Mitsubishi PUHZ-W50VHA2 User manual

SERVICE MANUAL
CONTENTS
TECHNICAL CHANGES...................................... 2
1. SAFETY PRECAUTION................................... 3
2. SPECIFICATIONS............................................ 6
3. DATA ............................................................... 8
4. OUTLINES AND DIMENSIONS....................... 9
5. WIRING DIAGRAM........................................ 10
6. WIRING SPECIFICATIONS ............................11
7. REFRIGERANT SYSTEM DIAGRAM ............... 12
8. TROUBLESHOOTING ................................... 13
9. DISASSEMBLY PROCEDURE...................... 47
Notes:
•This manual describes service
data of outdoor unit only.
•
RoHS compliant products have
<G> mark on the spec name
plate.
R410A
PARTS CATALOG (OCB605)
SPLIT-TYPE, AIR TO WATER HEAT PUMP
No. OCH605
REVISED EDITION-A
November 2015
[Model Name]
PUHZ-W50VHA2
Salt proof model
PUHZ-W50VHA2-BS
[Service Ref.]
PUHZ-W50VHA2
PUHZ-W50VHA2R1
PUHZ-W50VHA2-BS
PUHZ-W50VHA2R1-BS
•PleasevoidOCH605.
Revision:
•AddedPUHZ-W50VHA2R1
andPUHZ-W50VHA2R1-BS
inREVISEDEDITION-A.
•Somedescriptionshavebeen
modified.

2
TECHNICAL CHANGES
Service ref. have been changed as follows.
PUHZ-W50VHA2 PUHZ-W50VHA2R1
PUHZ-W50VHA2-BS PUHZ-W50VHA2R1-BS
1.TheinstallationdirectionofLEV-Bassyhasbeenchangedtoreducehighfrequencynoise.
OCH605A

3
SAFETY PRECAUTION
1
1-1. 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 air conditioner, 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.
Cautions for units utilizing refrigerant R410A
1-2. CAUTIONS RELATED TO NEW REFRIGERANT
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.
Use the specified refrigerant only.
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.
OCH605A

4
[1] Cautions for service
(1) Perform service after recovering the refrigerant left in the unit completely.
(2) Do not release refrigerant in the air.
(3) After completing service, charge the cycle with specified amount of refrigerant.
[2] Additional refrigerant charge
When charging directly from cylinder
·CheckthatcylinderforR410Aonthemarketisasyphontype.
·Chargingshouldbeperformedwiththecylinderofsyphonstoodvertically.(Refrigerantischargedfromliquidphase.)
Gravimeter
Unit
[3] Service tools
Use the below service tools as exclusive tools for R410A refrigerant.
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 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 —
OCH605A

5
Although"-BS"modelhasbeendesignedtoberesistanttosaltdamage,observethefollowingprecautionstomaintainthe
performance of the unit.
1.Avoidinstallingtheunitinalocationwhereitwillbeexposeddirectlytoseawaterorseabreeze.
2.Ifthecoverpanelmaybecomecoveredwithsalt,besuretoinstalltheunitinalocationwherethesaltwillbewashedawayby
rainwater.(Ifasunshadeisinstalled,rainwatermaynotcleanthepanel.)
3.Toensure thatwaterdoesnotcollectinthebaseoftheoutdoorunit,makesure thatthebaseislevel,notatangle.Water
collectinginthebaseoftheoutdoorunitcouldcauserust.
4.Iftheunitisinstalledinacoastalarea,cleantheunitwithwaterregularlytoremoveanysaltbuild-up.
5.Iftheunitisdamagedduringinstallationormaintenance,besuretorepairit.
6.Besuretochecktheconditionoftheunitregularly.
7.Besuretoinstalltheunitinalocationwithgooddrainage.
1-4. PRECAUTIONS FOR SALT PROOF TYPE "-BS" MODEL
1-3. CAUTIONS FOR REFRIGERANT PIPING WORK
Tools for R410A (The following table shows whether conventional tools can be used or not.)
Gauge manifold
Charge hose
Gas leak detector
Refrigerant recovery equipment
Refrigerant cylinder
Safety charger
Charge valve
Vacuum pump
Bender
Pipe cutter
Welder and nitrogen gas cylinder
Refrigerant charging scale
Vacuum gauge or thermis-
tor vacuum gauge and
vacuum valve
Charging cylinder
Air purge, refrigerant charge
and operation check
Gas leak check
Refrigerant recovery
Refrigerant charge
Prevent compressor malfunction
when charging refrigerant by
spraying liquid refrigerant
Prevent gas from blowing out
when detaching charge hose
Vacuum drying and air
purge
Bend the pipes
Cut the pipes
Weld the pipes
Charge refrigerant
Check the degree of vacuum. (Vacuum
valve prevents back flow of oil and refri-
gerant to thermistor vacuum gauge)
Refrigerant charge
Tool exclusive for R410A
Tool exclusive for R410A
Tool for HFC refrigerant
Tool exclusive for R410A
Tool exclusive for R410A
Tool exclusive for R410A
Tool exclusive for R410A
Tools for other refrigerants can
be used if equipped with adap-
ter for reverse flow check
Tools for other refrigerants can be used
Tools for other refrigerants can be used
Tools for other refrigerants can be used
Tools for other refrigerants can be used
Tools for other refrigerants
can be used
Tool exclusive for R410A
Tools and materials Use R410A tools Can R22 tools be used?
(Usable if equipped
with adapter for rever-
se flow)
Can R407C tools be used?
(Usable if equipped
with adapter for rever-
se flow)
: Prepare a new tool. (Use the new tool as the tool exclusive for R410A.)
: Tools for other refrigerants can be used under certain conditions.
: Tools for other refrigerants can be used.
OCH605A

