcharge
An error can be detected
by the discharge temper-
ature superheat and by
the liquid level of an ac-
cumulator shown below.
1.If the liquid level of an
accumulator AL=2
(overflow level) is de-
tected during opera-
tion (the first
detection), the out-
door unit stops at
once, turns to anti-re-
start mode for 3 min-
utes, and restarts after
3 minutes automati-
cally.
(1) Overcharged refrigerant
(2) Liquid level heater discon-
nection
(3) Heater failure by control
board failure
Check the refrigerant amount.
(4) Thermistor failure (TH2,
TH3, TH4)
Check the resistance of the ther-
mistor
(5) Thermistor input circuit
failure on the main board
Check the temperature and the pres-
sure of the sensor with LED monitor.
(6) Faulty mounting of ther-
mistor (TH1, TH11, TH12,
TH2, TH3, TH4)
2.If the liquid level of an
accumulator AL=2
(overflow level) is de-
tected again within 30
minutes after first stop
of the outdoor unit (the
second detection), the
outdoor unit will make
an error stop, and the
error code "1500" is
displayed.
3.If the liquid level of an accu-
mulator AL=2 (overflow lev-
el) is detected more than 30
minutes after the outdoor
unit stops, and the operation
described in step 1 above
will start.
4.For 30 minutes after the
stop of the outdoor unit, pre-
liminary errors will be dis-
played on the LED display.
5.When the inhibiting switch for ab-
normal draw turns on, the opera-
tion described in step 1 above will
start on the outdoor unit even in
the second detection or later.
2500 Water leakage When the drain sensor
detects water or its tip be-
comes immersed in wa-
ter.
(1) Water leakage due to
problems with such equip-
ment as a humidifier
Check for water leakage around the
humidifier and clogging of outlet of
the drain pan.
2502 Drain pump
failure
The drain sensor detects
water or its tip becomes
immersed in water in 3
min. or later after the
drain pump turns on. The
sensor detects submer-
gence when the temper-
ature rises within 20deg
in 40 sec. from the start
of indirectly heated heat-
er on the drain sensor
runs, or the temperature
of the drain sensor is
63°C [145°F] or less after
40 sec. or later.
(1) Drain water level rises and
the drain sensor became
immersed in water.
Check the drain pump
(2) Disconnected the indirect-
ly heated heater on the
drain sensor.
Measure the resistance value of the
indirectly heated heater on the drain
sensor. (Normal value is 82 ohm be-
tween 1-3 of CN50
(3) The detection circuit
(board) failure
If no fault is found, the indoor board
is faulty.
(4) LEV in the indoor unit fail-
ure.
When the in door unit is operated in
fan mode, check the rise of TH2 and
TH3 nearly the room temperature.
Error Code Error definition and error
detection method Cause Check method and remedy

- 15 -
[ V Troubleshooting ]
2503 Drain sensor
failure
When a short or an open
is detected during opera-
tion (cannot be detected
during OFF).
Short :
detectable at 90°C
[194°F] or higher
Open :
detectable at
-40°C [-40°F] or lower
(1) Thermistor failure
(2) Connector contact failure
(loose connector)
(3) Disconnected wire or par-
tial disconnected ther-
mistor wire
Check the thermistor resistance.
0°C [32°F]: 15kohm
10°C [50°F]: 9.7kohm
20°C [68°F]: 6.4kohm
30°C [86°F]: 4.3kohm
40°C [104°F]: 3.1kohm
(4) Indoor board (detection
circuit) failure
Check the connector contact.
If no fault is found, the indoor board
is a failure.
2600 Water leakage - Water leaks from the pipes in
such as the humidifier.
Check the location of the leak.
2601 Water supply
cut-off
- (1) The water tank of the hu-
midifier is empty.
Check the amount of supply water.
Check for the solenoid valve and for
the connection.
(2) The solenoid valve for hu-
midification is OFF.
Check the connector.
(3) Disconnected float switch Check the connecting part.
(4) Poor operation of float
switch
Check for the float switch.
(5) Frozen water tank Turn off the power source of the wa-
ter tank to defrost, and turn it on
again.
4102 Open phase The operation cannot be
started because of the re-
serve phase of one of the
power lines (R, S or T).
(1) Power supply error
Open phase of power
supply voltage
Power-supply voltage
drop
Check the voltage of the power sup-
ply terminal block (TB1)
(2) Faulty wiring
Between the power sup-
ply terminal block TB1
and the main board CN20
Measure voltages between pins 3, 5
and 7 of the connector on the main
board. If the voltage does not be
measured 180VAC or more, the wir-
ing is faulty.
Between the high pres-
sure switch 63H1, H2 and
the main board CN38
Check whether the connector on the
main board is disconnected.
Check whether the wiring to CN38 is
opened.
(3) The fuse on the main
board failure
Check whether the fuses on the
main board (FO1 and FO2) are
blown.
(4) The main board failure If the above faults are not found, the
main board is faulty.
4103 Reverse
phase/open
phase
1.When turning on the
power, the operation
cannot be started be-
cause of the open
phase of one of the
power lines (R, S, T).
(1) Faulty wiring Check whether the phase of the
power supply terminal block (TB1) is
normal.
Check the wiring between the power
supply terminal block (TB1) and the
main boards (CN20).
(2) Main board failure. If the above faults are not found, the
main board is faulty.
2.The operation cannot
be started because of
the reserve phase of
one of the power lines
(R, S, T).
(1) Refer to 4102 error
Error Code Error definition and error
detection method Cause Check method and remedy
TB1
R 7Pin
S 5Pin
T 3Pin
CN20

