Mitsubishi Electric PUHZ-W85VAA User manual

SERVICE MANUAL
No. OCH681
R410A
April 2018
PARTS CATALOG (OCB681)
[Model Name]
PUHZ-W85VAA
PUHZ-W112VAA
PUHZ-W85YAA
PUHZ-W112YAA
CONTENTS
1. REFERENCE MANUAL································ 2
2. SAFETY PRECAUTION ······························· 3
3. SPECIFICATIONS ········································ 5
4. DATA····························································· 6
5. OUTLINES AND DIMENSIONS···················· 7
6. WIRING DIAGRAM······································· 8
7. WIRING SPECIFICATIONS ························ 10
8. REFRIGERANT SYSTEM DIAGRAM ········ 11
9. TROUBLESHOOTING································ 13
10. MONITORING THE OPERATION DATA BY THE REMOTE CONTROLLER ···· 50
11. DISASSEMBLY PROCEDURE··················· 56
Note:
• This manual describes
service data of the outdoor
units only.
AIR TO WATER HEAT PUMP UNITS
[Service Ref.]
PUHZ-W85VAA.UK
PUHZ-W112VAA.UK
PUHZ-W85YAA.UK
PUHZ-W112YAA.UK

2
OCH681
INDOOR UNIT SERVICE MANUAL
1-1. FOR AIR TO WATER SYSTEM
Model name Service ref. Service
manual No.
EHPT20X-VM2HB
EHPT20X-VM6HB
EHPT20X-YM9HB
EHPT20X-TM9HB
EHPT20X-VM6B
EHPT20X-YM9B
EHPT20X-VM2HB.UK
EHPT20X-VM6HB.UK
EHPT20X-YM9HB.UK
EHPT20X-TM9HB.UK
EHPT20X-VM6B.UK
EHPT20X-YM9B.UK
OCH531
OCB531
EHPX-VM2B
EHPX-VM6B
EHPX-YM9B
EHPX-VM2B.UK
EHPX-VM6B.UK
EHPX-YM9B.UK
OCH532
OCB532
EHPX-VM2C
EHPX-VM6C
EHPX-YM9C
EHPX-VM2CR2.UK
EHPX-VM6CR2.UK
EHPX-YM9CR2.UK
OCH571
OCB571
EHPT20X-VM2C
EHPT20X-VM6C
EHPT20X-YM9C
EHPT20X-TM9C
EHPT20X-MHCW
EHPT20X-VM2C2
EHPT20X-VM2CR2.UK
EHPT20X-VM6CR2.UK
EHPT20X-YM9CR2.UK
EHPT20X-TM9CR2.UK
EHPT20X-MHCWR2.UK
EHPT20X-VM2C2R2.UK
OCH570
OCB570
PAC-IF011B-E
PAC-IF032B-E
PAC-IF011B-E
PAC-IF032B-E OCB427
PAC-IF061B-E PAC-IF061B-ER2 OCB572
PAC-SIF051B-E PAC-SIF051B-ER2 OCB536
1REFERENCE MANUAL

3
OCH681
2SAFETY PRECAUTION
2-2. CAUTIONS RELATED TO NEW REFRIGERANT
Cautions for units utilizing refrigerant R410A
Charge refrigerant from liquid phase of gas cylinder.
If the refrigerant is charged from gas phase, composition change may occur in refrigerant and the efficiency
will be lowered.
Do not use refrigerant other than R410A.
If other refrigerant (R22, etc.) is used, chlorine in refrigerant can cause deterioration of refrigerant oil, etc.
Use a vacuum pump with a reverse flow check valve.
Vacuum pump oil may flow back into refrigerant cycle and that can cause deterioration of refrigerant oil, etc.
Use the following tools specifically designed for use with R410A refrigerant.
The following tools are necessary to use R410A refrigerant.
Handle tools with care.
If dirt, dust or moisture enters into refrigerant cycle, that can cause deterioration of refrigerant oil or malfunction
of compressor.
Do not use a charging cylinder.
If a charging cylinder is used, the composition of refrigerant will change and the efficiency will be lowered.
Electronic refrigerant charging scale
Vacuum pump adaptor
Gauge manifold
Torque wrench
Gas leak detector
Charge hose
Tools for R410A
Ventilate the room if refrigerant leaks during operation. If refrigerant comes into contact with
a flame, poisonous gases will be released.
Never use any refrigerant other than that specified.
Doing so may cause a burst, an explosion, or fire when the unit is being used, serviced, or disposed of.
Correct refrigerant is specified in the manuals and on the spec labels provided with our products.
We will not be held responsible for mechanical failure, system malfunction, unit breakdown or accidents caused
by failure to follow the instructions.
Use the specified refrigerant only.
2-1. ALWAYS OBSERVE FOR SAFETY
Before obtaining access to terminal, all supply circuits must be disconnected.
Preparation before the repair service.
• Prepare the proper tools.
• Prepare the proper protectors.
• Provide adequate ventilation.
• After stopping the operation of the heat pump units, turn off the power-supply breaker.
• Discharge the condenser before the work involving the electric parts.
Precautions during the repair service.
• Do not perform the work involving the electric parts with wet hands.
• Do not pour water into the electric parts.
• Do not touch the refrigerant.
• Do not touch the hot or cold areas in the refrigerating cycle.
• When the repair or the inspection of the circuit needs to be done without turning off the power,
exercise great caution not to touch the live parts.
2SAFETY PRECAUTION 2SAFETY PRECAUTION

4
OCH681
Electronic weighing scale
Unit
[3] Service tools
Use the below service tools as exclusive tools for R410A refrigerant.
[1] Cautions for service
(1) Perform service after recovering the refrigerant left in unit completely.
(2) Do not release refrigerant in the air.
(3) After completing service, charge the cycle with specified amount of refrigerant.
(4) If moisture or foreign matter might have entered the refrigerant piping during service, ensure to remove them.
[2] Additional refrigerant charge
When charging directly from cylinder
(1) Check that cylinder for R410A on the market is a syphon type.
(2) Charging should be performed with the cylinder of syphon stood vertically. (Refrigerant is charged from liquid phase.)
No. Tool name Specifications
1Gauge manifold
· Only for R410A
· Use the existing fitting specifications. (UNF1/2)
· Use high-tension side pressure of 5.3 MPa·G or over.
2Charge hose · Only for R410A
· Use pressure performance of 5.09 MPa·G or over.
3Electronic weighing scale —
4Gas leak detector · Use the detector for R134a, R407C or R410A.
5Adaptor for reverse flow check · Attach on vacuum pump.
6Refrigerant charge base —
7Refrigerant cylinder · Only for R410A · Top of cylinder (Pink)
· Cylinder with syphon
8Refrigerant recovery equipment —