6
SPECIFICATIONS
2
2-1. SPECIFICATIONS
PUHZ-W50VHA2
noitidnocgnitarepolanimoN
)ycneuqerF,egatloV,esahP(ylppusrewoP
Nominal water flow rate (Heating mode) L/min Heating(A7/W35)
Heating 7+)blub-yrD(erutarepmetriaedistuOWkyticapaC °C
(A7/W35) 6+)blub-teW(erutarepmetriaedistuOPOC °C
53+/03+)teltuo/telni(erutarepmetretaWWktupnirewoP °C
Heating WkyticapaC Heating(A2/W35)
(A2/W35) 2+)blub-yrD(erutarepmetriaedistuOPOC °C
1+)blub-teW(erutarepmetriaedistuOWktupnirewoP °C
Pressure difference (water circuit) )teltuo/telni(erutarepmetretaWaPk －/+35°C
Heating pump input (based on EN14511) kW Cooling(A35/W7)
53+)blub-yrD(erutarepmetriaedist
uOnim/L)edomgnilooC(etarwolfretawlanimoN °C
Cooling 42+)blub-teW(erutarepmetriaedistuOWkyticapaC °C
(A35/W7) EER (COP) Water temperature (inlet/outlet) +12/+7°C
Power input kW Cooling(A35/W18)
Cooling 53+)blub-yrD(erutarepmetriaedistuOWkyticapaC °C
(A35/W18) EER (COP) Outside air temperature (Wet-bulb) + 24°C
81+/32+)teltuo/telni(erutarepmetretaWWktupnirewoP °C
Pressure difference (water circuit) kPa
Cooling pump input (based on EN14511) kW
Note: "COP" and "Power input" in the above table are values that contains the "pump input (based on EN 14511) ".
regnahcxetaehetalP
snoitacificepstinuroodtuO
Service ref.
MITSUBISHI
Running current Heating
(A7/W35)
MWA1-28LM
A
Cooling
(A35/W7) A
Power factor Heating
(A7/W35)
39 mm
:A
%
Cooling
(A35/W7)
mm2.862:B
%
Atnerruc.xaM mm39:W
AezisrekaerB mm523:H
gnisacretuO mm2.45:D
hsiniflanretxE setalp28
lortnoctnar
egirfeR
Compressor
Model
Motor output kW
Start type
Protection devices
Maximum outlet water temperature
Oil (Model) L
WretaehesacknarC
Heat exchanger Air
Water
Fan Fan(drive)×No.
Fan motor output
kW
Air flow m
3
/min
(CFM)
Defrost method
Noise level
Cooling dB
Dimensions Width mm (in)
Depth mm (in)
Height mm (in)
)bl(gkthgieW
Refrigerant
*1 Hot gas with 4-way valve
Quantity kg (lb)
*2 at distance of 1 m from outdoor unit
Guaranteed operating Heating °C
*3 grille
range (Outdoor) Cooling
Outlet water temp. Heating
(Max in heating, Min in cooling)
Cooling
Nominal return water Heating
temperature range Cooling
nim/L
egnaretarwolfretaW
50
Plate fin coil
Plate heat exchanger
Inverter
1[, 230 V, 50 Hz
16
2.94
1.01
(Min.1.50) 5.00
4.50
1.53
10
1.11
14.3
64 (141)
950 (37-3/8)
330 +30
*3
(13+1-3/16)
13.0
HP switch
Discharge thermo
48
*2
-
0.9
SNB130FTCM
5.4
Galvanized plate
0.01
Hermetic twin rotary
6.8
PUHZ-W50VHA2(R1)
PUHZ-W50VHA2(R1)-BS
97
97
Linear expansion valve
Munsell 3Y 7.8/1.1
12.9
4.50
4.50
4.44
(Min.1.50) 5.00
0.01
3.50
1.43
12
1.7 (3.7)
+60
+5
*4 With the optional air outlet guide, the operation at
*5 For details of the min. return water temperature at
each water flow rate, refer to “2-2. AVAILABLE RANGE
(WATER FLOW RATE, RETURN WATER TEMP.)”.
−15°C outdoor temperature is possible.
Comp. Surface thermo
Overcurrent detection
46
*2
0.35 (FV50S)
740 (29-3/16)
R410A
(1,760)
Reverse cycle
*1
Propeller fan × 1
0.086
40
45
50
55
60
65
Ambient temperature [°C]
Maximum outlet water temperature [ °C ]
W
H
D
Water OUT
Water IN
Ref. IN
(Heating)
Ref. OUT
(Heating)
Thermistor
(
TH
3
2
)
A
B
°C
°C
°C
°C
°C
Heating dB(SPL)
6.5 to 14.3
−15 to +21
−5
(*4)
*5
to +46
+9 to +59
+8 to +28
PUHZ-W50VHA2-BS
−20 −15 −10 −5 0 5 10
PUHZ-W50VHA2R1 PUHZ-W50VHA2R1-BS
OCH605A

7
2-2. AVAILABLE RANGE (WATER FLOW RATE, RETURN WATER TEMP.)
Note: If using the unit out of the available range, the parts of unit might be damaged.
<Heating>
Table 1
5.0
6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0
7.0
9.0
11.0
13.0
15.0
17.0
19.0
Water flow rate [L/min]
Return water temp [:]
<Applicable Models>
• PUHZ-W50VHA2
• PUHZ-W50VHA2R1
• PUHZ-W50VHA2-BS
• PUHZ-W50VHA2R1-BS
Available range
<Cooling>
Table 4
7.06.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0
Water flow rate [L/min]
5.0
7.0
9.0
11.0
13.0
15.0
17.0
19.0
Return water temp [:]
<Applicable Models>
• PUHZ-W50VHA2
• PUHZ-W50VHA2R1
• PUHZ-W50VHA2-BS
• PUHZ-W50VHA2R1-BS
Available range
OCH605A

