LG Electronics LG3ZMSS288 Quad Zone Mini Split System User Manual

Please read this manual carefully before operating

your set and retain it for future reference.

General

Multi-Inverter Type

P/NO : MFL68280204

SERVICE MANUAL

AIR

CONDITIONER

- 2 -

Only for training and service purposes

LGE Internal Use Only

Air Conditioner Service Manual

TABLE OF CONTENTS

Part 1 General Information ..........................................................................................................3

1. Safety Precautions........................................................................................................4

2. Model Line Up................................................................................................................7

3. Nomenclature ..............................................................................................................10

Part 2 Functions & Controls......................................................................................................14

1. List of Functions & Accessory ..................................................................................15

2. Air Flow .......................................................................................................................17

3. Air Purifying.................................................................................................................19

4. Installation Functions.................................................................................................20

5. Reliability .....................................................................................................................21

6. Convenience Functions & Controls .........................................................................22

7. Special Function & KIT...............................................................................................29

Part 3 Basic Control ..................................................................................................................32

1. Normal operation ........................................................................................................33

2 Compressor control ....................................................................................................33

3. EEV( Electronic Expansion Valve) control ..............................................................33

4. Oil return control ........................................................................................................34

5. Defrost control ...........................................................................................................34

6. Protection control ......................................................................................................35

Part 4 Test Run..........................................................................................................................36

1. Check before Test Run .............................................................................................37

2. Test Run Flow chart ..................................................................................................38

3. Test Runing.................................................................................................................39

Part 5 Trouble Shooting Guide ...............................................................................................41

1. Self-diagnosis Function .....................................................................................42

2. Pump Down .........................................................................................................44

3. Evacuation...........................................................................................................45

4. Gas Charging ......................................................................................................46

5. Cycle Part ............................................................................................................47

6. Electronic Parts...................................................................................................48

Part 1 General Information

- 3 -

Only for training and service purposes

LGE Internal Use Only

1. Safety Precautions ............................................................................................................4

2. Model Line Up .....................................................................................................................7

3. Nomenclature....................................................................................................................10

Part 1 General Information

- 4 -

Only for training and service purposes

LGE Internal Use Only

1. Safety Precautions

1.1 Cautions in Repair

To prevent injury to the user or other people and property damage, the following instructions must be followed.

n Incorrect operation due to ignoring instruction will cause harm or damage. The seriousness is classified by the follow-

ing indications.

This symbol indicates the possibility of death or serious injury.

This symbol indicates the possibility of injury or damage to properties only.

n Meanings of symbols used in this manual are as shown below.

Be sure to disconnect all remote electric power supplies before servicing. Internal

components and circuit boards are at main potential when the equipment is con-

nected to the power cables. This voltage is extremely dangerous and may cause

death or severe injury if come in contact with it.

Do not touch the discharging refrigerant gas during the repair work.

The refrigerant gas can cause frostbite.

Release the refrigerant gas completely at a well-ventilated place first.

Otherwise, when the pipe is disconnected, refrigerant gas or refrigerating machine

oil discharges and it can cause injury.

When the refrigerant gas leaks during work, execute ventilation. If the refrigerant

gas touches to a fire, poisonous gas generates. A case of leakage of the refriger-

ant and the closed room full with gas is dangerous because a shortage of oxygen

occurs. Be sure to execute ventilation.

When removing the front panel or cabinet, execute short-circuit and discharge

between high voltage capacitor terminals. If discharge is not executed, an electric

shock is caused by high voltage resulted in a death or injury.

Be sure to provide the grounding when repairing the equipment in a humid or wet

place, to avoid electrical shocks.

Be sure not to do.

Be sure to follow the instruction.

Dangerous Voltage

Be sure to provide grounding.

Part 1 General Information

- 5 -

Only for training and service purposes

LGE Internal Use Only

Do not use a defective or underrated circuit breaker. Use the correctly rated

breaker and fuse. Otherwise there is a risk of fire or electric shock.

Install the panel and the cover of control box securely. Otherwise there is risk of

fire or electric shock due to dust, water etc.

Indoor/outdoor wiring connections must be secured tightly and the cable should be

routed properly so that there is no force pulling the cable from the connection ter-

minals. Improper or loose connections can cause heat generation or fire.

Do not touch, operate, or repaire the product with wet hands. Hoding the plug by

hand when taking out. Otherwise there is risk of electric shock or fire.

Use a vacuum pump or Inert (nitrogen) gas when doing leakage test or air purge.

Do not compress air or Oxygen and Do not use Flammable gases. Otherwise, it

may cause fire or explosion.

- There is the risk of death, injury, fire or explosion.

Do not turn on the breaker or power under condition that front panel, cabinet, top

cover, control box cover are removed or opened.

- Otherwise, it may cause fire, electric shock, explosion or death.

Be sure to earth the air conditioner with an earthing conductor connected to the

earthing terminal.

Conduct repair works after checking that the refrigerating cycle section has cooled

down sufficiently. Otherwise, working on the unit, the hot refrigerating cycle section

can cause burns.

Do not tilt the unit when removing panels. Otherwise, the water inside the unit can

spill and wet floor.

Do not use the welder in a well-ventilated place. Using the welder in an enclosed

room can cause oxygen deficiency.

Be sure to turn off power switch before connect or disconnect connector, or parts

damage may be occurred.

Part 1 General Information

- 6 -

Only for training and service purposes

LGE Internal Use Only

1.2 Inspections after Repair

Check to see if the parts are mounted correctly and wires are connected. Im-

proper installation and connections can cause an electric shock or an injury.

Check the installation platform or frame has corroded. Corroded installation plat-

form or frame can cause the unit to fall, resulting in injury.

Be sure to check the earth wire is correctly connected.

After the work has finished, be sure to do an insulation tset to check the resist-

ance is 2[Mohm] or more between the charge section and the non-charge metal

section (Earth position). If the resistance value is low, a disaster such as a leak or

electric shock is caused at user’s side.

Check the drainage of the indoor unit after the repair. If drainage is faulty the

water to enter the room and wet floor.

Check to see if the power cable plug is not dirty or loose. If the plug is dust or

loose it can cause an electrical shock or fire.

Do not use a joined power cable or extension cable, or share the same power

outlet with other electrical appliances. otherwise, it can cause an electrical shock,

excessive heat generation or fire.

Do not insert hands or other objects through the air inlet or outlet while the prod-

uct is operating. There are sharp and moving parts that could cause personal in-

jury.

Do not block the inlet or outlet of air flow. It may cause product failure

Part 1 General Information

- 7 -

Only for training and service purposes

LGE Internal Use Only

2. Model Line Up

2.1 Indoor units

* Indicates color of panel – ART COOL : Gold(G), White Silver(H), Blue(B), Gallery(1)

ART COOL Mirror : Mirror(R), Silver(V), White(W)

Category

Chassis

Model names

Capacity, kW(kBtu/h Class)

2.1(7) 2.6 (9) 3.5 (12) 4.2(15) 5.3 (18) 7.03 (24) 10.6 (36)

Wall mounted

SB

AMNW07GDBB0

[LMN078HVT]

ASNW09GB1B0

[LSN090HSV4]

ASNW12GB1B0

[LSN120HSV4]

AMNW15GDBB0

[LMN158HVT]

SC

ASNW18GC2B0

[LSN180HSV4]

AMNW24GDCB0

[LMN248HVT]

ART COOL Mirror

SB

ASNW09GBRB0

[LAN090HSV4]

ASNW12GBRB0

[LAN120HSV4]

SC

ASNW18GCRB0

[LAN180HSV4]

ART COOL Gallery

SF

AMNW09GAF11

[LMAN097HVP]

AMNW12GAF11

[LMAN127HVP]

Ceiling

cassette

4-way

TR

AMNW07GTRA0

[LMCN077HV]

AMNW09GTRA0

[LMCN097HV]

AMNW12GTRA0

[LMCN125HV]

TQ

AMNW18GTQA0

[LMCN185HV]

Ceiling

concealed

duct

Low static pressure

(Slim)

L1

AMNW09GL1A0

[LMDN096HV]

L2

AMNW12GL2A0

[LMDN126HV]

AMNW18GL2A0

[LMDN186HV]

High Static pressure

BG

AMNW24GBGA0

[LMHN240HV]

AMNW36GBGA0

[LMHN360HV]

Vertical AHU

NJ

AMNW24GNJA0

[LMVN240HV]

AMNW36GNJA0

[LMVN360HV]

Part 1 General Information

- 8 -

Only for training and service purposes

LGE Internal Use Only

2.2 Outdoor units

Multiple Piping Type

Branch Distribution type

Model Name

A2UW18GFH0

[LMU180HHV]

A3UW24GFH0

[LMU240HHV]

A4UW30GFH0

[LMU300HHV]

No. of connectable indoor units (Min. ~ Max.)

2 ~ 2 2 ~ 3 2 ~ 4

Total capacity index of connectable indoor units

24 33 40

Power supply 208/230V, 1Ø, 60Hz

Chassis

Model Name

A5UW36GFH0[LMU360HHV] A6UW42GFH0[LMU420HHV]

No. of connectable indoor units (Min. ~ Max.)

2 ~ 5 2 ~ 6

Total capacity index of connectable indoor units

48 56

Power supply

208/230V, 1Ø, 60Hz

Chassis

Part 1 General Information

- 9 -

Only for training and service purposes

LGE Internal Use Only

2.3 BD(Branch distributor) units

2.4 Branches

Branch

Type

No. of

BD

Units

Accessory

Model Name

Applicable

Model

Specifications

Gas Liquid

Y-

Branch

2

PMBL5620

MULTI F MAX

To BD unit Ø19.05 (3/4)

Ø19.05 (3/4)

To ODU

Ø19.05 (3/4)

To BD unit Ø9.52 (3/8)

Ø9.52 (3/8)

To ODU

Ø9.52 (3/8)

No. of connectable indoor units(Min. ~ Max.)

1 ~ 2 1 ~ 3 1 ~ 4

Model name PMBD3620 PMBD3630 PMBD3640 PMBD3641

Connectable indoor unit capacity kBtu/h 9 ~ 24 9 ~ 24 9 ~ 24 9 ~ 36

BD unit

Part 1 General Information

- 10 -

Only for training and service purposes

LGE Internal Use Only

3. Nomenclature

3.1 Indoor Unit(Global)

AMN W G07 BDL0

Serial number

Indicates that this is multi system indoor unit using R410A

Model type

W : DC Inverter heat pump

Ex) 7,000 Btu/h Class

→ '07', 18,000 Btu/h Class → '18'

Cooling/heating capacity

Electrical rating

G : 1Φ, 208~230V, 60Hz

Chassis naem(Only Multi)

Indoor unit type(Only Multi)

A : ART COOL Gallery

D : Wall Mounted, ART COOL Mirror

T : Ceiling cassette, B : Ceiling concealed duct

N : Vertical AHU

Function

A : Basic, L : Plasma (Wall mounted)

C : Plasma(ceiling cassette)

Front panel design/color of ART COOL type

R : Mirror, 1 : Gallery

Part 1 General Information

- 11 -

Only for training and service purposes

LGE Internal Use Only

Code Type Code of Model Meaning

1 Production Center, A~Z L: Chang-won R22

Refrigerant A: Chang-won R410A

2 Product Type A~Z S: Split Type Air Conditioner

3 Cooling/Heating/Inverter A~Z C: Cooling Only

H: Heat Pump

X: C/O + E/Heater

Z: H/P + E/Heater

V: AC Inverter C/O

N: AC Inverter H/P

Q: DC Inverter C/O

W: DC Inverter H/P

4, 5 Capacity 0~9 Cooling/Heating Capacity

Ex. "09" ’ 9,000 Btu/h Class

6 Electric Range 1~9 1: 115V/60Hz

A~Z 2: 220V/60Hz

3: 208-230V/60Hz

5: 200-220V/50Hz

6: 220-240V/50Hz

7: 110V, 50/60Hz

7 Chassis A~Z Name of Chassis

8 Look A~Z Look,

Color (Artcool Model)