5
OCH681
3SPECIFICATIONS
Service Ref. PUHZ-W85VAA.UK PUHZ-W85YAA.UK
OUTDOOR UNIT
Power source (Phase, cycle, voltage) Single, 50 Hz, 230 V 3-Phase, 50 Hz, 400 V
Max. current A22.0 11.5
External nish Munsell: N8.75
Munsell N2.75 (FRONT PANEL)
Refrigerant control Linear Expansion Valve
Compressor Hermetic
Model SNB220FEGMC-L1 SNB220FEAMC-L1
Motor output kW 1.5
Starter type Inverter
Protection devices HP switch, Comp. surface thermo
Discharge thermo, Over current detection
Crankcase heater W —
Heat exchanger Plate n coil
Fan Fan (drive) × No. Propeller fan x 1
Fan motor output kW 0.074
Air ow
K/min (CFM)
44(1,550)
Defrost method Reverse cycle
(PWL)Sound power level Heating dB 58
Dimensions W mm (inch) 1050 (41-5/16)
D mm (inch) 480 (18-7/8)
H mm (inch) 1020 (40-3/16)
Weight kg (lb) 97 (214) 110 (243)
Refrigerant R410A
Charge kg (lb) 2.4 (5.3)
Oil (Model) L 0.60(FV50S)
Water pipe connection G1(ISO 228/1)
Service Ref. PUHZ-W112VAA.UK PUHZ-W112YAA.UK
OUTDOOR UNIT
Power source (Phase, cycle, voltage) Single, 50 Hz, 230 V 3-Phase, 50 Hz, 400 V
Max. current A28.0 13.0
External nish Munsell: N8.75
Munsell N2.75 (FRONT PANEL)
Refrigerant control Linear Expansion Valve
Compressor Hermetic
Model DNB28FBAMT DNB28FBBMT
Motor output kW 2.2
Starter type Inverter
Protection devices HP switch, LP switch, Comp. surface thermo
Discharge thermo, Over current detection
Crankcase heater W —
Heat exchanger Plate n coil
Fan Fan (drive) × No. Propeller fan x 1
Fan motor output kW 0.2
Air ow
K/min (CFM)
50 (1,760)
Defrost method Reverse cycle
(PWL)Sound power level Heating dB 60
Dimensions W mm (inch) 1050 (41-5/16)
D mm (inch) 480 (18-7/8)
H mm (inch) 1020 (40-3/16)
Weight kg (lb) 118 (260) 131 (289)
Refrigerant R410A
Charge kg (lb) 3.3 (7.3)
Oil (Model) L 1.0 (FVC68D)
Water pipe connection G1(ISO 228/1)

6
OCH681
4DATA
4-1. COMPRESSOR TECHNICAL DATA
Service Ref. PUHZ-W85VAA.UK PUHZ-W85YAA.UK PUHZ-W112VAA.UK PUHZ-W112YAA.UK
Compressor model SNB220FEGMC-L1 SNB220FEAMC-L1 DNB28FBAMT DNB28FBBMT
Winding
Resistance (Ω)
U-V 0.95 1.65 0.74 0.94
U-W 0.95 1.65 0.74 0.94
W-V 0.95 1.65 0.74 0.94
(at 20:)
4-2. NOISE CRITERION CURVES
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
90
80
70
60
50
40
30
20
10
OCTAVE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.0002 µbar)
63 125 250 500 1000 2000 4000 8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
BAND CENTER FREQUENCIES, Hz
COOLING
MODE
HEATING
49
SPL(dB)
47
LINE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
90
80
70
60
50
40
30
20
10
OCTAVE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.0002 µbar)
63 125 250 500 1000 2000 4000 8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
BAND CENTER FREQUENCIES, Hz
COOLING
MODE
HEATING
45
SPL(dB)
45
LINE
1.5 m
1 m
MICROPHONE
UNIT
GROUND
PUHZ-W112VAA.UK
PUHZ-W112YAA.UK
PUHZ-W85VAA.UK
PUHZ-W85YAA.UK

7
OCH681
5OUTLINES AND DIMENSIONS
PUHZ-W85VAA.UK PUHZ-W112VAA.UK PUHZ-W85YAA.UK PUHZ-W112YAA.UK
Unit: mm

8
OCH681
6WIRING DIAGRAM
C. B.
21S4
X51 X52
31 21S4
(GN)
SV3/SS
(WH)
31
X54
31 SV1/CH
(GY)
71
MS
3~
5CNF1(WH)
MF1
63H
t°
51LEV-A
(WH)
31
63H
(YE)
31
TH33
(YE)
1 2
t°
14
t° t°
TH3
(WH)
TH7/6
(RD)
LEV-A
M
5
51LEV-B
(RD)
LEV-B
M
5
2 1
t°
TH4
TH4
(WH)
2 1
t°
TH34
TH34
(RD)
63L
31
63L
(RD)
63HS
(WH)
W112
only
TRANS
TH33 TH7 TH6 TH3 63HS
CN4
(WH)
1 3
CNDC
(PK)
1
2
3
CNS
(WH)
31
F2
F1
F3
F4
CNAC
(WH)
1 3
CNDM
(WH)
1 2
2
12
3 4
7
CN2
(RD)
SW4 SW8
SW1
SW9 SW7
SW6
SW5
*1
1 7
SW2
SYMBOL NAME SYMBOL NAME
TB1
MC
MF1
21S4
63H
63L
63HS
TH3
TH4
TH6
TH7
TH8
TH33
TH34
LEV-A, LEV-B
DCL1, DCL2, DCL3
Terminal Block <Power Supply, Indoor/Outdoor>
Motor for Compressor
Fan Motor
Solenoid Valve (4-Way Valve)
High Pressure Switch
Low Pressure Switch
High Pressure Sensor
Thermistor <Liquid>
Thermistor <Discharge>
Thermistor <Plate Hex Liquid>
Thermistor <Ambient>
Thermistor <Heat Sink>
Thermistor <Comp. Surface>
Thermistor <Inlet Water>
Linear Expansion Valve
Reactor
CY1, CY2
P. B.
C. B.
Capacitor
Power Circuit Board
Controller Circuit Board
Switch <Manual Defrost, Defect History
Record Reset, Refrigerant Address>
Switch <Function Switch>
Switch <Function Switch>
Switch <Function Switch>
Switch <Function Switch, Model Select>
Switch <Function Switch>
Switch <Function Switch>
Switch <Function Switch>
Connector <Connection for Option>
Connector <Connection for Option>
Connector <Connection for Option>
Fuse <T6.3AL250V>
SW1
SW2
SW4
SW5
SW6
SW7
SW8
SW9
CNDM
SV1/CH
SV3/SS
F1, F2, F3, F4
P. B.
TO
INDOOR UNIT
OG BNYE
L N S1 S2 S3 TB1
POWER SUPPLY
~/N
230V 50Hz
RD BU
CNAC2
(RD)
CNAC1
(WH)
LI NI
EI
~+
-
E3
IC600
CY1
CY2
U
V
W
RD
BK
WH
MC
MS
3~
DCL1
BK
DCL3
3131
E2
E4
TB1A
TB3A TB1B TB3B
31
CNDC
(PK)
1 2
t°
TH8
CN6
(WH)
1 7
CN2
(RD)
7
CN4
(WH)
2
1
2
2
BK
BK
BK
BK
U
V
WIC500
+
~
RD
DS
GNYE
TB2B
WH
DCL2
TB2A
BK
RD WH
8
8
1 2 3 4 5 6 7
1 2 3 4 5 6 7
OFF
ON
85V
MODEL SW6 *2
OFF
ON
112V
*1 MODEL SELECT
The black square ( ) indicates
a switch position.
*2 SW6 -1 to 3 : Function Switch
LED3
PUHZ-W85VAA.UK PUHZ-W112VAA.UK