8
DATA
3
3-1. NOISE CRITERION CURVES
PUHZ-W50VHA2 PUHZ-W50VHA2R1
PUHZ-W50VHA2-BS PUHZ-W50VHA2R1-BS
1.5 m
1 m
MICROPHONE
UNIT
GROUND
3-2. STANDARD OPERATION DATA
Mode Cooling(A35/W7) Heating(A7/W35)
Total
Capacity W4,500 5,000
Input kW 1.53 1.11
Electrical circuit
Outdoor unit PUHZ-W50VHA2
Phase,Hz 1,50
Voltage V 230
Current A6.8 5.4
Refrigerantcircuit
Dischargepressure MPa 2.51 2.13
Suction pressure MPa 0.83 0.68
Dischargetemperature ºC 69 68
Condensingtemperature ºC 43 37
Suction temperature ºC 6 6
Water
conditions
Flowvolume L/min 12.9 14.3
Outletwatertemperature ºC 7 35
Outdoor
conditions
Intake air
temperature
D.B. ºC 35 7
W.B. ºC 24 6
TheunitofpressurehasbeenchangedtoMPabasedoninternationalSIsystem.
Theconversionfactoris:1(MPa)=10.2(kgf/cm2)
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 bar)
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)
46
LINE
OCH605A

9
PUHZ-W50VHA2 PUHZ-W50VHA2R1
PUHZ-W50VHA2-BS PUHZ-W50VHA2R1-BS
Earth terminal
Handle for moving
Terminal Connections Left•••• Power supply wiring Right•• Controller wiring
Handle for moving
Service panel
23
371
740
322
950
473
Water IN
Air Intake
Water OUT
Handle for moving
Rear Air Intake
Handle for moving
50
see Detail
Power supply wiring hole (2-
[
27Knock Out)
Front cover
40
119
34
Side Air Intake
Handle for moving
Rear Air Intake
Side Air Intake
Air Discharge
2-12 x 36 oval holes (Foundation Bolt M10)
2-U Shaped notched holes (Foundation Bolt M10)
Installation Feet
53
417
37028
175 175600
19
33030
Drain hole (5-[33)
30
81 219
220 145145145
Detail
ISO 228/1-G1 B
85 269
24
<Foundation bolt height>
Please secure the unit firmly with 4 foundation (M10) bolts. (Bolts and washers must be purchased locally.)
Service space
Dimensions of space needed for service access are shown in the below diagram.
FREE
Over 300mm
Over 10mm
The diagram below shows a basic example. Explanation of particular details are given in the installation manuals etc.
Over 500mm
Over 10mm
1 FREE SPACE (Around the unit) 2 SERVICE SPACE 3 FOUNDATION BOLTS
Less than
Over
Over
Over300
500
500
Over10
30
FOUNDATION
OUTLINES AND DIMENSIONS
4
Unit: mm
OCH605A

10
5WIRING DIAGRAM
PUHZ-W50VHA2 PUHZ-W50VHA2R1
PUHZ-W50VHA2-BS PUHZ-W50VHA2R1-BS
TB1
MC
MF1
21S4
63H
TH3
TH4
TH6
TH7
TH8
LEV-A, LEV-B
ACL
Terminal Block
<Power Supply, Indoor/Outdoor>
Motor for Compressor
Fan Motor
Solenoid Valve(4-Way Valve)
High Pressure Switch
63HS High Pressure Sensor
Thermistor<Liquid>
Thermistor<Discharge>
Thermistor<Plate HEX Liquid>
Thermistor<Ambient>
Thermistor<Heat Sink>
TH34 Thermistor<Comp. Surface>
TH32 Thermistor<Inlet Water>
Linear Expansion Valve
Reactor
CY1, CY2 Capacitor
Power Circuit Board
P. B.
Controller Circuit Board
Switch <Manual Defrost, Defect History
Record Reset, Function Switch>
Switch<Function Switch, Model Select>
Switch<Function Switch>
SW1
Connector<Connection for Option>
Connector<Connection for Option>
CNDM
SW6
SW8
Switch<Function Switch>
SW7
SV1/CH
Connector<Connection for Option>
SV3/SS
C. B.
SYMBOL NAME SYMBOL NAME
Switch<Model Select>
Switch<Function Switch>
SW5
Switch<Function Switch>
SW2
Switch<Function Switch>
SW4
SW9
Fuse<T10AL250V>
F1, F2
Fuse<T6.3AL250V>
F3, F4
TBL4 TBL2
S/N1 R/L1
CNAC2
(RD)
3
E3
1
CNAC1
(WH)
3
1
BK
E4
BK
EI
BK
1
CNDC
(PK)
3
MS
3~
MF1
1
3
1
7
34 11 1 2 2
1 7
1
CNF1
(WH)
TRANS
CNDC
(PK)
TH7/6
(RD)
TH3
(WH)
TH4
(WH)
TH7 TH6 TH3 TH4
1 2
TH32
(BK)
TH32
2 1
TH34
(RD)
TH34
63HS
63HS
(WH)
31
CNS
(WH)
63H
(YE)
3
1
63H
C. B.
P. B.
LED3
2
7
CN2
(RD)
F3
1 2
1 3
CNAC
(WH)
CN4
(WH)
12
34
F4
F2
F1
21S4
(GN)
SV3/SS
(WH)
1 31 3
X52
SV1/CH
(GY)
X54 X51
21S4
IC710
MS
3~
MC
CN2
(RD)
1
7
7
TH8
LEV-A
(WH)
LEV-A
CNDM
(WH)
13
ACL
Q600
DB2
M
51
LEV-B
(RD)
LEV-B
M
51
2
12
CN4
(WH)
12
CN6
(WH)
U
V
W
RD
WH
BK
LN
RD
WH
BN
OG
YE
GNYE
TB1
CY1
CY2
S1 S2 S3
POWER SUPPLY
~/N 230V 50Hz
TO INDOOR UNIT
*
1
*
1
SW6
SW1
SW8
SW2 SW7
SW5
SW4
SW9
Vo
Wo
Uo DB1
DB3
1 2 3 4 5 6 7 8
MODEL SW6
*1 MODEL SELECT
SW5-6 *2
OFF
ON
50V
OFF
ON
1 2 3 4 5 6
*2 SW5 -1 to 5 : Function Switch
The black square ( ) indicates a switch position.
OCH605A