9 Function A~Z

10 Serial No. 1~9 LG Model Development Serial No.

12 - 345678910

Basic A

Basic+4Way B

Basic+Deodorizing Filter (Carbon filter) C

Plasma+(A/changeove)+A/clean+2Way+Ion E

Plasma+(A/changeove)+A/clean+4way+Ion+Lamp F

Plasma+(A/changeove)+A/clean+Low A G

Plasma+(A/changeove)+A/clean+4way+Low A H

Plasma+(A/changeove)+A/clean L

Plasma+(A/changeove)+A/clean+4way M

Plasma+(A/changeove)+A/clean+PTC N

Plasma+(A/changeove)+Autoclean+4way+PTC P

Plasma+(A/changeove)+A/clean+4way+Low A+PTC Q

Smart(Robot) Cleaning R

Eco eye+Plasma+Allergy Filter+4way S

Plasma+Allergy Filter+4way U

Allergy Filter+4way V

Allergy Filter+2way W

Basic+Low Ambient Y

Basic+(A/clean)+4way+Low A Z

A S - W 1 2 6 B M S 0

Part 1 General Information

- 12 -

Only for training and service purposes

LGE Internal Use Only

A4U W G30 F H 0

Electrical rating

Indicates that this is multi system outdoor unit using R410A

Ex) A4U : Connectable max. 4 indoor units

A6U : Connectable max. 6 indoor units

Model type

W : DC inverter heat pump

Ex) 24,000 Btu/h Class

→ ‘24’, 42,000 Btu/h Class → ‘42’

Cooling/heating capacity

G : 1Φ, 208~230V, 60Hz

Multi type

Function

A : Basic

H : High Heat

F : Free joint multi type

Serial number

3.2 Outdoor Unit(Global)

Part 1 General Information

- 13 -

Only for training and service purposes

LGE Internal Use Only

P M BD 36 2 0

Serial number

Number of connectable indoor units

Max. capacity of connectable indoor units

“36” mean that 7~36kBtu/h Class Indoor unit connected to BD unit

BD : Branch distributor

M : Multi system outdoor unit

P : Parts

3.3 BD units(Global)

Part 2 Functions & Controls

- 14 -

Only for training and service purposes

LGE Internal Use Only

Part 2 Functions & Controls

1. List of Functions & Accessory......................................................................................15

2. Air flow ............................................................................................................................17

2.1 Auto swing (left & right) ...............................................................................................17

2.2 Auto swing (up & down) ..............................................................................................17

2.3 Chaos swing (up/down)...............................................................................................17

2.4 Air flow step.................................................................................................................18

2.5 Chaos wind (auto wind)...............................................................................................18

2.6 Jet Cool Mode Operation ............................................................................................18

2.7 Swirl wind Swing .........................................................................................................18

3. Air purifying ....................................................................................................................19

3.1 PLASMA Air Purifying System.....................................................................................19

4. Installation Functions ....................................................................................................20

4.1 E.S.P. (External Static Pressure) Setting ....................................................................20

5. Reliability ........................................................................................................................21

5.1 Hot start.......................................................................................................................21

5.2 Self-diagnosis Function...............................................................................................21

5.3 Soft dry operation........................................................................................................21

6. Convenience Functions & Controls ............................................................................22

6.1 Cooling & heating Operations ....................................................................................22

6.2 Auto cleaning operation...............................................................................................23

6.3 Auto Operation (Artificial Intelligence) .........................................................................23

6.4 Auto restart Opeartion .................................................................................................24

6.5 Child Lock Function.....................................................................................................25

6.6 Forced operation.........................................................................................................25

6.7 Group Control..............................................................................................................26

6.8 Sleep Timer Operation ................................................................................................27

6.9 Timer(On/Off) ..............................................................................................................27

6.10 Weekly Program........................................................................................................27

6.11 Two Thermistor Control .............................................................................................28

7. Special Function & KIT ..................................................................................................29

7.1 Low Ambient control....................................................................................................29

7.2 Space Control .............................................................................................................29

7.3 Auto Elevation Grille....................................................................................................29

7.4 Defrost Control(Heating) .............................................................................................31

Part 2 Functions & Controls

- 15 -

Only for training and service purposes

LGE Internal Use Only

[Note]

O : Applied, X : Not applied

Accessory model name : Installed at field, ordered and purchased separately by the corresponding model name, sup-

plied with separate package.

1. List of Functions & Accessory

1.1 List of Functions

• Indoor

Category Functions

Wall Mounted ART COOL Mirror

ART COOL

Gallery

Ceiling cassette

4-way

Ceiling concealed

duct (Low static

pressure)

Ceiling concealed

duct (High static

pressure)

Vertical Air Han-

dling Unit

Air flow

Air supply outlet

1 1 3 4 1 1 1

Airflow direction control (left & right)

Auto Auto Auto X X X X

Airflow direction control (up & down)

Auto Auto Auto Auto X X X

Auto swing (left & right)

O O O X X X X

Auto swing (up & down)

O O O O X X X

Airflow steps (fan/cool/heat)

6 / 6 / 6 6 / 6 / 6 5 / 5 / 5 4 / 5 / 4 3 / 3 / 3 3 / 3 / 3 3 / 3 / 3

Chaos wind(auto wind)

O O O O X X X

Jet cool/heat

O / O O / O O / O O / X X / X X / X X / X

Swirl wind

X X X O X X X

Air purify-

ing

Triple filter (Deodorizing)

X X X X X X X

Ventilation Kit

- - - PTVK430 X X X

Plasma air purifier

O O X PTPKQ0 X X X

Allergy Safe filter

X X X X X X X

Long-life prefilter (washable / anti-fung

O O O O O O X

Installation

Drain pump

X X X O O O X

E.S.P. control

X X X X O O O

Electric heater

X X X X X X

ANEH053B1(5kW)

ANEH103B2(10kW)

High ceiling operation

X X X O X X X

Auto Elevation Grille

X X X X X X X

Reliability

Hot start

O O O O O O O

Self diagnosis

O O O O O O O

Soft dry operation

O O O O O O O

Conven-

ience

Auto changeover

X X X X X X X

Auto cleaning

O O O X X X X

Auto operation(artificial intelligence)

O O O O O O O

Auto Restart

O O O O O O O

Child lock*

O O O O O O O

Forced operation

O O O O X X X

Group control*

O O O O O O O

Sleep mode

O O O O O X O

Timer(on/off)

O O O O O X O

Timer(weekly)*

O O O O O X O

Two thermistor control*

O O O O O O O

Individual

control

Standard Wired remote controller

PREMTB10U

Deluxe wired remote controller

X X X X X X X

Simple wired remote controller

PQRCVCL0Q / PQRCVCL0QW O O O

Simple wired remote controller(for hotel use)

X X X X X X X

Wireless remote controller*

O O O O PQWRHQ0FDB

Network

function

General central controller (Non LGAP

X X X X X X X

Network Solution(LGAP)

O O O O O O O

Dry contact

PQDSA(1)/PQDSB(1) / PQDSBC / PQDSBNGCM1

PI 485(for Indoor Unit)

X X X X X X X

Special

function kit

Zone controller

X X X X X X X

CTI(Communication transfer interface

X X X X X X X

Electronic thermostat

X X X X X X X

Others

Remote temperature sensor

X X X PQRSTA0

Group control wire

PZCWRCG3

Telecom shelter controller

X X X X X X X

Connector for water level sensor

O X O X X X X

Part 2 Functions & Controls

- 16 -

Only for training and service purposes

LGE Internal Use Only

[Note]

○ : Applied, × : Not applied

• Outdoor

1.2 List of Accessory

[Note]

O : Applied, × : Not applied

Accessory model name : Installed at field, ordered and purchased separately by the corresponding model name, supplied with separate

package.

Category Functions

A2UW18GFH0[LMU180HHV]

A3UW24GFH0[LMU240HHV]

A4UW30GFH0[LMU300HHV]

A5UW36GFH0[LMU360HHV]

A6UW42GFH0[LMU420HHV]

Reliability

Defrost/Deicing O

High pressure switch X

Low pressure switch X

Phase protection X

Restart delay (3-minutes) O

Self diagnosis O

Soft start O

Test function X

Convenience

Night Silent Operation O

Wiring Error Check O

Peak Control O

Mode Lock O

Forced Cooling Operation (Outdoor Unit) O

Network function Network soluation(LGAP) O

Device

A2UW18GFH0[LMU180HHV]

A3UW24GFH0[LMU240HHV]

A4UW30GFH0[LMU300HHV]

A5UW36GFH0[LMU360HHV]

A6UW42GFH0[LMU420HHV]

Central Controller

AC Ez (Simple Controller) PQCSZ250S0 PQCSZ250S0

AC Ez Touch PACEZA000 PACEZA000

AC Smart IV PACS4B000 PACS4B000

ACP IV PACP4B000 PACP4B000

AC Manager IV PACM4B000 PACM4B000

PI485 PMNFP14A0/PMNFP14A1 PMNFP14A0/PMNFP14A1

BNU (Building Network Unit)

LONWORKS Gateway PLNWKB000 PLNWKB000

BACnet Gateway PQNFB17C0 PQNFB17C0

Installation

Y branch X PMBL5620

Header branch X X

Air Guide X X

PDI (power distribution indicator) PQNUD1S00 PQNUD1S00

ODU Dry Contact X X

Low Ambient Kit O (Logical operation) O (Logical operation)

Part 2 Functions & Controls

- 17 -

Only for training and service purposes

LGE Internal Use Only

2. Air flow

2.1 Auto swing (left & right)

RightLeft

110° ~ 120°

Open

Close

110° ~ 120°

Mode2

Mode3

Mode4

Mode5

Mode6

Mode7

Mode8

Mode9

OPEN

CLOSED

7~8°

110~120°

• By the horizontal airflow direction control key input, the left/right louver automatically operates with the auto swing or it

is fixed to the desired direction.

2.2 Auto swing (up & down)

• By the auto swing key input, the upper/lower vane automatically operates with the auto swing or it is fixed to the de-

sired direction.

2.3 Chaos swing (up/down)

• By the Chaos swing key input, the upper/lower vane automatically operates with the chaos swing or it is fixed to the

desired direction.

NOTE: Some Models are different by swing width and swing pattern.

Part 2 Functions & Controls

- 18 -

Only for training and service purposes

LGE Internal Use Only

2.4 Air flow step

• Indoor fan motor control have 6 steps.

• Air volume is controlled "SH", "H", "Med", Low" by remote controller.

• "LL" step is selected automatically in Hot start operation.

2.5 Chaos wind (auto wind)

• When "Auto" step selected and then operated, the high, medium, or low speed of the airflow mode is operated for

2~15 sec. randomly by the Chaos Simulation

2.6 Jet Cool Mode Operation

• While in heating mode or Fuzzy operation, the Jet Cool key cannot be input.

When it is input while in the other mode operation (cooling, dehumidification, ventilation), the Jet Cool mode is oper-

ated.

• In the Jet Cool mode, the indoor fan is operated at super-high speed for 30 min. at cooling mode operation.

• In the Jet Cool mode operation, the room temperature is controlled to the setting temperature, 18°C.

• When the sleep timer mode is input while in the Jet Cool mode operation, the Jet Cool mode has the priority.

• When the Jet Cool key is input, the upper/lower vanes are reset to those of the initial cooling mode and then operated

in order that the air outflow could reach further.

2.7 Swirl wind Swing

• It is the function for comfort cooling/heating operation.

• The diagonal two louvers are opened the more larger

than the other louvers. After one minute, it is opposite.

• Comparison of Air Flow Types

4-Open (conventional) Swirl Swing (New)

LL Very low, In heating mode

L Low

M Med

H High

SH Super high

Auto Chaos wind

Step Discription

Vane 4

Vane 2

Vane 1 Vane 3

Part 2 Functions & Controls

- 19 -

Only for training and service purposes

LGE Internal Use Only

3.1 PLASMA Air Purifying System

The PLASMA Air Purifying System not only removes microscopic contaminants and dust, but also removes house mites,

pollen, and pet fur to help prevent allergic diseases like asthma. This filter that can be used over and over again by sim-

ply washing with water.

3. Air purifying

Ionizer

Photo-Catalyst Coated Mesh

Dust particles

Odour

Dust electrode discharge

Odour molecule

Generating plasma

+

Polluted Air

Purified fresh Air

+4.8KV discharge

+

Part 2 Functions & Controls

- 20 -

Only for training and service purposes

LGE Internal Use Only

4.1 E.S.P. (External Static Pressure) Setting

4. Installation Functions

This is the function that decides the strength of the wind for each wind level and because this function is to make

the installation easier.