9
OCH681
8
8
1 2 3 4 5 6 7
1 2 3 4 5 6 7
OFF
ON
85Y
MODEL SW6 *2
OFF
ON
112Y
*1 MODEL SELECT
The black square ( ) indicates
a switch position.
*2 SW6 -1 to 3 : Function Switch
TB1
TB2
MC
MF1
21S4
63H
63L
63HS
TH3
TH4
TH6
TH7
TH8
TH33
TH34
LEV-A, LEV-B
ACL1, ACL2,
ACL3, ACL4
CY1, CY2
CK
RS
Terminal Block <Power Supply>
Terminal Block <Indoor/Outdoor>
Motor for Compressor
Fan Motor
Solenoid Valve (4-Way Valve)
High Pressure Switch
Low Pressure Switch
High Pressure Sensor
Thermistor <Liquid>
Thermistor <Discharge>
Thermistor <Plate Hex Liquid>
Thermistor <Ambient>
Thermistor <Heat Sink>
Thermistor <Comp. Surface>
Thermistor <Inlet Water>
Linear Expansion Valve
Reactor
Capacitor
Capacitor
Rush Current Protect Resistor
SW1
SW2
SW4
SW5
SW6
SW7
SW8
SW9
CNDM
SV1/CH
SV3/SS
F1, F2,
F3, F4
P. B.
N. F.
CONV. B.
C. B.
Power Circuit Board
Noise Filter Circuit Board
Converter Circuit Board
Controller Circuit Board
Switch <Manual Defrost,
Defect History Record Reset,
Refrigerant Address>
Switch <Function Switch>
Switch <Function Switch>
Switch <Function Switch>
Switch <Function Switch,
Model Select>
Switch <Function Switch>
Switch <Function Switch>
Switch <Function Switch>
Connector <Connection for Option>
Connector <Connection for Option>
Connector <Connection for Option>
Fuse <T6.3AL250V>
SYMBOL NAME SYMBOL NAME
P. B.
N. F.
t°
C. B.
21S4
X51 X52
31 21S4
(GN)
SV3/SS
(WH)
31
X54
31 SV1/CH
(GY)
71
MS
3~
5CNF1(WH)
MF1
63H
t°
51LEV-A
(WH)
31
63H
(YE)
31
TH33
(YE)
1 2
t°
14
t° t°
TH3
(WH)
TH7/6
(RD)
LEV-A
M
5
51LEV-B
(RD)
LEV-B
M
5
2 1
t°
TH4
TH4
(WH)
63L
31
63L
(RD)
63HS
(WH)
W112
only
TRANS
TH33 TH7 TH6 TH3
2 1
t°
TH34
(RD)
TH34
63HS
CN4
(WH)
1 3
TH8
CNDC
(PK)
1
2
3
CNS
(WH)
31
F2
F1
F3
F4
CNAC
(WH)
1 3
CNDM
(WH)
1 2
2
12
3 4
7
CN2
(RD)
CNL
(BU)
CNDC
(PK)
3 131
3272
1 1 1 1 13 2 2 7 2
CN7
(WH)
CN6
(WH)
CN4
(WH)
CN2
(RD)
CN5
(RD)
BK
RD
RD
RS
L3OUT
X52CB
TB-L3
L3IN
TB-L2
TB-N
TB-L1
X52CA
TB-U
TB-V
TB-W
U W
V
CNCT
(RD)
CNAC2
(RD)
MC
MS
3~
CNAC1
(WH)
1 13 2 3
2
E3E2EI
BK BK BK
LI1
LI2
LI3
NI
GNYE
S1
S2
S3
CONV. B.
1
33
1
2
ACL1
ACL2
ACL3
BK
CK
BK BK
WH WH RD RD
L1-A2 L1-OU L2-A2 L2-OU L3-A2 L3-OU
L1-IN L1-A1
N-IN
CK-OU
BK
RD
LO1
LO2
RD
WH
LO3 BK
NO BU
BK
WH
RD
CN7
(WH)
ACL4
RD
TB1
L2
L1
N
L3
TO
INDOOR
UNIT
WH
BK
BU
POWER
SUPPLY
3N~
400V 50Hz
TB2
BN OG YE
CY1
CY2
1 7
SW1
SW9 SW7
SW6
*1
SW4 SW8 SW5
SW2
LED3
PUHZ-W85YAA.UK PUHZ-W112YAA.UK

10
OCH681
7WIRING SPECIFICATIONS
FIELD ELECTRICAL WIRING (power wiring specifications)
Outdoor unit model W85V W112V
W85Y, W112Y
Outdoor unit power supply ~/N (single), 50 Hz, 230 V ~/N (single), 50 Hz, 230 V
3N~ (3 ph 4-wires), 50 Hz, 400 V
Outdoor unit input capacity Main switch (Breaker) *1 25A 32A 16A
Wiring Wire No. × size (mm2)
Outdoor unit power supply 3 × Min 2.5 3 × Min 4 5 × Min 1.5
Indoor unit-Outdoor unit *2 3 × 1.5 (polar) 3 × 1.5 (polar) 3 × 1.5 (polar)
Indoor unit-Outdoor unit earth *2 1 × Min 1.5 1 × Min 1.5 1 × Min 1.5
Remote controller-Indoor unit *3 2 ×0.3 (Non-polar) 2 ×0.3 (Non-polar) 2 ×0.3 (Non-polar)
Circuit rating
"Outdoor unit L-N (single)
Outdoor unit L1-N, L2-N, L3-N (3 phase)" *4 230 V AC 230 V AC 230 V AC
Indoor unit-Outdoor unit S1-S2 *4 230 V AC 230 V AC 230 V AC
Indoor unit-Outdoor unit S2-S3 *4 24 V DC 24 V DC 24 V DC
Remote controller-Indoor unit *4 12 V DC 12 V DC 12 V DC
*1. A breaker with at least 3.0 mm contact separation in each pole shall be provided. Use earth leakage breaker (NV).
Make sure that the current leakage breaker is one compatible with higher harmonics.
Always use a current leakage breaker that is compatible with higher harmonics as this unit is equipped with an inverter.
The use of an inadequate breaker can cause the incorrect operation of inverter.
*2.Maximum 45 m
If 2.5 mm² is used, maximum 50 m.
If 2.5 mm² is used and S3 is separated, maximum 80 m.
*3. The 10 m wire is attached in the remote controller accessory.
*4. The gures are NOT always against the ground.
S3 terminal has 24 V DC against S2 terminal. However between S3 and S1, these terminals are NOT electrically insulated by the transformer or other device.
S1
S2
S3
S1
S2
S3
Warning:
· In case of A-control wiring, there is high voltage potential on the S3 terminal caused by electrical circuit design that has no electrical insulation
between power line and communication signal line. Therefore, please turn off the main power supply when servicing. And do not touch the S1, S2, S3
terminals when the power is energized. If isolator should be used between indoor unit and outdoor unit, please use 3-pole type.
Notes: 1. Wiring size must comply with the applicable local and national codes.
2.
Power supply cables and the cables between Interface unit/Flow temp. controller and outdoor unit shall not be lighter than polychloroprene
sheathed exible cables. (Design 60245 IEC 57
)
3. Be sure to connect the cables between
Interface unit/Flow temp. controller and outdoor unit directly to the units (no intermediate connections
are allowed).
Intermediate connections may result in communication errors. If water enters at the intermediate connection point, it may cause insufcient
insulation to ground or a poor electrical contact.
(If an intermediate connection is necessary, be sure to take measures to prevent water from entering the cables.)
4. Install an earth line longer than power cables.
5. Do not construct a system with a power supply that is turned ON and OFF frequently.
6. Use self-extinguishing distribution cable for power supply wiring.
7. Properly route wiring so as not to contact the sheet metal edge or screw tip.
Outdoor Unit
3 poles isolator
Power
supply
Isolator
Indoor unit
(Interface unit /
Flow temp.
controller)
Never splice the power cable or the Interface unit/Flow temp. controller-outdoor unit connection cable, otherwise it may result in smoke emission, a re or communi-
cation failure.

