Mitsubishi Electric PURY-80TMU, PURY-100TMU-A, CMB-104, CMB-105, CMB-106 Service Manual

AIR CONDITIONERS CITY MULTI

Models PURY-80TMU, 100TMU

PURY-80TMU-A, 100TMU-A
CMB-104, 105, 106, 108, 1010, 1013, 1016NU-F

Service Handbook

–1–

Contents

1 PRECAUTIONS FOR DEVICES .............................................................. 3

[1] Storage of Piping Material ................................................................. 3

[2] Brazing .............................................................................................. 4

[3] Airtightness Test ................................................................................ 5

[4] Vacuuming ........................................................................................ 5

2 COMPONENT OF EQUIPMENT ............................................................. 6

[1] Appearance of Components ............................................................. 6

[2] Refrigerant Circuit Diagram and Thermal Sensor ........................... 13

[3] Electrical Wiring Diagram ................................................................ 14

[4] Standard Operation Data ................................................................ 18

[5] Function of Dip SW and Rotary SW ................................................ 20

3 TEST RUN ............................................................................................. 23

[1] Before Test Run .............................................................................. 23

[2] Test Run Method ............................................................................. 27

4 GROUPING REGISTRATION OF INDOOR UNITS WITH REMOTE

CONTROLLER ....................................................................................... 28

5 CONTROL .............................................................................................. 34

[1] Control of Outdoor Unit ................................................................... 34

[2] Control of BC Controller .................................................................. 37

[3] Operation Flow Chart ...................................................................... 38

[4] List of Major Component Functions ................................................ 44

[5] Resistance of Temperature Sensor ................................................. 47

6 REFRIGERANT AMOUNT ADJUSTMENT ............................................ 48

[1] Refrigerant Amount and Operating Characteristics ........................ 48

[2] Adjustment and Judgement of Refrigerant Amount ........................ 48

7 TROUBLESHOOTING ........................................................................... 54

[1] Principal Parts ................................................................................. 54

[2] BC Controller Disassembly Procedure ........................................... 80

[3] Self-diagnosis and Countermeasures Depending on the Check

Code Displayed ............................................................................... 86

[4] LED Monitor Display ..................................................................... 108

8 PREPARATION, REPAIRS AND REFRIGERANT REFILLING WHEN

REPAIRING LEAKS ............................................................................. 118

[1] Location of leaks: Extension piping or indoor units (when cooling) 118

[2] Location of leaks: Outdoor unit (Cooling mode) ............................. 118

[3] Location of leaks:

Extension piping or indoor units (Heating mode)

119

[4] Location of leaks: Outdoor unit (when heating) ............................. 119

–2–

Safety precautions

Before installation and electric work

Before installing the unit, make sure you read all
the “Safety precautions”.
The “Safety precautions” provide very important
points regarding safety. Make sure you follow
them.
This equipment may not be applicable to
EN61000-3-2: 1995 and EN61000-3-3: 1995.
This equipment may have an adverse effect on
equipment on the same electrical supply system.
Please report to or take consent by the supply.
authority before connection to the system.

Symbols used in the text

Warning:
Describes precautions that should be observed to
prevent danger of injury or death to the user.

Caution:
Describes precautions that should be observed to
prevent damage to the unit.

Symbols used in the illustrations

: Indicates an action that must be avoided.

: Indicates that important instructions must be followed.

: Indicates a part which must be grounded.

: Beware of electric shock (This symbol is displayed on the

main unit label.) <Color: Yellow>

Warning:

Carefully read the labels affixed to the main unit.

Warning:

• Use the specified cables for wiring. Make the connections

securely so that the outside force of the cable is not
applied to the terminals.

- Inadequate connection and fastening may generate heat and
cause a fire.

• Have all electric work done by a licensed electrician
according to “Electric Facility Engineering Standard” and
“Interior Wire Regulations”and the instructions given in
this manual and always use a special circuit.

- If the power source capacity is inadequate or electric work is

performed improperly, electric shock and fire may result.

• Securely install the cover of control box and the panel.

- If the cover and panel are not installed properly, dust or water

may enter the outdoor unit and fire or electric shock may
result.

• After completing service work, make sure that refrigerant
gas is not leaking.

- If the refrigerant gas leaks and is exposed to a fan heater,

stove, oven, or other heat source, it may generate noxious
gases.

• Do not reconstruct or change the settings of the protection
devices.

- If the pressure switch, thermal switch, or other protection

device is shorted and operated forcibly, or parts other than
those specified by Mitsubishi Electric are used, fire or

explosion may result.

*

▲

▲

▲

▲

▲

–3–

[1] Storage of Piping Material

(1) Storage location

Store the pipes to be used indoors. (Warehouse at site or owner’s warehouse)
Storing them outdoors may cause dirt, waste, or water to infiltrate.

(2) Pipe sealing before storage

Both ends of the pipes should be sealed until immediately before brazing.
Wrap elbows and T’s in plastic bags for storage.

11

11

1 PRECAUTIONS FOR DEVICES

–4–

[2] Brazing

No changes from the conventional method, but special care is required so that foreign matter (ie. oxide scale, water, dirt,
etc.) does not enter the refrigerant circuit.

Example : Inner state of brazed section

When non-oxide brazing was not used When non-oxide brazing was used

Items to be strictly observed :

1. Do not conduct refrigerant piping work outdoors on a rainy day.

2. Apply non-oxide brazing.

3. Use a brazing material (Bcup-3) which requires no flux when brazing between copper pipes or between a copper pipe
and copper coupling.

4. If installed refrigerant pipes are not immediately connected to the equipment, then braze and seal both ends of them.

Reasons :

1. A flux generally contains chlorine. A residual flux in the refrigerant circuit may generate sludge.

Note :

• Commercially available antioxidants may have adverse effects on the equipment due to its residue, etc. When
applying non-oxide brazing, use oxygen free nitrogen (OFN).

–5–

[3] Airtightness Test

Items to be strictly observed :

1. Pressurize the equipment with nitrogen up to the design pressure and then judge the equipment’s airtightness, taking
temperature variations into account.

Reasons :

1. Use of oxygen as the pressurized gas may cause an explosion.

[4] Vacuuming

1. Standard degree of vacuum for the vacuum pump
Use a pump which reaches 65 Pa (0.0094 psi) or below after 5 minutes of operation.
In addition, be sure to use a vacuum pump that has been properly maintained and oiled using the specified oil. If the
vacuum pump is not properly maintained, the degree of vacuum may be too low.

2. Required accuracy of the vacuum gauge
Use a vacuum gauge that can measure up to 650 Pa (0.094 psi). Do not use a general gauge manifold since it cannot
measure a vacuum of 650 Pa (0.094 psi).

3. Evacuating time

• Evacuate the equipment for 1 hour after 650 Pa (0.094 psi) has been reached.

• After envacuating, leave the equipment for 1 hour and make sure that the vacuum is not lost.

4. Operating procedure when the vacuum pump is stopped
In order to prevent a backflow of the vacuum pump oil, open the relief valve on the vacuum pump side or loosen the
charge hose to drawn in air before stopping operation.
The same operating procedure should be used when using a vacuum pump with a check valve.

–6–

SV block Fusible plug

Accumulator

CV block

Compressor

4-way valve

22

22

2 COMPONENT OF EQUIPMENT

[1] Appearance of Components

In case of -A type.

–7–

Controller Box

–8–

MAIN board

CNS1 CNS2 CN40 CN41

CNVCC3
Power Source
for control

1-2 30V
1-3 30V
4-6 12V
5-6 5V

CN51
Indication distance

3-4 Compressor ON/OFF
3-5 Trouble

CNRS3
Serial transmission to
INV board

CN3D

CN3S

LD1
Service LED

SW1

SW2SWU1SWU2SW3SW4CNAC3

Power Output

5 L1
3 L3
1 G

CN20
Power Input

7 L1
5 L2
3 L3
1 G

CNVCC5
Power Source for control(5V)

–9–

INV board

CNDC2
1-3 DC-325V

CN15V2
Power Output
for IPM control

CNVCC4
Power Output (5V)

CNL2
Choke coil

CNVCC2
Power Output

1-2 30V, 1-3 30V
4-6 12V, 5-6 5V

CNDR2
Output to
G/A board

CNCT

CNTH

CNRS2
Serial transmission
to MAIN board

CN52C
Control for 52C

CNFAN
Control for MF1

CNAC2
Power Input

5 L1
3 L3
1 G

SW1

–10–

G/A board

CNIPM1

CN15V1

CNDR1

CNE CNDC1

Power board

–11–

BC controller

CNTR

CN02
M-NET
transmission

CN03

CN12
Power
supply

1 EARTH
3 N
5 L

SW4 SW2 SW1SW5

–12–

RELAY 10 board

RELAY 4 board

–13–

[2] Refrigerant Circuit Diagram and Thermal Sensor

–14–

[3] Electrical Wiring Diagram

1

MC

P

N

–15–

2 CMB-104·105·106NU-F

F01

250VAC

6.3A F

CMB-106NU-F ONLY

Circuit
board

(Symbol explanation)

BC controller

(Box internal layout)

T5

T4

T6

T1

T3

T2

1

3

1

1

2

3

1

2

1

2

1

2

3

4

1

123456 123456 1 3 5

2

3

4

5

6

7

8

3

321 21

1

1

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

3

3

5

7

1

3

5

7

1

3

5

7

1

3

5

7

1

3

5

7

1

3

5

7

X2

X1

X30

X4

X3

X31

X6

X5

X32

X8

X7

X33

X10

X9

X34

X12

X11

X35

3

G

2

2

Fuse AC250V 6.3A T

F01

Terminal

T1~6

CN31

CN30

CN29

SV6B

SV6A

SV6C

SV4A

SV4C

SV5B

SV4B

SV5C

SV5A

CN28

CN27

SV1B

SV1A

SV1C

SV2A

SV2C

SV3C

SV2B

SV3B

SV3A

CONT.B

TR

Terminal block
(for Transmission)

TB02

Terminal block
(for power source)

TB01

Solenoid valve

SV1~6A,B,C

Expansion valve

Thermistor sensor

Transformer

Name

Symbol

TR

TH11,12,15,16

LEV1,3

PS1,3

Pressure sensor

CONT.B

Note : 1.TB02 is transmission

terminal block.

Never connect power

line to it.

2.The initial set values

of switch on CONT.B

are as follows.

SW1 : 0

SW2 : 0

TB01

TB02

L1
L2

~208V-230V 60Hz

⎫
⎬
⎭

⎫
⎬
⎭

Power source

M1

M2

Shield wire

Transmission line

DC 30V

LEV1LEV3

TB01

LEV1

PS3

PS1

TH16

TH15

TH12

TH11

CN07

CN11

CN10

CN13

CN03

CNP3

CNP1

CN02

CONT.B

CN05

CN12

CNTR

CN26

TB02

TR

CMB-105 106NU-F ONLY

–16–

3 CMB-108·1010NU-F

⎫

⎬

⎭

⎫

⎬

⎭

–17–

4 CMB-1013·1016NU-F

⎫

⎬

⎭

⎫

⎬

⎭

–18–

[4] Standard Operation Data

1 Cooling

Outdoor unit

Items

PURY-80TMU(-A) PURY-100TMU(-A)

Indoor

Outdoor

Quantity

Quantity in operation

Model

Main pipe

Branch pipe

Total piping length

26.7˚C(80˚F)/19.4˚C(67˚F) 26.7˚C(80˚F)/19.4˚C(67˚F)

35˚C(95˚F) 35˚C(95˚F)

44

44

24 24 20 10 48 16 24 10

5(16.4) 5(16.4)

5(16.4) 5(16.4) 5(16.4) 5(16.4) 5(16.4) 5(16.4) 5(16.4) 5(16.4)

25(82) 25(82)

Hi Hi Hi Hi Hi Hi Hi Hi

10 kg(67 oz) 12 kg(86 oz)

330 460 430 300 410 330 460 300

2000 140 2000 150

235 235

2.03/0.49 1.90/0.39
(294/71) (276/57)

1.92/1.92 1.79/1.79

(279/279) (25/25)

107(225) 110(230)

50(122) 47(117)

7(45) 7(45)

10(50) 10(50)

12(54) 12(54)

75(167) 70(158)

26(79) 30(86)

15(59) 15(59)

Indoor unit fan notch

Refrigerant volume

Compressor volts / Frequency

Outdoor unit

Indoor unit

BC controller (1, 3)

Oil return

High pressure/Low pressure

BC controller liquid/Intermediate

Pressure

DB/WB

Q’ty

–

m

(Ft)

–

kg(oz)

V

V/Hz

A

Pulse

MPa

(psi)

˚C

(˚F)

Condition

Sectional temperature

LEV opening

Discharge (TH1)

Heat exchanger outlet (TH5)

Accumulator

Suction (Comp)

Shell bottom (Comp)

LEV inlet

Heat exchanger outlet

Inlet

Outlet

Outdoor
unit

Indoor
unit

Ambient temp.

Indoor unit

Piping

208 230 208 230

134/76 134/76 171/98 171/98

27.4 24.8 35.2 31.8

–19–

2 Heating

Outdoor unit

Items

PURY-80TMU(-A) PURY-100TMU(-A)

Indoor

Outdoor

Quantity

Quantity in operation

Model

Main pipe

Branch pipe

Total piping length

21.1˚C(70˚F) 21.1˚C(70˚F)

8.3˚C(47˚F)/6.1˚C(43˚F) 8.3˚C(47˚F)/6.1˚C(43˚F)

44

44

24 24 20 10 48 16 24 10

5(16.4) 5(16.4)

5(16.4) 5(16.4) 5(16.4) 5(16.4) 5(16.4) 5(16.4) 5(16.4) 5(16.4)

25(82) 25(82)

Hi Hi Hi Hi Hi Hi Hi Hi

10 kg(67 oz) 12 kg(86 oz)

600 950 750 400 750 600 950 400

60 700 60 800

150 235

1.81/0.35 1.76/0.36
(263/51) (256/53)

1.72/1.37 1.67/1.37

(249/199) (242/199)

100(212) 95(203)

–2(28) –1(30)

–1(30) –1(30)

–4(25) –2(28)

–1(30) –1(30)

45(113) 40(104)

38(100) 40(104)

80(176) 85(185)

208 230 208 230

149/85 149/85 174/100 174/100

27.5 24.9 35.6 32.2

Indoor unit fan notch

Refrigerant volume

Compressor volts / Frequency

Outdoor unit total current

Indoor unit

BC controller (1, 3)

Oil return

High pressure/Low pressure

BC controller liquid/Intermediate

Pressure

DB/WB

Q’ty

–

m

(Ft)

–

kg(oz)

V

V/Hz

A

Pulse

MPa

(psi)

˚C

(˚F)

Condition

Sectional temperature

LEV opening

Discharge (TH1)

Heat exchanger outlet (TH5)

Accumulator

Suction (Comp)

Shell bottom (Comp)

LEV inlet

Heat exchanger outlet

Inlet

Outlet

Outdoor
unit

Indoor
unit

Ambient temp.

Indoor unit

Piping

–20–

[5] Function of Dip SW and Rotary SW

(1) Outdoor unit

SWU
SW1

SW2

SW3

SW4

1~2
1~8

9~10

1

2

3

4
5
6

7

8

9

10

1

2

3

4

5
6

7

8
9

10

1
2
3
4
5
6
7
8
9

10

Unit address setting
For self diagnosis/
operation monitoring

–

Centralized control switch

Deletion of connection
information.

Deletion of error history.

–

–
Disregard ambient air
sensor errors, liquid
overflow errors.
Forced defrosting

Defrost prohibited timer

–

–
SW3-2 Function valid/
invalid
Indoor unit test operation

Defrosting start tempera­ture of TH7.
Defrosting end tempera­ture of TH5.

–
Pump down operation

Target Td (High pressure)
at Heating

–

–
Models

–

–

–

–

LED Display

–

–

–

–

–

Set on 51~100 with the dial switch.

LED monitering display

–
Centralized control not
connected.
Storing of refrigeration
system connection
information.

–

–

–
Errors valid.

Ordinary control

50 min.

–

–
SW3-2 Function invalid

Stop all indoor units.

–6°C

(21˚F)

8°C

(46˚F)

–

Invalid

49˚C

(120˚F)

–

–

Model 80

–

–

–

–

“˚F” “psig” Display

–

–

–

–

–

–
Centralized control
connected.
Deletion of refrigeration
system connection
information.
Deletion

–

–
Disregard errors.

Start forced defrosting.

90 min.

–

–
SW3-2 Function valid

All indoor units test
operation ON.

–3°C

(27˚F)

15°C

(59˚F)

–

Valid

53˚C

(127˚F)

–

–

Model 100

–

–

–

–

“˚C” “kgf/amG” Display

–

–

–

–

–

Before power is turned on.
During normal operation when power
is on.
Should be set on OFF.
Before power is turned on.

Before power is turned on.

During normal operation when power
is on.

–

–
During normal operation when power
is on.

During normal operation when power
is on. (Except during defrosting)

–

–
During normal operation when power
is on.
When SW3-1 is ON after power is
turned on.
During normal operation when power
is on.
During normal operation when power
is on. (Except during defrosting)

–
During compressor stop when power
is on.
During normal operation when power
is on.

–

–
When switching on the power.

–

–

–

–

When switching on the power

–

–

–

–

–

During normal
operation when
power is on.

10 minutes or
more after
compressor
starts.

Switch Function

Function according to switch operation Switch set timing

When off When on When off When on

Note:

• SWU1~2=00 when shipped from the factory. Other factory settings are indicated by shaded portions.

• If the address is set from 01 to 50, it automatically becomes 100.

–21–

(2) Indoor unit

DIP SW1, 3

Model 32 40 48

Capacity (model name) code

16 20 25

SW2 setting

Model 08 10 12 16 20 24

Capacity (model name) code

45 681013

SW2 setting

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

Note 1: The shaded part indicates the setting at factory shipment. (For the SW not being shaded, refer to the

table below.)

2: The DipSW setting is only effective during unit stopping (remote controller OFF) for SW1, 2, 3 and 4 commonly

and the power source is not required to reset.)

3: When both SW1-7 and SW1-8 are being set to ON, the fan stops at the heating thermostat of OFF.

Setting of DIP SW2

Model

Switch

SW1

SW3

3

6

7

3

4

6

8

PLFY-NAMU-A

ON

ON

OFF

ON

ON

OFF

OFF

Indoor unit inlet

None

100h

Ineffective

Fan output display

At stationary heating

Very low speed

SW1-7 setting

Ineffective

–

Heat pump

None

None

None

1st setting

Down blow B, C

–

Effective

–

–

Built in remote controller

Provided

2500h

Effective

Thermo. ON signal display

Always at heat.

Low speed

Set airflow

Effective

–

Cool.only

Provided

Provided

Provided

2nd setting

Horizontal

–

Ineffective

–

–

Room temp. sensor position

Clogged filter detect.

Filter duration

OA intake

Remote display select.

Humidifier control

Heating thermo. OFF airflow

Heating thermo. OFF airflow

Power failure automatic
return

–

Model selection

Louver

Vane

Vane swing function

Vane horizontal angle

Vane angle set for cooling

–

Heating 4deg (7.2 deg) up
Note : °C scale (°F scale)

–

–

Always ineffective for PKFY-NAMU

Not provided for PKFY-NAMU
Provided for PLFY-NGMU (ON) setting

Always down blow B,C for
PKFY-NAMU

SW1

SW3

1

2

3

4

5

6

7

8

9

10

1

2

3

4

5

6

7

8

9

10

Switch SW name

Operation by SW

Switch set timing

OFF ON OFF ON

Remarks

At unit stopping

(at remote

controller OFF)

Cooling capacity saving
for PKFY-NAMU,
effective/ineffective

PDFY-NMU-A

ON

ON

OFF

OFF

OFF

OFF

OFF

PKFY

OFF

OFF

OFF

ON

OFF

OFF

NAMU-A NGMU-A

OFF ON

–22–

Setting of DIP SW4 Setting of DIP SW5

1234

ON OFF ON OFF

OFF OFF OFF ON

ON OFF OFF ON

OFF OFF ON ON

––––

OFF OFF ON –

PDFY-10 ~ 32

PLFY-12 ~ 24

PLFY-32 ~ 48

PKFY-P-8

PKFY-P-12

PDFY-40, 48

Model Circuit board used

SW4

Phase control

Relay selection

–23–

33

33

3 TEST RUN

[1] Before Test Run

(1) Check points before test run

1 Neither refrigerant leak nor loose power source/ transmission lines should be found, if found correct immediately.

2 Confirm that the resistance between the power source terminal block and the ground exceeds 2MΩ by measur-

ing it with a DC500V megger. Do not run if it is lower than 2MΩ.
Note : Never apply the megger to the MAIN board. If applied, the MAIN board will be broken.