• If you set ESP incorrectly, the air conditioner may malfunction.

• This setting must be carried out by a certificated-technician.

TEMP

FAN

SPEED

OPER

MODE

When pressing the button and button

simultaneously for more than 3 seconds, the system will be

entered into the installer setting mode.

- After entering into the installer setting mode, select the

E.S.P code value by pressing the button.

* E.S.P code value : 03

1

Select the desired air flow rate with

the button. Whenever pressing

the button, [SLo

→

Lo

→

Med

→

Hi

→

Po] will be indicated.

2

Select the desired air flow rate value with the temperature

up(▲), down(▼) button.

* E.S.P value range : 0~255

-

E.S.P value will be indicated at the upper right section of the

display window.

3

When pressing the button, currently established E.S.P

value will be set up.

4

When pressing the button and button simultaneously for

more than 3 seconds after the setting has been completed, the

setting mode will be released.

- If there isn’t any button input for more than 25 seconds, the

installer setting mode will also be released.

5

OPER

MODE

OPER

MODE

FAN

SPEED

FAN

SPEED

OPER

MODE

• Precaution shall be taken not to alter the E.S.P value corresponded to each air flow section.

• E.S.P value can be varied according to the products.

• In the case of going to the next air flow rate stage by pressing the fan-speed button during the setup of the E.S.P value,

the E.S.P value of previous air flow rate will be maintained by remembering the E.S.P value prior to the shift.

Part 2 Functions & Controls

- 21 -

Only for training and service purposes

LGE Internal Use Only

5.1 Hot start

• When heating is started, the indoor fan is stopped or very slow to prevent the cold air carry out

• When the temp. of heat exchanger reach 30°C(model by model), indoor fan is started.

5.2 Self-diagnosis Function

• The air conditioner installed can self-diagnosed its error status and then transmits the result to the central control.

Therefore, a rapid countermeasure against failure of the air conditioner allows easy management and increases the

usage life of air conditioner.

• Refer to trouble shooting guide.

5.3 Soft dry operation

• When the dehumidification operation input by the remote control is received, the intake air temperature is detected and

the setting temp is automatically set according to the intake air temperature.

• While compressor off, the indoor fan repeats low airflow speed and stop.

• While the intake air temp is between compressor on temp. and compressor off temp., 10-min dehumidification opera-

tion and 4-min compressor off repeat.

Compressor ON Temp. ‘ Setting Temp+0.5°C

Compressor OFF Temp. ‘ Setting Temp-0.5°C

• In 10-min dehumidification operation, the indoor fan operates with the low airflow speed.

5. Reliability

Intake air Temp. Setting Temp.

26°C ≤ intake air temp. 25°C

24°C ≤ intake air temp.< 26°C intake air temp. -1°C

22°C ≤ intake air temp. < 24°C intake air temp. -0.5°C

18°C ≤ intake air temp. < 22°C intake air temp.

intake air temp. < 18°C 18°C

Part 2 Functions & Controls

- 22 -

Only for training and service purposes

LGE Internal Use Only

6.1 Cooling & heating Operations

6.1.1 Cooling Mode

• Operating frequency of compressor depends on the load condition, like the difference between the room temp. and

the set temp., frequency restrictions.

• If the compressor operates at some frequency, the operating frequency of compressor cannot be changed within 30

seconds. ( not emergency conditions)

• Compressor turned off when

- intake air temperature is in between ±0.5°C of the setting temp. limit for three minutes continuously.

- intake air temperature reaches below 1.0°C of the temperature of setting temp..

• Compressors three minutes time delay.

- After compressor off, the compressor can restart minimum 3 minutes later.

6. Convenience Functions & Controls

6.1.2 Heating Mode

• Operating frequency of compressor depend on the load condition, The difference between the room temp. and set

temp., frequency restrictions.

• If compressor operates at some frequency, the operating frequency of compressor cannot be changed within 30 sec-

onds.

• Condition of compressor turned off

- When intake air temperature reaches +4°C above the setting temperature.

• Condition of compressor turned on

- When intake air temperature reaches +2°C above the setting temperature.

* Condition of indoor fan turned off

- While in compressor on : indoor pipe temp. < 20°C

- While in compressor off : indoor pipe temp. < 30°C

• While in defrost control, between the indoor and outdoor fans are turned off.

• Compressor 2minutes delay

- After compressor off, the compressor can restart minimum 2 minutes later.

CST/Duct type indoor unit matched with

Universal Outdoor unit

CST/ Duct/CVT type indoor unit

matched with Single Outdoor unit/Multi

Outdoor unit/Multi V Outdoor unit

Thermo ON : +2 °C above setting temp.

Thermo OFF : +4 °C above setting temp.

Thermo ON : Setting temp.

Thermo OFF : +3 °C above setting temp.

NOTE: Some Models are different by temperature of thermo ON/OFF.

Part 2 Functions & Controls

- 23 -

Only for training and service purposes

LGE Internal Use Only

6.3 Auto Operation (Artificial Intelligence)

• When any of operation mode is not selected like the moment of the power on or when 3 hrs has passed since the op-

eration off, the operation mode is selected.

• When determining the operation mode, the compressor, the outdoor fan, and the 4 way valve are off and only the in-

door fan is operated for 15 seconds. Then an operation mode is selected according to the intake air temp at that mo-

ment as follows.

24°C ≤ Inatake Air Temp ‘ Fuzzy Operation for Cooling

21°C ≤ Inatake Air Temp < 24°C ‘ Fuzzy Operation for Dehumidification

Inatake Air Temp < 21°C ‘ Fuzzy Operation for Heating

• If any of the operation modes among cooling / dehumidification / heating mode operations is carried out for 10 sec or

longer before Fuzzy operation, the mode before Fuzzy operation is operated.

6.3.1 Fuzzy Operation for Cooling

• According to the setting temperature selected by Fuzzy rule, when the intake air temp is 0.5°C or more below the set-

ting temp, the compressor is turned off. When 0.5°C or more above the setting temp, the compressor is turned on.

Compressor ON Temp ‘ Setting Temp + 0.5°C

Compressor OFF Temp ‘ Setting Temp + 0.5°C

• At the beginning of Fuzzy mode operation, the setting temperature is automatically selected according to the intake air

temp at that time.

26°C≤ Intake Air Temp ‘ 25°C

24°C≤ Intake Air Temp<26°C ‘ Intake Air Temp + 1°C

22°C≤ Intake Air Temp<24°C ‘ Intake Air Temp + 0.5°C

18°C≤ Intake Air Temp<22°C ‘ Intake Air Temp

Intake Air Temp<18°C ‘ 18°C

• When the Fuzzy key (Temperature Control key) is input after the initial setting temperature is selected, the Fuzzy key

value and the intake air temperature at that time are compared to select the setting temperature automatically accord-

ing to the Fuzzy rule.

• While in Fuzzy operation, the airflow speed of the indoor fan is automatically selected according to the temperature.

6.2 Auto cleaning operation

• Function used to perform Self Cleaning to prevent the Unit from Fungus and bad odor.

• Used after the Cooling Operation before turning the unit off, clean the Evaporator and keep it dry for the next opera-

tion.

• The function is easy to operate as it is accessed through the Remote controller.

Unit

Operation

ON

OFF

Comp.

Indoor

Fan

ON

OFF

ON

OFF

Setting step

OFFL Low

Setting step

(Cooling Only)

Part 2 Functions & Controls

- 24 -

Only for training and service purposes

LGE Internal Use Only

6.3.2 Fuzzy Operation for Dehumidification

• According to the setting temperature selected by Fuzzy rule, when the intake air temp is 0.5°C or more below the set-

ting temp, the compressor is turned off. When 0.5°C or more above the setting temp, the compressor is turned on.

Compressor ON Temp ‘ Setting Temp + 0.5°C

Compressor OFF Temp ‘ Setting Temp+0.5°C

• At the beginning of Fuzzy mode operation, the setting temperature is automatically selected according to the intake air

temp at that time.

26°C ≤ Intake Air Temp ‘ 25°C

24°C ≤ Intake Air Temp<26°C ‘ Intake Air Temp+1°C

22°C ≤ Intake Air Temp<24°C ‘ Intake Air Temp+0.5°C

18°C ≤ Intake Air Temp<22°C ‘ Intake Air Temp

Intake Air Temp<18°C ‘ 18°C

• When the Fuzzy key (Temperature Control key) is input after the initial setting temperature is selected, the Fuzzy key

value and the intake air temperature at that time are compared to select the setting temperature automatically accord-

ing to the Fuzzy rule.

• While in Fuzzy operation, the airflow speed of the indoor fan repeats the low airflow speed or pause as in dehumidifi-

cation operation.

6.3.3 Fuzzy Operation for Heating

• According to the setting temperature selected by Fuzzy rule, when the intake air temp is 3°C or more above the setting

temp, the compressor is turned off. When below the setting temp, the compressor is turned on.

Compressor ON Temp ‘ Setting Temp

Compressor OFF Temp ‘ Setting Temp + 3°C

• At the beginning of Fuzzy mode operation, the setting temperature is automatically selected according to the intake air

temp at that time.

20°C≤Intake Air Temp ‘ Intake Air Temp + 0.5°C

Intake Air Temp<20°C ‘ 20°C

• When the Fuzzy key (Temperature Control key) is input after the initial setting temperature is selected, the Fuzzy key

value and the intake air temperature at that time are compared to select the setting temperature automatically accord-

ing to the Fuzzy rule.

• While in Fuzzy operation, the airflow speed of the indoor fan is set to the high or the medium according to the intake air

temperature and the setting temperature.

Notes: The Temp. of Comp. Turn ON and OFF is different in heating mode and fuzzy operation for heating. Please,

refer 6.1

6.4 Auto restart Operation

• Whenever there is electricity failure to the unit, and after resumption of the power, unit will start in the same mode prior

to the power failure. Memorized condition are on / off condition, operating mode (cooling/ heating), set temperature and

fan speed. The unit will memorize the above conditions and start with same memorized condition.

Part 2 Functions & Controls

- 25 -

Only for training and service purposes

LGE Internal Use Only

6.5 Child Lock Function

6.6 Forced operation

• To operate the appliance by force in case when the remote control is lost, the forced operation selection switch is on

the main unit of the appliance, and operate the appliance in the standard conditions.

• The operating condition is set according to the outdoor temp. and intake air temperature as follows.

• The unit select the last operation mode in 3 hours.

• Operating procedures when the remote control can't be used is as follows :

- The operation will be started if the ON/OFF button is pressed.

- If you want to stop operation, re-press the button.

Indoor temp.

over 24°C

21~24°C

below 21°C

Setting temp.

22°C

23°C

24°C

Setting speed of

indoor fan

High speed

Operating Mode

Cooling

Healthy Dehumidification

Heating

It is the function to use preventing children or others from careless using.

FAN

SPEED

FAN

SPEED

FAN

SPEED

During the operation, when pressing the button and

button for approx. 3 seconds, the ‘Child Lock’ Function can

be used.

- At the time of initial setting of the ‘Child Lock’, the ‘CL’ Will

be indicated approx. 3 seconds at the temperature Display

section before resuming to the previous mode.

After the setting of the ‘CL’, if another button is setup, the

button can not be recognized as the ‘CL’ is indicated at the

temperature display section for approx. 3 seconds.

1

If the ‘CL’ function is wanted to be used under the operation

standby state, press the

button and Button for approx.

3 seconds under the standby mode state and the system will

be the ‘CL’ state.

2

As for the releasing method, when pressing the Button and

button for approx. 3 seconds, the ‘CL’ function can be

released.

3

TEMP

FAN

SPEED

OPER

MODE

Part 2 Functions & Controls

- 26 -

Only for training and service purposes

LGE Internal Use Only

6.7 Group Control

GND

12V

Signal wire

GND

12V

B Y R B Y R

MASTER SLAVE

Signal wire

GND

12V

Signal wire

1. When installing more than 2 units of air conditioner to

one wired remote controller, please connect as the

right figure.

• If it is not event communication indoor unit, set the unit

as slave.

• Check for event communication through the product

manual.