11
OCH681
8REFRIGERANT SYSTEM DIAGRAM
PUHZ-W85VAA.UK PUHZ-W85YAA.UK
Symbol Parts name Detail
COMP Compressor DC inverter scroll compressor (Mitsubishi Electric Corporation)
H/P SW High pressure switch (63H) For protection (OFF: 4.15MPa)
REV/V Reversing (4-way) valve (21S4) Change the refrigerant circuit (Heating / Cooling) and for Defrosting
CHECK/V Charge plug High pressure/Low pressure/For production test use
P-SENSOR Pressure sensor (63HS) For calculation of the condensing temperature from high pressure
LEV-A Linear expansion valve -A Heating: Secondary LEV Cooling: Primary LEV
LEV-B Linear expansion valve -B Heating: Primary LEV Cooling: Secondary LEV
TH3 Liquid temperature thermistor Heating: Evaporating temperature Cooling: Sub cool liquid temperature
TH4 Discharge temperature thermistor For LEV control and for compressor protection
TH6
Plate HEX liquid temperature thermistor
Heating: Sub cool liquid temperature
Cooling: Evaporating temperature
TH7 Ambient temperature thermistor For fan control and for compressor frequency control
TH8 Heat sink temperature thermistor For power board protection
TH33 Comp. surface temperature thermistor For protection
TH34 Inlet water temperature thermistor For freeze protection and for compressor frequency control
Rec Receiver For accumulation of refrigerant
P/B Power circuit board For ow temp. controller
Plate HEX Plate Heat Exchanger MWA1-44DM
TH1, THW1 Outlet water temperature thermistor For ow temp. controller <Reference>
System example
REV/V
CHECK/V(H)
H/P SW
TH4
TH33
COMP
CHECK/V(L)
Strainer2
(#100)
Strainer1
LEV - ALEV - B
Strainer3
(#100)
(#100) (#100)
Strainer4
Rec
CHECK/V(C)
TH34
Plate HEX
Water IN
Water OUT
TH8
TH3
P/B
TH7
Heat exchanger
P -SENSOR
TH6
Muffler
Distributer
Refrigerant flow in cooling
Refrigerant flow in heating

12
OCH681
PUHZ-W112VAA.UK PUHZ-W112YAA.UK
REV/V
CHECK/V(H)
H/P SW
TH4
COMP
CHECK/V(L)
Strainer2
(#100)
Strainer1
LEV -ALEV -B
Strainer3
(#100)
(#100) (#100)
Strainer4
Rec
CHECK/V(C)
Plate HEX
Water OUT
Water IN
Water IN
Water OUT
TH8
TH3
P/B
TH7
Heat exchanger
P -SENSOR
Strainer5
(#100)
L/P SW
Distributer
TH6
TH33
TH34
Refrigerant flow in cooling
Refrigerant flow in heating
Symbol Parts name Detail
COMP Compressor DC inverter scroll compressor (Mitsubishi Electric Corporation)
H/P SW High pressure switch (63H) For protection (OFF: 4.15MPa)
L/P SW Low pressure switch (63L) For protection (OFF: -0.03MPa)
REV/V Reversing (4-way) valve (21S4) Change the refrigerant circuit (Heating / Cooling) and for
Defrosting
CHECK/V Charge plug High pressure/Low pressure/For production test use
P-SENSOR Pressure sensor (63HS) For calculation of the condensing temperature from high
pressure
LEV-A Linear expansion valve -A Heating: Secondary LEV Cooling: Primary LEV
LEV-B Linear expansion valve -B Heating: Primary LEV Cooling: Secondary LEV
TH3 Liquid temperature thermistor Heating: Evaporating temperature
Cooling: Sub cool liquid temperature
TH4 Discharge temperature thermistor For LEV control and for compressor protection
TH6
Plate HEX liquid temperature thermistor
Heating: Sub cool liquid temperature
Cooling: Evaporating temperature
TH7 Ambient temperature thermistor For fan control and for compressor frequency control
TH8 Heat sink temperature thermistor For power board protection
TH33 Comp. surface temperature thermistor For protection
TH34 Inlet water temperature thermistor For freeze protection and for compressor frequency control
Rec Receiver For accumulation of refrigerant
P/B Power circuit board For ow temp. controller
Plate HEX Plate Heat Exchanger MWA1-44DM
TH1, THW1 Outlet water temperature thermistor For ow temp. controller <Reference>
System example

13
OCH681
9 TROUBLESHOOTING
9-1. TROUBLESHOOTING
<Check code displayed by self-diagnosis and actions to be taken for service (summary)>
Present and past check codes are logged, and they can be displayed on the control board of outdoor unit. Actions to be taken
for service, which depends on whether or not the trouble is reoccurring in the field, are summarized in the table below. Check
the contents below before investigating details.
Unit conditions at service Check code Actions to be taken for service (summary)
The trouble is reoccurring.
Displayed
Not displayed
Judge what is wrong and take a corrective action according
to “9-2. SELF-DIAGNOSIS ACTION TABLE”.
Conduct troubleshooting and ascertain the cause of the
trouble according to “9-3. TROUBLESHOOTING OF
PROBLEMS”.
The trouble is not reoccurring.
Logged
Not logged
1Consider the temporary defects such as the work of
protection devices in the refrigerant circuit including
compressor, poor connection of wiring, noise, etc.
Re-check the symptom, and check the installation
environment, refrigerant amount, weather when the
trouble occurred, matters related to wiring, etc.
2Reset check code logs and restart the unit after finishing
service.
3There is no abnormality in electrical component,
controller board, remote controller, etc.
1Re-check the abnormal symptom.
2Conduct troubleshooting and ascertain the cause of the
trouble
according to “9-3. TROUBLESHOOTING OF
PROBLEMS”.
3Continue to operate unit for the time being if the cause
is not ascertained.
4There is no abnormality concerning of parts such as
electrical component, controller board, remote controller,
etc.