3 Confirm that the Ball valve at both gas and liquid sides are fully opened.

Note : Close the cap.

4 Be sure that the crankcase heater has been powered by turning the main power source on at least 12 hours

before starting the test run. The shorter powering time causes compressor trouble.

(2) Caution at inverter check

Because the inverter power portion in outdoor unit electrical part box have a lot of high voltage portion, be sure to follow
the instructions shown below.

During energizing power source, never touch inverter power portion because high voltage (approx. 580V) is
applied to inverter power portion.

When checking,

Shut off main power source, and check it with tester, etc.

Allow 10 minutes after shutting off main power source.

Open the MAIN board mounting panel, and check whether voltage of both ends of electrolytic capacitor is
20V or less.

1

2

1

2

3

–24–

(3) Check points for test run when mounting options

(4) Attention for mounting drain water lifting-up mechanism

Check point

Local remote controller displays code
No. “2503”, and the mechanism stops.

No overflow from drain pan.

Drain water comes out by operation of
drain pump.

Sound of pump operations is heard, and
drain water comes out.

No water leak from connecting portions
of each water piping.

Water is supplied to water supply tank,
and float switch is operating.

Built-in optional parts

Mounting of drain
water lifting-up
mechanism

Mounting of perme­able film humidifier

Content of test run

Release connector of pump circuit,
check error detection by pouring
water into drain pan water inlet.

After that, connect connector of
circuit.

Check pump operations and drain­age status in cooling (test run) mode.

Check humidifier operations and water
supply status in heating (test run) mode.

1

2

3

4

5

Result

1

2

3

Work

Disassembling and
assembling of drain
water lifting-up
mechanism

Mounting of float
switch

Electric wiring

Float switch moves smoothly.

Float switch is mounted on
mounting board straight without
deformation.

Float switch does not contact the
copper pipe.

Wiring procedure is exactly followed.

Connector portion is tightly hooked.

Content of test run

Lead wire from control box not
damaged.

Rubber cap properly inserted in to
drain water outlet of drain pan?

Insulation pipe of gas and liquid
pipes dealt with as shown in the right
figure?

Drain pan and piping cover mounted
without gap?

Drain pan hooked on cut projection
of the mechanism?

Float switch installed without contacting the
drain pan?

No mistakes in wiring?

Connectors connected securely and
tightly?

No tension on lead wire when sliding
control box?

1

2

3

1

2

3

Check point Result

Insulation pipe

No gap

–25–

(5) Check points for system structure

Check points from installation work to test run.

Trouble

Not operate.

Not cool (at cooling).

Not heat (at heating).

Not cool, not heat, error stop.

Condensation drip in piping.

Not cool, not heat, error stop.

Water leak, condensation drip in drain piping.

Error stop, not operate.

Electric shock.

Error stop, not operate.

Classification

Installation and
piping

Power source
wiring

Portion

1

2

3

4

5

6

7

8

1

2

3

Check item

Instruction for selecting combination of outdoor unit,
and indoor unit followed? (Maximum number of indoor
units which can be connected, connecting model name,
and total capacity.)

Follow limitation of refrigerant piping length? For example,
70m (229ft) or less (total length : 220m (721ft)) at the farthest.

Connecting piping size of branch piping correct?

Refrigerant piping diameter correct?

Refrigerant leak generated at connection?

Insulation work for piping properly done?

Specified amount of refrigerant replenished?

Pitch and insulation work for drain piping properly done?

Specified switch capacity and wiring diameter of main
power source used?

Proper grounding work done on outdoor unit?

The phases of the L line (L1, L2, L3) correct?

–26–

Classification

Transmission
line

Portion Check item

1

Limitation of transmission line length followed? For example,
200m (656ft) or less (total length : 500m (1640ft)) at the farthest.

2 1.25mm2 (AWG16) or more transmission line used?

(Remote controller 10m (32ft) or less 1.25mm2 (AWG16))

3 2-core cable used for transmission line?

4

Transmission line apart from power source line by 5cm (2in) or more?

5 One refrigerant system per transmission line?

6

The short circuit connector is changed form CN41 to
CN40 on the MAIN board when the system is centralized
control? (Just one outdoor unit. Not all outdoor units.)

7 • No connection trouble in transmission line?

8 Connection of wrong remote controller line terminals?

• MA Remote controller : TB15

• M-NET Remote controller : TB5

Trouble

Erroneous operation, error stop.

Erroneous operation, error stop.

Error stop in case multiple-core
cable is used.

Erroneous operation, error stop.

Not operate.

Not operate.

Error stop or not operate.

Never finish the initial mode.

System set

Before starting

Error stop or not operate.

Can not be properly set with power
source turned on.

Not operate.

Set temperature not obtained at
heating operations (Thermostat
stop is difficult)

Error stop.

Error stop, compressor trouble.

1

2

1

2

3

4

Address setting properly done? (M-NET Remote
controller, indoor unit and outdoor unit.)

Setting of address No. done when shutting off power
source?

Address numbers not duplicated?

Turned on SW3-8 on indoor unit circuit board when
mounting room thermistor sensor?

Refrigerant piping ball valve (Liquid pressure pipe, gas
pressure pipe) opened?

Turn on power source 12 hours before starting operations?

2 31

SET TEMP. ON/OFF

PAR-F27MEA-US

FILTER

CHECKTEST

CLOCK ON OFF

MODE

DRY COOL

DAILY

TIMER

CHECK

AUTO

ONCLOCK

SET TEMP.

REMAINDER

NOT AVAILABLE

SENSOR

INSIDE

FILTER

TEST RUN

VENTILATION

EROR CODE

AUTO
OFF

CENTRALLY CONTROLLED

AUTO FAN

HEAT

STAND BY
DEFROST

FAN
SPEED

TIMER FAN SPEED

LOUVER VENTILATION

AIR DIRECTION

TIMER SET

SET TEMP. ON/OFF

PAR-F27MEA-US

FILTER

CHECKTEST

CLOCK ON OFF

MODE

DRY COOL

DAILY

TIMER

CHECK

AUTO

ONCLOCK

SET TEMP.

REMAINDER

NOT AVAILABLE

SENSOR
INSIDE

FILTER

TEST RUN

VENTILATION

EROR CODE

AUTO
OFF

CENTRALLY CONTROLLED

AUTO FAN

HEAT

STAND BY
DEFROST

FAN
SPEED

TIMER FAN SPEED

LOUVER VENTILATION

AIR DIRECTION

TIMER SET

–27–

[2] Test Run Method

Operation procedure

1

Turn on universal power supply at least 12 hours before starting → Displaying “HO” on display panel for about two
minutes

2 Press

TEST

button twice → Displaying “TEST RUN’’ on display panel

3 Press

MODE

button → Make sure that air is blowing out

4

Press

MODE

button to change from cooling to heating operation, and vice versa → Make sure that warm or cold

air is blowing out

5 Press

FAN SPEED

adjust button → Make sure that air blow is changed

6

Press

AIR DIRECTION

or

LOUVER

button to change direction of air blowing make sure that horizontal or

downward blow is adjustable.

7 Make sure that indoor unit fans operate normally

8 Make sure that interlocking devices such as ventilator operate normally if any

9 Press button to cancel test run → Stop operation

Note 1: If check code is displayed on remote controller or remote controller does not operate normally.

2: Test run automatically stops operating after two hours by activation of timer set to two hours.
3: During test run, test run remaining time is displayed on time display section.
4: During test run, temperature of liquid pipe in indoor unit is displayed on remote controller room temperature

display section.

5: When pressing

FAN SPEED

adjust button, depending on the model, “NOT AVAILABLE” may be displayed on

remote controller. However, it is not a malfunction.

6: When pressing

AIR DIRECTION

or

LOUVER

button, depending on the model, “NOT AVAILABLE” may be

displayed on remote controller. However, it is not a malfunction.

–28–

4

GROUPING REGISTRATION OF INDOOR UNITS WITH M-NET REMOTE CONTROLLER

(1) Switch function

• The switch operation to register with the remote controller is shown below:

Registration/
ordinary mode
selector switch

Registration/ordinary
mode selection switch

Switch to assign indoor
unit address

Registration switch

Confirmation switch

Delete switch

Registered mode
selector switch

Switch to assign
interlocked unit address

A + B

C

D

E

F

G

H

This switch selects the ordinary mode or registered mode (ordinary

mode represents that to operate indoor units).

* To select the registered mode, press the

FILTER

+

LOUVER

button continuously for over 2 seconds under stopping state.

[Note] The registered mode can not be obtained for a while after

powering.

Pressing the

FILTER

+

LOUVER

button displays “CENTRALLY

CONTROLLED”.

This button assigns the unit address for “INDOOR UNIT ADDRESS

NO.”

This button is used for group/interlocked registration.

This button is used to retrieve/identify the content of group and

interlocked (connection information) registered.

This button is used to retrieve/identify the content of group and

interlocked (connection information) registered.

This button selects the case to register indoor units as group (group

setting mode) or that as interlocked (interlocked setting mode).

*The unit address is shown at one spot for the group setting mode

while at two spots for the interlocked setting mode.

This button assigns the unit address of “OA UNIT ADDRESS NO.”

Symbol

of switch

G Registered mode

selector switch

E Confirmation switch

C Switch to assign

indoor unit address

H Switch to assign inter-

locked unit address

D Registration switch

A

+

FILTER

TEST RUN

Name Name of actual switch Description

of TEMP

of TIMER SET

B

Registration/
ordinary mode
selector switch

SET TEMP. ON/OFF

PAR-F27MEA-US

FILTER

CHECK TEST

CLOCK ON OFF

MODE

DRY COOL

DAILY

TIMER

CHECK

AUTO

ONCLOCK

SET TEMP.

REMAINDER

NOT AVAILABLE

SENSOR

INSIDE

FILTER

TEST RUN

VENTILATION

EROR CODE

AUTO

OFF

CENTRALLY CONTROLLED

AUTO FAN

HEAT

STAND BY
DEFROST

FAN
SPEED

TIMER FAN SPEED

LOUVER VENTILATION

AIR DIRECTION

TIMER SET

F Delete switch

LOUVER

TIMER

MODE

→

→

–29–

(2) Attribute display of unit

• At the group registration and the confirmation/deletion of registration/connection information, the type (attribute) of the
unit is displayed with two English characters.

Display Type (Attribute) of unit/controller

Indoor unit connectable to remote controller

Outdoor unit
Local remote controller

System controller (MJ)

[Description of registration/deletion/retrieval]

• The items of operation to be performed by the remote controller are given below. Please see the relating paragraph for
detail.

1 Group registration of indoor unit

• The group of the indoor units and operating remote controller is registered.

• It is usually used for the group operation of indoor units with different refrigerant system.

2 Retrieval/identification of group registration information of indoor units

• The address of the registered indoor units in group is retrieved (identified).

3 Retrieval/identification of registration information

• The connection information of any unit (indoor/outdoor units, remote controller or the like) is retrieved (identified).

4 Deletion of group registration information of indoor units

• The registration of the indoor units under group registration is released (deleted).

5 Deletion of the address not existing

• This operation is to be conducted when “6607” error (No ACK error) is displayed on the remote controller caused by
the miss setting at test run, or due to the old memory remained at the alteration/modification of the group composi­tion.

Caution:

When MELANS (MJ-103MTRA for example) is being connected, do not conduct the group/pair registration using
the remote controller. The group/pair registration should be conducted by MELANS. (For detail, refer to the instruc­tion exclusively prepared for MELANS.)

–30–

(3) Group registration of indoor unit

1) Registration method

• Group registration of indoor unit ........................................................................ 1

The indoor unit to be controlled by a remote controller is registered on the remote controller.

[Registration procedure]

1 With the remote controller under stopping or at the display of “HO”, continuously press the

FILTER

+

LOUVER

button

(A + B) at the same time for 2 seconds to change to the registration mode. (See the figure below.)

2 Assign the indoor unit address to “INDOOR UNIT ADDRESS NO.” by operating the

(Room temperature

adjustment) (C).
Then press the

TEST RUN

button (D) to register. In the figure below, the “INDOOR UNIT ADDRESS NO.” is being set

to 001.

3 After completing the registration, press the

FILTER

+

LOUVER

button (A + B) at the same time for 2 seconds to

change to the original ordinary mode (with the remote controller under stopping).

• Remote controller under stopping • “HO” under displaying

Ordinary mode

INDOOR UNIT
ADDRESS NO

ERROR CODE
OA UNIT ADDRESS NO

˚C

INDOOR UNIT
ADDRESS NO

ERROR CODE
OA UNIT ADDRESS NO

˚C

ERROR CODE
OA UNIT ADDRESS NO

˚C

1

1

Group setting mode

• Confirm the indoor unit address No.

• Confirm the connection of the transmission line.

ERROR CODE
OA UNIT ADDRESS NO

˚C

ERROR CODE
OA UNIT ADDRESS NO

˚C

• Registration complete

• Registration error

Indicates the type of unit
(Indoor unit in this case)

“88” flickers indicating registra­tion error. (when the indoor unit
registered is not existing)

2 Assign the

address (C)

1 Change to the

registration
mode (A + B)

3 Press the

registration
switch (D)

Remote controller

▲

▼

System example

Indoor units

Group

2 + 3

–31–

2) Method of retrieval/confirmation

• Retrieval/confirmation of group registration information on indoor unit............... 2

The address of the indoor unit being registered on the remote controller is displayed.

[Operation procedure]

1 With the remote controller under stopping or at the display of “HO”, continuously press the

FILTER

+

LOUVER

button

(A + B) at the same time for 2 seconds to change to the registration mode.

2 In order to confirm the indoor unit address already registered, press

TIMER

button (E). (See figure below.) When the

group of plural sets is registered, the addresses will be displayed in order at each pressing of

TIMER

button (E).

3 After completing the registration, continuously press the

FILTER

+

LOUVER

button (A + B) at the same time for 2

seconds to change to the original ordinary mode (with the remote controller under stopping).

• Retrieval/confirmation of registration information ................................................ 3

The registered information on a certain unit (indoor unit, outdoor unit, remote controller or the like) is displayed.

[Operation procedure]

1 With the remote controller under stopping or at the display of “HO”, continuously press the

FILTER

+

LOUVER

button

(A + B) at the same time for 2 seconds to change to the registration mode.

2 Operate

MODE

button (G) for the interlocked setting mode. (See figure below.)

3 Assign the unit address of which registration information is desired to confirm with the (TIMER SET) switch

(H). Then press the

TIMER

button (E) to display it on the remote controller. (See figure below.)

Each pressing of

TIMER

button (E) changes the display of registered content. (See figure below.)

4 After completing the retrieval/confirmation, continuously press the

FILTER

+

LOUVER

button (A + B) at the same

time for 2 seconds to change to the original ordinary mode (with the remote controller under stopping).

• Registered

• No registration.

ERROR CODE
OA UNIT ADDRESS NO

˚C

ERROR CODE
OA UNIT ADDRESS NO

˚C

▲

▼

1 Press the switch for confirmation (E)

Note: Only one address will be displayed

when the registration is one even the
switch is how often pressed

Indicates the type of unit
(Indoor unit in this case)

1

1

SET TEMP. ON/OFF

PAR-F27MEA-US

FILTER

CHECK TEST

CLOCK ON OFF

MODE TIMER FAN SPEED

LOUVER VENTILATION

AIR DIRECTION

TIMER SET

–32–

3) Method of deletion

• Deletion of group registration information of indoor unit ...................................... 4

[Operation procedure]

1 With the remote controller under stopping or at the display of “HO”, continuously press the

FILTER

+

LOUVER

button (A + B) at the same time for 2 seconds to change to the registration mode.

2 Press the

TIMER

button (E) to display the indoor unit address registered. (As same as 2)

3 In order to delete the registered indoor unit being displayed on the remote controller, press the

CLOCK→ ON→ OFF

TIMER

(F) button two times continuously. At completion of the deletion, the attribute display section will be shown as “ – – “.
(See figure below.)
Note: Completing the deletion of all indoor units registered on the remote controller returns to “HO” display.

4 After completing the registration, continuously press the

FILTER

+

LOUVER

button (A + B) at the same time for 2

seconds to change to the original ordinary mode (with the remote controller under stopping).

ERROR CODE
OA UNIT ADDRESS NO

˚C

INDOOR UNIT
ADDRESS NO

ERROR CODE
OA UNIT ADDRESS NO

˚C

INDOOR UNIT
ADDRESS NO

ERROR CODE
OA UNIT ADDRESS NO

˚C

1 Set the address

2 Press the switch for

confirmation (E)

• Registered

• No registration

* Same display will appear when

the unit of “007” is not existing.

1 Press the switch for confirmation (F)

twice continuously.

• Deletion completed

• Deletion completed

In case of group re­gistration with other
indoor unit is existing

In case of no group
registration with other
indoor unit is existing

▲

▼

1

1

▼

▲

1 + 2

“– –” indicates the
deletion completed.

ßC

ßC

(Alternative

display)

ßC

ßC

(Alternative

display)

INDOOR UNIT
ADDRESS NO

ERROR CODE
OA UNIT ADDRESS NO

˚C

2

SET TEMP. ON/OFF

PAR-F27MEA-US

FILTER

CHECK TEST

CLOCK ON OFF

MODE TIMER FAN SPEED

LOUVER VENTILATION

AIR DIRECTION

TIMER SET

SET TEMP. ON/OFF

PAR-F27MEA-US

FILTER

CHECK TEST

CLOCK ON OFF

MODE TIMER FAN SPEED

LOUVER VENTILATION

AIR DIRECTION

TIMER SET

–33–

4) Deletion of information on address not existing

• Deletion of information on address not existing ................................................... 5

This operation is to be conducted when “6607” error (No ACK error) is displayed on the remote controller caused by
the miss setting at test run, or due to the old memory remained at the alteration/modification of group composition,
and the address not existing will be deleted.
Note: The connection information (connection between indoor unit and outdoor unit) on the refrigerant system can

not be deleted.
An example to delete the system controller of “250” from the indoor unit of “007” is shown below.

[Operation procedure]

1 With the remote controller under stopping or at the display of “HO”, continuously press the

FILTER

+

LOUVER

button

(A + B) at the same time for 2 seconds to change to the registration mode.

2 Operate

MODE

button (G) for the interlocked setting mode ( ii ). (See the figure below.)

3 Assign the unit address existing to “OA UNIT ADDRESS No.” with the (TIMER SET) switch (H), and press

TIMER

button (E) to call the address to be deleted. (See the figure below.) As the error display on the remote controller

is usually transmitted from the indoor unit, “OA UNIT ADDRESS No.” is used as the address of the indoor unit.

4 Press the

CLOCK→ ON→ OFF

TIMER

button (F) twice. (See the figure below.)

5 After completing the deletion, continuously press the

FILTER

+

LOUVER

button (A + B) at the same time for 2

seconds to return to the original ordinary mode (with the remote controller under stopping).

INDOOR UNIT
ADDRESS NO

ERROR CODE
OA UNIT ADDRESS NO

ßC

INDOOR UNIT
ADDRESS NO

ERROR CODE
OA UNIT ADDRESS NO

ßC

(Alternative

display)

INDOOR UNIT
ADDRESS NO

ERROR CODE
OA UNIT ADDRESS NO

ßC

INDOOR UNIT
ADDRESS NO

ERROR CODE
OA UNIT ADDRESS NO

ßC

(Alternative

display)

*

INDOOR UNIT
ADDRESS NO

ERROR CODE
OA UNIT ADDRESS NO

ßC

INDOOR UNIT
ADDRESS NO

ERROR CODE
OA UNIT ADDRESS NO

ßC

(Alternative

display)

*

▲

▲

▼

When both indoor
unit and interlocked
unit addresses are
existing

Deletion of
address not
existing

1 Set the address (H)

3 Press the deletion switch (F) twice

• Deletion completed

• Deletion completed

1 + 2

3

3

2 Press the switch for

confirmation (E)

SET TEMP. ON/OFF

PAR-F27MEA-US

FILTER

CHECK TEST

CLOCK ON OFF

MODE TIMER FAN SPEED

LOUVER VENTILATION

AIR DIRECTION

TIMER SET

–34–

55

55

5 CONTROL

[1] Control of Outdoor Unit

(1) Initial processing

• When turning on power source, initial processing of microcomputer is given top priority.

• During initial processing, control processing corresponding to operation signal is suspended. The control process­ing is resumed after initial processing is completed. (Initial processing : Data processing in microcomputer and
initial setting of each LEV opening, requiring approx. 2 minutes at the maximum.)

(2) Control at staring

• In case unit is started within 2 hours after turning on power source at low ambient temperature (+5˚C (41˚F) or
less), the unit does not start operating for 30 minutes at the maximum.

(3) Bypass, capacity control

• Solenoid valve consists of bypass solenoid valve (SV1, SV2) bypassing between high pressure side and low
pressure sides. The following operation will be provided.