2. When installing more than 2 wired remote controllers to one

air conditioner, please connect as the right picture.

• When installing more than 2 units of wired remote controller to one

air conditioner, set one wired remote controller as master and the

others all as slaves, as shown in the right picture.

• You cannot control the group as shown in the right for some prod-

ucts.

•

Refer to the product manual for more detail.

When controlling multiple indoor units with event communication function with one remote controller, you must change the

master/slave setting from the indoor unit.

- Indoor units, the master/slave configuration of the product after completion of indoor unit power ‘OFF’ and then ‘ON’ the

power after 1 minutes elapsed sign up.

- For ceiling type cassette and duct product group, change the switch setting of the indoor PCB.

- For wall-mount type and stand type product, change the master/slave setting with the wireless remote controller. (Refer to

wireless remote controller manual for detail)

h When installing 2 remote controllers to one indoor unit with event communication function, set the master/slave of the re-

mote controller. (Refer to remote controller master/slave selection)

When controlling the group, some functions excluding basic operation setting, fan level Min/Mid/Max, remote controller

lock setting and time setting may be limited.

<When simultaneously connecting

2 sets of wired remote controller>

• When controlling in groups, set the master/slaver of the remote controller. Refer to Installer setting section on how to set mas-

ter/slave for more detail.

12345678 12345678

#3 switch OFF: Master

(Factory default setting)

#3 switch ON: Slave

Part 2 Functions & Controls

- 27 -

Only for training and service purposes

LGE Internal Use Only

6.8 Sleep Timer Operation

• When the sleep time is reached after <1,2,3,4,5,6,7,0(cancel) hr> is input by the remote control while in appliance op-

eration, the operation of the appliance stops.

• While the appliance is on pause, the sleep timer mode cannot be input.

• While in cooling mode operation, 30 min later since the start of the sleep timer, the setting temperature increases by

1°C. After another 30 min elapse, it increases by 1°C again.

• When the sleep timer mode is input while in cooling cycle mode, the airflow speed of the indoor fan is set to the low.

• When the sleep timer mode is input while in heating cycle mode, the airflow speed of the indoor fan is set to the

medium.

6.9 Timer(On/Off)

6.9.1 On-Timer Operation

• When the set time is reached after the time is input by the remote control, the appliance starts to operate.

• The timer LED is on when the on-timer is input. It is off when the time set by the timer is reached.

• If the appliance is operating at the time set by the timer, the operation continues.

While in Fuzzy operation, the airflow speed of the indoor fan is automatically selected according to the temperature.

6.9.2 Off-Timer Operation

• When the set time is reached after the time is input by the remote control, the appliance stops operating.

• The timer LED is on when the off-timer is input. It is off when the time set by the timer is reached.

• If the appliance is on pause at the time set by the timer, the pause continues.

6.10 Weekly Program

• If necessary, an operator can make an On/Off reservation of the product for a period of one week.

- On/Off schedule of operation for a period of ONE week.

• No need to turn the unit On/OFF manually during working days.

On/Off time is scheduled in micom of the wired remote control.

Operation Time Table (Example)

Mon Tue Wed Thu Fri Sat Sun

OFF

Setting

Temp.

On

Off

25°C 25°C 25°C 25°C 25°C

09:00

12:00

08:00

17:00

09:00

12:00

08:00

12:00

09:00

12:00

Part 2 Functions & Controls

- 28 -

Only for training and service purposes

LGE Internal Use Only

6.11 Two Thermistor Control

When pressing the button and button

simultaneously for more than 3 seconds, the system will be

entered into the installer setting mode.

- After entering into the installer setting mode, select the

thermistor sensor setting code value by pressing the

button.

* Thermistor sensor selection code value : 04

1

Select the desired setting value with the temperature up(▲),

down(▼) button.

2

When pressing the button, currently established

thermistor sensor location will be set up.

3

When pressing the button and button

simultaneously for more than 3 seconds after the setting

has been completed, the setting mode will be released.

- If there isn’t any button input for more than 25 seconds,

the installer setting mode will also be released.

4

OPER

MODE

OPER

MODE

Code value

*Setting value

01: Remote

controller

02: Indoor unit

03: 2TH

OPER

MODE

Value

TEMP

FAN

SPEED

OPER

MODE

h The function of 2TH has different operation characteristics according to the product.

This is the function to select the temperature sensor to judge the room temperature.

Temperature sensor selection Function

01 Remote controller Operation in remote controller temperature sensor

02 Indoor unit Operation in indoor unit temperature sensor

03 2TH

Cooling

Operation of higher temperature by comparing indoor unit's and wired remote

controller’s temperature.

(There are products that operate at a lower temperature.)

Heating

Operation of lower temperature by comparing indoor unit's and wired remote

controller's temperature.

Part 2 Functions & Controls

- 29 -

Only for training and service purposes

LGE Internal Use Only

7.2 Space control

Vanes angle can be controlled by pair, considering its

installation environment.

• For example direct drafts can be annoying, leading to

discomfort and reduced productivity vane control

helps to eliminate this problem.

• Easily controlled by wired remote control.

• Air Flow can be controlled easily regarding any space

environment.

7.3 Auto Elevation Grille

• Auto Elevation Grille is automatically down to height

of max. 3.1 m. So it enables to install the Indoor unit

at high ceiling space. And Auto Elevation Grille

makes you cleaning the filter easily.

7.1 Low Ambient control

• This Function is for cooling operating in outdoor low temperature .

• If outdoor temperature drops below certain temperature, liquid back is prevented by reducing outdoor fan speed.

• It can prevent frosting of evaporator and keep cooling operation

7. Special Function & KIT

T2°C

T1°C

Outdoor pipe

Outdoor

Fan Speed

Setting Speed Off Off

Setting

Speed

Setting

Speed

Part 2 Functions & Controls

- 30 -

Only for training and service purposes

LGE Internal Use Only

n ELEVATION GRILL (REMOTE CONTROLLER_Accessory)

• How to Use Remote Controller

• Main Components of Lift Grill

As for operation of Remote Controller, use it by directing the trans-

mitter part of Remote Controller to the receiver part of front panel

directly under front panel.

• Do not drop it down or into water. Or else there is worry about trou-

ble failure.

• Do not press hard the Remote Controller button with nail (ballpoint

pen or other sharp substance). Or else there is worry about trouble

failure.

• In case when obstacle such as curtain hides the signal reception

part of receiver in between the space interval, Remote Controller

operation is infeasible.

¿ Lift grill front panel assembly

¡ Bolts for installation (4 EA, P/No. 3A00255K)

¬ Instruction manual

√ Remote Controller for lift grill

Ascend

Signal transmitter

Descend

Stop

Part 2 Functions & Controls

- 31 -

Only for training and service purposes

LGE Internal Use Only

7.4 Defrost Control (Heating)

• Defrost operation is controlled by timer and sensing temperature of outdoor pipe.

• The first defrost starts only when the outdoor pipe temperature falls below -11°C after starting of heating operation and

more than 10 minutes operation of compressor.

• Defrost ends after 15 minutes passed from starting of defrost operation when the outdoor rises over 40°C even before

12 minutes.

• The second defrost starts only when the outdoor pipe temperature falls below – 6°C after from ending of the first de-

frost and more than 10 minutes operation of compressor.

Automatic stop distance

S

If you want to change automatic distance setting,

consult with your sale agency.

Automatic Stop Distance of Grill

Ceiling height

Low

Medium

High

(

Height: 3~4 m)

Automatic stop distance

1.5±0.5 m 2.5±0.5 m 3.5±0.5 m

- Depress the down button( ).

Then suction grill descends and stops automatically at a certain

distance.

- You may stop it at wanted distance point by depressing the stop but-

ton ( ) when descending.

- Depress the up button( ).

Then suction grill goes up and enters into the front panel.

1. Stop the Air Conditioner Operation

2. Descend the Suction Grill

3. Raise the Suction Grill

- Depress the stop button( ).

Make use of this when you want to stop it at your wished posi-

tion.

4. Stop the Suction Grill during Rising

• Always stop the air conditioner operation for safety before operating lift grill.

• Take heed _ there is worry about dust fall etc. when suction grill descends.

• In case when the set automatic stop distance goes wrong, check the set value of operation panel and con-

firm if there is neither obstacle nor mankind.

• When you are not to remove obstacle, stop the operation before touching the obstacle.

• How to Operate the Lift Grill

Part 3. Basic Control

- 32 -

Only for training and service purposes

LGE Internal Use Only

Part 3. Basic Control

1. Normal operation..............................................................................................................33

2 Compressor control .........................................................................................................33

3. EEV( Electronic Expansion Valve) control ....................................................................33

4. Oil return control .............................................................................................................34

5. Defrost control .................................................................................................................34

6. Protection control ............................................................................................................35

6.1 High pressure protection control ..........................................................................35

6.2 Low pressure protection control ..........................................................................35

6.3 Discharge temperature control ...........................................................................35

6.4 Input Current control ...........................................................................................35

Part 3. Basic Control

- 33 -

Only for training and service purposes

LGE Internal Use Only

Basic principle is to control the rpm of the motor by changing the working frequency of the compressor.

Three phase voltage is supplied to the motor and the time for which the voltage will supplied is controlled by IPM

(intelligent power module).

Switching speed of IPM defines the variable frequency input to the motor.

1. Normal operation

Fuzzy control : Maintain evaporating temperature (Te) to be constant on cooling mode and constant condensing temper-

ature (Tc) on heating mode by fuzzy control to ensure the stable system performance.

2. Compressor control

Cooling and heating load

System capacity

Linear control

Inverter linear control as cooling and heating load increasing

Actuator Cooling operation Heating operation Stop state

Compressor Fuzzy control Fuzzy control Stop

Fan Fuzzy control Fuzzy control Stop

EEV

Super heating

fuzzy control

Super heating & Sub cooling

fuzzy control

Min. Pulse

EEV operates with fuzzy control rules to keep the degree of superheat (about 2~3℃) at the evaporator outlet status.

The degree of superheat = Tsuction – Tevaporation

Tsuction : temperature at suction pipe sensor(℃)

Tevaporation : evaporation temperature (℃)

3. EEV( Electronic Expansion Valve) control

Part 3. Basic Control

- 34 -

Only for training and service purposes

LGE Internal Use Only

Outdoor unit

Oil return operation recovers oil amount in compressor by collecting oil accumulated in pipe.

Each cycle component operates as shown on the below table during oil return operation.

4. Oil return control

Defrost operation eliminates ice accumulated on heat exchanger, recovering performance of heat exchanger.

Each cycle component operates as shown on the below table during defrost operation.

5. Defrost control

Component Starting Running Ending

Compressor Normal control Setting value Normal control

Fan Normal control Off Normal control

EEV (Thermo on) Normal control Setting value Normal control

EEV (Thermo off) Min. Pulse Setting value Min. Pulse

4 way valve On Off On

Component Starting Running Ending

Fan Normal control Off Normal control

Defrost signal Off On Off

Outdoor unit

Component Starting Running Ending

Compressor Normal control Setting value Normal control

Fan Normal control Off Normal control

EEV (Thermo on) Normal control Setting value Normal control

EEV (Thermo off) Min. Pulse Setting value Min. Pulse

4 way valve On Off On

Component Starting Running Ending

Fan Normal control Off Normal control

Oil return signal Off On Off

Indoor unit

Part 3. Basic Control

- 35 -

Only for training and service purposes

LGE Internal Use Only

6.1 High pressure protection control

6.2 Low pressure protection control

n Cooling Mode

n Heating mode

6.4 Input Current control

6. Protection control

h Remarks: The data of pressure and frequency are different model by model.