14
OCH681
9-2. SELF-DIAGNOSIS ACTION TABLE
<Abnormalities detected when the power is turned on>
Note: Refer to indoor unit section for code P, code E, and Code L.
Abnormal point and detection method Cause Judgment and action
None —
1
No voltage is supplied to terminal
block (TB1) of outdoor unit.
a) Power supply breaker is
turned off.
b) Contact failure or
disconnection of power
supply terminal
c) Open phase (L or N phase)
2 Electric power is not charged
to power supply terminal of
outdoor power circuit board.
a) Contact failure of power
supply terminal
b) Open phase on the outdoor
power circuit board
3 Electric power is not supplied
to outdoor controller circuit
board.
a) Disconnection of connector
(CNDC)
4 Disconnection of reactor (DCL
or ACL)
5 Disconnection of outdoor noise
filter circuit board or parts failure
in outdoor noise filter circuit
board
6 Defective outdoor power circuit
board
7 Open of rush current protect
resistor(RS)(Y)
8 Defective outdoor controller
circuit board
1 Check following items.
a) Power supply breaker
b) Connection of power supply terminal block
(TB1)
c) Connection of power supply terminal block
(TB1)
2 Check following items.
a) Connection of power supply terminal block
(TB1)
b) Connection of terminal on outdoor power
circuit board
Check connection of the connector LI or NI.
Refer to "9-6.TEST POINT DIAGRAM".
3Check connection of the connector (CNDC)
on the outdoor controller circuit board.
Check connection of the connector, CNDC
on the outdoor power circuit board(V)/the
noise filter(Y). Refer to "9-6.TEST POINT
DIAGRAM".
4Check connection of reactor. (DCL or ACL)
Refer to "9-6.TEST POINT DIAGRAM".
5 a) Check connection of outdoor noise filter
circuit board.
b) Replace outdoor noise filter circuit board.
Refer to "9-6.TEST POINT DIAGRAM".
6 Replace outdoor power circuit board.
7 Replace rush current protect resistor(RS).
Power circuit board might be short-circuit.
Check the power circuit board.(Refer to "9-6.
TEST POINT DIAGRAM".)
8 Replace controller board (When items above
are checked but the units cannot be repaired).
F5
(5201)
63H connector open
Abnormal if 63H connector circuit is open for
3 minutes continuously after power supply.
63H: High pressure switch
1 Disconnection or contact failure
of 63H connector on outdoor
controller circuit board
2 Disconnection or contact failure
of 63H
3 63H is working due to defective
parts.
4 Defective outdoor controller
circuit board
1 Check connection of 63H connector on
outdoor controller circuit board.
Refer to "9-6.TEST POINT DIAGRAM".
2 Check the 63H side of connecting wire.
3 Check continuity by tester.
Replace the parts if the parts are defective.
4 Replace outdoor controller circuit board.
F3
(5202)
63L connector open (W112 only)
Abnormal if 63L connector circuit is open for
3 minutes continuously after power supply.
63L: Low pressure switch
1 Disconnection or contact failure
of 63L connector on outdoor
controller circuit board
2 Disconnection or contact failure
of 63L
3 63L is working due to
refrigerant leakage or defective
parts.
4 Defective outdoor controller
circuit board
1 Check connection of 63L connector on
outdoor controller circuit board.
Refer to "9-6.TEST POINT DIAGRAM".
2 Check the 63L side of connecting wire.
3 Check refrigerant pressure.
Charge additional refrigerant.
Check continuity by tester.
Replace the parts if the parts are defective.
4 Replace outdoor controller circuit board.
Check code

15
OCH681
Check Code Abnormal point and detection method Judgment and action
Eb
(6845)
Miswiring of indoor/outdoor unit
connecting wire (converse wiring or
disconnection)
Outdoor controller circuit board can
automatically set the unit number of indoor
units.
Abnormal if the indoor unit number cannot
be set within 4 minutes after power on
because of miswiring (converse wiring
or disconnection) of indoor/outdoor unit
connecting wire.
EC
(6846)
Startup time over
The unit cannot finish startup process
within 4 minutes after power on.
Cause
1 Contact failure of indoor/
outdoor unit connecting wire
2 Diameter or length of indoor/
outdoor unit connecting wire is
out of specified capacity.
3 Do NOT use refrigerant
address 0, as 0 is used for FTC
(Master). The address range is
1 to 6. (In case of multiple out-
door units control.)
4 Noise has entered into power
supply or indoor/outdoor unit
connecting wire.
1
Contact failure or miswiring of
indoor/outdoor unit connecting wire
2 Diameter or length of indoor/
outdoor unit connecting wire is
out of specified capacity.
4 Defective transmitting receiving
circuit of outdoor controller circuit
board
5 Defective transmitting receiving
circuit of indoor controller board
6 Defective indoor power board
7 Do NOT use refrigerant
address 0, as 0 is used for FTC
(Master). The address range is
1 to 6. (In case of multiple out-
door units control.)
8 Noise has entered into power
supply or indoor/outdoor unit
connecting wire.
Indoor/outdoor unit connector
miswiring, excessive number of units (2
units or more)
1. Outdoor controller circuit board can
automatically check the number of
connected indoor units. Abnormal if the
number cannot be checked automatically
due to miswiring of indoor/outdoor unit
connecting wire and etc. after power is
turned on for 4 minutes.
2. Abnormal if outdoor controller circuit
board recognizes the number of
connected indoor units as “2 units or
more”.
1 Check disconnection or looseness or polarity
of indoor/outdoor unit connecting wire of
indoor and outdoor units.
2 Check diameter and length of indoor/outdoor
unit connecting wire.
Total wiring length: 80 m
(including wiring connecting each indoor unit
and between indoor and outdoor unit)
Also check if the connection order of flat
cable is S1, S2, S3.
3 Check the number of indoor units that are
connected to one outdoor unit. (If EA is
detected)
4–6 Turn the power off once, and on again to
check.
Replace outdoor controller circuit board,
indoor controller board or indoor power
board if abnormality occurs again.
7
Check if refrigerant addresses (SW1-3 to
SW1-6 on outdoor controller circuit board) are
overlapping in case of
multiple outdoor units
control .
8 Check transmission path, and remove the
cause.
Note: The descriptions above, 1–8, are for EA,
Eb and EC.
1
Contact failure or miswiring of
indoor/outdoor unit connecting wire
2 Diameter or length of indoor/
outdoor unit connecting wire is
out of specified capacity.
3 2 or more indoor units are
connected to one outdoor unit.
4 Defective transmitting receiving
circuit of outdoor controller
circuit board
5 Defective transmitting receiving
circuit of indoor controller board
6 Defective indoor power board
7 Do NOT use refrigerant
address 0, as 0 is used for FTC
(Master). The address range
is 1 to 6. (In case of multiple
outdoor units control.)
8 Noise has entered into power
supply or indoor/outdoor unit
connecting wire.
EA
(6844)
F9
(4119)
2 connector open (W112 only)
Abnormal if both 63H and 63L connector
circuits are open for three minutes
continuously after power supply.
63H: High pressure switch
63L: Low pressure switch
1 Disconnection or contact failure
of connector (63H,63L) on
outdoor controller circuit board
2 Disconnection or contact failure
of 63H, 63L
3 63H and 63L are working due
to defective parts.
4 Defective outdoor controller
board
1 Check connection of connector (63H,63L) on
outdoor controller circuit board.
Refer to "9-6.TEST POINT DIAGRAM".
2 Check the 63H and 63L side of connecting
wire.
3 Check continuity by tester.
Replace the parts if the parts are defective.
4 Replace outdoor controller circuit board.
EE
Incorrect connection
The outdoor unit does not receive the sig-
nals of I/F or FTC.
1 A device other than Interface
unit or Flow temp. controller
unit is connected to the unit.
1 Connect I/F or FTC to the unit.