1) Bypass solenoid valves SV1 and SV2 (both “open” when turned on)

• PURY-80·100TMU(-A)

Item

SV1

ON (Open) OFF (Close)

When Pd reaches

2.70MPa (391psi) or
more

When Pd is 2.35MPa
(341psi) and after 30
seconds

SV2

ON (Open) OFF (Close)

When starting compressor

After thermost “ON is returned
and after 3 minutes restart

When compressor stops in
cooling or heating mode

After operation stops

During defrosting operations

During oil recovery operations

During 20Hz operations, at
fall in low pressure or low
pressure saturation tempera­ture. (3minutes or more after
starting)

When high pressure rises
(Pd)

When high pressure rises
(Pd) during 20Hz operations
(3 minutes after starting)

When discharge temperature
rises
(3 minutes after starting)

Turned on for 4 minutes

Turned on for 4 minutes

Always turned on

Always turned on

Turned on for 3 minutes

Always turned on.

–

–

Turned on for 4 minutes

Turned on for 4 minutes

Always turned on.

–

–

Always turned on.

When Ps is 0.15MPa
(21.3psi) or less

When Ps is 0.25MPa
(35.6psi) or more

When Pd reaches 2.5MPa
(377psi) or more

When Pd is 2.30MPa
(334psi) and after 30
seconds

Turned on when high
pressure (Pd) exceeds
pressure limit

When high pressure (Pd)
is 1.96MPa (284psi) or
less

When temp. exceeds
130˚C (266˚F) and Pb
reaches 1.47MPa (213psi)
or more

When discharge temp. is
115˚C (239˚F) or less

Compressor

Bypass
solenoid
valve (SV1)

(4-minute)

(2-minute) (4-minute) (3-minute)

Start

Thermo.
OFF

Thermo.
ON

Defrost­ing time
(*1)

Stop

–35–

(4) Frequency control

• Depending on capacity required, capacity control change and frequency change are performed to keep constant
evaporation temperature in cooling operations, and high pressure saturation temperature in heating operation.

• Frequency change is performed at the rate of 2Hz/second across 20 ~ 105Hz range.

1) Frequency control starting

• 60Hz is the upper limit for 3 minutes after starting.

• 75Hz is the upper limit within 30 minutes at the first starting compressor after turning on power source.

2) Pressure limit
The upper limit of high pressure (Pd) is set for each frequency.
When the limit is exceeded, frequency is reduced every 10 seconds.
(Frequency decrease rate (Hz) : 22% of the present value)

<80> <100>

3) Discharge temperature limit
Discharge temperature (Td) of compressor is detected during operation. If the upper limit is exceeded, the frequency
is reduced. (Change rate : 5% of the present value)

• 30 seconds after starting compressor, control is performed every minute.

• Operation temperature is 130˚C (266˚F).

4) Periodical frequency control
Frequency controll is periodically performed except for the frequency controls at operation start, status change, and
protection.

1 Cycle of periodical frequency control

Periodical frequency control is performed every minute after the time specified below has passed.

• 20 sec after starting compressor or finishing defrostoing operations

• 20 sec after frequency control by discharge temperature or pressure limit

2 Amount of frequency change

The amount of frequency change is controlled corresponding to evaporation temperature and high pressure
saturation temperature.

3 Back up of frequency control by bypass valve

During 20Hz operations, frequency is backed up by turning on (opening) bypass valve (SV2).

• Cooling
During 20Hz operations 3 minutes after starting compressor, bypass valve is turned on when,
Ps is 0.15MPa (21.3psi) or less and turned off when Ps is 0.25MPa (35.6psi) or more.

• Heating
During 20Hz operations 3 minutes after starting compressor, SV2 turned on when high pressure (Pd) exceeds
pressure limit and turned off when Pd falls to 1.96MPa (284psi) or less.

▼

0.15MPa 0.25MPa
(21.3psi) (35.6psi)

▼

1.96MPa 2.65MPa
(284psi) (384psi)

▼

▼

ON

OFF

ON

OFF

–36–

(5) Oil return control (Electronic expansion valve <SLEV>)

• Oil return LEV (SLEV) opening is dependent on compressor frequency and ambient temperature.

• SLEV is closed (0) when compressor stops, and SLEV is set (64) for 10 minutes after starting compressor.

(6) Defrost operation control

1) Starting of defrost operations

• After integrated 50 minutes of compressor operations, defrosting operations start when –6˚C (21˚F) or less of
piping temperature (TH7) is detected for 3 consecutive minutes.

• Forcible defrosting operations start by turning on forcible defrost switch (SW2-7) if 3 minutes have already elapsed
after compressor start or completion of defrosting operations.

2) Completion of defrosting operations
Defrosting operations stop when 10 minutes have passed since start of defrosting operation, or piping temperature
(TH5) reaches 8˚C (46˚F) or more.
(Defrosting operations do not stop for 4 minutes after starting, except when piping temperature exceeds (TH5 and
TH7) 20˚C (68˚F) and 0.98MPa (142psi).

3) Defrosting prohibition
Defrosting operations do not start during oil recovery, and for 10 minutes after starting compressor.

4) Trouble during defrosting operations
When trouble is detected during defrosting operations, the defrosting operations stop, and defrosting prohibition
time decided by integrated operation time of compressor is set to be 20 minutes.

5) Change in number of operating indoor units during defrosting operations

• In case number of operating indoor units changes during defrosting operations, the defrosting operations continue,

and control of unit number change is performed after the defrosting operations are finished.

• Even in case all indoor units stop or thermostat is turned off during defrosting operations, the defrosting operations

do not stop until expected defrosting activities are completed.

(7) Control of liquid level detecting heater

Detect refrigerant liquid level in accumulator, and heat refrigerant with liquid level heater for judging refrigerant
amount. 6 steps of duty control is applied to liquid level heater depending on frequency and outdoor air temperature,
1minute after starting compressor.

(8) Control of outdoor unit fan and outdoor unit heat exchanger capacity

1) Control system
Depending on capacity required, control outdoor fan flow rate with phase control, for maintaining evaporation
temperature (0˚C (32˚F)) in cooling operations, and high pressure saturated temperature (49˚C (120˚F)) in heating
operations.

2) Control

• Outdoor unit fan stops when compressor stops.

• Fan is in full operation for 5 seconds after starting.

• Outdoor unit fan stops during defrosting operations.

–37–

Mode

Connection

2000

Superheat

control *1

60

Differential

Pressure control

*2

2000

60

LEV1

LEV3

*1

*2

*3

Superheat
control

Differential
pressure control

–

Control every minute so that superheat amount detected by bypass inlet and oulet
temperatures (TH12, TH15) stay in the specified range.

Control every minute so that detected differential pressure (PS1, PS3) stay in the
specified range.

60 or more pulses are sometimes detected because of rise in liquid side pressure (PS1).

• Liquid level
control *3

• Differential
pressure control

*2

60

Differential

Pressure control

*2

[2] Control of BC Controller

(1) Control of SVA, SVB and SVC

SVA, SVB and SVC are turned on and off depending on connection mode.

Cooling Heating Stop Defrost

SVA ON OFF OFF OFF

SVB OFF ON OFF OFF

SVC ON OFF OFF OFF

(2) Control of LEV

LEV opening (sj) is controlled corresponding to operation mode as follows: (Number of pulse)

Operation mode Cooling-only Heating-only Cooling-main Heating-main Stop

* The above parts of BC controllers are color-corded and shown with the name plate inside the BC controller unit.

–38–

YES

NO

YES

NO

YES

NO

Normal operations
Trouble observed
Stop

Start

Breaker

turned on

Set indoor ad-

dress No. to remote

controller

Operation

mode

Error mode

Cooling-only, Heating-only,
Cooling/heating mixed

Error stop

Operation

mode

Operation

mode

52C ON

[3] Operation Flow Chart

(1) Outdoor unit

Note : 1 For about 3 minutes after turning on power source, address and group information of outdoor unit, BC, controller indoor unit,

and remote controller are retrieved by remote controller, during which “HO” blinks on and off on remote controller. In case
indoor unit is not grouped to remote controller, “HO” display on remote controller continues blinking even after 3 minutes after
turning on power source.

Note : 2 Two trouble modes included indoor unit side trouble, (BC controller trouble) and outdoor unit side trouble. In the case of indoor

unit side trouble, error stop is observed in outdoor unit only when all the indoor units are in trouble. However, if one or more
indoor units are operating normally, outdoor unit shows only LED display without undergoing stop.

Note : 3 Operation mode conforms to mode command by BC controller.

Note : 4 In case BC controller issues cooling/heating mixed operation mode, outdoor unit decides operation mode of cooling-main

operation or heating-main operation.

Note : 3

Note : 2

Note : 1

Fan

“HO” blinks on the remote

controller

1. 52C OFF

2. Inverter output 0Hz

3. Outdoor fan Stop

4. All solenoid valve OFF

Cooling (Cooling-

only) operations

Heating (Heating-

only) operations

Cooling-main

operations

Heating-main

operations

Operation mode command to (BC controller) outdoor unit

Error code blinks on the
outdoor controller board

Error command to

BC controller

Error code blinks on the

remote controller

Cooling/heating mixed

Note : 4

–39–

(2) BC controller

Note : 1 Two error modes include indoor unit side trouble, BC controller trouble, and outdoor unit side trouble. In the case of indoor

unit side trouble, error stop is observed in the concerned indoor unit only, and in the cases of BC controller and outdoor unit
side troubles, error stop is observed in all the indoor units, BC controller, and outdoor unit.

YES

NO

YES

NO

YES

NO

Normal operations
Trouble observed
Stop

Solenoid valve OFF,

LEV fully closed.

Start

Breaker

turned on

Operation
command

1. Operation mode judgement
(cooling-only, heating-only,
cooling/heating mixed)

2. Transmission to outdoor unit

Receiving operation mode

command from outdoor unit

Error mode

Cooling-only

operations

Heating-only

operations

Cooling-main

operations

Heating-main

operations

Operation mode

Operation mode

Operation mode

Cooling/heating mixed

Note : 1

Fan

Error stop

Error code blinks on the
outdoor controller board

Error command to

BC controller

Error code blinks on the

remote controller

–40–

(3) Indoor unit

YES

NO

YES

NO

YES

NO

YES

NO

YES

NO

YES

NO

YES

NO

YES

NO

Normal operations
Trouble observed
Stop

Start

Breaker

turned on

Operation SW

turned on

1. Protection function
self-holding cancelled.

2. Indoor unit LEV fully
closed.

Remove controller
display extinguished

3-minute drain

pupm ON

FAN stop

Drain pump

ON

Error mode

Error stop

Error code blinks on
the remote controller

Indoor unit LEV
fully closed

Error code
blinks on the
outdoor
controller board

Operation mode

Heating

mode

Cooling

display

Cooling mode

Dry mode

Heating

display

Fan mode

Cooling/heating
automatic display

Cooling/heating
automatic mode

Fan display

Dry display

Prohibition Prohibition

Heating
operations

Cooling
operations

Prohibition Prohibition

Cooling/heating
automatic
operations

Dry
operation

Fan
operations

Prohibition “Remote
controller blinking”

Note :3Note :3 Note :3

Note :1

Note :2

Note :1

Note : 1 Indoor unit LEV fully closed : Opening 41

Note : 2 Two error modes include indoor unit trouble, (BC controller trouble) and outdoor unit side trouble. In the case of indoor unit

trouble, error stop is observed in the concerned indoor unit only, and in the cases of (BC controller and) outdoor unit side
troubles, error stop is observed in all the indoor units connected.

Note : 3 “Prohibition” status is observed (when several indoor units are connected to one connection, of BC controller and) when

connection mode is different from indoor unit operation mode. (Operation mode display on the remote controller blinks on
and off, fan stops, and indoor unit LEV is fully closed.)

Error command
to outdoor unit

–41–

(4) Cooling operation

YES

NO

YES

YES

NO

NO

1. Inverter output 0Hz

2. Indoor unit LEV, oil return LEV,
Subcool coil bypass LEV fully
closed

3. Solenoid valve OFF

4. Outdoor unit fan stop

5. BC controller solenoid valve OFF

6. BC controller LEV fully closed

1. Inverter frequency control

2. Indoor unit LEV, oil return LEV
control

3. Solenoid valve control

4. Outdoor unit fan control

5. BC controller solenoid valve control

6. BC controller LEV control

Cooling operation

4-way valve OFF

Indoor unit fan

operations

Test run start

Thermostat ON

Normal operations
Test run
Stop

3-minute

restart

prevention

–42–

YES

YES

NO

YES

YES

NO

NO

NO

(5) Heating operation

Normal operations
Defrosting operations
Stop
Test run

1. Indoor unit fan very low speed
operations

2. Inverter output 0Hz

3. Indoor unit LEV, oil return LEV
fully closed

4. Solenoid valve OFF

5. Outdoor unit fan stop

6. BC controller solenoid valve
OFF

7. BC controller LEV fully closed

1. Indoor and outdoor unit fan
control

2. Inverter frequency control

3. Indoor unit LEV, oil return LEV
control

4. Solenoid valve control

5. BC controller solenoid valve
control

6. BC controller LEV control

1. Indoor unit fan stop

2. Inverter defrost frequency control

3. Indoor unit LEV fully opened, oil
return LEV fully closed

4. Solenoid valve control

5. Outdoor unit fan stop

6. BC controller solenoid valve control

7. BC controller LEV control

Heating operation

4-way valve ON

Defrosting

operation

Test run star t

4-way valve OFF

Thermostat ON

3-minute

restart

prevention

Note : 1 When outdoor unit starts defrosting, it transmits defrost operations command to (BC controller and) indoor unit, and the

indoor unit starts defrosting operations.
Similarly when defrosting operation stops, indoor unit returns to heating operation after receiving defrost end command of
outdoor unit.

Note : 2 Defrosting start condition : After integrated 50 minutes of compressor operations, and –6˚C (21˚F) or less outdoor unit coil

temperature. (TH7)

Defrosting end condition : After 15 minutes of defrosting operation or the outdoor unit coil temperature (TH5 and TH7)

having risen to 8˚C (46˚F) or more.

Note : 1
Note : 2

–43–

YES

NO

YES

YES

NO

(6) Dry operation

Normal operations
Thermostat ON
Stop

1. Indoor unit fan stop

2. Inverter output 0Hz

3. Indoor unit LEV, oil return LEV
closed

4. Solenoid valve OFF

5. Outdoor unit fan stop

6. BC controller solenoid valve OFF

7. BC controller LEV fully closed

1. Outdoor unit (Compressor) intermit­tent operations

2. Indoor unit fan intermittent opera­tions
(Synchronized with compressor :
low speed, OFF operations)

Dry operations

4-way valve OFF

Inlet temp. 18˚C (64˚F)

Note : 2

Thermostat ON

Test run star t

Note : 1

Note : 1 When indoor unit inlet temperature exceeds 18˚C (64.4˚F), outdoor unit (compressor) and indoor unit fan start intermittent

operations synchronously. Operations of outdoor unit, BC controller, indoor unit LEV and solenoid valve accompanying
compressor are the same as those in cooling operations.

Note : 2 Thermostat is always kept on in test run, and indoor and outdoor unit intermittent operation (ON) time is a little longer than

normal operations.

–44–

Low pressure shell scroll type
with capacity control mechanism
Winding resistance:
Each phase 0.388Ω
(20˚C(68˚F))

Setting 2.94MPa (426psi)
OFF

R120=7.465kΩ
B25/120=4057

Rt = 7.465exp
{4057( - )}

R0=15kΩ
B0/100=3460
Rt =
15exp{3460( - )}

0˚C (32˚F) : 15kΩ
10˚C (50˚F) : 9.7kΩ
20˚C (68˚F) : 6.4kΩ
25˚C (77˚F) : 5.3kΩ
30˚C (86˚F) : 4.3kΩ
40˚C (104˚F) : 3.1kΩ

[4] List of Major Component Functions

MC

63HS

63LS

63H

TH1
(discharge)

TH5
(piping
temperature)

TH6 (outdoor
air tempera­ture)

Compres­sor

High
pressure
sensor

Low
pressure
sensor

Pressure
switch

Thermistor

Adjust refrigerant circulation by controlling operating
frequency and capacity control valve with operating
pressure.

1) High press. detection.

2) Frequency control and high pressure protection

1) Detects low pressure

2) Calculates the refrigerant circulation configuration.

3) Protects the low pressure

1) High pressure detection

2) High pressure protection

1) Discharge temperature detection

2) High pressure protection

20˚C (68˚F) : 250kΩ 70˚C (158˚F) : 34kΩ
30˚C (86˚F) : 160kΩ 80˚C (176˚F) : 24kΩ
40˚C (104˚F) : 104kΩ 90˚C (194˚F) : 17.5kΩ
50˚C (122˚F) : 70kΩ 100˚C (212˚F) : 13.0kΩ
60˚C (140˚F) : 48kΩ 110˚C (230˚F) : 9.8kΩ

1) Frequency control

2) Defrost control and liquid level detection at heating

1) Outdoor air temperature detection

2) Fan control, liquid level heater, and opening setting
for oil return

Name Application Specification Check method

Pressure
0~0.98MPa
(0~142psi)
Vout 0.5~3.5 V

Gnd (black)
Vout (white)
Vc (DC5V) (red)

Pressure
0~2.94MPa
(0~426psi)
Vout 0.5~3.5 V

Gnd (black)
Vout (white)
Vc (DC5V) (red)

Con­nector

Con­nector

1

273+t

1

273+t

Continuity check

Resistance value
check

Outdoor unit

Symbol

(function)

63HS

63LS

1

273+120

1

273+0

–45–

Name Application Specification Check method

Outdoor unit

Symbol

(function)

Thermistor

Solenoid
valve

Linear
expansion
valve

Linear
expansion
valve

Thermistor

THHS

SV1
(discharge ­suction
bypass)

SV2
(discharge ­suction

bypass)

SV3 ~ 6

SLEV

LEV

TH21
(inlet air
temperature)

TH22
(piping
temperature)

TH23
(gas side
piping
temperature)

1) Detects the inverter cooling fin temperature.

2) Provides inverter overheating protection.

3) Controls the control box cooling fan.

1) High/low press. bypass at starting/stopping and
capacity control at low load

2) Discharge press. rise suppression

Capacity control and high press. rise suppression
(backup for frequency control)

Control of heat exchanger capacity.

Adjustment of liquid refrigerant (oil) return foam
accumulator

1) Adjust superheat of outdoor unit heat exchanger
outlet at cooling.

2) Adjust subcool of indoor unit heat exchanger at
heating.

Indoor unit control (thermostat)

1) Indoor unit control (freeze prevention, hot adjust,
etc.)

2) LEV control in heating operation (Subcool detec­tion)

LEV control in cooling operation
(Superheat detector)

R50=17kΩ
B25/50=4170
Rt =
17exp{4170( - )}

-20˚C (-4˚F) : 605.0kΩ

-10˚C (14˚F) : 323.3kΩ
0˚C (32˚F) : 180.9kΩ
10˚C (50˚F) : 105.4kΩ
20˚C (68˚F) : 63.8kΩ
30˚C (86˚F) : 39.9kΩ
40˚C (104˚F) : 25.7kΩ
50˚C (122˚F) : 17.0kΩ
60˚C (140˚F) : 11.5kΩ
70˚C (158˚F) : 8.0kΩ
80˚C (176˚F) : 5.7kΩ
90˚C (194˚F) : 4.1kΩ
100˚C (212˚F) : 3.0kΩ

AC 208~230V
Open at energizing and
close at deenergizing

DC12V stepping motor drive
Valve opening 0~480 pulse

DC12V
Opening of stepping motor
driving valve
41~2,000 pulses

R0 = 15kΩ
B0/100 = 3460

Rt =
15exp {3460 ( - )}

0˚C (32˚F) : 15kΩ
10˚C (50˚F) : 9.7kΩ
20˚C (68˚F) : 6.4kΩ
25˚C (77˚F) : 5.3kΩ
30˚C (86˚F) : 4.3kΩ
40˚C (104˚F) : 3.1kΩ

• Continuity check
by tester

• Temperature of
inlet and outlet.

Continuity check
with tester for
white-red-orange
yellow-brown-blue

Resistance value
check

Indoor unit

1

273+50

1

273+t

1

273+t

1

273+0

–46–

Name Application Specification Check method

BC controller

Symbol

(function)

1

273+t

Pressure
sensor

Thermistor

PS1

PS3

TH11
(liquid inlet
temperature)

TH12
(bypass outlet
pressure)

TH15
(bypass outlet
temperature)

TH16
(bypass inlet
temperature)

1) Liquid pressure (high-pressure) detection

2) LEV control

1) Intermediate pressure detection

2) LEV control

LEV control (liquid refrigerant control)

LEV control (superheat control)

LEV control (superheat control)

LEV control (subcool control)

R0=15kΩ
B0/100=3460
Rt =
15exp{3460( - )}

0˚C (32˚F) : 15kΩ
10˚C (50˚F) : 9.7kΩ
20˚C (68˚F) : 6.4kΩ
25˚C (77˚F) : 5.3kΩ
30˚C (86˚F) : 4.3kΩ
40˚C (104˚F) : 3.1kΩ

Continuity check
by a tester

Same as LEV of
indoor unit.