Pressure range Compressor

Pd ≥ 4069 kPa Off

3938 kPa ≤ Pd < 4069 kPa

3Hz down

3840 kPa ≤ Pd < 3938 kPa

3Hz down

3709 kPa ≤ Pd < 3840 kPa

Frequency holding

3611 kPa ≤ Pd < 3709 kPa

3 Hz up

Pd < 3611 kPa

Normal control

Pressure range Compressor

Pe

>

310 kPa

Normal control

278 kPa

<

Pe ≤ 310 kPa

3Hz down

245 kPa

<

Pe ≤ 278 kPa

3Hz down

212 kPa

<

Pe ≤ 245 kPa

3Hz down

Pe ≤ 212 kPa Off

Pressure range Compressor

Pe

>

294 kPa

Normal control

255 kPa

<

Pe ≤ 294 kPa

3Hz down

229 kPa

<

Pe ≤ 255 kPa

3Hz down

203 kPa

<

Pe ≤ 229 kPa

3Hz down

Pe ≤ 203 kPa Off

6.3 Discharge temperature control

Temperature range Compressor

Td ≥ 105 ℃ Off

100℃ ≤ Td

<

105℃

5Hz down

95℃ ≤ Td

<

100℃

5Hz down

93℃ ≤ Td

<

95℃

Frequency holding

90℃ ≤ Td

<

93℃

3 Hz up

Td

<

90℃

Normal control

Normal control Frequency down Comp off

Input current Less than 10A 14A or less Over than 14A

Part 4. Test Run

- 36 -

Only for training and service purposes

LGE Internal Use Only

Part 4. Test Run

1. Check before Test Run.....................................................................................................37

2. Test Run Flow chart .........................................................................................................38

3. Test Running.....................................................................................................................39

Part 4. Test Run

- 37 -

Only for training and service purposes

LGE Internal Use Only

Check to see whether there is any refrigerant leakage, and check whether the power or transmission

cable is connected properly.

Check liquid pipe and gas pipe valves are fully opened.

NOTE: Be sure to tighten caps.

Confirm that 500 V megger shows 2.0 MΩ or more between power supply terminal block and

ground. Do not operate in the case of 2.0 MΩ or less.

NOTE: Never carry out mega ohm check over terminal control board.

Otherwise the control board may break.

Immediately after mounting the unit or after leaving it turned off for an extended length of

time, the resistance of the insulation between the power supply terminal board and the

ground maydecrease to approx. 2.0 MΩ as a result of refrigerant accumulation in the internal

compressor.

If the insulation resistance is less than 2.0 MΩ, turn on the main power supply.

1

2

3

1. Check before Test Run

Part 4. Test Run

- 38 -

Only for training and service purposes

LGE Internal Use Only

• Each indoor unit should be tested.

• If the unit has accessory, it should be tested.

Is cold air discharged for

more than 3 minutes ?

START

Test operation for indoor unit

Operation mode change

to Heating mode

Operate the unit in cooling mode.

Does Test operation start?

*Refer to Part 5.Trouble Shooting

- 4. Gas Charging, 6.Electric Parts

Yes

No

Yes

*Refer to Part 5.Trouble Shooting

- 4. Gas Charging, 5.Cycle Parts

No

Is hot air discharged ?

After Hot Start

Yes

No

Is there any temperature

difference between intake and

discharged air?

Yes

No

Is the operating current

normal ?

Yes

Normal

*Refer to Part 5.Troulbe Shooting

No

* Check the load (In/Out Temp.)

* Check pipe length and amount of

refrigerant

* Check for abnormal sound in

outdoor unit (comp.,Fan, others )

2. Test Run Flow chart

Part 4. Test Run

- 39 -

Only for training and service purposes

LGE Internal Use Only

• Check that all tubing and wiring have been properly con-

nected.

• Check that the gas and liquid side service valves are fully

open.

3.1.1 Prepare remote controller

❶ Remove the battery cover by pulling it according to

the arrow direction.

❷ Insert new batteries making sure that the (+) and (–)

of battery are installed correctly.

❸ Reattach the cover by pushing it back into position.

NOTE:

• Use 2 AAA(1.5volt) batteries. Do not use rechargeable

batteries.

• Remove the batteries from the remote controller if the sys-

tem is not going to be used for a long time.

3.1.2 Precautions in test run

n The initial power supply must provide at least 90% of

the rated voltage.

Otherwise, the air conditioner should not be operated.

n For test run, carry out the cooling operation firstly

even during heating season. If heating operation is

carried out firstly, it leads to the trouble of compres-

sor. Then attention must be paid.

n Carry out the test run more than 5 minutes without

fail. (Test run will be cancelled 18 minutes later auto-

matically)

n The forced operation is started by pressing button for

2 seconds.

The test run is started by pressing button for 3~6 sec-

onds.

n To cancel the test run, press any button.

3.1.3 Settlement of outdoor unit

n Anchor the outdoor unit with a bolt and nut(ø10mm)

tightly and horizontally on a concrete or rigid mount.

n When installing on the wall, roof or rooftop, anchor the

mounting base securely with a nail or wire assuming the

influence of wind and earthquake.

n In the case when the vibration of the unit is conveyed to

the hose, secure the unit with an anti-vibration rubber.

3.1.4 Evaluation of the performance

Operate unit for 15~20 minutes, then check the system re-

frigerant charge:

1. Measure the pressure of the gas side service valve.

2.

Measure the temperature of the intake and discharge of air.

3.

Ensure the difference between the intake temperature and the

discharge is more than 8°C (Cooling) or reversely (Heating).

Bolt

Tubing connection

Discharge

temperature

Discharge air

Discharge

temperature

Discharge air

Intake temperature

Chassis cover

Discharge

temperature

Discharge air

Intake

temperature

3.1 SPLIT, ART cool, ART cool deluxe Type

3. Test Running

Part 4. Test Run

- 40 -

Only for training and service purposes

LGE Internal Use Only

3.2 Ceiling Cassette Type

3.2.1 PRECAUTIONS IN TEST RUN

• The initial power supply must provide at least 90% of the rated voltage.

Otherwise, the air conditioner should not be operated.

CAUTION:

① For test run, carry out the cooling operation first even during winter season. If heating operation is carried out

first, it leads to the trouble of compressor.

② Carry out the test run more than 5 minutes without stopping.

(Test run will be cancelled 18 minutes later automatically)

• The test run is started by pressing the room temperature checking button and down timer button for 3 seconds

at the same time.

• To cancel the test run, press any button.

3.2.2 CHECK THE FOLLOWING ITEMS WHEN INSTALLATION IS COMPLETE

• After completing work, be sure to measure and record trial run properties, and store measured data, etc.

• Measuring data are room temperature, outside temperature, suction temperature, blow out temperature,

air velocity, air volume, voltage, current, presence of abnormal vibration and noise, operating pressure, piping

temperature.

• As to the structure and appearance, check following items.

o Is the circulation of air adequate?

o Is the drainage OK?

o Is the heat insulation complete

(refrigerant and drain piping)?

o Is there any leakage of refrigerant?

o Does the romote controller works properly?

o Is there any error on wiring?

o Aren't terminal screws loosened?

M4......118N.cm{12kgf.cm} M5......196N.cm{20kgf.cm}

M6......245N.cm{25kgf.cm} M8......588N.cm{60kgf.cm}

Part 5. Trouble Shooting

- 41 -

Only for training and service purposes

LGE Internal Use Only

Part 5. Trouble Shooting

1. Self-diagnosis Function.................................................................................................42

1.1 Error Indicator (Indoor)................................................................................................42

1.2 Error Indicator (Outdoor) .............................................................................................43

2. Pump Down.....................................................................................................................44

3. Evacuation ......................................................................................................................45

4. Gas Charging..................................................................................................................46

5. Cycle Part........................................................................................................................47

6. Electronic Parts ..............................................................................................................48

6.1 The Product doesn t operate at all..............................................................................48

6.2 The Product doesn't operate with the remote controller .............................................49

6.3 The Compressor/Outdoor Fan are don't operate ........................................................49

6.4 When indoor Fan does not operate.............................................................................51

6.5 When the louver does not operate..............................................................................52

6.6 Troubleshooting Indoor Error ......................................................................................53

6.7 Troubleshooting Outdoor Error....................................................................................59

Part 5. Trouble Shooting

- 42 -

Only for training and service purposes

LGE Internal Use Only

1. Self-diagnosis Function

1.1 Error Indicator (Indoor)

Ceiling Cassette Type Display

The number of times to blink = Error code

10 degrees 1 degrees

Error Indicator

•

The function is to self-diagnoisis airconditioner and express the troubles identifically if there is any trouble.

•

Error mark is ON/OFF for the operation LED of evaporator body in the same manner as the following table.

•

If more than two troubles occur simultaneously, primarily the highest trouble fo error code is expressed.

• After error occurrence, if error is released, error LED is also released simultaneously.

• To operate again on the occurrence of error code, be sure to turn off the power and then turn on.

• Having or not of error code is different from Model.

Indoor Error

00 No Error ON

01 Indoor Room themistor error OFF

02 Indoor in-piping sensor error OFF

03 Remote controller error OFF

04 Drain Pump error OFF

05 Communcation error between in and out OFF

06 Indoor Out-Piping sensor error OFF

07 Differnt mode operation OFF

09 EEPROM Check Sum Error OFF

10 Indoor BLDC Fan Lock OFF

Error code

Description

Indoor Status

Standard Libero Type Display

The number of times to blink = Error code

Cooling

Heating

Plasma

1 degrees

10 degrees

Libero-R

Cooling

Heating

Preheating

1 degrees

10 degrees

Libero-E

Power

Plasma

Preheating

1 degrees

10 degrees

Artcool Mirror

Part 5. Trouble Shooting

- 43 -

Only for training and service purposes

LGE Internal Use Only

1.2 Error Indicator (Outdoor)

Outdoor Error

Ex) Error 21 (DC Peack)

1 Time 1 Time 1 Time

2 Times2 Times2 Times

1 Sec.

2 Sec. 2 Sec.

1 Sec. 1 Sec.

LED01G

(RED)

LED02G

(GREEN)

◑ :

A light on the display panel is blink.

Error

Code

Contents

LED01G/M

(Red)

LED02G/M

(Green)

case of Error

Outdoor

Status

21 DC Link Peak (IPM Fault)

2times ◑ 1times ◑

Over Rated Current

Off

22 CT 2 (Max CT)

2times ◑ 2times ◑

Input Over Current

Off

23

DC Link Low Volt.

2times ◑ 3times ◑

DC Link Volt is below 140Vdc

Off

DC Link High Volt.

DC Link Volt is above 420Vdc

25 Low Voltage/Over Voltage

2times ◑ 5times ◑

Abnormal AC Volt Input

Off

26 DC Compressor Position Error

2times ◑ 6times ◑

Compressor Starting Fall Error

Off

27 PSC/PFC Fault Error

2times ◑ 7times ◑

Over Inverter PCB input current

Off

29 COMP Over Current

2times ◑ 9times ◑

Over Inverter Compressor Current

Off

32 D-Pipe High

3times ◑ 2times ◑

D-Pipe Temp. High

Off

35 Low Pressure Error

3times ◑ 5times ◑

Excessive decrease of Low Pressure

Off

39 Communication Error

3times ◑ 9times ◑

Communication Error Between PFC

Micom and INV Micom

Off

40 CT Sensor (Open/Short)

4times ◑

○

CT Circuit Malfunction

Off

41 INV. D-Pipe Th Error

4times ◑ 1times ◑

Open/Short

Off

43 High Pressure Sensor Error

4times ◑ 3times ◑

Open/Short

Off

44 Outdoor Air Th Error

4times ◑ 4times ◑

Open/Short

Off

45 Cond. Mid-Pipe Th Error

4times ◑ 5times ◑

Open/Short

Off

46 Suction Pipe Th Error

4times ◑ 6times ◑

Open/Short

Off

48 Cond. Out-Pipe Th Error

4times ◑ 8times ◑

Open/Short

Off

51 Capacity Over

5times ◑ 1times ◑

Over combination

Off

53 Signal Error (Indoor <-> Outdoor)

5times ◑ 3times ◑

Communication Poorly

Off

54 3-Phase Wrong wiring

5times ◑ 4times ◑

3-Phase Wrong Wring of Outdoor Unit

(Reverse Phase/Omission of Phase)

Off

60 EEPROM Check Sum Error

6times ◑

○

Check Sum Mismatching

Off

61 Cond. Pipe Th High

6times ◑ 1times ◑

Cond. Temp. High

Off

62 Heaksink Th High

6times ◑ 2times ◑

Heatsink Temp. High

Off

65 Heaksink Th Error

6times ◑ 5times ◑

Open/Short

Off

67 Outdoor BLDC Fan Lock

6times ◑ 7times ◑

Outdoor Fan is not operation

Off

73 PFC Fault Error(S/W)

7times ◑ 3times ◑

Over Current of Outdoor Unit PFC

Off

Part 5. Trouble Shooting

- 44 -

Only for training and service purposes

LGE Internal Use Only

2. Pump Down

This function gathers the refrigerant present in the system to ODU

Use this function to store refrigerant of system in ODU for leakage or IDU replacement.