16
OCH681
Check Code Abnormal point and detection method Judgment and action
U1
(1302)
High pressure (High pressure switch
63H operated)
Abnormal if high pressure switch 63H
operated (4.15 MPa) during compressor
operation.
63H: High pressure switch
Cause
U2
(1102)
U3
(5104)
Open/short circuit of outdoor unit
temperature thermistor (TH4, TH33)
Abnormal if open (-20: or less) or
short (217: or more) is detected during
compressor operation.
(Detection is inoperative for 10 minutes
of compressor starting process and for 10
minutes after and during defrosting.)
TH4: Thermistor <Discharge>
TH33: Thermistor <Comp. surface>
1
Disconnection or contact failure
of connectors (TH4, TH33) on
the outdoor controller circuit
board
2 Defective thermistor
3 Defective outdoor controller
circuit board
1
Check connection of connector (TH4, TH33) on
the outdoor controller circuit board.
Check breaking of the lead wire for
TH4, TH33. Refer to "9-6.TEST POINT
DIAGRAM".
2 Check resistance value of TH4, TH33 or
temperature by microprocessor.
(Thermistor/TH4, TH33: Refer to "9-4. HOW
TO CHECK THE PARTS".) (SW2 on A-Control
Service Tool: Refer to "9-7. FUNCTION OF
SWITCHES, CONNECTORS AND JUMPERS".)
3 Replace outdoor controller board.
<Abnormalities detected while unit is operating>
High discharge temperature
(1) Abnormal if TH4 exceeds 125: or
110: continuously for 5 minutes.
Abnormal if TH4 exceeds 110: or
more continuously for 30 seconds after
90 seconds have passed since the
defrosting operation started.
(2) Abnormal if discharge superheat
(Cooling: TH4−T63HS /
Heating: TH4−T63HS)
exceeds 70: continuously for 10
minutes.
TH4: Thermistor <Discharge>
High comp. surface temperature
Abnormal if TH33 exceeds 125:.
In the case of high comp. surface
temperature error, compressor does
not restart unless the thermistor (TH33)
becomes less than 95:.
TH33: Thermistor <Comp. surface>
1 Overheated compressor
operation caused by shortage
of refrigerant
2 Defective operation of stop
valve
3 Defective thermistor
4 Defective outdoor controller
board
5 Defective action of linear
expansion valve
6 Clogging with foreign objects in
refrigerant circuit
Note: Clogging occur in the
parts which become below
freezing point when water
enters in refrigerant circuit.
7 In the case of the unit does not
restart:
Detection temp. of thermistor
(TH33) ] 95:
1 Check intake superheat.
Check leakage of refrigerant.
Charge additional refrigerant.
2 Check if stop valve is fully open.
34
Turn the power off and check if U3 is
displayed when the power is turned on again.
When U3 is displayed, refer to “Judgment
and action” for U3.
5 Check linear expansion valve.
Refer to "9-4. HOW TO CHECK THE
PARTS".
6 After recovering refrigerant, remove water
from entire refrigerant circuit under vacuum
more than 1 hour.
1 Defective operation of stop
valve (Not fully open)
2 Clogged or broken pipe
3 Locked outdoor fan motor
4 Malfunction of outdoor fan
motor
5 Short cycle of outdoor unit
6 Dirt of outdoor heat exchanger
7 Decreased airflow caused by
defective inspection of outside
temperature thermistor
(It detects lower temperature
than actual temperature.)
8 Disconnection or contact failure
of connector (63H) on outdoor
controller board
9 Disconnection or contact failure
of 63H connection
0 Defective outdoor controller
board
1 Defective action of linear
expansion valve
2 Malfunction of fan driving circuit
1 Check if stop valve is fully open.
2 Check piping and repair defect.
3–6 Check outdoor unit and repair defect.
7 Check the detected temperature of outside
temperature thermistor on LED display.
(SW2 on A-Control Service Tool : Refer to
"9-7. FUNCTION OF SWITCHES,
CONNECTORS AND JUMPERS".)
8–0 Turn the power off and check F5 is
displayed when the power is turned again.
When F5 is displayed, refer to “Judgment
and action” for F5.
1 Check linear expansion valve.
Refer to "9-4. HOW TO CHECK THE
PARTS".
2 Replace outdoor controller board.

17
OCH681
Check code Abnormal point and detection method Cause Judgment and action
U5
(4230)
Temperature of heat sink
Abnormal if TH8 detects temperature indi-
cated below.
W85V, W112V ···································78:
W85Y, W112Y ····································85:
TH8: Thermistor <Heat sink>
1
The outdoor fan motor is locked.
2 Failure of outdoor fan motor
3 Air flow path is clogged.
4 Rise of ambient temperature
5 Defective thermistor
6 Defective input circuit of
outdoor power circuit board
7
Failure of outdoor fan drive circuit
12 Check outdoor fan.
3 Check air flow path for cooling.
4 Check if there is something which causes
temperature rise around outdoor unit.
(Upper limit of ambient temperature is 46:.)
Turn off power, and on again to check if U5 is
displayed within 30 minutes.
If U4 is displayed instead of U5, follow the
action to be taken for U4.
5 Check resistance value of TH8 or tempera-
ture by microprocessor. (TH8: Refer to
"9-4. HOW TO CHECK THE PARTS".)
(SW2 on A-Control Service Tool: Refer to "9-7.
FUNCTION OF SWITCHES, CONNECTORS
AND JUMPERS". )
6 Replace outdoor power circuit board.
7 Replace outdoor controller circuit board.
U4
(TH3:5105)
(TH6:5107)
(TH7:5106)
(TH8:5110)
(TH34:5105)
Open/short of outdoor unit thermistors
(TH3, TH34, TH6, TH7, and TH8)
Abnormal if open or short is detected
during compressor operation.
Open detection of TH3, TH34 and TH6 is
inoperative for 10 seconds to 10 minutes
after compressor starting and 10 minutes
after and during defrosting.
Note: Check which unit has abnormality in
its thermistor by switching the mode
of SW2. (PAC-SK52ST)
(Refer to "9-7. FUNCTION OF
SWITCHES, CONNECTORS AND
JUMPERS".)
1 Check connection of connector (TH3, TH34,
TH7/6) on the outdoor controller circuit board.
Check connection of connector (CN3) on the
outdoor power circuit board. Check breaking of
the lead wire for TH3, TH34, TH6, TH7, TH8.
Refer to "9-6.TEST POINT DIAGRAM".
2
Check resistance value of TH3, TH34,
TH6,TH7,TH8 or check temperature by
microprocessor.
(TH3,TH34,TH6,TH7,TH8: Refer to "9-6.
TEST POINT DIAGRAM".) (SW2 on
A-Control Service Tool: Refer to "9-7.
FUNCTION OF SWITCHES, CONNECTORS
AND JUMPERS".)
3 Replace outdoor controller circuit board.
Note: Emergency operation is available in case
of abnormalities of TH3, TH34,
TH6 and
TH7.
1 Disconnection or contact failure
of connectors
Outdoor controller circuit board :
TH3, TH34, TH7/6
Outdoor power circuit board :
CN3
2 Defective thermistor
3 Defective outdoor controller
circuit board
()
U6
(4250)
Power module
Check abnormality by driving power module
in case overcurrent is detected.
(UF or UP error condition)
1 Outdoor stop valve is closed.
2 Decrease of power supply voltage
3
Looseness, disconnection or converse
of compressor wiring connection
4 Defective compressor
5
Defective outdoor power circuit board
1 Open stop valve.
2 Check facility of power supply.
3 Correct the wiring (U•V•W phase) to compressor. Refer to "9-6.
TEST POINT DIAGRAM" (Outdoor power circuit board).
4 Check compressor referring to "9-4. HOW TO
CHECK THE PARTS".
5 Replace outdoor power circuit board.
U7
(1520)
Too low superheat due to low discharge
temperature
Abnormal if discharge superheat is
continuously detected less than or equal
to −15: for 3 minutes even though linear
expansion valve has minimum open pulse
after compressor starts operating for 10
minutes.
1 Disconnection or loose
connection of discharge
temperature thermistor (TH4)
2 Defective holder of discharge
temperature thermistor
3 Disconnection or loose connection
of linear expansion valve’s coil
4
Disconnection or loose connection
of linear expansion valve’s connector
5 Defective linear expansion valve
12 Check the installation conditions of
discharge temperature thermistor (TH4).
3 Check the coil of linear expansion valve.
Refer to "9-5. HOW TO CHECK THE
COMPONENTS".
4 Check the connection or contact of LEV-A and
LEV-B on outdoor controller circuit board.
5 Check linear expansion valve. Refer to "9-4.
HOW TO CHECK THE PARTS".
Thermistors Open detection Short detection
Symbol Name
TH3
Thermistor <Liquid> −40 °C or below 90 °C or above
TH6 Thermistor <Plate hex liquid> −40 °C or below 90 °C or above
TH7 Thermistor <Ambient> −40 °C or below 90 °C or above
TH8 Thermistor <Heat sink> −35 °C or below 102 °C or above
TH34 Thermistor <Inlet Water> −40 °C or below 90 °C or above
U8
(4400)
Outdoor fan motor
Abnormal if rotational frequency of the fan motor
is not detected during DC fan motor operation.
Fan motor rotational frequency is abnormal if;
• 100 rpm or below detected continuously
for 15 seconds at 20: or more outside
air temperature.
• 50 rpm or below or 1500 rpm or more
detected continuously for 1 minute.
1 Failure in the operation of the
DC fan motor
2 Failure in the outdoor circuit
controller board
1 Check or replace the DC fan motor.
2 Check the voltage of the outdoor circuit
controller board during operation.
3 Replace the outdoor circuit controller board.
(When the failure is still indicated even after
performing the action 1 above.)