1

273+0

AC 208~230V
Open when energized
Closed when de-energized

12V DC stepping motor drive
0 to 2000 valve opening
pulse

Supplies refrigerant to cooling indoor
unit.

Supplies refrigerant to heating indoor
unit.

Supplies refrigerant to cooling indoor
unit.

Liquid level control
pressure control

Liquid level control
pressure control

SVA

SVB

SVC

LEV1

LEV3

Solenoid
valve

Electronic
expansion
valve

Pressure
0~2.94MPa
(0~426psi)
Vout 0.5~3.5 V

Gnd (black)
Vout (white)
Vc (DC5V) (red)

Con­nector

PS1
PS3

–47–

[5] Resistance of Temperature Sensor

Thermistor for low temperature
Thermistor Ro= 15kΩ± 3% (TH3 ~ 9) Thermistor R120 = 7.465kΩ± 2% (TH1, 10)
R

t = 15exp {3460 ( - )} Rt = 7.465exp {4057 ( - )}

∗˚F= × ˚C + 32 ∗˚F= × ˚C + 32

Thermistor R

o = 33kΩ± 1% (TH2) Thermistor R50 = 17kΩ± 2% (THHS)

R

t = 33exp {3965 ( - )} Rt = 17exp {4170 ( - )}

∗˚F= × ˚C + 32 ∗˚F= × ˚C + 32

1

273+tc

1

273+tc

1

273+tc

1

273+tc

1

273+50

Temperature (˚C)[˚F] Temperature (˚C)[˚F]

Temperature (˚C)[˚F] Temperature (˚C)[˚F]

Resistance (kΩ)

Resistance (kΩ)

Resistance (kΩ)

Resistance (kΩ)

1

273+0

1

273+120

1

273+0

9
5

9
5

9
5

9
5

–48–

66

66

6 REFRIGERANT AMOUNT ADJUSTMENT

Clarify relationship between the refrigerant amount and operating characteristics of CITY MULTI, and perform service
activities such as decision and adjustment of refrigerant amount on the market.

[1] Refrigerant Amount and Operating Characteristics

The followings are refrigerant amount and operating characteristics which draw special attention.

During cooling operations, required refrigerant amount tends to increase (refrigerant in accumulator decreases)
in proportion to increase in the number of operating indoor units. However, the change of increase rate is small.

During heating operations, liquid level of accumulator is the highest when all the indoor units are operating.

Discharge temperature hardly changes when increasing or decreasing refrigerant amount with accumulator
filled with refrigerant.

Compressor shell temperature is 20~70 (36~126) degrees higher than low pressure saturation temperature
(Te) when refrigerant amount is appropriate.
→ Judged as over replenishment when temperature difference from low pressure saturation temperature (Te)
is 10 (18) degrees or less.

[2] Adjustment and Judgement of Refrigerant Amount

(1) Symptom

The symptoms shown in the table below are the signs of excess or lack of refrigerant amount. Be sure to adjust the
amount of refrigerant in refrigerant amount adjustment mode, by checking operation status, judging refrigerant
amount, and performing selfdiagnosis with LED Dip s/w 1, 1-10, for overall judgement of excess or lack of refriger­ant amount.

Tendency of
discharge
temperature

During cooling operations, discharge temperature tends to rise at
overload than low temperature.

During heating operations, discharge temperature tends to rise at low
temperature than overload.

The lower the operating frequency is, the higher the discharge
temperature tends to become of deteriorated compressor efficiency.

Comparison including
control system

Emergency stop at 1500 remote controller display (excessive
refrigerant replenishment)

Operating frequency does not fully increase, thus resulting in
insufficient capacity

Emergency stop at 1102 remote controller display (discharge
temperature trouble)

Emergency stop occurs when the remote control display is at

1501. (insufficient refrigerant)

Excessive refrigerant replenishment

Insufficient refrigerant replenishment

Insufficient refrigerant

1

2

3

4

5

1

2

3

4

Note : ˚C Scale (˚F Scale)

–49–

(2) Refrigerant Volume Adjustment Operation

1) Operating Characteristics Refrigerant Volume
Characteristic items related to operating characteristics and the refrigerant volume are shown below.

If the number of indoor units in operation increases during cooling, the required volume of refrigerant tends to
increase (the amount of refrigerant in the accumulator tends to decrease), but the change is minimal.

The liquid level in the accumulator is at its highest when all the indoor units are operating during heating.

If there is refrigerant in the accumulator, even if the volume of refrigerant is increased or decreased, there is practi­cally no change in the outlet temperature.

During cooling, the discharge temperature rises more easily when there is an
overload than when the temperature is low.

During heating, the discharge temperature rises more easily when the tempera­ture is low than when there is an overload.

The lower the operating frequency, the less efficient the compressor is, making it
easier for the discharge temperature to rise.

The compressor shell temperature becomes 20~70 (36~126) deg. higher than the low pressure saturation tempera­ture (TH2) if the refrigerant volume is appropriate. If the difference with the low pressure saturation temperature
(TH2) is 10 (18) deg. or less, it can be judged that the refrigerant is overcharged.

2) Adjusting and Judging the Refrigerant Volume

1 Symptoms

Overcharging with refrigerant can be considered as the cause of the following symptoms. When adjusting the
refrigerant volume, be sure that the unit is in the operating condition, and carry out refrigerant volume judgment and
self-diagnosis by the LED’s, judging overall whether the volume of refrigerant is in excess or is insufficient. Perform
adjustments by running the unit in the refrigerant volume adjustment mode.

2 Refrigerant Volume
a Checking the Operating Condition

Operate all the indoor units on cooling or on heating, checking the discharge temperature, sub-cooling, low pres­sure saturation temperature, inlet temperature, shell bottom temperature, liquid level, liquid step, etc. and rendering
an overall judgment.

1

2

3

4

5

Tendency of
discharge
Temperature

Comparison
when control is
included.

Emergency stop occurs when the remote control display is at 1500 (refrigerant
overcharge).

The operating frequency doesn’t rise high enough and capacity is not achieved.

Emergency stop occurs when the remote control display is at 1102 (outlet
temperature overheating).

Emergency stop occurs when the remote control display is at 1501 (insufficient
refrigerant).

1

2

3

4

Refrigerant overcharge

Insufficient refrigerant

Insufficient refrigerant

Judgement

Refrigerant volume tends toward
insufficient.

Rifrigerant volume tends toward
overcharge.

Condition

1 Outlet temperature is high. (125°C (257˚F) or higher)

2 Low pressure saturation temperature is extremely low.

3 Inlet superheating is high (if normal, SH = 20 (36) deg or lower).

4 Shell bottom temperature is high (the difference with the low pressure saturation

temperature is 70 (126) deg. or greater)

5 Shell temperature is low (the difference with the low pressure saturation tem-

perature is 10 (18) deg. or lower).

6 Dischange superheating is low (if normal, SH = 20 (36) deg or higher).

Note : ˚C Scale (˚F Scale)

Note : ˚C Scale (˚F Scale)

–50–

b Check the refrigerant volume by self-diagnosis using the LED.

Set the self-diagnosis switch (SW1) as shown below and check the past information (history) concerning the
refrigerant volume.

Set SW1 as shown in he figure at right.

If LD8 lights up, it indicates the refrigerant charge abnormal delay state just before emergency stop due to refriger­ant overcharge (1500).

3 Additional Refrigerant Charge Volume

At the time of shipping from the factory, the outdoor unit is charged with the amount of coolant shown in the follow­ing table, but since no extension piping is included, please carry out additional charging on-site.

Outdoor Unit Model Name PURY-80TMU(-A) PURY-100TMU(-A)
Refrigerant Charge Volume 10.0kg 11.0kg

(22lb 1oz) (26lb 8oz)

Calculation Formula
Calculate the additional refrigerant volume by calculating the size of the extension liquid piping and its length units (m)[ft].

Additional Refrigerant Volume (kg) = (0.16 × L

1) + (0.06 × L2) + (0.024 × L3) + A

[ (oz) = (1.72 × L1) + (0.65 × L2) + (0.20 × L3) + A ]

L

1: Length of ø12.7 (3/4") liquid pipe (m) [ft]

L2: Length of ø9.52 (3/8") liquid pipe (m) [ft]
L3: Length of ø6.35 (1/4") liquid pipe (m) [ft]
A: refer to the calculation table.

In the calculation results, round up fractions smaller than 0.01 kg. (Example: 18.54 kg → 18.6 kg)

1.0oz (653.97oz → 654oz)

(α Calculation Table)

Total Capacity of A

Connected Indoor Units kg (oz)

32 1.0 (36)

33~64 1.5 (53)

65~130 2.0 (71)

1234 567 8910

ON

–51–

(3) Refrigerant Amount Adjustment Mode Operations

1 Procedure

Depending on the operating conditions, it may be necessary either to charge with supplementary refrigerant, or to
drain out some, but if such a case arises, please follow the procedure given below flow chart.

Notes 1 As the refrigerant volume can not be adjusted in the heating mode, retrieve the refrigerant, evacu-

ate air and then fill the specified volume of refrigerant if it is necessary to adjust the refrigerant
volume in the winter season.

Notes 2 A refrigerant volume adjustment performed in the cooling mode must be done with a gauge reading of 1.27MPa

(184.8psi) or higher.
If the pressure does not reach this guage reading the refrigerant cannot be collected halfway.
Therefore, collect used refrigerant and evacuate the unit completely, and then fill new refrigerant up to a specified
quantity.

Notes 3 Judgment by the AL is at best only a rough guideline. Please do not add refrigerant based on the

AL reading alone. (Be sure to obtain calculations of the correct amount before adding refrigerant.)

Notes 4 When supplementing the refrigerant volume, please be careful to charge with liquid refrigerant.

TH1 SC11

SC16 Pd (High pressure)

1234 567 8910

ON

1234 567 8910

ON

1234 567 8910

ON

1234 567 8910

ON

–52–

YES

NO

Adjustment starts.

Start cooling operation of all indoor
units in a test run mode. Note 1

Has the

compressor been

operated for more than

30min?

Was the operation
condition stabilized?

The high pressure
> 1.27MPa (185psi)

TH1 ≤ 115˚C? (239˚F)

Are all indoor
units SHs more
than 2 (3.6) deg?

Is the LEV opening

degree stable when SH

< 2 (3.6) deg?

Is the

thermostat turned

on/off in order for the indoor

unit to prevent from

frosting?

Adjustment completed.

*Operate for 5 minutes after adjusting the refrigerant and make a judgement.

Fill refrigerant little by little from the
low-pressure side service port.

Stop the refrigerant volume adjustment
and retrieve the refrigerant. After
evacuating air, fill the specified volume
of refrigerant.

Retrieve the refrigerant little by little
from the low-pressure side service
port.

Note 1) As the refrigerant volume can not be adjusted in the heating mode,

retrieve the refrigerant, evacuate air and then fill the specified
volume of refrigerant if it is necessary to adjust the refrigerant
volume in the winter season.

5deg ≤ SC11?

10 (18) ≤ SC16 ≤ 30(54) deg?

30 (54) deg < SC16?

TH1 ≤ 110˚C? (230˚F)

Fill refrigerant little by little from the
low-pressure side service port.

*Operate for 5 minutes after adjusting the refrigerant and make a judgement.

*Operate for 5 minutes after adjusting the refrigerant and make a judgement.

Fill refrigerant little by little from the
low-pressure side service port.

Fill refrigerant little by little from the
low-pressure side service port.

*Operate for 5 minutes after adjusting the refrigerant and make a judgement.

Note 2

Note 3

Note 2) SC11 : Liquid refrigerant sub-cool for BC controller inlet

Note 3) SC16 : Liquid refrigerant sub-cool for BC controller outlet

Note 4) ˚C Scale (˚F Scale)

–53–

1 Time required for recovering refrigerant from low pressure service port (minute)

0.34~0.44 0.44~0.54 0.54~0.74
(49.8~64) (64~78.2) (78.2~106.7)

1 (35.2) 4.0 3.5 3.5

2 (70.4) 8.0 7.0 6.5

3 (105.6) 12.0 10.5 10.0

4 (140.8) 16.0 14.0 13.0

5 (176) 20.0 18.0 16.5

6 (211.2) 24.0 21.5 19.5

7 (246.4) 28.0 25.0 23.0

8 (281.6) 32.0 28.5 26.0

9 (316.8) 36.0 32.0 29.5

10 (352) 40.0 35.5 32.5

11 (388.8) 44.0 39.0 36.0

2 Additional evacuation and refrigerant replacement

R2 series has unique refrigerant circuit structure which makes possible 2-pipe cooling-heating simultaneous
operations. Therefore, in the case of total replacement or replenishment of refrigerant in this system, the following
evacuation and refrigerant replenishment procedures are required.
1 Perform evacuation by connecting to system analyzer joint of service port of high pressure ball valve and high

pressure charge plug, and joint of service port of low pressure ball valve and low pressure charge plug.

2 Perform refrigerant charge from low pressure circuit only, after finishing evacuation, closing vacuum pump valve,

shutting off high pressure circuit of system analyzer, and opening valve of refrigerant cylinder.
(In case service port of ball valve and charge plug can not be joined as shown in the figure, use two vacuum
pumps and evacuate high pressure side and low pressure side circuits separately.)

Note 1: Though refrigerant gas itself is harmless, airtight room should be opened before gas release for preventing

oxygen shortage.

2: When releasing gas, use blotting paper, etc. so that oil spouted with the gas does not spread out.

A Ball valve of the high pressure side
B Service port
C Ball valve of the low pressure side
D Charge plug
E High pressure
F Low pressure
G Evacuation
H Evacuation
I Replenish of refrigerant
J System analyzer
K Lo knob

Low pressure

MPa (psi)
Refrigerant amount
to be drawn out kg (oz)

K

G

H

I

J

P

O

R

M

S

T

L

N

A

B

C

F

E

D

L Hi knob
M 3-way joint
N Valve
O Valve
P Flon 22 cylinder
R Scale
S Vacuum pump
T A high-precision gravimeter measurable up to 0.1kg

(3.5oz) should be used. If you are unable to prepare
such a high-precision gravimeter, you may use a
charge cylinder.

–54–

77

77

7 TROUBLESHOOTING

[1] Principal Parts

Pressure Sensor

(1) Judging Failure

1) Check for failure by comparing the sensing pressure according to the high pressure/low pressure pressure sensor
and the pressure gauge pressure.
Turn on switches 1, 3, 5, 6 (High) and 2, 4, 5, 6 (Low) of the digital display select switch (SW1) as shown below, and
the sensor pressure of the high pressure/low pressure sensors is displayed digitally by the light emitting diode LD1.

High Pressure

Low Pressure

1 In the stopped condition, compare the pressure readings from the gauge and from the LD1 display.

(a) If the gauge pressure is 0~0.098MPa (0~14.2 psi), the internal pressure is dropping due to gas leakage.
(b) If the pressure according to the LD1 display is 0~0.098MPa (0~14.2 psi), there is faulty contact at the connec-

tor, or it is disconnected. Proceed to 4.
(c) If the pressure according to the LD1 display is 3.14MPa (455 psi) or higher, proceed to 3.
(d) If other than (a), (b) or (c), compare the pressure readings during operation. Proceed to 2.

2 Compare the pressure readings from the gauge and from the LD1 display while in the running condition.

(a) If the difference between the two pressures is within 0.098MPa (14.2 psi), both the affected pressure sensor

and the main MAIN board are normal.
(b) If the difference between the two pressures exceeds 0.098MPa (14.2 psi), the affected pressure sensor is faulty

(deteriorating performance).
(c) If the pressure reading in the LD1 display does not change, the affected pressure sensor is faulty.

3 Disconnect the pressure sensor from the MAIN board and check the pressure according to the LD1 display.

(a) If the pressure is 0~0.098MPa (0~14.2 psi) on the LD1 display, the affected pressure sensor is faulty.
(b) If the pressure is 3.14MPa (455 psi) (in the case of the low pressure sensor, 0.98MPa (142 psi)) or higher, the

MAIN board is faulty.

4 Disconnect the pressure sensor from the MAIN board and short out the No. 2 and No. 3 pins of the connector

(63HS, 63LS), then check the pressure by the LD1 display.
(a) If the pressure according to the LD1 display is 3.14MPa (455 psi) (in the case of the low pressure sensor,

0.98MPa (142 psi)) or higher, the affected pressure sensor is faulty.

(b) If other than (a), the MAIN board is faulty.

2) Pressure sensor configuration.
The pressure sensors are configured in the circuit shown in the figure at right. If DC 5 V is applied between the red
and black wires, a voltage corresponding to the voltage between the white and black wires is output and this voltage
is picked up by the microcomputer. Output voltages are as shown below.

High Pressure 0.1 V per 0.098MPa (14.2 psi)
Low Pressure 0.3 V per 0.098MPa (14.2 psi)

1234 567 8910

ON

1234 567 8910

ON

Connector

Vout 0.5~3.5 V

GND (Black)
Vout (White)
Vcc (DC5V) (Red)

63HS/

63LS

–55–

Solenoid Valve (SV1~6)

Check if the control board’s output signals and the operation of the solenoid valves match.
Setting the self-diagnosis switch (SW1) as shown in the figure below causes the ON signal of each relay to be output to
the LED’s.
Each LED shows whether the relays for the following parts are ON or OFF. When a LED lights up, it indicates that the
relay is ON.

12345678

1) In the case of SV1 (Bypass Valve)
(a) When the compressor starts, SV1 is ON for 4 minutes, so check operation by whether the solenoid valve is

emitting an operating noise.

(b) Changes in the operating condition by solenoid valve operation can be confirmed by the temperature of the

bypass circuit and the sound of the refrigerant.

2) In the case of SV2 (Bypass)
(a) SV2 goes ON in accordance with the rise in the high pressure in the cooling mode and heating mode, so check

its operation by the LED display and the operating noise emitted by the solenoid valve.
(Conditions during operation: See Control of Outdoor Unit.)

(b) Changes in the operating condition by solenoid valve operation can be confirmed by the temperature of the

bypass circuit and the sound of the refrigerant.

3) SV3 ~ 6 (Control of heat exchanger capacity)
(a) Operations can be confirmed by LED display and operating sound of solenoid valve, because one or more of

SV3 ~5 are turned on depending on conditions during cooling-only operations.

(b) Operation can be confirmed by LED display and operating sound of solenoid valve, because all of SV3 ~ 5 are

turned on during heating-only operations.

(c) Operations can be confirmed by LED display and operating sound of solenoid valve, because one or more of

SV3 ~6 are turned on depending on conditions during cooling-principal and heating-principal operations.

SW1

LED

1234 567 8910

ON

1234 567 8910

ON

SV6SV5

SV4SV3SV2SV1

* Connector connection specifications on the pressure sensor body side.

The connector’s pin numbers on the pressure sensor body side differ from the pin numbers on the main circuit board
side.

Vcc

Vout

GND

Sensor Body Side

Pin1
Pin2
Pin3

MAIN Board Side

Pin3
Pin2
Pin1

–56–

(d) The refrigerant flow is as following figure. Hot gas (high pressured) flows in cooling mode and cool gas/liquid

(low pressured) flows in heating mode. Please refer to the Refrigerant Circuit Diagram.
And, ON/OFF of Solenoid valve is depends on the amount of running indoor units, ambient temperature and so
on. So please check by LED Monitor Display.
If the SV coil is taken off, then it is possible to open caps and check plungers. But the special tool which is on
the Service Parts List is needed.

* Closed torque : 13kg·m (1.3N·m)

(0.958lbFFt)

(1

25
32

")

–57–

Judgment methods and likely failure mode

Caution:

The specifications of the outdoor unit (outdoor LEV) and indoor unit (indoor LEV) differ. For this reason, there are
cases where the treatment contents differ, so follow the treatment specified for the appropriate LEV as indicated in
the right column.

1 Disconnect the control board connector and connect

the check LED as shown in the figure below.

When the base power supply is turned on, the indoor LEV
outputs pulse signals for 10 seconds, the outdoor LEV
outputs pulse signals for 17 seconds, and BC controller
outputs pulse signals for 10-20 seconds.
If the LED does not light up, or lights up and remains on,
the driver circuit is abnormal.

1 If the LEV is locked up, the drive motor turns with no

load and a small clicking sound is generated.
Generation of this sound when the LEV is fully closed
or fully open is abnormal.