• Procedure

n

This function start Dip switch setting status of ODU PCB.

(1) Set the Dip switch as follow after shutting the power source down.

(2) Reset the power.

(3) Check that the Red LED of PCB is on during work.(The indoor unit is operated by force.)

(4) Pump down during forced cooling operation.

CAUTION

1. Use pump down function within guaranteed temperature range

IDU : 20~32C

ODU : 0~40C

2. Make certain that IDU doesn't run with thermo off mode during operation

3. After the compressor is starting operation, please complete Pump Down within 4 minutes.

4. Pump Down can be stopped (The compressor is turned off), because of compressor protection.

In this case, reset the power.

6

18,24,30kBtu/h class 36,42kBtu/h class

Part 5. Trouble Shooting

- 45 -

Only for training and service purposes

LGE Internal Use Only

• Procedure

(1) Connect the vacuum pump to the center hose

of charge set center hose

(2) Evacuation for approximately one hour.

– Confirm that the gauge needle has moved to-

ward 0.8Torr.

(3) Close the valve (Lo side) on the charge set,

turn off the vacuum pump, and confirm that

the gauge needle does not move (approxima-

tely 5 minutes after turning off the vacuum

pump).

(4) Disconnect the charge hose from the vacuum

pump.

– Vacuum pump oil.

If the vacuum pump oil becomes dirty or de-

pleted, replenish as needed.

WARNING

Use a vacuum pump or lnert (nitrogen) gas when

doing leakage test or air purge. Do not compress

air or Oxygen and do not use Flammable gases.

Otherwise, it may cause fire or explosion.

- Otherwise, it may cause personal injury.

Lo

Open

Vacuum pump

3-Way

valve

Outdoor unit

Liquid side

Indoor unit

Gas side

3-Way

valve

OPEN

Vacuum

Gage

OPEN

3. Evacuation (All amount of refrigerant leaked)

Part 5. Trouble Shooting

- 46 -

Only for training and service purposes

LGE Internal Use Only

Lo

Charging

cylinder

Outdoor unit

Indoor unit

Liquid side

Gas side

Open

3-Way

valve

3-Way

valve

OPEN

Open

Check valve

(1)

Vacuum

Gage

• Procedure

(1) Connect the charge hose to the charging

cylinder.

– Connect the charge hose which you dis-con-

nected from the vacuum pump to the valve at

the bottom of the cylinder.

– If you are using a gas cylinder, also use a scale

and reverse the cylinder so that the system can

be charged with liquid.

(2) Purge the air from the charge hose.

– Open the valve at the bottom of the cylinder

and press the check valve on the charge set to

purge the air. (Be careful of the liquid refriger-

ant). The procedure is the same if using a gas

cylinder.

(3) Open the valve (Lo side on the charge set and

charge the system with liquid refrigerant.

– If the system can not be charged with the spec-

ified amount of refrigerant, it can be charged

with a little at a time (approximately 150g each

time) while operating the air conditioner in the

cooling cycle; however, one time is not suffi-

cient, wait approximately 1 minute and then re-

peat the procedure (pumping down-pin).

(4) Immediately disconnect the charge hose from

the 3-way valve’s service port.

–

Stopping partway will allow the gas to be discharged.

–

If the system has been charged with liquid refrig-

erant while operating the air conditioner turn off

the air conditioner before disconnecting the hose.

(5)

Mount the valve stem nuts and the service port nut.

– Use torque wrench to tighten the service port

nut to a torque of 1.8 kg.m.

– Be sure to check for gas leakage.

WARNING

When installing or relocation the unit, make sure

that no substance other than the specified refriger-

ant(R410A) enter the refrigerant circult.

- Any presence of foreign substance such as air can

cause an abnormal pressure rise and may result in

explosion or injury.

This is different from previous procedures.

Because you are charging with liquid refrigerant

from the gas side, absolutely do not attempt to

charge with larger amounts of liquid refrigerant

while operating the air conditioner.

4. Gas Charging (After Evacuation)

Part 5. Trouble Shooting

- 47 -

Only for training and service purposes

LGE Internal Use Only

Trouble analysis

1. Check temperature difference between intake and discharge air, and check for the operating current too.

Case Symptom Supposed Caused

Temp. difference : approx. 0°C

Current : less than 80% of rated current

Temp. difference : approx. 8°C

Current : less than 80% of rated current

Temp. difference : less than 8°C

Current : over the rated current

Temp. difference : over 8°C

All amount of refrigerant leaked out.

Check refrigeration cycle.

Refrigerant leakage Clog of refrigeration cycle

Defective Compressor.

Excessive amount of refrigerant

Normal

Case 1

Case 2

Case 3

Case 4

Temperature difference between intake and discharge air depends on room air humidity. When the room air humidity is

relativery higher, temperature difference is smaller. When the room air humidity is relatively lower temperature difference

is larger.

2. Check temperature and pressure of refrigeration cycle in cooling mode.

1. The suction pressure is usually 8.5~9.5kg/cm2G(Cooling) at normal condition.(R410A)

2. The temperature can be measured by attaching the thermometer to the low pressure tubing and wrap it with putty.

NOTICE

Suction pressure

(Compared with Cause of Trouble Description

the normal value)

Defective compressor Current is low.

Defective 4-way reverse valve

Excessive amount of High pressure does not quickly

Normal refrigerant rise at the beginning of

operation.

Insufficient amount of Current is low.

Lower Higher refrigerant (Leakage)

Clogging

High

Higher

Temperature of Discharge

Air (Compared with the

normal valve)

5. Cycle Part

Part 5. Trouble Shooting

- 48 -

Only for training and service purposes

LGE Internal Use Only

6.1 The Product doesn’t operate at all

The operation check of the Indoor PCB Assembly

Procedure

1) The input voltage of power mod-

ule.

2) The output voltage of power mod-

ule.

4) IC04D(7805)

5) IC01A(KIA7036)

Specification

1) AC230V ± 30V

: Check the rated voltage

2) 12V ± 3V

4) DC5V

5) The voltage of micom pin 19

: DC4.5V↑

Remedy

1) Check the power outlet.

2) Replace

PCB Assembly

4) Replace PCB Assembly

5) Replace PCB Assembly

Turn on the main power again.

Turn off the main power and

wait for 10 seconds.

Yes

No

A "Beeping" sound is made

from the indoor unit

Check the voltage of power supply (AC208/230V,60Hz) and check

for the following :

* The voltage of main power supply.

* The voltage applied to the unit.

* The connecting method of Indoor/Outdoor connecting cable (each color)

* The PCB Assembly (Fuse, Noise Filter, Power Module, Bridge Diode, etc.)

Primarily, the operating condition of

Micom is O.K.

* Check, Remote controller & Receiver.

* Check CN-DISP1, CN-DISP2 of

indoor PCB

6. Electronic Parts

Part 5. Trouble Shooting

- 49 -

Only for training and service purposes

LGE Internal Use Only

Turn on the main power.

When in air circulation mode, compressor/outdoor fan is stopped.

Check the sensor for Indoor temperature is attatched as close as to be effected by the

themperature of Heat Exchange (EVA.)

Operate Cooling Mode by setting the disired temperature of the remote controller is less

than one of the Indoor temperature by 1°C at least.

6.3 The Compressor/Outdoor Fan are don't operate

6.2 The Product doesn't operate with the remote controller

Turn on the main power

Yes

No

A "Beeping" sound is made

from the indoor unit

* Refer to 6.1

* Check the voltage of power

(AC208/230V,60Hz).

Is it possible to turn on the unit

by ON/OFF button on display?

Yes

No

Is the remote controller

working properly?

Yes

* When the mark ( ) is displayed

in LCD screen, replace battery.

No

* Check the contact point of CN-DISP 1, 2 connector & Re connector.

* Check display PCB Assembly

- Voltage between CN-DISP1 - should be DC +5V,

- If problem still persists, Replace display PCB

3 6

Part 5. Trouble Shooting

- 50 -

Only for training and service purposes

LGE Internal Use Only

Turn off main power.

Check the electrical wiring diagram of Outdoor side.

Check the open or short of connecting wires between Indoor and Outdoor.

When the sensor circuit for Indoor temperature and connector are in bad connection or are

not engaged, Compressor/Outdoor fan is stopped.

• Check the related circuit of R02H(12.1K), R01H(1K), R04H(6.2K), R03H(1K), C01H(102),

C02H(102), Micom(pin No. ⑪, ⑫).

• Check the Indoor temperature sensor is disconnected or not (about 10K at 25°C).

Check the Relay(RY-PWR, RY-START) for driving Compressor.

• Check the voltage between brown and blue cable of terminal to connect the Outdoor

(About AC208/230).

• Check the related circuit of relay in Outdoor PCB Ass'y.

Check Point

Between Micom(No. 19) and

GND

DC 5V DC 0V

DC 12VDC 1V↓

Between IC01M(No. 10) and

GND

Comp. ON Comp. OFF

Check the Relay(RY-PWR, RY-CHARGE) for driving Compressor.

• Check the voltage between brown and blue cable of terminal to connect the Outdoor

(About AC208/230).

• Check the related circuit of relay in Outdoor PCB Ass'y.

Check Point

Between Micom(No. 11) and

GND

DC 5V DC 0V

DC 12VDC 1V↓

Between IC01M(No. 16) and

GND

Comp. ON Comp. OFF

36,42kBtu/h class

18,24,36kBtu/h class

Part 5. Trouble Shooting

- 51 -

Only for training and service purposes

LGE Internal Use Only

6.4 When indoor Fan does not operate.

Check the SSR high speed operation by remote control.

(the Indoor Fan Motor is connected)

Turn off main power.

Check the connection of CN-FAN.

Check the Fan Motor.

Check the Fuse(AC250V, T2A).

Turn on the main power

Check the related circuit of indoor Fan Motor.

• The pin No.

38

of micom and the part for driving SSR.(Q01M)

• Check the related pattern.

• Check the SSR.

- SSR Open: Indoor Fan Motor never operate.

- SSR short: Indoor Fan Motor always operates in case of ON or OFF.

The voltage of Pin No 1(orange) and 3(black) of CN-FAN.

About AC 160V over About AC 50V over

SSR is not damaged Check SSR

Part 5. Trouble Shooting

- 52 -

Only for training and service purposes

LGE Internal Use Only

• Confirm that the vertical louver is normally geared with the shaft of Stepping Motor.

• If the regular torque is detected when rotating the vertical louver with hands ⇒ Normal

• Check the connecting condition of CN-U/D or CN0L/R Connector

• Check the soldering condition(on PCB) of CN-U/D or CN0L/R Connector

Check the operating circuit of the vertical louver

• Confirm that there is DC +12V between pin ¿ of CN-U/D, CN0L/R and GND.

• Confirm that there is a soldering short at following terminals.

- Between 1 , 2 , 3 and 4 of MICOM - Between

17

,

18

,

19

and

20

of MICOM

- Between 4 , 5 , 6 and 7 of IC01M - Between 5 , 6 , 7 and 8 of IC01M

6.5 When the louver does not operate.

If there are no problems after above checks.