18
OCH681
U9
(4220)
Detailed
codes
To find out the detail history (latest) about U9 error, turn ON SW2-1, 2-2 and 2-6.
Refer to "9-7. FUNCTION OF SWITCHES, CONNECTORS AND JUMPERS".
01
Overvoltage error
• Increase in DC bus voltage to
W85V, W112V: 430V
W85Y, W112Y: 760V
1 Abnormal increase in power source
voltage
2 Disconnection of compressor wiring
3 Defective outdoor power circuit
board
4 Compressor has a ground fault.
1 Check the field facility for the power
supply.
2
Correct the wiring (U.V.W phase) to
compressor. Refer to "9-7. FUNCTION
OF SWITCHES, CONNECTORS AND
JUMPERS". (Outdoor power circuit board).
3 Replace outdoor power circuit board.
4 Check compressor for electrical insula-
tion. Replace compressor.
02
Undervoltage error
• Instantaneous decrease in DC
bus voltage to
W85V, W112V : 200V
W85Y, W112Y : 350V
1 Decrease in power source voltage,
instantaneous stop
2 Defective converter drive circuit in
outdoor power circuit board (
W85V,
W112V
)
3 Defective 52C drive circuit in outdoor
power circuit board
4 Defective outdoor converter circuit
board (
W85Y, W112Y )
5 Disconnection or loose connection
of rush current protect resistor RS
(
W85Y, W112Y )
6 Defective rush current protect
resistor RS (
W85Y, W112Y )
7 Disconnection or loose connection
of CN2 on the outdoor power circuit
board /controller circuit board (
W85V,
W112V )
8 Power circuit failure on DC supply for
15 V DC output on outdoor controller
circuit board (
W85V, W112V )
1 Check the field facility for the power
supply.
2 Replace outdoor power circuit board.
(
W85V, W112V )
3 Replace outdoor power circuit board.
4 Replace outdoor converter circuit
board. (
W85Y, W112Y )
5 Check RS wiring. (
W85Y, W112Y )
6 Replace RS. ( W85Y, W112Y )
7 Check CN2 wiring. ( W85V, W112V )
8 Replace outdoor controller circuit board.
(
W85V, W112V )
04
Input current sensor error/
L1-phase open error
• Decrease in input current
through outdoor unit to 0.1A
only if operation frequency is
more than or equal to 40Hz
or compressor current is more
than or equal to 6A.
1 L1-phase open (
W85Y, W112Y )
2 Disconnection or loose connection
between TB1 and outdoor noise filter
circuit board (
W85Y, W112Y )
3 Disconnection or loose connection
of CN5 on the outdoor power circuit
board/CNCT on the outdoor noise
filter board
4 Defective ACCT (AC current trans) on
the outdoor noise filter circuit board
( W85Y, W112Y )
5 Defective input current detection
circuit in outdoor power circuit board
6 Defective outdoor controller circuit
board
1 Check the field facility for the power
supply. (
W85Y, W112Y )
2 Check the wiring between TB1 and
outdoor noise filter circuit board. ( W85Y,
W112Y )
3 Check CN5/CNCT wiring. (
W85Y, W112Y )
4 Replace outdoor noise filter circuit
board. (
W85Y, W112Y )
5 Replace outdoor power circuit board.
6 Replace outdoor controller circuit board.
08
Abnormal power synchronous
signal
• No input of power synchronous
signal to power circuit board
• Power synchronous signal
of 44 Hz or less, or 65 Hz or
more is detected on power
circuit board.
1 Distortion of power source voltage,
noise superimposition.
2 Disconnection or loose connection
of earth wiring
3 Disconnection or loose connection
of CN2 on the outdoor power circuit
board /controller circuit board
4 Defective power synchronous signal
circuit in outdoor controller circuit
board
5 Defective power synchronous signal
circuit in outdoor power circuit board
1 Check the field facility for the power
supply.
2 Check earth wiring.
3 Check CN2 wiring.
4 Replace outdoor controller circuit board.
5 Replace outdoor power circuit board.
Continue to the next page
Abnormal point and detection method Cause Judgment and action
Check code