- 16 -
[ V Troubleshooting ]
4108 Overcurrent
protection
1.First detection
If 51C2 is started dur-
ing the operation of
No.2 compressor, the
outdoor unit stops
once, turns to anti-re-
start mode for 3 min-
utes, and restarts after
3 minutes.
2.Second detection
If 51C2 is started
again within a minute
after restarting in com-
pliance with 1. above,
the unit makes an er-
ror stop and the error
code "4108" will ap-
pear.
3.There will be a minute
grace period of an er-
ror stop when No.2
compressor restarts
after the outdoor unit
stops and LED indi-
cates, which means
the grace period, will
appear.
(1) Overload operation that
exceeds unit use limit
Check the unit working condition.
(2) Power supply error
Power-supply voltage
drop
Open phase of power
supply voltage
Check the voltage of the power sup-
ply terminal block (TB1).
Check for open phase.
(3) Faulty wiring Check 52C2 connector and the wir-
ing.
(4) Compressor failure
Compressor open phase
or grounding fault
Compressor lock
Check the wiring and apply a meg-
ger to the compressor.
Start operation under no-load condi-
tions.
Remove the power wire on the com-
pressor-side, insulate the power line
and start operation.
→The compressor is faulty if
52C2ON normally turns on.
4115 Power supply
sync signal ab-
normality
The frequency cannot be
determined when the
power is switched on.
(The frequency cannot
be detected or the out-
door fan cannot be con-
trolled by phase control.)
(1) Power supply error Check the voltage of the power sup-
ply terminal block (TB1).
(2) A fuse is blown Check the fuses on the main board
(F1 and F2).
(3) Faulty wiring Measure voltages between pins 1, 5
and 7.
If the voltage (AC200V) is not the
same as the power supply voltage,
the wiring is faulty.
(4) Main board failure If none of the items described above
is applicable, and if the trouble reap-
pears even after the power is
switched on again, replace the MAIN
board.
Error Code Error definition and error
detection method Cause Check method and remedy