• Confirm the assembly condition that are catching and interfering parts in the link of the

vertical louver

Part 5. Trouble Shooting

- 53 -

Only for training and service purposes

LGE Internal Use Only

Ω

10kΩ

Check the resistance

Check the voltage

V

2.5Vdc

Check Point

1. Unplug the sensor on Indoor unit PCB.

2. Estimate the resistance of each sensor.

3. If the resistance of the sensor is 10KΩ/ 5KΩ at 25°C, then sensor is normal.

4. If the resistance of the sensor is 0 KΩ or ∞, then sensor is abnormal. ’ Change the sensor.

5. Plug the sensor on Indoor unit PCB and Power ON.

6. Estimate the voltage of each sensor.

7. If the voltage of the sensor is 2.5Vdc at 25°C, then sensor is normal.

8. If the resistance of the sensor is 0 or 5Vdc, then sensor is abnormal. ’ Repair or Change the PCB.

6.6 Troubleshooting Indoor Error

01

02

06

Indoor air sensor

Indoor inlet pipe sensor

Indoor outlet pipe sensor

• Open / Short

• Soldered poorly

• Internal circuit error

• Open / Short

• Soldered poorly

• Internal circuit error

• Open / Short

• Soldered poorly

• Internal circuit error

Normal resistor : 10KΩ/ at 25°C (Unplugged)

Normal voltage : DC 2.5V / at 25°C (plugged)

Normal resistor : 5KΩ/ at 25°C (Unplugged)

Normal voltage : DC 2.5V / at 25°C (plugged)

Normal resistor : 5KΩ/ at 25°C (Unplugged)

Normal voltage : DC 2.5V / at 25°C (plugged)

Display

code

Title Cause of error Check point & Normal condition

Part 5. Trouble Shooting

- 54 -

Only for training and service purposes

LGE Internal Use Only

Check the Volt.

Indoor Unit

V

12Vdc

12V S GND

Check the Volt.

Wired R/C

V

12Vdc

12V S GND

CN-REMO

Check Point

1. Check the wire connection. (Open / Short) ’ Repair the connection

2. Check the soldering state of connector. (Soldered poorly) ’ Repair or Change the PCB.

3. Check the volt. Of main PCB power source. (DC 12V) ’ Repair or Change the main PCB.

4. Check the installation of wired remote controller. (Noise interference) ’ Adjust the state of installation

03

Communication

Wired R/C

• Open / Short

• Wrong connection

• Connection of wire

• Main PCB Volt. DC12V

• Noise interference

Display

code

Title Cause of error Check point & Normal condition

Part 5. Trouble Shooting

- 55 -

Only for training and service purposes

LGE Internal Use Only

Check the resistance

Ω

0Ω

CN Float

CN-Float

CN-D/PUMP

04

Drain pump

/ Float switch

• Float switch Open.

(Normal : short)

• The connection of wire(Drain pump/ Float switch)

• Drain pump power input. (230V)

• Drain tube installation.

• Indoor unit installation. (Inclination)

Display

code

Title Cause of error Check point & Normal condition

Check Point

1. Check the wire connection. (Open, Soldered poorly) ’ Repair the connection or change the PCB.

2. Check the resistance of float switch (Abnormal : Open, Normal : short) ’ Check the float switch.

3. Check the level of water

4. Check the volt. Of Drain pump power supply. (AC 230V) ’ Repair or Change the main PCB.

Part 5. Trouble Shooting

- 56 -

Only for training and service purposes

LGE Internal Use Only

07

Different Operation Mode

• One of Indoor Unit oper-

ate cooling Another Unit

operate heating

• At the same time, this model cannot use cool and

heating mode

Display

code

Title Cause of error Check point & Normal condition

Check Point

1. Check another indoor model operation mode

2. Operating the same mode with the first operated indoor unit

3. Clearing the "CH07"

Press the on/off button or mode change button and matching the indoor unit mode same as the first operated

indoor unit

Part 5. Trouble Shooting

- 57 -

Only for training and service purposes

LGE Internal Use Only

09

Indoor EEPROM Check

Sum Error

• Check sum error

1. Check the poor soldering

2. Check the insertion condition of the EEPROM

3. Check the PCB Connection

Display

code

Title Cause of error Check point & Normal condition

Check Point

1. Check the EEPROM Direction

2. If the EEPROM value & the Program value are not matched, the Code is Displayed

3. After Checking the connection and Insertion, replace the PCB or Option PCB

Part 5. Trouble Shooting

- 58 -

Only for training and service purposes

LGE Internal Use Only

10

Indoor BLDC Fan Motor

Lock

The Fan is not operated

properly

Check the Indoor fan locking

Display

code

Title Cause of error Check point & Normal condition

Check Point

Check the PCB during the Power on

1. Check the Voltage Red line to Black line

’ The Voltage is about [input voltage x 1.414]

’ if the Voltage does not come with the above Voltage,

’ Check the power input

’ Replace the PCB & Motor

2. Check the Voltage Black line to White

’ the Voltage is DC 15V

’ Check the Power input

’ Replace the motor

Check the Motor

1. Check the shaft

’ if the shaft is not turn smoothly, the Motor Power IC is defected

’ replace the motor

2. Check the motor resistance(if the shaft is turn smoothly, check the resistance)

’ Check Red line to Black line, Blue line to Black line

’ The resistance should infinite

’ replace the motor

Tester

Fan motor

connector

Yellow

Blue

White

Black

Red

6.7 Troubleshooting Outdoor Error

Part 5. Trouble Shooting

- 59 -

Only for training and service purposes

LGE Internal Use Only

21

DC PEAK

(IPM Fault)

• Instant over current

• Over Rated current

• Poor insulation of IPM

• An instant over current in the U,V,W phase

- Comp lock

- The abnormal connection of U,V,W

• Over load condition

- Overcharging of refrigerant Pipe length.

Outdoor Fan is stop

• Poor insulation of compressor

Display

code

Title Cause of error Check point & Normal condition

Is installation

condition normal?

No

Yes

Recheck power and installation condition

1. Check Pipe clogging/distortion

2. Check Covering (Indoor/Outdoor Unit)

3. Check EEV connector assemble condition/normal

operation

4. Check refrigerant pressure

→ Reassemble or manage if abnormality found

1. Check resistance between each terminal of compressor

(0.438~0.628±7%)

2. Check insulation resistance between compressor

terminal and pipe (over 2MΩ)

→ Replace compressor if abnormality found

Are the resistance

Between each phase and

insulation resistance of Inverter

compressor normal?

No

Yes

1. Check inverter PCB assembly U,V,W connector

connection condition

2. Check wire disconnection and wiring

3. Check compressor terminal connection condition

(bad contact)

→ Reassemble if abnormality found

Is compressor

Wire connection

condition normal?

No

Yes

Check inverter PCB assembly IPM normality

→ Replace inverter PCB assembly

Is inverter PCB assembly normal?

No

n Error Diagnosis and Countermeasure Flow Chart

n Comp checking method

Comp

Copper

pipe

Model

Resistance(Ω)

Resistance(Ω) at 20°C

18,24,30

kBtu/h class

36,42k

Btu/h class

Terminal

V-W

Inverter Comp.

0.628(at 25˚C)

W-U

0.628(at 25˚C)

U-V

V-W

W-U

U-V

0.628(at 25˚C)

0.438(at 25˚C)

2MΩ

Inverter

comp.

V-GND

W-GND

U-GND

Terminal

2MΩ

Constant

comp.

V

U

W

Comp

WARNING

Before checking PCB or each outdoor electric parts, wait for 3 minutes after the power is off. When measuring at standby state

of power supply, after checking the measurement mode of the meter, be careful of the short-circuits with other parts.

Part 5. Trouble Shooting

- 60 -

Only for training and service purposes

LGE Internal Use Only

▶18,24,30kBtu/h class

25 26 27 29

30

32

33

P

W V U

NwNvNu

33

32

30

29

27

26

25

U1

IPM Check Point

1. Wait until inverter PCB DC voltage is discharged after main power off.

2. Pull out V, V, W COMP connector.

3. Set multi tester to resistance mode.

4.

If the value between P and N terminal of IPM is short(0Ω) or open(hundreds MΩ), PCB needs to be replaced.(IPM damaged)

5. Set the multi tester to diode mode.

6. In case measured value is different from the table, PCB needs to be replaced.(PCB damaged).

27 26 25 24 23 22 21

P U V W Nu Nv Nw

0.4 ~ 0.6 V

27 26 25 24 23 22 21

P U V W Nu Nv Nw

0.4 ~ 0.6 V

PFC_IPM check

U, V, W ‘ R S T

Part 5. Trouble Shooting

- 61 -

Only for training and service purposes

LGE Internal Use Only

CN_INPUT_VOLT_N (BL)

CN_INPUT_VOLT_L (BR)

U

V

W

1. Wait until inverter PCB DC voltage is discharged after main power off.

2. Pull out CN(L), CN(N) connectors and U,V,W COMP Connector.

3. Set multi tester to resistance mode.

4.

If the value between P and N terminal of IPM is short(0Ω) or open(hundreds MΩ), PCB needs to be replaced.(IPM damaged)

5. Set the multi tester to diode mode.

6. In case measured value is different from the table, PCB needs to be replaced.(PCB damaged).

0.3 ~ 0.5 V

Black

Red

25-26

P

W

V

U

ں

ڹ

ڸ

13-15

11-12 8-9

IGBTM check

U, V, W

▶36,42kBtu/h class

Sequence of

Measurement

Normal

Standards

1 P-U 0.3V~0.5V

2 P-V 0.3V~0.5V

3 P-W 0.3V~0.5V

Part 5. Trouble Shooting

- 62 -

Only for training and service purposes

LGE Internal Use Only

22

Max. C/T

Input over current

(18,24,30kBtu/h class 19A↑

36,42kBtu/h class 37A ↑)

1. Malfunction of Compressor

2. Blocking of Pipe

3. Low Voltage Input

4. Refrigerant, Pipe length, Blocked...

Display

code

Title Cause of error Check point & Normal condition

n Error Diagnosis and Countermeasure Flow Chart

Is installation

condition normal?

No

Yes

Recheck power and installation condition

Yes

1. Check Pipe clogging/distortion

2. Check Covering (Indoor/Outdoor Unit)

3. Check EEV connector assemble condition/normal

operation

4. Check refrigerant pressure

→ Reassemble or manage if abnormality found

Is inverter PCB assembly

power connection normal?

No

Check connection between inverter PCB assembly and

bridge diode(misconnection, disconnection)

→ wiring again if abnormality found

Yes

Is input voltage normal?

No

Check

L1~L2 phase is 230V 15%

→ Check connection condition and wiring if power is

abnormal

Yes

Is inverter PCB assembly

normal?

No

Check inverter PCB assembly IPM normality

→ Replace inverter PCB assembly

Are the resistance

Between each phase and

insulation resistance of Inverter

compressor normal?

No

1. Check resistance between each terminal of compressor

(0.438~0.628±7%)

2. Check insulation resistance between compressor

terminal and pipe (over 2MΩ)

→ Replace compressor if abnormality found

Is compressor

Wire connection

condition normal?

No

1. Check inverter PCB assembly U,V,W connector

connection condition

2. Check wire disconnection and wiring

3. Check compressor terminal connection condition

(bad contact)

→ Reassemble if abnormality found

WARNING

Before checking PCB or each outdoor electric parts, wait for 3 minutes after the power is off. When measuring at standby state

of power supply, after checking the measurement mode of the meter, be careful of the short-circuits with other parts.

Part 5. Trouble Shooting

- 63 -

Only for training and service purposes

LGE Internal Use Only

Check Point

1. Check the power source.(230V ±15%)

2. Check the fan operation is right.

3. Check the current.

4. Check the install condition.

5. Check the CT Sensor Output signal

(18/24/30 kBtu/h class - Check output the CT Sensor : DC 2.5±0.2V)

(36/42 kBtu/h class - Check output pin 1.2 of the CT Sensor : 5V )

Vdc

2.5V

I_INI_IN

GNDGND

Red

Black

▶36,42kBtu/h class

▶18,24,30kBtu/h class

Part 5. Trouble Shooting

- 64 -

Only for training and service purposes

LGE Internal Use Only

23

DC Link High / Low Volt

• DC Link Voltage is

above 420Vdc

• DC Link Voltage is

below 140Vdc

• Check CN_(L), CN_(N) Connection

• Check Input Voltage

• Check PCB DC Link voltage sensor parts

Display

code

Title Cause of error Check point & Normal condition

n Error Diagnosis and Countermeasure Flow Chart

Is Inverter PCB assembly

Power connection normal?

No

Check connection from terminal block to

Inverter PCB assembly CN(L), CN(N)

Yes

Is input voltage normal ?

No

Yes

Is Inverter PCB Normal?

No

Replace inverter PCB assembly

Recheck power and installation

condition

Yes

Check L1~L2 Voltage is 230V±15%

WARNING

Before checking PCB or each outdoor electric parts, wait for 3 minutes after the power is off. When measuring at standby state

of power supply, after checking the measurement mode of the meter, be careful of the short-circuits with other parts.