Measure the resistance between the coils (red - white, red

- orange, brown - yellow, brown - blue) using a tester. They
are normal if the resistance is within 150Ω± 10%.

1 If you are checking the indoor unit’s LEV, operate the

indoor unit’s blower and the other indoor units in the
cooling mode, then check the piping temperatures
(liquid pipe temperatures) of the indoor units by the
operation monitor through the heat source unit’s
control board. When the fan is running, the linear
expansion valve is fully closed, so if there is leakage,

the temperature sensed by the
thermistor (liquid pipe temperature
sensor) will become low. If the
temperature is considerably low
compared to the remote control’s
intake temperature display, it can
be judged that there is a fully

closed failure. In the case of
minimal leakage, it is not necessary to replace the
LEV if there are no other effects.

1 Check for pins not fully inserted on the connector and

check the colors of the lead wires visually.

2 Disconnect the control board’s connector and conduct

a continuity check using a tester.

Microcomputer
driver circuit
failure

LEV mechanism
is locked.

The LEV motor
coils have a
disconnected wire
or is shorted.

Fully closed
failure (valve
leaks)

Faulty wire
connections in
the connector or
faulty contact.

Failure Mode Judgment Method Treatment Affected LEV

Thermistor
liquid pipe
(tempera­ture sensor)

Linear
Expansion
Valve

In the case of driver circuit
failure, replace the control
board.

Replace the LEV.

Replace the LEV coils.

If there is a large amount of
leakage, replace the LEV.

Check the continuity at the
places where trouble is found.

Indoor

BC controller

Indoor

BC controller

Indoor

BC controller

Indoor

BC controller

Indoor

BC controller

Indoor, BC controller

Outdoor

–58–

Outdoor LEV (SLEV) Coil Removal Procedure (configuration)
As shown in the figure, the outdoor LEV is made in such a way that the coils and the body can be separated.

<Removing the Coils>
Fasten the body tightly at the bottom (Part A in the figure) so
that the body will not move, then pull out the coils toward the
top. If they catch on the stopper and are difficult to take out,
turn the coils left and right until the stoppers are free from the
stopper indentations, then pull the coils out.
If you take out the coils only without gripping the body, undue
force will be applied to the piping and the pipe may be bent
over, so be sure to fasten the body in such a way that it will not
move.

Par t A

Coils

Stopper

Lead Wires

–59–

Check Valves Block

The refrigerant flow in the pipe 6, 7, 8 and 9 are depend on ON/OFF of the SV3, 4, 5 and 6.
Please confirm by LED monitor display.
You can open the cap of valve A, B and C, but 3 types of hexagon socket screw keys. The size is as follows.

* Closed torque : A : 1.7kg·m (0.17N·m) [0.125lbFFt]

B : 20kg·m (2.0N·m) [1.47lbFFt]
C : 13kg·m (1.3N·m) [0.96lbFFt]

1mm = 0.04”

–60–

Intelligent Power Module (IPM)

Measure resistances between each terminal of IPM with tester, and use the results for troubleshooting. Specified
resistance value is dependent on tester type to be used for resistance measurement, because diode inside IPM has
non-linearity, thus difference of impedance and voltage in tester being influential. As the internal impedance of
resistance range of analog tester equals to the center value of meter indication, the affect of internal impedance can
be minimized if the tester having close center value of resistance range. Because internal voltage is normally 1.5V,
the tester to be used for troubleshooting of IPM should satisfy the following conditions.

Internal voltage 1.5V (Power source : one dry cell battery)

Central value of resistance range 10 ~ 40Ω

The measured values for troubleshooting are shown in the table below.
(Use the minimum range for tester resistance range.)

Diode stack
Perform continuity check with tester. Judged as normal if the following characteristics are observed.
(Use the minimum range for tester resistance range.)

1 10~50Ω∞

2 10~50Ω∞

3 10~50Ω∞

1 ∞ 10~50Ω

2 ∞ 10~50Ω

3 ∞ 10~50Ω

123

1
2
3

+

—

Tester ⊕

Tester -

+–

Tester -

Tester

⊕

+–

W

P

External view Internal circuit diagram

Judged value

P

Tester —

Tester

+

U

2~
100Ω

2~
100Ω

2~
100Ω

2~
100Ω2~100Ω2~100Ω2~100Ω

V

W

∞
∞
∞

N

UVWN

∞∞∞∞

N

P

B

1 4 7 10 16

V

V

U

P

W

N

B

U

3

2

1
6

5

4
9

8

7

11

13

10

14

15

12

16

Pre-Driver

Pre-Driver

Pre-Driver

Pre-Driver

Pre-Driver

Pre-Driver

Over heating
protection circuit

–61–

(2) Trouble and remedy of remote controller

Symptom Cause Checking method & countermeasure

1

2

Despite pressing of
remote controller
ON/OFF switch,
operation does not
start and there is no
electronic sound.

(No powering signal

appears.)

At about 10 seconds
after turning remote
controller operation
switch ON, the
display distinguishes
and the operation
stops.

1) M-NET transmission power source is not supplied
from outdoor unit.
1 Main power source of outdoor unit is not

connected.

2 Disconnection of connector on outdoor unit circuit

board.
Main board : CNS1, CNVCC3
INV board : CNDC2, CNVCC2, CNL2
G/A board : CNDC1

3 Faulty power source circuit of outdoor unit.

• Faulty INV board,

• Blown fuse (F1 on INV board)

• Broken diode stack

• Broken resistor (R1) for rush current protection

2) Short circuit of transmission line.

3) Erroneous wiring of M-NET transmission line at outdoor unit.
1 Transmission line disconnection or slipping off from terminal

block.

2

Erroneous connection of indoor/outdoor transmission line to TB7.

4) Disconnection of transmission wiring at remote controller.

5) Faulty remote controller.

The cause of 2) and 3) is
displayed with self-diagnosis
LED for 7102 error.

1) Power source is not fed to indoor unit from transformer.

1 Main power source of indoor unit is not turned on.
2 Disconnection of connector (CND, CNT, CN3T) on indoor controller board.
3 Blown fuse on indoor controller board.
4 Faulty or disconnected transformer of indoor unit.
5 Faulty indoor controller board.

2) Faulty outdoor control circuit board.
As normal transmission fails between indoor and outdoor units, outdoor unit model can not be
recognized.

Checking method & countermeasure

a) Check transmission terminal block of

remote controller for voltage.
i) In case of 17 ~ 30V

→ Faulty network remote controller

ii) In case of less than 17V

→ See “Transmission Power Circuit

(30V) Check Procedure”.

Check indoor LED3

Lighting?

Check for the change of LED
display by operating dip switch
SW1 for self-diagnosis.

Extinguishing or
unable to confirm

Check indoor unit
power source terminal
block voltage

AC 208~230V?

Check fuse on circuit
board

Blown?

Check connection of con­nector (CND, CNT, CN3T)

Disconnected?

Check transformer
resistance value

Within rated?

Check self-diagnosis
function of outdoor unit

Changed?

Faulty indoor
controller board

Check main power source
of power source wiring.

Apply power
source again.

Check 208V/230V
circuit for short circuit
and ground fault.

Improper connector
connection

Check cause of trans­former disconnection.

•Ground fault on circuit
board

•Ground fault on
sensor, LEV

Check self-diagnosis function af­ter powering outdoor unit again.

Changed?

Accidental
trouble

Faulty outdoor unit
control circuit board

Repair
faulty point.

NO

YES

YES

NO

NO

YES

YES

NO

NO

YES

YES

Lighting

*1 Check the transformer in accordance with the “TROUBLE SHOOTING” in the indoor unit’s service handbook.

NO

*1

–62–

Symptom Cause

3 “HO” display on re-

mote controller does
not disappear and
ON/OFF switch is
ineffective.

(Without using MELANS)

1) Outdoor unit address is set to “000.”

2) Erroneous address.

1 Address setting of indoor unit to be coupled with remote controller Incorrect.

(Indoor unit = remote controller - 100.)

2 Address setting of remote controller Incorrect.

(Remote controller = indoor unit + 100.)

3) Faulty wiring of transmission terminal block TB5 of indoor unit in the same group with remote
controller.

4) Centralized control SW2-1 of outdoor unit is turned ON.

5) Setting to interlocking system from indoor unit (Switch 3-1 = OFF), while Fresh Master is intended to
be used by remote controller operation (indoor unit attribute).

6) Disconnection or faulty wiring of indoor unit transmission line.

7) Disconnection between indoor unit M-NET transmission line terminal block (TB5) and connector
CN2M.

8) More than 2 sets of power supply connector (CN40) are inserted into centralized control transmis­sion line of outdoor unit.

9) Faulty outdoor unit control circuit board.

10)Faulty indoor controller board.

11)Faulty remote controller.

(Interlocking control with MELANS)

12)No grouping registration from MELANS (Neglecting to set the relation between indoor unit and
network remote controller).

13)Disconnection of centralized control transmission line (TB7) at outdoor unit.

14)At system connected with MELANS, power supply connector (CN40) is inserted to centralized
control transmission line of outdoor unit.

Checking method & countermeasure

In case MELANS is not used

In case with MELANS used

When MELANS is used, “HO” display on the remote controller will disappear at the group registration of the indoor unit and local
remote controller.
If “HO” does not disappear after the registration, check the items 12) ~ 14) in the Cause column.

Same symptom for all
units in a single refriger­ant system?

Check outdoor unit
address

51 ~ 100?

Check centralized
control switch SW2-1 at
outdoor unit

ON?

Faulty outdoor unit
control circuit board

Outdoor unit
address set­ting miss

Switch setting
miss
Change from
ON to OFF

Address setting
miss of remote
controller

Indoor address
setting miss

Transmission line
wiring miss of in­door unit M-NET

Disconnection
of CN2M
connector

Setting miss of
Fresh Master
SW3-1

Repair spot
in trouble

Confirm address of remote
controller with “HO” displayed

Indoor unit + 100?

Check address of
coupling indoor unit

Remote controller

-100?

Check voltage of indoor unit M­NET transmission terminal block

17 ~ 30V?

Check connection between indoor unit M-NET trans­mission terminal block (TB5) and connector CN2M

Disconnection?

Check Fresh Master SW3-1

Faulty indoor controller board
or remote controller

ON?

NO

NO

NO

YES

YES

YES

NO

YES

YES

YES

YES

NO

–63–

Symptom Cause Checking method & countermeasure

4 “88” appears on re-

mote controller at
registration and
access remote
controller

a) Confirm the address of unit to be

coupled.

b) Check the connection of transmission

line.

c) Check the transmission terminal block

voltage of unit to be coupled.
i) Normal if voltage is DC17 ~ 30V
ii) Check the item d) in case other than i).

d) Confirm the power source of outdoor unit

to be coupled with the unit to be
confirmed.

e) Confirm that the centralized control

transmission line (TB7) of outdoor unit is
not Disconnection.

f) Confirm the voltage of centralized control

transmission line.
i) Normal in case of 10V ~ 30V
ii) Check the items 7) ~ 10) left in case

other than i).

[Generates at registration and confirmation]

1) Erroneous address of unit to be coupled.

2) Disconnection of transmission line of unit to be
coupled (No connection).

3) Faulty circuit board of unit to be coupled.

4) Installation miss of transmission line.

[Confirmation of different refrigerant system controller]

5) Disconnection of power source of outdoor unit to be
confirmed.

6) Disconnection of centralized control transmission
line (TB7) of outdoor unit.

7) Power supply connector (CN40) is not inserted into
centralized control transmission line in grouping
with different refrigerant system without using
MELANS.

8) More than 2 sets of power supply connector are
inserted into the centralized control transmission line
of outdoor unit.

9) In the system connected with MELANS, power
supply connector (CN40) is inserted into the
centralized control transmission line of outdoor unit.

10)Short circuit of centralized control transmission line.

–64–

Transmission Power Circuit (30 V) Check Procedure
If “ ” is not displayed by the remote control, investigate the points of the trouble by the following procedure and correct it.

No. Check Item Judgment Response

1

2

3

4

5

6

7

8

9

10

Disconnect the transmission line from TB3
and check the TB3 voltage.

Check if the following connectors are
disconnected in the outdoor unit’s control
box.
MAIN Board: CNS1, CNVCC3, CNVCC5
INV Board: CNVCC2, CNVCC4, CNL2,
CNDC2

Disconnect the wires from CNVCC3 on the
Main board and check the voltage between
pins 1 and 3 on the wire side of the
CNVCC3.

Tester + ..... 1 pin

Tester - ..... 3 pin

Disconnect the wiring from CNVCC2 on the
INV board and check the voltage between
pins 1 and 3 of CNVCC2.

Tester + ..... 1 pin

Tester - ..... 3 pin

Disconnect the wiring from CNL2 on the
INV board, and check the resistance at
both ends of choke coil L2.

Check the voltage between pins 1 and 3 of
CNDC2 on the INV board.

Check the resistance at both ends of F01
on the G/A board.

Check the resistance at both ends of R1.

Check the DS.

Check the voltage between RS and T on
power supply terminal block TB1.

DC24~30 V

Except the above-mentioned

Connector disconnected

Except the above-mentioned

DC24~30 V

Except the above-mentioned

DC24~30 V

Except the above-mentioned

0.5~2.5Ω

Except the above-mentioned

DC265~357 V

Except the above-mentioned

0Ω

Except the above-mentioned

20~24Ω
Except the above-mentioned

refer to “Judging Diode
stack Failure”
Except the above-mentioned

AC187~253 V

Except the above-mentioned

Check the transmission line for the following, and
correct any defects.
Broken wire, short circuit, grounding, faulty
contact.

Go to No. 2

Connect the connectors as shown on the electric
wiring diagram plate.

Go to No. 3

Check the wiring between CNS1 and TB3 for the
following, and correct any defects.
Broken wire, short circuit, grounding, faulty
contact.
If there is no trouble, replace the Main board.

Go to No. 4

Check the wiring between CNVCC2 and
CNVCC3 for the following, and correct any
defects.
Broken wire, short circuit, grounding, faulty
contact.

Go to No. 5

Go to No. 6

Replace choke coil L2.

Replace the INV board.

Go to No. 7

Go to No. 8

Replace F01

Go to No. 9
Replace R1

Go to No. 10
Replace DS

Check the wiring to TB1 for the following and
correct any defects.
Broken wire, faulty contact.

Check the power supply wiring and base power
supply, and correct any defects.

–65–

(3) Investigation of transmission wave shape/noise

Control is performed by exchanging signals between outdoor unit, indoor unit and remote controller by M-NET
transmission. If noise should enter into the transmission line, the normal transmission will be hindered causing
erroneous operation.

1) Symptom caused by the noise entered into transmission line

Cause Erroneous operation Error code

Signal changes and is misjudged as the signal of other
address.

Transmission wave shape changes to other signal due to
noise.

Transmission wave shape changes due to noise, and can
not be received normally thus providing no reply (ACK).

Transmission can not be made continuously due to the
entry of fine noise.

Transmission can be made normally, but reply (ACK) or
answer can not be issued normally due to noise.

2) Method to confirm wave shape

Check the wave shape of transmission line with an oscilloscope to confirm that the following conditions are being
satisfied.

1 The figure should be 104μs/bit ± 1%.
2 No finer wave shape (noise) than the transmission signal (52μs ± 1%) should be allowed. *1
3 The sectional voltage level of transmission signal should be as follows.

*1 However, minute noise from the DC-DC converter or inverter operation may be picked up.

Noise entered into
transmission line

6600

6602

6607

6603

6607
6608

<with transmission>

<without transmission>

No fine noise allowed *1

No fine noise allowed *1

Logic value Transmission line voltage level

0VHL = 2.0V or more

1VBN = 1.3V or less

VHL

VBN

52 μs
Logical

52 μs52 μs

Logical

52 μs
value “0”

52 μs
value “1”

–66–

3) Checking and measures to be taken

(a) Measures against noise

Check the items below when noise can be confirmed on wave shape or the error code in the item 1) is generated.

Items to be checked Measures to be taken

(b) When the wave height value of transmission wave shape is low, 6607 error is generated, or remote controller is

under the state of “HO.”

Items to be checked Measures to be taken

1 Wiring of transmission and power lines in

crossing.

2 Wiring of transmission line with that of other

system in bundle.

3 Use of shield wire for transmission line (for

both indoor unit control and centralized
control).

4 The shield is to be daisy changed exactly the

same as the transmission line.

5 Are the unit and transmission lines grounded

as instructed in the INSTALLATION MANUAL?

6 Earthing of the shield of transmission line (for

indoor unit control) to outdoor unit.

7 Arrangement for the shield of transmission line

(for centralized control).

Isolate transmission line from power line (5cm (2") or more).
Never put them in a same conduit.

Wire transmission line isolating from other transmission line.
Wiring in bundle may cause erroneous operation like crosstalk.

Use specified transmission wire.

Type : Shield line CVVS/CPEVS
Wire diameter : 1.25mm

2

(16-2AWG) or more

The transmission line is wired with 2-jumper system. Wire the shield
with jumper system as same for transmission line.
When the jumper wiring is not applied to the shield, the effect against
noise will be reduced.

Connect to ground as shown in the INSTALLATION MANUAL.

One point earthing should be made at outdoor unit.
Without earthing, transmission signal may be changed as the noise on
the transmission line has no way to escape.

For the shield earth of the transmission line for centralized control, the
effect of noise can be minimized if it is from one of the outdoor units in
case of the group operation with different refrigerant systems, and from
the upper rank controller in case the upper rank controller is used.
However, the environment against noise such as the distance of trans­mission line, the number of connecting sets, the type of connecting con­troller, and the place of installation, is different for the wiring for central­ized control. Therefore, the state of the work should be checked as fol­lows.
a) No earthing

• Group operation with different refrigerant systems
One point earthing at outdoor unit

• Upper rank controller is used
Earthing at the upper rank controller

b) Error is generated even though one point earth is being con-

nected.
Earth shield at all outdoor units.

Connect to ground as shown in the user’s manual.

Check for earthing

Checking for wiring method

8 The farthest distance of transmission line is

exceeding 200m (656ft).

9 The types of transmission lines are different.

0 No transmission power (30V) is being supplied

to the idoor unit or the remote control.

A Faulty indoor unit/remote controller.

Confirm that the farthest distance from outdoor unit to indoor unit/
remote controller is less than 200m (656ft).

Use the transmission wire specified.

Type of transmission line : Shield wire CVVS/CPEVS
Wire dia. of transmission line : 1.25mm2 (16-2AWG) or more

Refer to “Transmission Power Supply (30V) Circuit Check Procedure.”

Replace outdoor unit circuit board or remote controller.

–67–

4) Treatment of Inverter and Compressor Troubles
If the compressor does not work when error codes 4240, 4250, 4340 or 4350 are detected, determine the point of
malfunction by following the steps in the LED monitor display and countermeasures depending on the check
code displayed, then perform the procedures below.

No.

Check Item Symptoms Treatment

*1 [Cautions when measuring the voltage and current of the inverter’s power circuit.]

Since the voltage and current on the inverter’s power supply side and its output side do not have a sine waveform, the
measurement values will differ depending on the measuring instrument and the circuit measured.
In particular, as the inverter’s output voltage has a pulse waveform, the output frequency also changes, so differences in
measurement values will be great depending on the measuring instrument.

1 When checking if the inverter’s output voltage is unbalanced or not (relative comparison of the voltages between

each of the lines), if you are testing with a portable tester, be sure to use an analog tester.
Use a tester of a type which can be used to judge if the IPM or diode module is faulty.
In particular, in cases where the inverter’s output frequency is low, there are cases where the variations in measured
voltage values between the different wires will be great when a portable digital tester is used, when in actuality they
are virtually equal, and there is danger of judging that the inverter is faulty.

2 It is recommended when checking the inverter’s output voltage values (when measuring absolute values), that, if a

measuring device for business frequencies is used, a rectified voltage meter (with a

symbol) be used.

Correct measurement values cannot be obtained with an ordinary portable tester. (either analog or digital)

1 If it was kept on for 12 hours or

longer as specified.

2 It was kept on for less than the

specified period.

1 The compressor stops and the

same error code is displayed.

1 The Inverter stops and the same

error code is displayed.

2 If the inverter’s output voltage is

output with good balance, *1.

3 If the balance in the inverter’s

output voltage is not good or if the
inverter’s output voltages are all 0 V
(a digital tester cannot be used) *1.

Go to [2].

Go to [2] after keeping the power on for the
specified time.

Perform the check of wiring shown in the
explanation of each error code.

Check the IPM is faulty. (Go to “Individual
Parts Failure Judgment Methods.”)