- 17 -
[ V Troubleshooting ]
4116 Fan rotation
speed abnor-
mality
1.If the fan rotation
speed is detected to
180rpm or lower, or
2000rpm or more dur-
ing the fan operation
in the indoor unit, the
unit stops once, turns
to anti-restart mode
for 3 minutes, and
makes fan to stop for
30 seconds.
2.If the fan rotation
speed is detected to
180rpm or lower, or
2000rpm or more
again when the restart
operation after 30 sec-
onds since the fan
stops, the unit makes
an error stop (fan also
stops), and the error
code "4116" will ap-
pear.
(1) The connector for fan rota-
tion speed detection
(CN33) on the indoor con-
trol board is blown
Check whether the connector for fan
rotation speed detection (CN33) on
the indoor control board is blown.
(2) The connector for fan out-
put (FAN 1) on the indoor
power board is blown
Check whether the connector for fan
output (FAN 1) on the indoor power
board is blown
(3) Disconnection of the con-
nector for fan rotation
speed detection (CN33) on
the indoor control board or
the connector for fan out-
put (FAN 1) on the indoor
power board
Check whether the wiring is discon-
nected.
(4) Clogged filter Check the filter.
(5) The indoor fan motor mal-
function
Check the indoor fan motor.
(6) The circuit of fan rotation
speed detection on the in-
door control board or the
circuit of fan output on the
indoor power board faulty
If the above faults are not found
(1) Malfunction occurs since the fan
is operated
Replace the indoor control
board. If the replacement does
not work, replace the indoor
power board.
(2) Malfunction occurs since the fan
is not operated
Replace the indoor power
board.
Motor abnor-
mality
[LOSSNAY only]
1.The motor keep run-
ning even if the power
is OFF.
2.The thermal overload
relay is ON. (Only for
the three-phase mod-
el)
(1) Board failure Replace the board.
(2) Motor malfunction
(3) Solenoid switch malfunc-
tion
Check for the motor and the solenoid
switch.
Error Code Error definition and error
detection method Cause Check method and remedy

- 18 -
[ V Troubleshooting ]
4121 Harmonics ac-
tion device er-
ror
Active filter (Communica-
tion error to PAC-
KB51AAC)
(1) Connecting switch to the
active filter in the indoor
unit is turned on, though
the unit is not connected to
the filter.
Turn the connecting switch to the ac-
tive filter in the indoor unit (DIP
switch on the outdoor control board
SW3-8) off.
(2) Wiring error Check whether the power supply
wiring of the active filter is connected
to the power supply terminal block in
the indoor unit.
Check the contact between the con-
nector of the main board CN51 and
CN3S (3D) to the active filter.
(3) Active filter failure Check details with LED3-5 on the
board of the active filter.
* Before decomposition process,
wait for 10 minutes or more since
the power supply is cut. Then con-
firm CHARGE (LED1) is turned off
and the charge voltage is low
enough to process.
* Check the active filter when it is in
failure.
4200 VDC sensor/
Circuit failure
If Vdc 150V or less or
400V or more is detected
before Inverter operation
(1) Connected to wrong volt-
age
Check the power supply voltage by
power supply terminal block (TB1)
(2) INV board failure If the power supply has no faults, re-
place the INV board.
Error Code Error definition and error
detection method Cause Check method and remedy
Detection error if
active filter
(LED display)
Error contents
OC (LED 3) is lit Over current (peak 60A min.)
OC (LED 3) blinks ACCT connector (AF board-CN4) blown
OV (LED 4) is lit DC bus over-voltage (410V min.)/under
voltage (300V max. in operation)
OH (LED 5) is lit Heating (Heat sink thermo (100°C) ON)
All LED are lit Flash stop, Interruption of service, Open-
phase, Power supply voltage rise/drop
All LED blink
Heat sink thermo ON before running,
Flash stop, Interruption of service, Open-
phase, Power supply voltage rise/drop
error delay

- 19 -
[ V Troubleshooting ]
4220 Bus voltage
drop protection
If Vdc 220V or less is de-
tected during Inverter op-
eration.
(1) Power supply environment Check whether the unit makes an in-
stantaneous stop when the detec-
tion result is abnormal or a power
failure occurs.
Check whether the power voltage is
180V or less across all phases.
(2) Voltage drop detected Check voltage between FN01-FN02
on the G/A board.
→If the voltage drops, refer to
(3).
Check voltage of the first part of
CNDC on the G/A board.
→If the voltage drops, replace G/
A board.
Check voltage of the second part of
CNDC on the INV board connector
→If the voltage drops, the wiring
connection failure.
Check solder of the second part of
CNDC on the INV board connector.
→Replace INV board if cracks
etc. are found.
(3) INV board failure Check whether DC12V is applied to
the inverter board connector
(CN52C) during inverter operation.
(4) 52C failure Check the resistance of 52C coil.
Check the voltage between 52C
contacts during the inverter opera-
tion.
(5) Diode stack failure Check the diode stack resistance
Error Code Error definition and error
detection method Cause Check method and remedy