11
WIRING SPECIFICATIONS6
FIELD ELECTRICAL WIRING (power wiring specifications)
Caution: Be sure to install N-line. Without N-line, it could cause damage to the unit.
Notes: 1. Wiring size must comply with the applicable local and national codes.
2. Power supply cables and the cables between 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 Controller and Outdoor unit directly to the units (no intermediate connections are al-
lowed).
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 longer than other cables.
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 Interface unit/
Flow temp. controller and outdoor unit, please use 3-pole type.
S1
S2
S3
S1
S2
S3
A-Control
Outdoor Unit
3 poles isolator
Power supply
Isolator
Interface unit/
Flow temp. controller
0VW5ledomtinuroodtuO
Outdoor unit power supply
Wiring
Wire No. ×
size (mm²)
Circuit rating
Outdoor unit L-N (single)
Outdoor unit L1-N, L2-N, L3-N (3phase)
Interface unit/Flow temp. controller-Outdoor unit S1-S2 *3
Interface unit/Flow temp. controller-Outdoor unit S2-S3 *3
Remote controller-Interface unit/Flow temp. controller *3
*1.A breaker with at least 3.0 mm contact separation in each pole shall be provided. Use earth leakage breaker (NV).
*2.Maximum 80 m
*3.The figures 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.
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.
230 V AC
24 V DC
12 V DC
~/N (single), 50 Hz, 230
Interface unit/Flow temp. controller-Outdoor unit *2 3 × 1.5 (polar)
Interface unit/Flow temp. controller-Outdoor unit earth *2 1 × Min. 1.5
Remote controller-Interface unit/Flow temp. controller 2 × 0.3 (Non-polar)
*3 230 V AC
A611*yticapacrekaerBtiucriCtinuroodtuO
5.1.niM×3htrae,ylppusrewoptinuroodtuO
OCH605A

12
REFRIGERANT SYSTEM DIAGRAM7
Distributor
TH7
Strainer(#100) Strainer(#100)
Receiver
LEV-B
TH6
TH32
Plate HEX
Water IN
Water OUT
Strainer
(#100)
TH3
CHECK/V
CHECK/V CHECK/V
H/P SW
TH4
TH8 P/B
LEV-A
COMP
REV/V
P-Sensor
Strainer
(#100)
TH34
Refrigerant flow in heating
Refrigerant flow in cooling
COMP
H/P SW
Plate HEX
REV/V
CHECK/V
P-Sensor
P/B
LEV-A
LEV-B
TH32
TH3
TH4
TH6
TH7
TH8
TH34
Receiver
DC inverter twin rotary compressor (Mitsubishi Electric Corporation)
For protection (OFF:4.15 MPa)
MWA1-28LM (MITSUBISHI)
Change the refrigerant circuit (Heating/Cooling) and for Defrosting
High pressure/Low pressure/For production test use
For calculation of the condensing temperature from high pressure
Inverter power board
Heating: Secondary LEV Cooling: Primary LEV
Heating: Primary LEV Cooling: Secondary LEV
For freeze protection and for compressor frequency control
Heating: Evaporating temperature Cooling: Sub cool liquid temperature
For LEV control and for compressor protection
Heating:Sub cool liquid temperature Cooling: Evaporating temperature
For fan control and for compressor frequency control
For power board protection
For compressor protection
For accumulation of refrigerant
Compressor
High pressure switch (63H)
Plate Heat Exchange
Reversing (4-way) valve (21S4)
Check valve
Pressure sensor (63HS)
Power board
Linear expansion valve-A
Linear expansion valve-B
Inlet water temperature thermistor
Liquid temperature thermistor
Discharge temperature thermistor
Plate HEX liquid temperature thermistor
Ambient temperature thermistor
Heat sink temperature thermistor
Comp.surface temperature thermistor
Receiver
Symbol Part name Detail
PUHZ-W50VHA2 PUHZ-W50VHA2R1
PUHZ-W50VHA2-BS PUHZ-W50VHA2R1-BS
OCH605A

13
TROUBLESHOOTING8
<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.
8-1. TROUBLESHOOTING
8-2. CHECK POINT UNDER TEST RUN
Before test run
• Afterinstallationofoutdoorunits,pipingworkandelectricwiringwork,re-checkthatthereisnowaterleakage,loosened
connections and incorrect polarity.
• Measureimpedancebetweenthegroundandthepowersupplyterminalblock(L,N)ontheoutdoorunitby500VMegger
andcheckthatitis1.0M or over.
• Turnonpowersupply12hoursbeforetestruninordertoprotectcompressor.
• Makesuretoreadoperationmanualbeforetestrun.(Especiallyitemstosecuresafety.)
Unit conditions at service Checkcode Actionstobetakenforservice(summary)
Thetroubleisreoccurring.
Displayed Judgewhatiswrongandtakeacorrectiveaction
accordingto“8-3.SELF-DIAGNOSISACTIONTABLE”.
Not displayed Conducttroubleshootingandascertainthecauseofthe
trouble.
Thetroubleisnotreoccurring.
Logged
1Consider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.
2Resetcheckcodelogsandrestarttheunitafternishing
service.
3There is no abnormality in electrical component,
controller board, etc.
Notlogged
1Re-check the abnormal symptom.
2Conducttroubleshootingandascertainthecauseofthe
trouble.
3Continuetooperateunitforthetimebeingifthecause
is not ascertained.
4Thereisnoabnormalityconcerningofpartssuchas
electrical component, controller board, etc.
OCH605A