Check the coil resistance and insulation
resistance of the compressor, and if it is
normal, run it again, and if the trouble occurs
again, replace the compressor.
* Insulation resistance : 1MΩ or more

Coil resistance : 0.11Ω (20˚C (68˚F))

Check the IPM.
Judge that the IPM is faulty. (Go to “Indi­vidual Parts Failure Judgment Methods.”)
If the IPM is normal, replace the G/A board,
then perform this item again with SW1-1 ON.
If the problem is not solved, replace the INV board.
If the problem is solved and you connect the
compressor again, turn SW1-1 OFF again.
Check the compressor’s coil resistance and
insulation resistance.

How many hours was the
power kept on before
operation?

When it is restarted, does
the trouble reappear?

Run the outdoor unit with
the wiring to the compressor
disconnected. At this time,
change SW1-1 on the INV
board to ON.
Note) The terminals of the 3
disconnected wires should
be isolated from each other.

1

2

3

–68–

5) Troubleshooting at breaker tripping

Check items Measures to be taken

1 Check the breaker capacity.

2 Check for a short circuit or grounding in the electrical

system other than the inverter.

3 Check the resistance between terminals on the terminal

block TB1 for power source.

4 Checking by powering again.

5 Operational check by operating air conditioner

The breaker’s capacity should be correct to “System
design” in data book.

Correct any defects.

Check each part inside the inverter power circuit

(resistance, megohm or the like).

a) Diode stack

Refer to “Troubleshooting of diode stack.”

b) IPM

Refer to “Troubleshooting of IPM.”
c) Rush current protection resistor
d) Electromagnetic contactor
e) DC reactor
* For c) ~ e), refer to “Individual Parts Failure Judge-

ment Methods.”

a) As there is a possibility of instantaneous short

circuit generated, find the mark of the short circuit

for repair.
b) When a) is not applicable, the compressor may be

faulty.

The ground fault of inverter output/compressor can

be supposed.

Disconnect the wiring to the compressor and check

the insulation resistance of the following parts with

a megger.
a) Compressor terminals.
b) Inverter output.

1 0 ~ several ohms or improper megohm value

1 Main power source circuit breaker tripping

2 No display of remote controller

1 Normal operation without breaker tripping.

2 Breaker tripping

–69–

6) Individual Parts Failure Judgment Methods.

Part Name Judgment Method

Diode Stack (DS) Refer to “Judging Diode Stack Failure.”

Intelligent Power Module(IPM) Refer to “Judging IPM Failure.”

Electromagnetic Contactor (52C) Measure the resistance value at each terminal.

DC Reactor (DCL) Measure the resistance between terminals: 1 Ω or lower

Measure the resistance between the terminals and the chassis: ∞

Cooling Fan (MF1) Measure the resistance between terminals: 0.1k~1.5kΩ

POWER board Measure the resistance valve at between each terminals, and between

each terminal and case.

A2 44/42 34/32 24 14

A1 43/41 33/31 23 13

[Caution at replacement of inverter parts]

1 IPM and G/A board should be replaced together at the same time.

When the IPM is damaged, the G/A board may possibly be broken, and the use of the broken G/A board damages
the normal IPM. Therefore, replace the IPM and G/A board together at the same time. However, if the G/A board is
damaged, judge that the IPM is faulty, then judge whether replacement is necessary or not.

2 Fully check wiring for loose and incorrect connections.

The incorrect or loose connection of the power circuit part wiring like IPM and diode module causes damage to the
IPM. Therefore, check the wiring fully. As the insufficient tightening of screws is difficult to find, tighten them together
additionally after finishing other works. For the wiring of the base for IPM, observe the wiring diagram below care­fully as it has many terminals.

3 Coat the grease provided uniformly onto the heat radiation surface of IPM /diode modules.

Coat the grease on the full surface in a thin layer, and fix the module securely with the screw for fastening. As the
radiation grease attached on the wiring terminal causes poor contact, wipe it off if attached.

Check Location Judgment Value

A1-A2 50~100kΩ

13-14, 23-24
33-34, 43-44

∞

Check Location

FN3-6, FN2-4

FN1-2, FN2-3, FN4-6

FN1, FN2, FN3, FN4,

FN6-case

Judgment Value

under 1Ω

∞

∞

FN2 FN4

FN1

FN6FN3

–70–

Motor

(Compressor)

G/A board

Red

UVW

N

P

White Blue

Blue

Capacitor

(C1)

Red

IPM

–71–

(4) Troubleshooting the major components of the BC controller

1) Pressure sensor
Pressure sensor troubleshooting flow

Check on the LED monitor dis­play.

• LPS of outdoor unit.

• HPS of outdoor unit

• PS1, PS3 of BC controller and
confirm the following relationship
HPS > PS1

PS3 > LPS

(puressure calculated value)

Check that refrigerant pip­ing and transmission line
connections are in agree­ment between outdoor
unit and BC controller.

START

Check pressure sensor, PS1,
PS3, connectors for discon­nection, looseness, or incor­rect attachment.

OK?

Stop the unit (compres­sor OFF).

At least

10 minutes passed since

stopping?

Check PS1, PS3 on LED
monitor display and confirm
that none of the detected
pressure values is below

0.098MPa (14.2psi).

OK?

OK?

OK?

OK?

Change board.

Repair faulty connection.

Change pres­sure sensor.

OK?

Replace the wrong
puressure sensor with the
correct pressure sensor, and
confirm it’s detected pres­sure is indicated correctly.

Short connectors 2 and 3 on the
board and check the pressure.

Pressure

range within 0 to

0.098MPa

(14.2psi)

Pressure
of at least 3.14MPa
(455psi) indicated?

Remove the pressure sensor
connector from the board, and
check the pressure.

Check for faulty connector on
applicable pressure sensor.

Correct refrigerant
piping and trans­mission line.

OK?

OK?

Note 3

Take corrective action.

HPS PS1 PS3 LPS
(pressure calculated
value) (The difference is
less than

0.098MPa

(14.2psi)

No board or pressure
sensor abnormality.

Check that refrigerant piping and
transmission line connections are
in agreement between outdoor
unit and BC controller.

Confirm the

following relationship PS1

PS3?

Correct refrigerant
piping and the trans­mission line.

Unit running?

Note 1

No

Note 2

No

No

Note 2

No

No

No

Ye s

No

Ye s

Ye s

Ye s

Ye s

Ye s

Ye s

Ye s

No

Note 4

No

No

No

Ye s

Ye s

Ye s

No

No

Ye s

–72–

Note 1 :

• Symptoms of incorrect i.e, reverse connection of PS1 and PS3 to BC controller board

Note 2 :

• Check using LED monitor display switch (outdoor MAIN board SW1)

Note 3 :

• Check CNP1 (liquid measurement) and CMP3 (intermediate) connectors on BC controller board for disconnection or
looseness.

Note 4 :

• With the sensor of the applicable connector removed from the board, use the LED monitor display switch (Note 1) to
check the pressure value.

Pressure Sensor Replacement Precaution

Symptom

Cooling-only Cooling-principal Heating-only Heating-principal

Normal

Insufficient
cooling.

SC11 large
SC16 small

PHM < 0

SC11 large
SC16 small

PHM < 0

Warm indoor SC
small. When SV
opens some
noise produced.

SC11 small
SC16 small

PHM < 0

Insufficient heating
Warm indoor SC small
When SV opens some
noise produced

Measured Data

High pressure of
outdoor

Low pressure of
outdoor

BC controller pressure
(liquid measurement)

(intermediate)

Signal

HPS

LPS

PS1

PS3

SW1 Setting Remarks

See converter.

See converter.

Convert saturation
temperature to
desired pressure
using converter.

1ON2345678910

1ON2345678910

1ON2345678910

1ON2345678910

(Pressure sensor output voltage)

–73–

2) Temperature Sensor

Thermistor troubleshooting flow

Start

Disconnect applicable thermistor
connector from the board.

Measure temperature of applicable
thermistor (actual measured value).

Check thermistor resistance value.

Compare temperature for thermistor
resistance value with actual mea­sured valued.

No

difference?

Insert applicable thermistor connector
into board, and check sensor input
temperature on LED monitor for differ­ence.

No

difference?

No abnormality

.

Change thermistor.

Check for connection
problem.

Change the controller
board.

Note 5

Ye s

No

No

Ye s

Note 4

Note 2

Note 1

Note 3

–74–

Note 1 :

• Board connector CN10 corresponds to TH11 through TH14, while connector
CN11 corresponds to TH15 through TS15. Remove the applicable connector
and check the sensor for each number.

Note 2, 3 :

1. Pull the sensor connector from the I/O board. Do not pull on the lead wire.

2. Measure resistance using a tester or other instrument.

3. Compare measured values with values on the graph below. A value within a range of ±10% is normal.

Resistance measurement point (connector)

Temperature sensor resistance (graph)

Note 4 :

• Check using LED monitor display switch (outdoor MAIN board SW1)

Measured Data Signal SW1 Setting Remarks

Liquid inlet
temperature

TH11 See converter.

Bypass outlet
temperature

TH12 See converter.

Bypass outlet
temperature

TH15 See converter.

Bypass inlet
temperature

TH16 See converter.

Touch the probes of the tester or other instrument
to the shaded areas to measure.

Resistance value
(kΩ)

Temperature ˚C (˚F)

1ON2345678910

1ON2345678910

1ON2345678910

1ON2345678910

Thermistor Ro=15 kΩ

Rt=15exp 3460 ( – )

1

273+tc

1

273+o

∗ When SW4-5 is turned OFF, "˚F" is indicated, while when SW4-5 is

turned ON, "˚C" is indicated.

Note : For more easier readings of temperature

scale convert to ˚C.

˚F = ˚C + 32

9
5

–75–

3) LEV, Solenoid Valve Troubleshooting Flow

No cooling
No heating

Check disconnection or looseness
of connectors.

Is there a problem?

Operate in cooling or heating (1 system
only when there are plural systems)

Cooling or heating

operation?

Heating operation

Note 1

Check if LEV 1 are fully open

LEV 1 fully open?

LEV3 are not

controlled

Check if LEV 1 are fully shut.

Ye s

Note 2

No

Ye s

No

Ye s

No

Ye s

Check if LEV3 is controlled by
superheat.

LEV3 is not controlled.

Check if SVA, SVC are ON.

SVA, SVC ON

Check if SVB is OFF.

SVB OFF

Check if LEV 3 are controlled by
differential pressure.

Completion

Check SVB

Check SVA, SVC

Check LEV3

Correct the problem.

Check LEV1

SVB ON

Check if SVB is ON.

SVA, SVC OFF

Check if SVA, SVC are OFF.

LEV 1 fully shut?

Ye s

No

Note 2

No

No

Ye s

Ye s

Note 3Note 3

No

Ye s Ye s

No

–76–

1 LEV

Note 1 :

• Symptoms of incorrect connection to BC controller LEV board

Improper installation is the same for 1 and 2, so it is omitted here.

Note 2 : Method for checking LEV full open, full closed condition

1 Check LEV full opening (pulse) using the LED monitor display (outdoor controller board SW1).

Full opened: 2000 pulses
Full closed: 60 pulses (LEV 1 may be greater than 60 during full heating operation.)

2 With LEV full opened, check for pressure differential by measuring temperature of piping on both sides.
3 With LEV full closed, check for refrigerant noise.

Note 3 :Use the following table to determine opening due to LEV differential pressure control and superheat

control.

• BC controller LEV basic operation characteristics

Region Failure mode

Operating mode

Description Normal range

LEV No. 1 3 Cooling-only Cooling-main Heating-only Heating-main

1) 1 3 Normal ←← ←

2) 3 1 Insufficient cooling
SH12 small,
SC11 small
SC16 small
Branch piping SC small

Insufficient cooling, insuf­ficient heating
SH12 small, SC11 small
SC16 large,
Branch piping SC small

PHM large

Heating indoor SC small

PHM large

Insufficient cooling
Heating indoor SC small

PHM large

Small

Large

Small

Large

High pressure (PS1) - medium pressure (PS3) is large.

High pressure (PS1) - medium pressure (PS3) is small.

SH12 is large.

High pressure (PS1) - mid pressure (PS3) is small.

SC16 and SH12 are small.

High pressure (PS1) - mid pressure (PS3) is large.

Heating-only
Heating-main
Cooling-main

Cooling-only
Cooling-main

Heating-only
Heating-main

Cooling-only
Cooling-main

Heating-only
Heating-main

LEV1
pulse

LEV3
pulse

2.0 ~ 3.5 kg/cm2G
(0.20~0.34MPa)
(28.4-99.5psi)

*SH12<25
(SH21.6<45)

2.0 ~ 3.5 kg/cm2G
(0.20~0.34MPa)
(28.4-99.5psi)

SC16>6
(SC28.8>10.8)
SH12>5
(SH21.6>9)

2.0 ~ 3.5 kg/cm2G
(0.20~0.34MPa)
(28.4-99.5psi)

* SH/SC ˚C Scale (SH/SC ˚F Scale)

–77–

6

6

5
4
3
2
1

5
4
3
2
1

2
5
1
3
4
6

Brown

Red

Blue

Orange

Yellow

White

Brown

Red

Blue

Orange

Yellow

White

To

LEV

10kΩ LED

(Self-diagnostic monitor)

Measured Data Signal OUTDOOR MAIN board SW1 Setting

LEV1 pulse

LEV 3 pulse

BC controller bypass
output superheat

BC controller
intermediate subcool

BC controller liquid
subcool

(Solenoid Valve Troubleshooting Flow)

–

–

–

SH12

SC16

SC11

Start

Visually check for disconnection between connec­tors and terminals, and confirm correct lead colors.

Intermediate
connector

Controller
board

Remove connectors from the board and
use a tester to check conduction.

• Check between connectors 1-3-5 and 2­4-6.

Use a tester to measure resistance
between each coil (red-white, red-orange,
brown-yellow, brown-blue).
Correct value is: 150Ω±10%

Adjust, repair.

Check for the following:
LEV full open: ticking sound
LEV full closed: no sound

Change LEV

OK?

Confirm if LEV is closed fully.

Attach check LEDs
illustrated nearby to board
connectors and confirm
that LEDs light for 10
seconds.

Change the
board.

1ON2345678910

1ON2345678910

1ON2345678910

1ON2345678910

1ON2345678910

OK?

OK?

Change LEV

Correction.

OK?

OK?

Change LEV

OK?

End

Ye s

No

Ye s

No

Ye s

No

Ye s

No

Ye s

No

Ye s

No

–78–

2 Solenoid Valve

Change the
solenoid valve.

Change the control
board.

208-230V output?

With the solenoid valve con­nector is disconnected from the
board, use remote controller to
turn on the unit and check the
output 208-230V from the con­troller board.

Conductance present?

Disconnect solenoid valve
connector from the board and
check for a solenoid coil
conductance.

Solenoid valve
faulty

Solenoid valve

troubleshooting

Check solenoid valve wiring
for incorrect connection, and
connector disconnection or
looseness.

No problem.

Operate cooler and heater for
the applicable solenoid valve’s
refrigerant system only.

Clicking noise

produced when working

timing?

Measure piping temperature
on both sides of solenoid
valve and check for following.
Solenoid valve ON:
no differential
Solenoid valve OFF:
differential

Solenoid valve
normal

OK?

Measure pipe temperature of
inlet and outlet sides of
solenoid valve.
No temperature differential: OK
Temperature differential: NG

Operation OFF?

No

OK?

Magnetic force

is OK?

Remove the coil and check for
a magnetic force.

Correct the problem.

Stop the unit.

Ye s

No

Note 1

No

Ye s

Ye s

Ye s

No

No

Ye s

Note 3

Ye s

Ye s

No

Ye s

No

–79–

Solenoid valves (SVA, SVB, SVC)
Coordination signals output from the board and solenoid valve operations.

Note 1 : (SVA, SVB, SVC)

SVA, SVB and SVC are turned on and off in accordance with operation mode.

Note 2 : (SVA, SVB, SVC)

Measure temperature of piping on either side of SVA 1-A
Measure temperature of piping on either side of SVB 1-B

4) BC controller transformer

Cooling Heating Stopped Defrosting

SVA ON OFF OFF OFF
SVB OFF ON OFF OFF

SVC ON OFF OFF OFF

Mode

Branch port

Normal Malfunction

CNTR(1)-(3) Approximately 90Ω

Open or shorted

CN03(1)-(3) Approximately 1.7Ω

* Disconnect the connector before measurement.

CNTR CN03

BC Controller control board

Red Blue Brown Brown

1A

B

–80–

[2] BC Controller Disassembly Procedure

(1) Service panel

Be careful on removing heavy parts.

Procedure Photos & Illustrations

1. Remove the two screws securing the electric panel
box, and then remove the box.

2. Remove the four screws securing the front panel
and then remove the panel. Two of the screws are
not visible until you remove the electric panel box.

3. Remove the two screws securing the ceiling panel.
Next, lifting up on the panel slightly, slide it inwards
and then remove it. The inside of the ceiling panel
is hooked on a pin.

4. Remove the single screw that secures the side
panel, and then remove the panel.

Celling panel

Celling panel
fixing screw

BC
control­ler unit

Pin

–81–

(2) Control Box

Be careful on removing heavy parts.

Procedure Photos

<CMB-P104, 105, 106NU-F>

1. Removing the single screw that secures the elec­tric panel box cover provides access to the box con­tents for checking.
1 Check electrical lead wires and transmission

lead terminal connections.

2 Check the transformer.
3 Check the address switch.
4 Use the self-diagnostic switch to check the LED

display.

2. Disconnect the power supply lead, transmission
lead, transformer lead connector, and address
switch wiring connector. Removing the screw se­curing the inner cover provides access for checking
the entire controller board.

3. Note the following precautions whenever replacing
the controller board.
1 Take care to avoid mistakes when connecting

leads and connectors, and double-check for in­complete and loose connections.

2 Check to make sure that DIP switch settings are

the same before and after replacement.

Important!

You do not need to remove the two electric panel
screws if you are checking electric panel box
contents only.

<CMB-P108, 1010, 1013, 1016NU-F>

Removing the single screw that secures the
electric panel box cover provides access to the
controller board and all of the relay board for
checking. So it is not necessary to work according
to above 2.

–82–

(3) Thermistor (Liquid and gas piping temperature detection)

Be careful when removing heavy parts.

Procedure Photos

1. Remove the service panel

1 Use the procedure under (1)-1.2 to check TH11,

TH12, and TH15.

2. Disconnect the piping sensor lead from the control­ler panel.

1 TH11 - TH12 (CN10)
2 TH15, TH16 (CN11)

3. Pull the temperature sensor from the temperature
sensor housing and replace it with a new sensor.

4. Connect the temperature sensor lead securely to
the controller board.

(4) Pressure Sensor

Procedure Photos

1. Remove the sensor panel.
1 Use the procedure under (1)-1.2 to check PS1

and PS3.

2. Disconnect the connector of the applicable pressure
sensor from the controller board and insulate the
connector.

1 Liquid pressure sensor (CNP1)
2 Intermediate pressure sensor (CNP3)

3. Install a new pressure sensor at the location shown
in the photograph, and plug the connector into the
controller board.

Important
1 In the case of gas leakage from the pressure sen-

sor, take actions to fix the leak before performing
the above procedure.

TH15

TH11

TH16

TH12

TH11

PS1

PS3

PS3

PS1

–83–

(5) LEV

Be careful on removing heavy parts.

Procedure Photos

1. Remove the service panel. See (1)-1.2.3.4.

2. Replace the applicable LEV.

Important!
1 When performing the above procedure, be sure to

allow for enough service space in the ceiling area
for welding.

2 When conditions require, the unit can be lowered

from the ceiling before staring work.

(6) Solenoid Valve Coil

Procedure Photos & Illustrations

1. Remove the service panel. See (1)-1.2.3.4.

2. Disconnect the connector of the applicable
solenoid valve.

3. Remove the solenoid valve coil.
1 SVA and SVB solenoid valve coils can be

serviced from the maintenance port. SVC can
be serviced from the back if service space is
available in the back. To remove the back
panel, remove the two screws that secure it.

4. When the solenoid valve is defective, remove the
unit front panel, disassemble the solenoid valve
block, and check the interior of the valve.
When disassembly space or footing for disassem­bly of the solenoid valve block in the vicinity of the
flow controller is not available, the unit can be
lowered from the ceiling to perform the work.
1 To view the interior of a valve, use a torque

wrench to open the screw cover of the mov­able component compartment and the plunger.

2 When replacing the screw cover and plunger,

tighten them to the specified torque.

SVA screw cover: .......... 20 kg·m (2.0 N·m) (1.47lbFFt)

SVB screw cover: .......... 13 kg·m (1.3 N·m) (0.96lbFFt)

SVA, B, C plungers: ...... 6 kg·m (0.6 N·m) (0.44lbFFt)

Important!

1 You cannot check the valve interiors of SVC.
2 Be sure to tighten screw covers and plungers to

specified torque values. Under-tightening can
cause gas leaks, over-tightening can cause
abnormal operation.