19
OCH681
UF
(4100)
Compressor overcurrent interruption
(When compressor locked)
Abnormal if overcurrent of DC bus or
compressor is detected within 30 seconds
after compressor starts operating.
1 Stop valve is closed.
2 Decrease of power supply
voltage
3 Looseness, disconnection or
converse of compressor wiring
connection
4 Defective compressor
5 Defective outdoor power board
1 Open stop valve.
2 Check facility of power supply.
3 Correct the wiring (U•V•W phase) to
compressor.
Refer to "9-6.TEST POINT DIAGRAM".
(Outdoor power circuit board).
4 Check compressor.
Refer to "9-4. HOW TO CHECK THE
PARTS".
5 Replace outdoor power circuit board.
Ud
(1504)
Overheat protection
Abnormal if TH3, condensing temperature
T63HS detects 70: or more during com-
pressor operation.
TH3: Thermistor <Liquid>
1
Defective outdoor fan (fan
motor) or short cycle of outdoor
unit during cooling operation
2 Defective TH3, condensing
temperature T63HS
3 Defective outdoor controller board
1 Check outdoor unit air passage.
23 Turn the power off and on again to check
the check code. If U4 is displayed, follow
the U4 processing direction.
UE
(1302)
Abnormal pressure of 63HS
Abnormal if 63HS detects 0.1 MPa or less.
Detection is inoperative for 3 minutes after
compressor starting and 3 minutes after
and during defrosting.
63HS: High pressure sensor
1 Disconnection or contact
failure of connector (63HS) on
the outdoor controller circuit
board
2 Defective pressure sensor
3 Defective outdoor controller
circuit board
1 Check connection of connector (63HS) on
the outdoor controller circuit board.
Check breaking of the lead wire for 63HS.
2 Check pressure by microprocessor.
(Pressure sensor/ 63HS)
(SW2: Refer to "9-7. FUNCTION OF
SWITCHES, CONNECTORS AND
JUMPERS".)
3 Replace outdoor controller board.
Abnormal point and detection method Cause Judgment and action
10
PFC error (Overvoltage/
Undervoltage/Overcurrent)
• PFC detected any of the fol-
lowing
a) Increase of DC bus voltage
to 430 V.
b) Decrease in PFC control
voltage to 12 V DC or lower
c) Increase in input current
(
W85V, W112V only)
1 Abnormal increase in power
source voltage
2 Decrease in power source
voltage, instantaneous stop
3 Disconnection of compressor
wiring
4
Misconnection of reactor
(DCL1-3)
5 Defective outdoor power circuit
board
6 Defective reactor (DCL1-3)
7 Disconnection or loose con-
nection of CN2 on the outdoor
power circuit board/controller
circuit board
12 Check the field facility for the power supply.
3 Correct the wiring (U•V•W phase) to
compressor. Refer to "9-6. TEST POINT
DIAGRAM". (Outdoor power circuit board).
4 Correct the wiring of reactor (DCL1-3).
5 Replace outdoor power circuit board.
6 Replace reactor (DCL1-3).
7 Check CN2 wiring.
20
PFC/IGBT error
(Undervoltage)
•
When Compressor is running,
DC bus voltage stays at 310 V or
lower for consecutive 10 seconds
( W85V, W112V only)
1 Incorrect switch settings on the
outdoor controller circuit board
for model select
2 Defective outdoor power circuit
board
3 Defective outdoor controller
circuit board
1 Correction of a model select
2 Replace outdoor power circuit board.
3 Replace outdoor controller circuit board.
UH
(5300)
Current sensor error or input current error
• Abnormal if current sensor detects –1.0A
to 1.0A during compressor operation. (This
error is ignored in case of test run mode.)
• Abnormal if 40A (
W85V, W112V ) of input
current is detected or 37A ( W85V, W112V )
or more of input current is detected for 10
seconds continuously.
1 Disconnection of compressor
wiring
2 Defective circuit of current
sensor on outdoor power circuit
board
3 Decrease of power supply
voltage
4 Leakage or shortage of
refrigerant
1 Correct the wiring (U•V•W phase) to
compressor. Refer to "9-6.TEST POINT
DIAGRAM" (Outdoor power circuit board).
2 Replace outdoor power circuit board.
3 Check the facility of power supply.
4 Check leakage of refrigerant.
UL
(1300)
Low pressure (63L operated)(W112
only)
Abnormal if 63L is operated (under
-0.03MPa) during compressor operation.
63L: Low pressure switch
1 Stop valve of outdoor unit is
closed during operation.
2 Disconnection or loose
connection of connector (63L)
on outdoor controller board
3 Disconnection or loose
connection of 63L
4 Defective outdoor controller
board
5 Leakage or shortage of
refrigerant
6 Malfunction of linear expansion
valve
1 Check stop valve.
2–4 Turn the power off and on again to check
if F3 is displayed on restarting.
If F3 is displayed, follow the F3 processing
direction.
5 Correct to proper amount of refrigerant.
6 Check linear expansion valve.
Refer to "9-4. HOW TO CHECK THE
PARTS".
U9
(4220)
Detailed
codes
From the previous page.
Check code

20
OCH681
Abnormal point and detection method Judgment and action
Cause
UP
(4210)
E0
or
E4
(6831
or
6834)
Remote controller transmission error (E0)/
signal receiving error (E4)
1 Abnormal if main remote controller
cannot receive normally any transmission
from indoor unit of refrigerant address “0”
for 3 minutes.
(Check code: E0)
1 Abnormal if indoor controller board
cannot receive normally any data from
remote controller board or from other
indoor controller board for 3 minutes.
(Check code: E4)
2 Indoor controller board cannot receive
any signal from remote controller for 2
minutes. (Check code: E4)
1 Check disconnection or looseness of indoor
unit or transmission wire of remote controller.
2 Check wiring of remote controller.
• Total wiring length: Max. 500 m
(Do not use cable o 3 or more.)
• The number of connecting indoor units:
Max. 6 units
• The number of connecting remote
controller: Max. 1 unit
If the cause of trouble is not in above 1–3,
3
Diagnose remote controller (PAC-IF011B-E only).
a) When “RC OK” is displayed,
Remote controllers have no problem.
Turn the power off, and on again to check.
If abnormality generates again, replace
indoor controller board.
b) When “RC NG” is displayed,
Replace remote controller.
c) When "RCE3" or "ERC00-66" is displayed,
noise may be causing abnormality.
Note: If the unit is not normal after replac-
ing indoor controller board in group
control, indoor controller board of
address “0” may be abnormal. For
the controllers other than PAC-
IF011B-E, refer to Installation
Manual or Service Handbook of
the indoor unit.
1 Contact failure at transmission
wire of remote controller
2 Miswiring of remote controller
3 Defective transmitting receiving
circuit of remote controller
4 Defective transmitting receiving
circuit of indoor controller board
of refrigerant address “0”
5 Noise has entered into the
transmission wire of remote
controller.
Compressor overcurrent interruption
Abnormal if overcurrent DC bus or
compressor is detected after compressor
starts operating for 30 seconds.
1 Stop valve of outdoor unit is
closed.
2 Decrease of power supply
voltage
3 Looseness, disconnection or
converse of compressor wiring
connection
4 Defective fan of indoor/outdoor
units
5 Short cycle of indoor/outdoor
units
6 Defective input circuit of
outdoor controller board
7 Defective compressor
8 Defective outdoor power circuit
board
9 DIP switch setting difference of
outdoor controller circuit board
1 Open stop valve.
2 Check facility of power supply.
3 Correct the wiring (U·V·W phase) to
compressor. Refer to "9-6.TEST POINT
DIAGRAM" (Outdoor power circuit board).
4 Check indoor/outdoor fan.
5 Solve short cycle.
6 Replace outdoor controller circuit board.
Note: Before the replacement of the outdoor
controller circuit board, disconnect the
wiring to compressor from the outdoor
power circuit board and check the output
voltage among phases, U, V, W, during
test run.
No defect on board if voltage among
phases (U-V, V-W and W-U) is same.
Make sure to perform the voltage check
with same performing frequency.
7 Check compressor. Refer to "9-4. HOW TO
CHECK THE PARTS".
8 Replace outdoor power circuit board.
9 Check the DIP switch setting of outdoor
controller circuit board.
E1
or
E2
(6201
or
6202)
Remote controller control board
1 Abnormal if data cannot be normally
read from the nonvolatile memory of the
remote controller control board.
(Check code: E1)
2 Abnormal if the clock function of remote
controller cannot be normally operated.
(Check code: E2)
1 Defective remote controller 1 Replace remote controller.
Check code