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8-3. SELF-DIAGNOSIS ACTION TABLE
<Abnormalities detected when the power is turned on>
Check Code Abnormal point and detection method Case 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
DisconnectionofconnectorRorS
3Electricpowerisnotsupplied
to outdoor controller circuit
board.
a)Disconnectionofconnector
(CNDC)
4Disconnectionofreactor
5Defectiveoutdoorpowercir-
cuit board
6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RorS.
Referto"8-6.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.
4Checkconnectionof"TBL2"and"TBL4"on
theoutdoorpowercircuitboard.
Refer to "8-6.TESTPOINTDIAGRAM".
5Replaceoutdoorpowercircuitboard.
6Replace outdoor controller circuit board
(Whenitemsabovearecheckedbutthe
unitscannotberepaired.)
F5
63H connector open
Abnormalif63Hconnectorcircuitisopen
for3minutescontinuouslyfrombeing
switchedon.
63H:High-pressureswitch
1Disconnectionorcontactfail-
ureof63Hconnectoronout-
door controller circuit board
2Disconnectionorcontactfail-
ureof63H
363Hisworkingduetodefec-
tive parts.
4Defectiveoutdoorcontroller
circuit board
1Checkconnectionof63Hconnectoron
outdoor controller circuit board.
Refer to "8-6.TESTPOINTDIAGRAM".
2Checkthe63Hsideofconnectingwire.
3Checkforcontinuityof63H.
Replacehighpressureswitchifitisdefec-
tive.
4Replace outdoor controller circuit board.
OCH605A

15
Check Code Abnormal point and detection method Case Judgment and action
EA
Miswiring of Interface unit/Flow temp.
controller-outdoor unit connecting wire
1.Outdoorcontrollercircuitboardcan
automatically check the number of
connectedInterfaceunit/Flowtemp.
controller. Abnormal if the number can-
not be checked automatically due to
miswiringofInterfaceunit/Flowtemp.
controller-outdoorunitconnectingwire
andetc.afterpoweristurnedonfor4
minutes.
2.Abnormalifoutdoorcontrollercircuit
boardrecognizesexcessivenumberof
Interfaceunit/Flowtemp.controller.
1Contactfailureormiswiring
ofInterfaceunit/Flowtemp.
controller-outdoor unit
connectingwire
2DiameterorlengthofInterface
unit/Flowtemp.controller-
outdoorunitconnectingwireis
out of specified capacity.
3Excessive number of Interface
unit/Flowtemp.controlleris
connectedto1outdoorunit.
(2unitsormore)
4Defectivetransmitting
receivingcircuitofoutdoor
controller circuit board
5Defectivetransmitting
receivingcircuitofInterface/
Flowtemp.controllerboard
6Noisehasenteredintopower
supplyorInterface/Flow
temp. controller-outdoor unit
connectingwire.
1Checkdisconnection,loosenessorpolarityof
Interfaceunit/Flowtemp.controller-outdoor
unitconnectingwireofInterfaceunit/Flow
temp. controller and outdoor units.
2CheckdiameterandlengthofInterfaceunit/
Flowtemp.controller-outdoorunitconnect-
ingwire.
Totalwiringlength:80m
(IncludingwiringconnectingeachInterface
unit/Flowtemp.controllerunitandbetween
Interfaceunit/Flowtemp.controllerandout-
doorunit)
Also check if the connection order of flat
cableisS1,S2,S3.
3CheckthenumberofInterfaceunit/Flow
temp.controllerthatisconnectedto1out-
doorunit.(IfEAisdetected.)
4–5Turnthepoweroffonce,andonagainto
check.
Replace outdoor controller circuit board
orInterface/Flowtemp.controllerboardif
abnormalityoccursagain.
6Checktransmissionpath,andremovethe
cause.
Note: The descriptions above, 1–6, are for
EA,EbandEC.
Eb
Miswiring of Interface unit/Flow temp.
controller-outdoor unit connecting wire
(converse wiring or disconnection)
Outdoor controller circuit board can
automatically set the unit number of
Interfaceunit/Flowtemp.controller.
AbnormaliftheInterfaceunit/Flow
temp. controller number cannot be
setwithin4minutesafterpoweron
becauseofmiswiring(conversewiringor
disconnection)ofInterfaceunit/Flowtemp.
controller-outdoorunitconnectingwire.
1Contactfailureormiswiring
ofInterfaceunit/Flowtemp.
controller-outdoor unit
connectingwire
2DiameterorlengthofInterface
unit/Flowtemp.controller-
outdoorunitconnectingwireis
out of specified capacity.
4Defectivetransmitting
receivingcircuitofoutdoor
controller circuit board
5Defectivetransmitting
receivingcircuitofInterface/
Flowtemp.controllerboard
6Noisehasenteredintopower
supplyorInterfaceunit/Flow
temp. controller-outdoor unit
connectingwire.
EC
Startup time over
The unit cannot finish startup process
within4minutesafterpoweron.
1ContactfailureofInterfaceunit
/Flowtemp.controller-outdoor
unitconnectingwire
2DiameterorlengthofInterface
unit/Flowtemp.controller-
outdoorunitconnectingwireis
out of specified capacity.
6Noisehasenteredintopower
supplyorInterfaceunit/Flow
temp. controller-outdoor unit
connectingwire.
OCH605A