Solenoid valve

LEV1

LEV3

LEV3

LEV1

Solenoid valve

–84–

Check Code List

Check Code Check Content

0403 Serial transmission abnormality

0900 Trial operation

1102 Discharge temperature abnormality

1111 Low pressure saturation temperature sensor abnormality (TH2)

1301 Low pressure abnormality (OC)

1302 High pressure abnormality (OC)

1368 Liquid side pressure abnormality (BC)

1370 Intermediate pressure abnormality (BC)

1500 Overcharged refrigerant abnormality

1501 Low refrigerant abnormality

1505 Suction pressure abnormality

2500 Leakage (water) abnormality

2502 Drain pump abnormality

2503 Drain sensor abnormality

4103 Reverse phase abnormality

4115 Power supply sync signal abnormality

4116 Fan speed abnormality (motor abnormality)

4200 VDC sensor/circuit abnormality

4220 Bus voltage abnormality

4230 Radiator panel overheat protection

4240 Over load protection

4250 IPM Alarm output / Bus voltage abnormality / Over Current Protection

4260 Cooling fan abnormality

Air inlet (TH21:IC)

5101

Discharge (TH1:OC)

Liquid pipe (TH22:IC)

5102

Thermal sensor

Low pressure saturation (TH2:OC)

abnormality

Gas pipe (TH23:IC)

5105

Liquid pipe (TH5)

5106 Ambient temperature (TH6)

5107 Heat exchanger inlet pipe (TH7)

5110 Radiator panel (THHS)

5201

Pressure sensor abnormality (OC)

Liquid side pressure sensor abnormality (BC)

5203 Intermediate side pressure sensor abnormality (BC)

5301 IDC sensor/circuit abnormality

6600 Multiple address abnormality

6602 Transmission processor hardware abnormality

6603 Transmission circuit bus-busy abnormality

–85–

Check Code Check Content

6606 Communications with transmission processor abnormality

6607 No ACK abnormality

6608 No response abnormality

6831 MA Not receiving communications abnormality

6834 MA Communications starting abnormality

6832 MA Communications Synchronous recovery Abnormality

6833 MA Communications Transmit/ receive Hardware Abnormality

7100 Total capacity abnormality

7101 Capacity code abnormality

7102 Connected unit count over

7105 Address setting abnormality

7106 Characteristics setting abnormality

7107 Connection number setting abnormality

7111 Remote control sensor abnormality

Intermittent fault check code

Trouble Delay Cope Trouble Delay Content

1202

Preliminary discharge temperature abnormality or preliminary discharge thermal sensor abnormality (TH1)

1205 Preliminary liquid pipe temperature sensor abnormality (TH5)

1211

Preliminary low pressure saturation abnormality or preliminary low pressure saturation sensor abnormality (TH2)

1214 Preliminary THHS sensor/circuit abnormality

1216 Preliminary heat exchanger inlet pipe thermal sensor abnormality (TH7)

1221 Preliminary ambient temperature thermal sensor abnormality (TH6)

1402 Preliminary high pressure abnormality or preliminary pressure sensor abnormality

1600 Preliminary overcharged refrigerant abnormality

1601 Preliminary lacked refrigerant abnormality

1605 Preliminary suction pressure abnormality

1607 CS circuit block abnormality

Preliminary IDC sensor/circuit abnormality

4300 Preliminary VDC sensor/circuit abnormality

Preliminary serial transmission abnormality

4320 Preliminary bus voltage abnormality

4330 Preliminary heat sink overheating abnormality

4340 Preliminary overload protection

4350 Preliminary overcurrent protection

4360 Preliminary cooling fan abnormality

–86–

Checking code Meaning, detecting method Cause Checking method & Countermeasure

Serial
transmission
abnormality

0403

If serial transmission cannot be
established between the MAIN and
INV boards.

1) Wiring is defective.

2) Switches are set wrong on the INV
board.

3) A fuse (F01) on the INV board is
defective.

4) The circuit board is defective.

Check 1, the connections, 2, contact
at the connectors and 3, for broken
wires in the following wiring.

CNRS2 - CNRS3

SW1-4 on the INV board should be
OFF.

If the fuse is melted, (if the resistance
between the both ends of fuse is ∞),
replace the fuse.

If none of the items in 1) to 3) is appli­cable, and if the trouble reappears even
after the power is switched on again,
replace the circuit board by the follow­ing procedure (when replacing the cir­cuit board, be sure to connect all the
connectors, ground wires, etc. se­curely).
1 If serial transmission is restored af-

ter the INV board only is replaced,
then the INV board is defective.

2 If serial transmission is not restored,

reinstall the INV board and replace
the MAIN board. If serial transmis­sion is restored, the MAIN board is
defective.

3 If serial transmission is not restored

by 1 and 2 above, replace both
boards.

[3] Self-diagnosis and Countermeasures Depending on the Check Code Displayed

(1) Mechanical

–87–

Checking code Meaning, detecting method Cause Checking method & Countermeasure

Discharge
temperature
abnormality
(Outdoor unit)

1102

1. When 140˚C (284˚F) or more
discharge temperature is de­tected during operations (the
first time), outdoor unit stops
once, mode is changed to re­start mode after 3 minutes, then
the outdoor unit restarts.

2. When 140˚C (284˚F) or more
temp. is detected again (the
second time) within 30 minutes
after stop of outdoor unit, emer­gency stop is observed with
code No. “1102” displayed.

3. When 140˚C (284˚F) or more
temp. is detected 30 or more
minutes after stop of outdoor
unit, the stop is regarded as the
first time and the process
shown in 1 is observed.

4. 30 minutes after stop of outdoor
unit is intermittent fault check
period with LED displayed
(1202).

See Refrigerant amount check.

Check operating conditions and opera­tion status of indoor/outdoor units.

Check operation status by actually
performing cooling or heating opera­tions.

Cooling : Indoor LEV
(Cooling-only) LEV1, 3 (BC)

SVA (BC)
Heating : Indoor LEV
(Heating-only) LEV3 (BC)

SVB (BC)

SV3 ~ 6

See Trouble check of LEV and sole-

noid valve.

Check address setting of indoor unit
connection.

Confirm that ball valve is fully opened.

Check outdoor fan.
See Trouble check of outdoor fan.

Check operation status of cooling-only
or heating-only.

See Trouble check of solenoid

valve.

Check resistance of thermistor.

Check inlet temperature of sensor
with LED monitor.

1) Gas leak, gas shortage.

2) Overload operations.

3) Poor operations of indoor LEV.

4) Poor operations of BC controller
LEV:
Cooling-only : LEV3
Cooling-main : LEV1, 3
Heating-only, Heating-main:

LEV3

Defronst : LEV3

5) Poor operations of BC controller
SVM :

Cooling-only, defrost

6) Poor operations of BC controller
SVA :

Cooling-only, Cooling-main

7) Poor operations of BC controller
SVB :

Heating-only, Heating-main

8) Poor operations of solenoid
valves.
SV (3 ~ 6)

Heating-only, Heating-main

9) Setting error of connection
address.

10)Poor operations of ball valve.

11)Outdoor unit fan block, motor
trouble, poor operations of fan
controller→Heating (Heating-only,
Heating-main).

3) ~ 11) : Rise in discharge
temp. by low pressure drawing.

12)Gas leak between low and high
pressures.
4-way valve trouble, compres­sor trouble, solenoid valve
SV1 trouble.

13)Poor operations of solenoid valve
SV2.
Bypass valve SV2 can not
control rise in discharge temp.

14)Thermistor trouble.

15)Thermistor input circuit trouble on
control circuit board.

–88–

Checking code Meaning, detecting method Cause Checking method & Countermeasure

1301

1302

Low pressure
abnoramlity

High pressure
abnoramlity 1
(Outdoor unit)

When starting from the stop mode
for the first time, (if at the start of bind
power transmission, the end of bind
power transmission, and in the mode
when the thermostat goes OFF im­mediately after the remote control
goes ON, the following compressor
start time is included), if the low pres­sure pressure sensor before start­ing is at 0.098MPa (14.2psi), opera­tion stops immediately.

1. When press. sensor detects

2.47MPa (398.2psi)

or more dur­ing operations (the first time),
outdoor unit stops once, mode
is changed to restart mode af­ter 3 minutes, then the outdoor
unit restarts.

2. When

2.94MPa (426psi)

or
more pressure is detected
again (the second time) within
30 minutes after stop of outdoor
unit,error stop is observed with
code No. “1302” displayed.

3. When

2.47MPa (398psi)

or
more pressure is detected 30
or more minutes after stop of
outdoor unit, the detection is re­garded as the first time and the
process shown in 1 is observed.

4. 30 minutes after stop of outdoor
unit is intermittent fault check
period with LED displayed.

5. Error stop is observed immedi­ately when press. switch
(2.94 MPa (426 psi)) ope­rates in addition to pressure
sensor.

1) Internal pressure is dropping due
to a gas leak.

2) The low pressure pressure sensor
is defective.

3) Insulation is torn.

4) A pin is missing in the connector,
or there is faulty contact.

5) A wire is disconnected.

6) The control board’s low pressure
pressure sensor input circuit is de­fective.

1) Poor operations of indoor LEV.

2) Poor operations of BC controller
LEV:

Heating-only, heating-principal:

LEV3

Defrost: LEV3

3) Poor operations of BC controller
SVM:

Cooling-only, defrost

4) Poor operations of BC controller
SVA:

Cooling-only, cooling-main

5) Poor operations of BC controller
SVB:

Heating-only, heating-main

6) Solenoid valve SV (3 ~ 6) trouble.

Cooling-only, cooling-main

7) Setting error of connection address.

8) Poor operations of ball valve.

9) Short cycle of indoor unit.

10)Clogging of indoor unit filter.

11)Fall in air volume caused by dust
on indoor unit fan.

12)Dust on indoor unit heat exchanger.

13)Indoor unit fan block, motor trouble.

8)~13) : Rise in high pressure
caused by lowered condensing
capacity in heating-only and
heating-principal operation.

14)Short cycle of outdoor unit.

15)

Dust on outdoor unit heat exchanger.

16)

Outdoor unit fan block, motor trou-ble,

poor operations of fan controller.

14)~16):Rise in high press.
caused by lowered condensing
capacity in cooling-only and
cooling-pincipal operation.

17)Poor operations of solenoid valves
SV1, 2 (Bypass valves (SV1, 2) can
not control rise in high pressure).

18)Thermistor trouble (TH5, TH6).

19)Pressure sensor trouble.

20)Control circuit board thermistor
trouble, press. sensor input circuit
trouble.

Refer to the item on judging low pres­sure pressure sensor failure.

Check operations status by actually
performing cooling or heating opera­tions.

Cooling : Indoor LEV

LEV1, 3 (BC)
SVA (BC)
SV3~6

Heating : Indoor LEV

LEV3 (BC)
SVB (BC)

See Trouble check of LEV and sole-

noid valve.

Check address setting of indoor unit
connector.

Confirm that ball valve is fully open-ed.

Check indoor unit and take measures
to trouble.

Check outdoor unit and take measures
to trouble.

Check outdoor unit fan
See Trouble check of outdoor unit

fan.

See Trouble check of solenoid valve.

Check resistance of thermistor.

Check Trouble check of pressure

sensor.

Check inlet temperature and press. of
sensor with LED monitor.

+0

-0.15

+0

-21

–89–

Checking code Meaning, detecting method Cause Checking method & Countermeasure

1302

1368

1370

Liquid
side

Intermedi­ate side

High pressure abnoramlity (BC controller)

High pressure
abnoramlity 2
(Outdoor unit)

When press. sensor detects

0.098MPa (14.22psi) or less just
before starting of operation, erro
stop is observed with code No.
“1302” displayed.

When liquid side press, sensor, gas
side pressure sensor, or interme­diate pressure sensor detects

2.94MPa (426psi) or more, error
stop is observed with code No.
“1368”, or “1370” displayed.

1) Fall in internal press. caused by
gas leak.

2) Press. sensor trouble.

3) Film breakage.

4) Coming off of pin in connector por­tion, poor contact.

5) Broken wire.

6) Press. sensor input circuit trouble
on control circuit board.

1) Poor operations of indoor LEV.

2) Poor operations of BC controller
LEV:

Heating-only, heating-principal:

LEV3

Defrost: LEV3

3) Poor operations of BC controller
SVM:

Cooling-only, defrost

4) Poor operations of BC controller
SVA:

Cooling-only, cooling-principal

5) Poor operations of BC controller
SVB:

Heating-only, heating-principal

6) Solenoid valve SV (3 ~ 6) trouble.

Cooling-only, cooling-principal

7) Setting error of connection address.

8) Poor operations of ball valve.

9) Short cycle of indoor unit.

10)Clogging of indoor unit filter.

11)Fall in air volume caused by dust
on indoor unit fan.

12)Dust on indoor unit heat exchanger.

13)Indoor unit fan block, motor trouble.

9)~13) : Rise in high pressure
caused by lowered condensing
capacity in heating-only and
heating-principal operation.

14)Short cycle of outdoor unit.

15)Dust on outdoor unit heat ex­changer.

16) Outdoor unit fan block, motor trou­ble, poor operations of fan control­ler.

14)~16) : Rise in high press.
caused by lowered condensing
capacity in cooling-only and
cooling-principal operation.

17)Poor operations of solenoid valves
SV1, 2.
(Bypass valves (SV1, 2) can not
control rise in high pressure.)

18)Thermistor trouble (TH5, TH6).

19)Pressure sensor trouble.

20)Control circuit board thermistor
trouble, press. sensor input circuit
trouble.

21)Poor mounting of thermistor.
(TH5, H6)

See Trouble check of pressure sen-

sor.

Check operations status by actually
performing cooling or heating opera­tions.

Cooling : Indoor LEV

LEV1, 3
SVA SV3~6

Heating : Indoor LEV

LEV3
SVB

See Trouble check of LEV and sole-

noid valve.

Check address setting of indoor unit
connector.

Confirm that ball valve is fully opened.

Check indoor unit and take measures
to trouble.

Check outdoor unit and take measures
to trouble.

Check outdoor unit fan.
See Trouble check of outdoor unit

fan.

See Trouble check of solenoid
valve.

Check resistance of thermistor.

Check Trouble check of pressure

sensor.

Check inlet temperature and press. of
sensor with LED monitor.

–90–

Checking code Meaning, detecting method Cause Checking method

1500

1501

Insufficient refrigerant abnormality

1.

When discharge superheart
10 (18) deg is keeping for 10
minutes or discharge superheat

20 (36) deg for 15 minutes,
outdoor unit stops once, and af­ter 3 minutes, the unit restarts.
For 60 minutes after unit stopped
is intermittent fault check period.

2.

When discharge superheart 10
(18) deg is keeping for 10 min­utes or discharge superheat 20
(36) deg for 15 minutes again
(second time), the unit stops and
error code 1500 is

displayed.

3.

In case of SW2-6 ON, the de­tection for the second time is fol­lowed by the first time.

1. When the unit condition is as
follows, the compressor is
stopped (1st detection) and af­ter 3 minutes, the compressor
is restarted automatically.

1 F<60Hz and TH10>85°C

(185˚F) continuously for 60
minutes.

2 F<60Hz and TH10>95°C

(203˚F) continuously for 15
minutes.

3 F 60Hz and TH10>100°C

(212˚F) continuously for 60
minutes.

4 F 60Hz and TH10>110°C

(230˚F) continuously for 15
minutes.

2.

If the temperature rises again as
above within 2 hours after the out­door unit is stopped (2nd detection),
an error stop is performed, and the
check code 1501 is displayed.

3.

If the temperature rises again as
above within 2 hours after the out­door unit is stopped, it becomes the
first detection again, and operation
is the same as in 1 above.

4.

The 2 hour period after the outdoor
unit stops is the abnormal delay pe­riod, and LED display is carried out
during the abnormal stop delay.

Overcharged
refrigerant
abnormality

Lacked
refrigerant
abnormal­ity

1) Excessive refrigerant charge.

2) Thermistor trouble (TH1).

3) Pressure sensor trouble (63HS).

4) Control circuit board trouble.

1) Gas leakage, insufficient gas.

2) Overload operation.

3) Indoor unit LEV operation is faulty.

4) Outdoor unit LEV1 operation is
faulty.

5) Outdoor unit SLEV operation is
faulty.

6) Ball valve operation is faulty.

7) The thermistor is faulty.

8) The control board’s thermistor in-
put circuit is faulty.

Check refrigerant amount.

Check resistance of thermistor.

See trouble shooting of pressure sensor.

Check temperature and pressure sen­sor with LED monitor.

Refer to the item on judging the refrig­erant volume.

Check the indoor and outdoor unit op­erating conditions.

Actually run the equipment in cooling
or heating mode and check the operat­ing condition.

Cooling : Indoor unit LEV

SLEV

Heating : Indoor unit LEV

SLEV

Refer to the item concerning judging
LEV failure.

Check with the ball valve fully open.

Check the thermistor’s resistance.

Check the sensor’s temperature read­ing by the LED monitor.

Note : °C Scale (°F Scale)

–91–

Checking code Meaning, detecting method Cause Checking method & Countermeasure

1505

2500

2502

2503

Suction
pressure
abnormality

Leakage (water)
abnormality

Drain pump
abnormality

Drain sensor
abnormality

Operation of
float switch

1. Judging that the state when the
suction pressure reaches 0MPa
during compressor operation
indicates high pressure by the
discharge temperature and low
pressure saturation tempera­ture, the back-up control by gas
bypassing will be conducted.

When drain sensor detects flood­ing during drain pump OFF.

When indirect heater of drain sen­sor is turned on, rise in tempera­ture is 20 (36) deg. or less (in wa­ter) for 40 seconds, compared with
the temperature detected before
turning on the indirect heater.

Short/open is detected during drain
pump operations. (Not detected
when drain pump is not operating.)
Short :

90˚C (194˚F) or more detected

Open :

-40˚C (-40˚F) or less detected

When float switch operates (point
of contact : OFF), error stop is ob­served with code No. “2503” dis­played.

• Operation while neglecting to open
ball valve. Especially for the ball
valve at low pressure side.
At cooling : Gas side ball valve
At heating : Liquid side ball valve

• When plural systems are existing,
the low pressure abruptly drop at
indoor stopping by the erroneous
wiring of transmission line (differ­ent connection of transmission line
and refrigerant piping).

• Temporary vacuum condition due
to refrigerant distribution unbalance
(insufficient refrigerant of low pres­sure line) immediately after charg­ing refrigerant.

1) Water leak due to humidifier or the
like in trouble.

1) Drain sensor sinks in water be­cause drain water level rises due
to drain water lifting-up mechanism
trouble.

2) Broken wire of indirect heater of
drain sensor.

3) Detecting circuit (circuit board)
trouble.

1) Thermistor trouble.

2) Poor contact of connector.
(insufficient insertion)

3) Full-broken of half-broken ther­mistor wire.

4) Indoor unit circuit board (detecting
circuit) trouble.

1) Drain up input trouble.

2) Poor contact of float switch circuit.

3) Float switch trouble.

Once vacuum operation protection is
commenced, do not attempt to
restart until taking the measures
below.
<Checking method>

• Check ball valve for neglecting to
open.

• Check extended piping for
clogging when ball valve is
opened.

• Check transmission line for errone­ous wiring. (Confirm the correct wir­ing and piping connection between
indoor and outdoor units by oper­ating indoor unit one by one.)

<Countermeasure>

• After checking with the above
method, make error reset by
power source reset.

• Then operate for 10~15-minutes
under the operation mode reverse
to that when the vacuum opera­tion protection occurred (Heating
if error occurred in cooling, while
cooling if it occurred in heating),
and then enter into the ordinary
operation state.

Check water leaking of humidifier
and clogging of drain pan.

Check operations of drain pump.

Measure resistance of indirect heater
of drain sensor.
(Normal: Approx. 82Ω between 1-3 of
CN50)

Indoor board trouble if no other
problems is detected.

Check resistance of thermistor.

0˚C (32˚F) : 15kΩ
10˚C (50˚F) : 9.7kΩ
20˚C (68˚F) : 6.4kΩ
30˚C (86˚F) : 4.3kΩ

Check contact of connector.
Indoor port trouble if no other
problem is detected.

Check drain pump operations.

Check connect contact.

Check float switch operations.

Note : °C Scale (°F Scale)

–92–

Checking code Meaning, detecting method Cause Checking method & Countermeasure

4103

4115

Reverse phase
abnormality

Power supply
sync signal
abnormality

Reverse phase (or open phase) in
the power system is being de­tected, so operation cannot be
started.

The frequency cannot be deter­mined when the power is switched
on.
(The power supply’s frequency
cannot be detected. The outdoor
fan cannot be controlled by phase
control.)

1) The phases of the power supply (L1,
L2, L3) have been reversed.

2) Open phase has occurred in the
power supply (L1, L2, L3).

3) The wiring is faulty.

4) The fuse is faulty.

5) The circuit board is faulty.

1) There is an open phase in the power
supply (L1, L2, L3).

2) The power supply voltage is dis­torted.

3) A fuse is defective.

4) The circuit board is defective.

If there is reverse phase before the
breaker, after the breaker or at the
power supply terminal blocks TB1, re­connect the wiring.

Check before the breaker, after the
breaker or at the power supply termi­nal blocks TB1, and if there is an open
phase, correct the connections.

a) Check if a wire is disconnected.
b) Check the voltage between each

of the wires.

Check 1 the connections, 2, the con­tact at the connector, 3, the tightening
torque at screw tightening locations and
4 for wiring disconnections.
TB1~CN20
Refer to the circuit number and the wir­ing diagram plate.

If F01 or F02 on the MAIN board is
melted, (Resistance between both
ends of the fuse is ∞), replace the fuses.

If none of the items in 1) to 4) is appli­cable, and if the trouble reappears even
after the power is switched on again,
replace the MAIN board (when replac­ing the circuit board, be sure to con­nect all the connectors, etc. securely).

Check before the breaker, after the
breaker or at the power supply termi­nal blocks TB1, and if there is an open
phase, correct the connections.

If the power supply voltage waveform
is distorted from a sine wave, improve
the power supply environment.

If F01 or F02 on the MAIN board is
melted, (Resistance between both
ends of the fuse is ∞), replace the fuses.

If none of the items in 1) to 3) is appli­cable, and if the trouble reappears even
after the power is switched on again,
replace the MAIN board (when replac­ing the circuit board, be sure to con­nect all the connectors, ground wires,
etc. securely).

–93–

Checking code Meaning, detecting method Cause Checking method & Countermeasure

4116

4200

Fan speed
abnormality
(motor
abnoramlity)

VDC
sensor/circuit
abnormality

(Detects only for PKFY-NAMU-A/
NGMU-A/NFMU-A)

1. Detecting fan speed below
180rpm or over 2000rpm dur­ing fan operation at indoor unit
(first detection) enters into the
3-minute restart prevention
mode to stop fan for 30 sec­onds.

2. When detecting fan speed be­low 180rpm or over 2000rpm
again at fan returning after 30
seconsd from fan stopping, er­ror stop (fan also stops) will be
commenced displaying 4116.

1 If VDC 150 V is detected just

before the inverter starts.

2 If VDC 400 V is detected just

before starting of and during
operation of the inverter.

1) Disconnection of or slipping off of
fan speed detecting connector
(CN33) of indoor controller board.

2) Disconnection of or slipping off of
fan output connector (FAN1) of in­door power board.

3) Disconnection of fan speed
detecting connector (CN33) of
indoor controller board, or that of
fan output connector (FAN1) of
indoor power board.

4) Filter cologging.

5) Trouble of indoor fan motor.

6) Faulty fan speed detecting circuit
of indoor controller board, or
faulty fan output circuit of indoor
power board.

1) Power supply voltage is abnor­mal.

2) The wiring is defective.

3) The rush current prevention
resistor (R1) is defective.

4) The electromagnetic contactor
(52C) is defective.

5) The diode stack (DS) is defective.

6) The reactor (DCL) is defective.

7) The INV board is defective.

• Confirm slipping off of connector
(CN33) on indoor controller
board.

• Confirm slipping off of connector
(FAN1) on indoor power board.

• Check wiring for disconnection.

• Check filter.

• Check indoor fan motor.

• When aboves have no trouble.

1) For trouble after operating fan.
Replace indoor controller board. If
not remedied, replace indoor
power board.

2) For trouble without operating fan.
Replace indoor power board.

• Check if an instantaneous power
failure or power failure, etc. has
occurred.

• Check if the voltage is the rated
voltage value.

Check 1, the connections, 2, contact
at the connectors, 3 tightening torque
at screw tightened portions, 4, wiring
polarities, 5, for broken wires, and 6,
for grounding in the following wiring.

TB1 ~ DS ~ POWER Board ~ 52C
~R1~ DCL ~ C1 ~ IPM ~ G/A
Board (F01) ~ CNDC1 ~ CNDC2
wiring

* Check if the wiring polarities are as

shown on the wiring diagram plate.

To judge failure of R1, go to “Indi-
vidual Parts Failure Judgment
Methods.”

To judge failure of the 52C, go to
“Individual Parts Failure Judgment
Methods.”

To judge failure of the DS, go to
“Individual Parts Failure Judgment
Methods.”

To judge failure of the DCL, go to
“Individual Parts Failure Judgment
Methods.”

If none of the items in 1) to 6) is
applicable, and if the trouble
reappears even after the power is
switched on again, replace the INV
board (when replacing the circuit
board, be sure to connect all the
connectors, ground wires, etc.
securely).

–94–

4220

4230

Bus
voltage
abnormality

Radiator
panel
overheat
protection

1 If VDC 220 V is de-

tected during inverter
operation.

If the cooling fan stays ON
for 5 minutes or longer dur­ing inverter operation, and
if THHS 100°C(212°F)
is detected.

1) The power supply voltage
is abnormal.

2) The wiring is defective.

3)

The rush current prevention
resistor (R1) is defective.

4)

The electromagnetic contactor
(52C) is defective.

5) The diode stack (DS) is
defective.

6) The reactor (DCL) is defec­tive.

7) The inverter output is
grounded.

8) The IPM is defective.

9) The circuit board is defec­tive.

1) The wiring is defective.

2) The INV boar’s fuse (F01)
is defective.

3) The cooling fan (MF1) is
defective.

4)

The THHS sensor is defective.

5) The air passage is clogged.

6) The IPM is defective.

7) The circuit board is defec­tive.

• Check if an instantaneous stop or power failure, etc.
has occurred.

• Check if the voltage is the rated voltage value.

Check 1, the connections, 2, contact at the connectors, 3
tightening torque at screw tightened portions, 4, wiring po­larities, 5, for broken wires, and 6, for grounding in the fol­lowing wiring.

TB1 ~ DS ~ POWER Board ~ 52C ~ R1 ~ DCL ~ C1 ~
IPM ~ G/A Board (F01) ~ CNDC1 ~ CNDC2 wiring
CN15V1

~

CN15V2 wiring

CNDR1

~

CNDR2 wiring

* Check if the wiring polarities are as shown on the wiring

diagram plate.

To judge failure of R1, go to “Individual Parts Failure Judg­ment Methods.”

To judge failure of the 52 C, go to “Individual Parts Failure
Judgment Methods.”

To judge failure of the DS, go to “Individual Parts Failure
Judgment Methods.”

To judge failure of the DCL, go to “Individual Parts Failure
Judgment Methods.”

• Check the wiring between the IPM and the compressor.

• Check the compressor’s insulation resistance.

Check the IPM.
Judge that the IPM is fauly, (Go to “Individual Parts Failure
Judgment Methods.”)

If none of the items in 1) to 8) is applicable, and if the trouble
reappears even after the power is switched on again,
replace the circuit board by following procedure (when re­placing the circuit board, be sure to connect all the connec­tors, ground wires, etc. securety)
1 If the problem is solved after the G/A board only is re-

placed, then the G/A board is defective.

2 If the problem is not solved, reinstall the G/A board and

replace the INV board. If the problem is solved, the INV
board is defective.

3 If the problem is not solved by 1 and 2 above, replace

both boards.

Check 1 connections, 2 contact at the connectors and 3 for
broken wires in the following wiring.
MF1~CNFAN

If the fuse is defective, replace the fuse.

To judge failure of the MF1, go to “Individual Parts Failure
Judgment Methods.”

To judge failure of the THHS, go to error code “5110”.

If the air passage of the heat sink is clogged, clear the air
passage.

Check the IPM.
Judge that the IPM is fauly, (Go to “Individual Parts Failure
Judgment Methods.”)

If none of the items in 1) to 6) is applicable, and if the trouble
reappears even after the power is switched on again,
replace the circuit board by following procedure (when re­placing the circuit board, be sure to connect all the connec­tors, ground wires, etc. securety)
1 If the problem is solved after the G/A board only is re-

placed, then the G/A board is defective.

2 If the problem is not solved, reinstall the G/A board and

replace the INV board. If the problem is solved, the INV
board is defective.

3 If the problem is not solved by 1 and 2 above, replace

both boards.

Checking code

Meaning, detecting method

Cause Checking method & Countermeasure

–95–

Checking code Meaning, detecting method Cause Checking method & Countermeasure

4240

4250

Over load
protection

IPM alarm
output /
Bus voltage
abnormality

If IDC 103 A is detected continu­ously for 10 minutes during opera­tion of the inverter after 5 or more
seconds have passed since the
inverter started.

1. IPM/VDC trouble

2. If IDC 200 A is detected dur­ing inverter operation.

3. If VDC 378 V or VDC 190 V
is detected during inverter op­erates.

1) Air passage short cycle.

2) The heat exchanger is clogged.

3) Power supply voltage.

4) External air temperature.

5) Capacity setting error.

6) The solenoid valves (SV1, 2) are
defective, or the solenoid valve
drive circuit is defective.

7) The wiring is defective.

8) Fan motor (MF) operation is defec­tive.

9) The inverter/compressor is defec­tive.

1) Self protection by IPM break out,
(over current, over heat, under con­trol voltage)

1) The power supply voltage is abnor­mal.

2) The wiring is defective.

3) The inverter / compressor is defec­tive.

(the same as error code 4220)

Is the unit’s exhaust short cycling?

Clean the heat exchanger.

If the power supply voltage is less than
187 V, it is outside specifications.

If the external air temperature is over 43°C
(109°F) it is outside the specifications.

• Is the indoor unit capacity total cor­rect?

• Are the outdoor/indoor unit capac­ity settings correct?

To judge failure of the solenoid valve,
go to “Individual Parts Failure Judg­ment Methods” for the “Solenoid Valve.”

Check 1 connections, 2 contact at the
connectors and 3 for broken wires in
the following wiring.

CNFAN1~MF1

Go to “Treating Fan Motor Related
Trouble.”

Go to “Treating Inverter/Compressor
Related Trouble.”

Go to the item for error code 4230,

4240.

• Check if an instantaneous power
failure or power failure, etc. has oc­curred.

• Check if the voltage is the rated volt­age value.

Check 1, the connections, 2, contact
at the connectors, 3 tightening torque
at screw tightened portions, 4, wiring
polarities, 5, for broken wires, and 6,
for grounding in the following wiring.
* Check if the wiring polarities are as

shown on the wiring diagram plate.

* Check the coil resistances and in-

sulation resistance of the compres­sor.

Go to “Treatment of Inverter/Compres­sor Related Trouble.”

Go to the item for error code 4220.

–96–

Checking code Meaning, detecting method Cause Checking method & Countermeasure

4260

5101

5105

5106

5107

5110

5111

Cooling fan
abnormality

Thermal sensor abnormality (BC controlled)

If the heat sink temperature (THHS)
100°C (212°F) for 20 minutes or longer
just before the inverter starts.

<Other than THHS>
1 A short in the thermistor or an

open circuit was sensed. The
outdoor unit switches to the
temporary stop mode with re­starting after 3 minutes, then if
the temperature detected by the
thermistor just before restarting
is in the normal range, restart­ing takes place.

2 If a short or open circuit in the

thermistor is detected just be­fore restarting, error code
“5101”, “5105”, “5106”, “5107”
is displayed.

3 In the 3 minute restart mode,

the abnormal stop delay LED is
displayed.

4 The above short or open circuit

is not detected for 10 minutes
after the compressor starts, or
for 3 minutes during defrosting
or after recovery following de-

frosting.
<THHS>
If a heat sink (THHS) temperature
of -40°C (-40˚F) is detected just
after the inverter starts or during in­verter operation.

1. When short (high temp. inlet) or

open (low temperature inlet) of

thermistor is detected during

operation, error stop will be

commenced displaying “5111”

or “5112”, or “5115” or “5116.

2. The above detectection is not

made during defrostig and 3-

minute after changing operation

mode.

Discharge
(TH1)

Heat
exchanger
inlet pipe
(TH5)

Ambient
tempera­ture (TH6)

Heat
exchanger
inlet pipe
(TH7)

Radiator
panel
(TH HS)

Liquid inlet
(TH11)

Bypass
outlet
(TH12)

Bypass
inlet
(TH15)

Intermedi­ate section
(TH16)

Thermal sensor abnormality (Outdoor Unit)

1) Same as “4230.”

1) Thermistor

2) Lead wires are being pinched.

3) Insulation is torn.

4) A connector pin is missing, or there
is faulty contact.

5) A wire is disconnected.

6) The thermistor input circuit on the
MAIN circuit board is faulty.
(In the case of the THHS, replace
the INV board.)

1) Thermistor trouble.

2) Biting of lead wire.

3) Broken cover.

4) Coming off of pin at connector por­tion, poor contact.

5) Broken wire.

6) Faulty thermistor input circuit of
control board.

Same as “4230.”

Check the thermistor’s resistance.

Check if the lead wires are pinched.

Check for tearing of the insulation.

Check if a pin is missing on the con­nector.

Check if a wire is disconnected.

Check the temperature picked up by
the sensor using the LED monitor.
If the deviation from the actual tem­perature is great, replace the MAIN cir­cuit board.
(In the case of the THHS, replace the
INV board.)

Check thermistor resistance.

Check lead wire biting.

Check broken cover.

Check coming off of pin at connector.

Check broken wire.

Check sensor sensing temperature. If
it deviates from the actual temerature
seriously, replace control panel.

Short Circuit Detection Open Circuit Detection

TH1

240°C (464˚F) or higher (0.57 kΩ)

15°C (59˚F) or lower (321 kΩ)

TH5

110°C (230˚F) or higher (0.4 kΩ)

-40°C (-40˚F) or lower (130 kΩ)

TH6

110°C (230˚F) or higher (0.4 kΩ)

-40°C (-40˚F) or lower (130 kΩ)

TH7

110°C (230˚F) or higher (1.14 kΩ)

-40°C (-40˚F) or lower (130 kΩ)

THHS – -40°C (-40˚F) or lower (2.5 MΩ)

Short Detected Open Detected

TH11

110°C (230˚F) or more (0.4 kΩ)

-40°C (-40˚F) or less (130 kΩ)

TH12

110°C (230˚F) or more (0.4 kΩ)

-40°C (-40˚F) or less (130 kΩ)

TH15

70°C (158˚F) or more (1.14 kΩ)

-40°C (-40˚F) or less (130 kΩ)

TH16

70°C (158˚F) or more (0.4 kΩ)

-40°C (-40˚F) or less (130 kΩ)

–97–

Checking code Meaning, detecting method Cause Checking method & Countermeasure

5201

5201

5203

5301

Pressure
sensor
abnormality
(outdoor unit)

IDC sensor/
circuit trouble

Pressure sensor abnormality (BC controller)

High
pressure
side

Intermedi­ate

1

When pressue sensor detects

0.098MPa (14.22psi) or less dur­ing operation, outdoor unit once
stops with 3 minutes restarting
mode, and restarts if the detected
pressure of pressure sensor ex­ceeds 0.098MPa (14.22psi)
imediately before restarting.

2 If the detected pressure of sen-

sor is less than

0.098MPa

(14.22psi)

immediately before
restarting, error stop is com­menced displaying 5201.

3 Under 3 minutes restarting

mode, LED displays intermittent
fault check.

4 During 3 minutes after com-

pressor start, defrosting and 3
minutes after defrosting opera­tions, trouble detection is ig­nored.

When high or intermidiate pressure
sensor detects 0.098MPa (14.2psi)
or less immediately before starting,
error stop is commenced display­ing “5201”, or “5203”.

• If IDC 20 A is detected just
before the inverter starts, or

• If IDC 10 A is detected dur­ing inverter operation after 5
seconds has passed since the
inverter started when the INV
board’s SW1-1 is OFF.

1) Pressutre sensor trouble.

2) Inner pressure drop due to a leak­age.

3) Broken cover.

4) Coming off of pin at connector por­tion, poor contact.

5) Broken wire.

6) Faulty thermistor input circuit of
MAIN board.

1) Pressure sensor trouble.

2) Inner pressure drop due to gas leak.

3) Broken cover.

4) Coming off of pin at connector por­tion, poor contact.

5) Broken wire.

6) Faulty pressure sensor input circuit
of control board.

1) Contact is faulty.

2) The current sensor (DCCT) is con­nected with reverse polarity.

3) An error was made in the SW1-1
setting.

4) The INV board is defective. The
current sensor (DCCT) is defective.

See Troubleshooting of pressure
sensor.

See troubleshooting of pressure
sensor.

Check the contacts of CNCT on the
INV board.

Check the DCCT polarity.

• With SW1-1 OFF, is the inverter’s
output wiring open?

• With SW1-1 OFF, is a compressor
which is not specified for this model
connected to the inverter’s output?

If none of the items in 1) to 3) is appli­cable, and if the trouble reappears
even after the power is switched on
again, replace the INV board and the
DCCT (when replacing the circuit
board, be sure to connect all the con­nectors, ground wires, etc. securely) by
the following procedure.
1 Replace the INV board only. If it

recovers, the INV board is defec­tive.

2 If it does not recover, reinstall the

INV board and replace the DCCT.
If it recovers, the DCCT is defec­tive.

If it does not recover after 1 and 2
above, both the INV board and the
DCCT are defective.

–98–

(2) Communication/system

Checking

code

6600

6602

Multiple address error

Transmission from units with the
same address is detected.

Note:

The address/attribute
shown on remote
controller indicates the
controller which has
detected error.

Transmission processor hardware
error

Though transmission processor
intends to transmit “0”, “1” is dis­played on transmission line.

Note:

The address/attribute
shown on remote
controller indicates the
controller which has
detected error.

Meaning, detecting method Cause Checking method & Countermeasure

At the genration of 6600 error, release the error by
remote controller (with stop key) and start again.
a) If the error occures again within 5 minutes.

→ Search for the unit which has the same address

with that of the source of the trouble.

When the same address is found, turn off
the power source of outdoor unit, BC con­troller, and indoor unit for 5 minutes or more
after modifying the address, and then turn
on it again.

b) When no trouble is generated even continuing

operation over 5 minutes.

→ The transmission wave shape/noise on the

transmission line should be investigated in ac­cordance with <Investigation method of trans­mission wave shape/noise>.

1) Two or more controllers of outdoor
unit, indoor unit, remote controller,
BC controller, etc. have the same
address.

2) In the case that signal has changed
due to noise entered into the trans­mission signal.

1) At the collision of mutual transmission data generated during the wiring work or polarity
change of the transmission line of indoor or outdoor unit while turning the power source
on, the wave shape is changed and the error is detected.

2) 100V power source connection to indoor unit or BC controller.

3) Ground fault of transmission line.

4) Insertion of power supply connector (CN40) of plural outdoor units at the grouping of
plural refrigerant systems.

5) Insertion of power supply connector (CN40) of plural outdoor units in the connection
system with MELANS.

6) Faulty controller of unit in trouble.

7) Change of transmission data due to the noise in transmission.

8) Connection system with plural refrigerant systems or MELANS for which voltage is not
applied on the transmission line for central control.

–99–

Transmission processor hardware
error

Transmission circuit bus-busy er­ror
1 Collision of data transmission:

Transmission can not be per­formed for 4~10 consecutive
minutes due to collision of data
transmission.

2 Data can not be transmitted on

transmission line due to noise
for 4~10 consecutive minutes.

Note:

The address/attribute
shown on remote
controller indicates the
controller which has
detected error.

Checking method and processing

1) As the voltage of short frequency like
noise is mixed in transmission line
continuously, transmission processor
can not transmit.

2) Faulty controller of generating unit.

a) Check transmission wave shape/noise on trans-

mission line by following <Investigation method
of transmission wave shape/noise>.

→ No noise indicates faulty controller of generat-

ing unit.

→ Noise if existed, check the noise.

Checking

code

6602

6603

Meaning, detecting method Cause Checking method & Countermeasure

Transmission line

installed while turning

power source on?

Check power source of indoor
unit.

208V ~ 230V?

Shut off the power source of outdoor/in­door units/BC controller and make it again.

Erroneous power
source work

Erroneous transmis­sion work

Check transmission line
work and shield finish

Ground fault or shield

contacted with transmission

line?

System composition?

Single refrigerant
system

Investigation of trans­mission line noise

Modification of
faulty point

Replace insertion
of CN40 to CN41

CN40 inserted?

Confirm supply power
connector CN40 of outdoor unit

MELANS connected
system

Investigation of the
cause of noise

* For the investigation method, follow <Investiga-

tion method of transmission wave shape/noise>

Modification of CN40
insertion method.

Only 1 set with

CN40 inserted?

Noise exist?

Faulty controller of
generating unit

Plural refrigerant
system

Confirm supply power
connector CN40 of outdoor unit

NO

YES

YES

YES

NO

NO

YES

NO

YES

NO

YES