16
<Abnormalities detected while unit is operating>
Check Code Abnormal point and detection method Case Judgment and action
U1
High pressure (High-pressure switch
63H operated)
Abnormalifhigh-pressureswitch63H
operated(*)duringcompressoroperation.
*4.15MPa
63H:High-pressureswitch
1Decreasedwaterflow
2Cloggedfilterofwaterpipe
3Dirtofplateheatexchanger
4Lockedwaterpump
5Malfunctionofwaterpump
6Cloggedorbrokenpipe
7Locked outdoor fan motor
8Malfunction of outdoor fan
motor
9Short cycle of outdoor unit
0Dirtofoutdoorheatexchanger
1Decreasedairflowcausedby
defective inspection of outside
temperature thermistor
 (Itdetectslowertemperature
thanactualtemperature.)
2Disconnectionorcontact
failureofconnector(63H)on
outdoor controller circuit board
3Disconnectionorcontactfail-
ureof63Hconnection
4Defectiveoutdoorcontroller
circuit board
5Defectiveoperationoflinear
expansion valve
6Malfunctionoffandrivingcir-
cuit
1–5Checkwatercircuitandrepairthedefect.
6Checkpipingandrepairthedefect.
7–0Checkoutdoorunitandrepairthedefect.
1Checkthedetectedtemperatureofoutside
temperaturethermistoronLEDdisplay.
(SW2:Referto"8-7.OUTDOORUNIT
OPERATIONMONITORFUNCTION".)
2–4TurnthepoweroffandcheckF5is
displayedwhenthepoweristurnedon
again.
WhenF5isdisplayed,referto“Judgment
andaction”forF5.
5Checklinearexpansionvalve.
Refer to "8-5.HOWTOCHECKTHE
COMPONENTS".
6 Replace outdoor controller circuit board.
U2
High discharge temperature
Abnormalifdischargetemperature
thermistor(TH4)exceeds125:or110:
continuouslyfor5minutes.
Abnormalifduringdefrostingdischarge
temperaturethermistor(TH4)exceeds
110:continuouslyfor30minutes.
High comp. surface temperature
Abnormal if comp. surface temperature
(TH34)exceeds125:.
Inthecaseofhighcomp.surfacetem-
perature error, compressor does not restart
unlessthethermistor(TH34)becomesless
than95:.
1Overheated compressor oper-
ation caused by insufficient
refrigerant
2Defectivethermistor
3Defectiveoutdoorcontroller
circuit board
4Defectiveoperationoflinear
expansion valve
5In the case of the unit does
not restart :
Detectiontemp.ofthermistor
(TH4orTH34)]95:
1Checkintakesuperheat.
Checkleakageofrefrigerant.
Chargeadditionalrefrigerant.
23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.
4Checklinearexpansionvalve.
Refer to "8-5.HOWTOCHECKTHE
COMPONENTS".
5Checkthethermistororreplaceoutdoorcon-
troller circuit board.
U3
Open/short circuit of discharge
temperature thermistor (TH4)/Comp.
surface thermistor (TH34)
Abnormalifopen(3:orless)orshort
(217:ormore)isdetectedduring
compressor operation.
(Open(3:orless)detectionisinoperative
for10minutesofcompressorstarting
processandfor10minutesafterorduring
defrosting.)
1Disconnectionorcontactfail-
ureofconnector(TH4/TH34)
on the outdoor controller cir-
cuit board.
2Defectivethermistor
3Defectiveoutdoorcontroller
circuit board
1Checkconnectionofconnector(TH4/TH34)
on the outdoor controller circuit board.
Checktheleadwireforthermistor(TH4/
TH34).Referto"8-6.TESTPOINT
DIAGRAM".
2Checkresistancevalueofthermistor(TH4/
TH34)ortemperatureonLEDdisplay.
(Thermistor(TH4/TH34):Referto"8-5.HOW
TOCHECKTHECOMPONENTS".)
(SW2:Referto"8-7.OUTDOORUNIT
OPERATIONMONITORFUNCTION".)
3Replace outdoor controller circuit board.
OCH605A

17
Check Code Abnormal point and detection method Case Judgment and action
U4
Open/short of outdoor unit thermistors
(TH3, TH6, TH32, TH34, TH6, TH7, and TH8)
Abnormal if open or short is detected
duringcompressoroperation.
OpendetectionofthermistorsTH3,TH32
andTH6isnotdetected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 "8-7.
OUTDOORUNITOPERATION
MONITORFUNCTION"
.)
1
Checkconnectionofconnector(TH3,TH32,
TH34,TH6/TH7)ontheoutdoorcontrollercircuit
board.Checkconnectionofconnector(CN6)on
theoutdoorpowercircuitboard.Checkthelead
wireforthermistor(TH3,TH32,TH34,TH6,TH7,
TH8).Referto"8-6.TESTPOINTDIAGRAM".
2Checkresistancevalueofthermistor(TH3,
TH32,TH34,TH6,TH7,TH8)orchecktem-
peratureonLEDdisplay.(Thermistor/TH3,
TH32,TH34,TH6,TH7,TH8:Referto"8-5.
HOWTOCHECKTHECOMPONENTS".)
(SW2:Referto "8-7.OUTDOORUNIT
OPERATIONMONITORFUNCTION".
)
3Replace outdoor controller circuit board.
U5
Temperature of heat sink
Abnormalifheatsinkthermistor(TH8)
detectstemperatureindicatedbelow.
W50VHA2••••••••••••• 77°C
1The outdoor fan motor is
locked.
2Failureofoutdoorfanmotor
3Airflowpathisclogged.
4Ambienttemperatureishigh.
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,refertocheckcodeU4.
5 Checkresistancevalueofthermistor(TH8)ortem-
peraturebymicrocomputer.(Thermistor/TH8:Refer
to "8-5.HOWTOCHECKTHECOMPONENTS".)
(SW2:Referto"8-7.OUTDOORUNIT
OPERATIONMONITORFUNCTION".)
6Replaceoutdoorpowercircuitboard.
7Replace outdoor controller circuit board.
U6
Power module
Checkabnormalitybydrivingpowermodule
in case overcurrent is detected.
(UForUPerrorcondition)
1Defectiveoutdoorpowercir-
cuit board
2
Decreaseofpowersupplyvoltage
3Looseness, disconnection or
reverseofcompressorwiring
connection
4Defectivecompressor
1Replaceoutdoorpowercircuitboard.
2Checkfacilityofpowersupply.
3Correctthewiring(U•V•Wphase)to
compressor. Refer to "8-6.TESTPOINT
DIAGRAM"(Outdoorpowercircuitboard).
4Checkcompressorreferringto
"8-4.HOW
TOCHECKTHEPARTS".
U7
Too low superheat due to low discharge
temperature
Abnormalifdischargesuperheatis
continuouslydetected−15:or less 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connec-
tion 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dis-
chargetemperaturethermistor(TH4).
3Checkthecoiloflinearexpansionvalve.
Refer to "8-5.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 "8-4.HOWTOCHECKTHEPARTS".
U8
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.
3Replace the outdoor circuit controller board.
(whenthefailureisstillindicatedevenafter
performingtheremedy1above.)
()
Thermistors Open detection Short detection
Symbol Name
TH3 Thermistor<Liquid> −40°Corbelow 90°Corabove
TH32 Thermistor <Inlet Water> −40°Corbelow 102°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
1Disconnectionorcontactfailure
of connectors
Outdoor controller circuit board:
TH3,TH32,TH34,TH6/TH7
 Outdoorpowercircuitboard:
CN6
2Defectivethermistor
3Defectiveoutdoorcontroller
circuit board
OCH605A

18
Check Code Abnormal point and detection method Case Judgment and action
U9
Detailed
codes
TofindoutthedetailsaboutU9error,turnONSW2-1,2-2,2-3,2-4,2-5and2-6whenU9erroroccurs.
Tofindoutthedetailhistory(latest)aboutU9error,turnONSW2-1,2-2and2-6.
Refer to "8-7.OUTDOORUNITOPERATIONMONITORFUNCTION".
01
Overvoltage error
•IncreaseinDCbusvoltageto
W50V:400V
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 "8-6.TESTPOINT
DIAGRAM"(Outdoorpowercircuitboard).
3Replaceoutdoorpowercircuitboard.
4Checkcompressorforelectricalinsulation.
Replace compressor.
02
Undervoltage error
•InstantaneousdecreaseinDC
busvoltageto
W50V:200V
1Decreaseinpowersource
voltage,instantaneousstop.
2Defectiveconverterdrivecir-
cuitinoutdoorpowercircuit
board
3Defective52Cdrivecircuitin
outdoorpowercircuitboard
4Disconnectionorloosecon-
nectionofCN2ontheoutdoor
powercircuitboard/controller
circuit board
5PowercircuitfailureonDC
supplyfor15VDCoutput
on outdoor controller circuit
board
1Checkthefieldfacilityforthepowersupply.
23Replaceoutdoorpowercircuitboard.
4CheckCN2wiring.
5Replace outdoor controller circuit board.
04
Input current sensor error
•Decreaseininputcurrent
throughoutdoorunitto0.1A
onlyifoperationfrequencyis
morethanorequalto40Hz
or compressor current is more
thanorequalto6A.
1Defectiveinputcurrentdetec-
tioncircuitinoutdoorpower
circuit board
2Defectiveoutdoorcontroller
circuit board
1Replaceoutdoorpowercircuitboard.
2Replace 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superimposi-
tion.
2Disconnectionorloosecon-
nectionofearthwiring
3Disconnectionorloosecon-
nectionofCN2ontheoutdoor
powercircuitboard/controller
circuit board
4Defectivepowersynchronous
signalcircuitinoutdoorcon-
troller 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.
4Replace outdoor controller circuit board.
5Replaceoutdoorpowercircuitboard.
10
PFC error (Overvoltage/
Overcurrent)
•PFCdetectedanyofthefol-
lowing
a)IncreaseofDCbusvoltage
to400V.
b)Increaseininputcurrentto
50Apeak
1Abnormalincreaseinpower
sourcevoltage
2Decreaseinpowersource
voltage,instantaneousstop
3Disconnectionofcompressor
wiring
4
Misconnectionofreactor(ACL)
5 Defectiveoutdoorpowercircuit
board
6 Defectivereactor(ACL)
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com-
pressor.Referto"8-6.TESTPOINT
DIAGRAM"(outdoorpowercircuitboard).
4Correctthewiringofreactor(ACL).
5Replaceoutdoorpowercircuitboard.
6Replacereactor(ACL).
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
(Formodelsequippedwith
single-phasePFConly)
NotapplicableforSW50VHA2 Checkfortheswitchsettingsformodelselect
on the outdoor controller circuit board.
OCH605A

19
Check Code Abnormal point and detection method Case Judgment and action
Ud
Overheat protection
Abnormalifoutdoorliquidthermistor
(TH3)detects70:ormoreorcondensing
temperatureofpressuresensor(63HS)
detects70:ormoreduringcompressor
operation.
1
Defectiveoutdoorfan(fan
motor)orshortcycleofout-
doorunitduringcoolingopera-
tion
2Defectiveoutdoorliquid
thermistor(TH3)
3Defectiveoutdoorcontroller
circuit board
4Defectivepressuresensor
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.
4Checkpressurebymicrocomputer.
(Pressuresensor/63HS)
(SW2:Referto"8-7.OUTDOORUNIT
OPERATIONMONITORFUNCTION".)
UF
Compressor overcurrent interruption
(When compressor locked)
AbnormalifovercurrentofDCbusor
compressorisdetectedwithin30seconds
aftercompressorstartsoperating.
1Decreaseofpowersupply
voltage
2Looseness, disconnection or
converseofcompressorwiring
connection
3Defectivecompressor
4Defectiveoutdoorpowerboard
5Decreasedwaterflow
6Cloggedfilterofwaterpipe
7Cloggedplateheatexchanger
8Lockedwaterpump
9Malfunctionofwaterpump
1Checkfacilityofpowersupply.
2Correctthewiring(U
•
V
•
Wphase)to
compressor.
Refer to "8-6.TESTPOINTDIAGRAM"
(Outdoorpowercircuitboard).
3Checkcompressor.Referto "8-4.HOWTO
CHECKTHEPARTS"
4Replaceoutdoorpowercircuitboard.
5
– 9Checkwatercircuitandrepairthedefect.
UH
Current sensor error or input current error
• Abnormalifcurrentsensordetects−1.0
Ato1.0Aduringcompressoroperation.
(Thiserrorisignoredduringtestrun.)
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compres-
sor. Refer to "8-6.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.
UP
Compressor overcurrent interruption
AbnormalifovercurrentDCbusor
compressor is detected after compressor
startsoperatingfor30seconds.
1
Decreaseofpowersupplyvolt-
age
2Looseness, disconnection or
converseofcompressorwiring
connection
3Defectivefanofoutdoorunits
4Shortcycleofindoor/outdoor
units
5Defectiveinputcircuitofout-
door controller circuit board
6Defectivecompressor
7Decreasedwaterflow
8Cloggedfilterofwaterpipe
9Cloggedplateheatexchanger
0Lockedwaterpump
1Malfunctionofwaterpump
1Checkfacilityofpowersupply.
2Correctthewiring(U•V•Wphase)to
compressor. Refer to "8-6.TESTPOINT
DIAGRAM"(Outdoorpowercircuitboard).
3Checkoutdoorfan.
4Solve short cycle.
5Replace outdoor controller circuit board.
6Checkcompressor.
Refer to "8-4.HOWTOCHECKTHEPARTS".
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.
7–1Checkwatercircuitandrepairthedefect.
OCH605A

20
Check Code Abnormal point and detection method Case Judgment and action
E0
or
E4
Remote controller transmission error
(E0)/signal receiving error (E4)
1Abnormal if main or sub remote
controller cannot receive any
transmission normally from Interface
unit/Flowtemp.controllerofrefrigerant
address“0”for3minutes.
(Checkcode:E0)
2Abnormal if sub-remote controller could
notreceiveanysignalfor2minutes.
(Checkcode:E0)
1
AbnormalifInterface/Flowtemp.
controller board cannot receive any
data normally from remote controller
boardorfromotherInterface/Flowtemp.
controllerboardfor3minutes.(Check
code:E4)
2 Interface/Flowtemp.controllerboard
cannotreceiveanysignalfromremote
controllerfor2minutes.(Checkcode:
E4)
1Contactfailureattransmission
wireofremotecontroller
2All remote controllers are set
as“sub”remotecontroller.
Inthiscase,E0isdisplayed
on remote controller, and E4
isdisplayedatLED(LED1,
LED2)ontheoutdoorcontrol-
ler circuit board.
3Miswiringofremotecontroller
4Defectivetransmittingreceiv-
ingcircuitofremotecontroller
5Noise has entered into the
transmissionwireofremote
controller.
1Checkdisconnectionorloosenessof
Interfaceunit/Flowtemp.controllerunitor
transmissionwireofremotecontroller.
2Setoneoftheremotecontrollers“main”,If
thereisnoproblemwiththeactionabove.
3Checkwiringofremotecontroller.
•Totalwiringlength:max.500m
(Donotusecable×3ormore.)
•Thenumberofconnectingremotecontroller
(Refertotheindoorunit'sInstallationManual.)
If the cause of trouble is not in 1–3 above,
4Diagnoseremotecontrollers.
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
Interface/Flowtemp.controllerboard.
b)When“RCNG”isdisplayed,replaceremote
controller.
c)When“RCE3”or“ERC00–66”isdisplayed,
noisemaybecausingabnormality.
E1
or
E2
Remote controller control board
1Abnormal if data cannot be read nor-
mally from the nonvolatile memory of
the remote controller control board.
(Checkcode:E1)
2Abnormal if the clock function of remote
controller cannot be operated normally.
(Checkcode:E2)
1Defectiveremotecontroller 1Replace remote controller.
E3
or
E5
Remote controller transmission error
(E3)/signal receiving error (E5)
1
Abnormal if remote controller could not
findblankoftransmissionpathfor6sec-
onds and could not transmit.
(
Check code:E3)
2 When remote controller receives the
transmitted data same time and com-
pares these data. Abnormal if the data is
judgedtobedifferentfor30continuous
times.(
Check code:E3)
1 AbnormalifInterface/Flowtemp.control-
ler board could not find blank of transmis-
sion path.(
Check code:E5)
2 WhenInterface/Flowtemp.controller
receives the transmitted data same time
and compares these data. Abnormal if
thedataisjudgedtobedifferentfor30
continuoustimes.(
Check code:E5)
1Refertotheindoorunit's
Installation Manual for remote
controller connection.
2Defectivetransmittingreceiv-
ingcircuitofremotecontroller
3Defectivetransmittingreceiv-
ingcircuitofInterface/Flow
temp. controller board
4Noise has entered into trans-
missionwireofremotecon-
troller.
1Refertotheindoorunit'sInstallationManual
for remote controller connection.
2–4Diagnoseremotecontroller.
a)When“RCOK”isdisplayed,remote
controllers have no problem.
Turnthepoweroff,andonagainto
check.
Whenbecomingabnormalagain,
replace indoor controller board.
b)When“RCNG”isdisplayed,replace
remote controller.
c)When“RCE3”or“ERC00–66”isdis-
played,noisemaybecausingabnor-
mality.
E6
Interface unit/Flow temp. controller-out-
door unit communication error (Signal
receiving error)
1AbnormalifInterface/Flowtemp.
controller board cannot receive any
signalnormallyfor6minutesafter
turningthepoweron.
2AbnormalifInterface/Flowtemp.
controller board cannot receive any
signalnormallyfor3minutes.
1
Contactfailure,shortcircuitor,
miswiring(conversewiring)of
Interfaceunit/Flowtemp.con-
troller-outdoorunitconnecting
wire
2Defectivetransmittingreceiving
circuitofInterface/Flowtemp.
controller board
3Defectivetransmittingreceiv-
ingcircuitofInterface/Flow
temp. controller board
4 Noise has entered into Interface
unit/Flowtemp.controller-
outdoorunitconnectingwire.
Note:CheckLEDdisplayontheoutdoor
controllercircuitboard.(Connect
A-controlservicetool,PAC-SK52ST.)
1Checkdisconnectionorloosenessof
Interfaceunit/Flowtemp.controller-outdoor
unitconnectingwireofInterfaceunit/Flow
temp. controller or outdoor unit.
2–4Turnthepoweroff,andonagainto
check.Ifabnormalitygeneratesagain,
replaceInterface/Flowtemp.controller
board or outdoor controller circuit board.
OCH605A