Part 5. Trouble Shooting

- 65 -

Only for training and service purposes

LGE Internal Use Only

Check Point

1. Check the REACTOR_IN and REACTOR_OUT1,2 Connection condition at the Main PCB.(Refer to outdoor

wiring diagram)

2. Measure the voltage as shown in figures.

3. If the measurements are significantly different from the levels shown in the figures, the PFCM is deemed to be

damaged.

IN

OUT

Red

Black

Vdc

Sequence of

Measurement

Normal

Standards

Sequence of

Measurement

Normal

Standards

1 C – E 0.3V~0.5V

2 C – E 0.3V~0.5V

ڹ

ڸ

0.3 ~ 0.5 V

< IGBT >

ڸ

ڹ

ڸ

ڹ

C : Collector / E : Emitter

1 A – C 0.3V~0.5V

2 A – C 0.3V~0.5V

< FRD >

A : Anode / C : Cathode

ڸ

ڹ

IGBT IGBT FRD

▶18,24,30kBtu/h class

Part 5. Trouble Shooting

- 66 -

Only for training and service purposes

LGE Internal Use Only

* Measuring input voltage

N

L

(+) (-)

▶36,42kBtu/h class

Part 5. Trouble Shooting

- 67 -

Only for training and service purposes

LGE Internal Use Only

Check Point

1. Check the Input Voltage (L1~L2 ‘ 230V±10%)

2. Check Input Voltage Sensor output voltage (2.5Vdc±10%)

25

Input voltage

• Abnormal Input voltage

(140Vac , 300Vac)

• Check the power source.

• Check the components.

Display

code

Title Cause of error Check point & Normal condition

Is Inverter PCB Normal?

No

Replace inverter PCB assembly

Is input voltage normal ?

No

Check L1~L2 Voltage is 230V±15%

Yes

Recheck power and

installation condition

Yes

< Input Power Source Check Point >

L1

L2

n Error Diagnosis and Countermeasure Flow Chart

Part 5. Trouble Shooting

- 68 -

Only for training and service purposes

LGE Internal Use Only

18,24,30kBtu/h class

Vdc

2.5V

GND

Red

Black

INV_CurINV_CurrententINV_Current

GNDGND

INPUT(V)INPUT(V) INPUT(V)

GND

< Inverter PCB>

< Input Voltage Sensing Check Point >

36,42kBtu/h class

Vdc

Part 5. Trouble Shooting

- 69 -

Only for training and service purposes

LGE Internal Use Only

26

DC Compressor

Position

• Compressor

Starting fail error

• Check the connection of comp wire “U,V,W”

• Malfunction of compressor

• Check the component of “IPM”, detection parts.

Display

code

Title Cause of error Check point & Normal condition

Is installation

condition normal?

No

Yes

Recheck power and installation condition

1. Check Pipe clogging/distortion

2. Check Covering (Indoor/Outdoor Unit)

3. Check EEV connector assemble condition/normal

operation

4. Check refrigerant pressure

→ Reassemble or manage if abnormality found

1. Check resistance between each terminal of compressor

(0.438~0.628±7%)

2. Check insulation resistance between compressor

terminal and pipe (over 2MΩ)

→ Replace compressor if abnormality found

Are the resistance

Between each phase and

insulation resistance of Inverter

compressor normal?

No

Yes

1. Check inverter PCB assembly U,V,W connector

connection condition

2. Check wire disconnection and wiring

3. Check compressor terminal connection condition

(bad contact)

→ Reassemble if abnormality found

Is compressor

Wire connection

condition normal?

No

Yes

Check inverter PCB assembly IPM normality

→ Replace inverter PCB assembly

Is inverter PCB assembly normal?

No

18,24,30kBtu/h class

Vdc

2.5V

GND

Red

Black

INV_CurINV_CurrententINV_Current

WARNING

Before checking PCB or each outdoor electric parts, wait for 3 minutes after the power is off. When measuring at standby state

of power supply, after checking the measurement mode of the meter, be careful of the short-circuits with other parts.

n Error Diagnosis and Countermeasure Flow Chart

Part 5. Trouble Shooting

- 70 -

Only for training and service purposes

LGE Internal Use Only

* Measuring resistance between each terminal of compressor

* Compressor wire connection

U

V

W

ȯ36,42kBtu/h class

Part 5. Trouble Shooting

- 71 -

Only for training and service purposes

LGE Internal Use Only

27

AC Input Instant over

Current Error

Inverter PCB input

current is over100A(peak)

for 2us

1. Overload operation (Pipe clogging/Covering/EEV

defect/Ref. overcharge)

2. Compressor damage (Insulation damage/Motor

damage)

3. Input voltage abnormal (L1,L2)

4. Power line assemble condition abnormal

5. Inverter PCB assembly Damage (input current

sensing part)

Display

code

Title Cause of error Check point & Normal condition

h PFCM Moudle checking method

① Set the multi tester to diode mode.

② Check short between input signal pin which are

placed below PFC Module.

③ Replace PCB assembly if it is short between pins

except No.4,5 pins.

CAUTION

PFCM module No.4,5 pins are internal short state.

No

1.Check Pipe clogging/distortion

2.Check Covering (Indoor/Outdoor Unit)

3.Check EEV connector assemble condition/normal operation

4.Check refrigerant pressure

→ Reassemble or manage if abnormality found

Is installation

condition normal?

Is compressor

Wire connection

condition normal?

1.Check inverter PCB assembly U,V,W connector connection condition

2.Check wire disconnection and wiring

3.Check compressor terminal connection condition(bad contact)

→ Reassemble if abnormality found

Is AC input Wire connection

condition normal?

1.Check L1,L2 connection condition

2.Check wire disconnection and wiring

→ Reassemble if abnormality found

Is inverter PCB assembly

normal?

Yes

No

Recheck power and

installation condition

Yes

No

Yes

No

Check

L~N phase voltage is 230V ± 15%

→ Check connection condition and wiring if power is abnormal

Is input voltage normal?

Check inverter PCB assembly PFCM normality

→ Replace inverter PCB assembly

WARNING

Before checking PCB or each outdoor electric parts, wait for 3 minutes after the power is off. When measuring at standby state

of power supply, after checking the measurement mode of the meter, be careful of the short-circuits with other parts.

n Error Diagnosis and Countermeasure Flow Chart

Part 5. Trouble Shooting

- 72 -

Only for training and service purposes

LGE Internal Use Only

29

Inverter compressor over

current

Inverter compressor input

current is over 30A

1. Overload operation

(Pipe clogging/Covering/EEV defect/Ref. over-

charge)

2. Compressor damage(Insulation damage/Motor

damage)

3. Input voltage low

4. ODU inverter PCB assembly damage

Display

code

Title Cause of error Check point & Normal condition

n Error Diagnosis and Countermeasure Flow Chart

Is installation

condition normal?

No

Yes

Recheck power and installation condition

1. Check Pipe clogging/distortion

2. Check Covering (Indoor/Outdoor Unit)

3. Check EEV connector assemble condition/normal

operation

4. Check refrigerant pressure

→ Reassemble or manage if abnormality found

Yes

Is input voltage normal?

No

Check

L1~L2 phase is 230V±15%

→ Check connection condition and wiring if power is

abnormal

Yes

Is inverter PCB assembly

normal?

No

Check inverter PCB assembly IPM normality

→ Replace inverter PCB assembly

Are the resistance

Between each phase and

insulation resistance of Inverter

compressor normal?

No

1. Check resistance between each terminal of compressor

(0.438~0.628±7%)

2. Check insulation resistance between compressor

terminal and pipe (over 2MΩ)

→ Replace compressor if abnormality found

Is compressor

Wire connection

condition normal?

No

1. Check inverter PCB assembly U,V,W connector

connection condition

2. Check wire disconnection and wiring

3. Check compressor terminal connection condition

(bad contact)

→ Reassemble if abnormality found

WARNING

Before checking PCB or each outdoor electric parts, wait for 3 minutes after the power is off. When measuring at standby state

of power supply, after checking the measurement mode of the meter, be careful of the short-circuits with other parts.

Part 5. Trouble Shooting

- 73 -

Only for training and service purposes

LGE Internal Use Only

Display

code

Title Cause of error Check point & Normal condition

32

High temperature in Dis-

charge pipe of the inverter

compressor

• Overload operation (Out-

door fan constraint,

screened, blocked)

• Refrigerant leakage (in-

sufficient)

• Poor INV Comp Dis-

charge sensor

• LEV connector displaced

/ poor LEV assembly

• Check outdoor fan constraint/ screened/ flow

structure

• Check refrigerant leakage

• Check if the sensor is normal

• Check the status of EEV assembly

CN- DISCHARGE

(BLACK 3Pin Connector)

Replace the Thermistor

Yes

CN_TH3

(RED 4Pin Connector)

WARNING

Before checking PCB or each outdoor electric parts, wait for 3 minutes after the power is off. When measuring at standby state

of power supply, after checking the measurement mode of the meter, be careful of the short-circuits with other parts.

Part 5. Trouble Shooting

- 74 -

Only for training and service purposes

LGE Internal Use Only

Display

code

Title Cause of error Check point & Normal condition

35 Low Presser Error

Excessive decrease of low

pressure

• Defective low pressure sensor

• Defective outdoor/indoor unit fan

• Refrigerant shortage/leakage

•

Deformation because of damage of refrigerant pipe

• Defective indoor / outdoor unit EEV

• Covering / clogging (outdoor unit covering during

the cooling mode / indoor unit filter clogging dur-

ing heating mode)

• SVC valve clogging

• Defective outdoor unit PCB

• Defective indoor unit pipe sensor

n Error diagnosis and countermeasure flow chart

Is service valve

opened?

Open service valve

Are communication cable/

piping normal?

Yes

No

Is amount of refrigerant

normal?

[refer refrigerant part]

Yes

No

Adjust the amount of

refrigerant (Additive charge)

check communication/

piping correction.

Is strainer Ok?*

No

Replace the strainer

No

Replace the pressure sensor

Yes

Check indoor / outdoor unit LEV

Check Indoor unit PCB

Check indoor / outdoor unit

installation conditions

Yes

Is there pipe crack or trace

of refrigerant leakage?

Weld / reconnect the cracked

portion and recharge refrigerant

No

Yes

* If the temperature difference between inlet and outlet of strainer

is so large that frost or ice formation can be seen or confirmed

then clogging of strainer should be checked

(Notice: it is not full ice forming of strainer, in case that there is

not at inlet portion but at outlet portion)

Are the value of manifold

gauge and pressure

sensor same?

(Is the low pressure value

actually low?)

Part 5. Trouble Shooting

- 75 -

Only for training and service purposes

LGE Internal Use Only

39

Transmission Error

Between (PFC Micom ’

INV Micom)

Communication Error

Between PFC Micom

and INV Micom.

1. Micom defect/Circuit defect

2. Different Micom S/W Version

3. ODU inverter PCB assembly damage

Display

code

Title Cause of error Check point & Normal condition

n Error Diagnosis and Countermeasure Flow Chart

Is Inverter PCB assembly normal?

No

Replace inverter PCB assembly

Is PFC Micom & INV Micom

S/W Program normal?

No

Upgrade Micom Program

Yes

Recheck power and installation condition

Part 5. Trouble Shooting

- 76 -

Only for training and service purposes

LGE Internal Use Only

Check Point

1. Check the Input Voltage (L1~L2 ‘ 230V±10%)

2. Check Input Voltage Sensor output voltage (2.5Vdc±10%)

Is Inverter PCB Normal?

No

Replace inverter PCB assembly

Is input voltage normal ?

No

Check L1~L2 Voltage is 230V±15%

Yes

Recheck power and

installation condition

Yes

< Input Power Source Check Point >

L1

L2

n Error Diagnosis and Countermeasure Flow Chart

40

C/T

Sensor Error

• Initial current error

•

Malfunction of current detection circuit.

(Open / Short)

•

Check CT Sensor output voltage :

2.5Vdc ±5%

Display

code

Title Cause of error Check point & Normal condition

WARNING

Before checking PCB or each outdoor electric parts, wait for 3 minutes after the power is off. When measuring at standby state

of power supply, after checking the measurement mode of the meter, be careful of the short-circuits with other parts.

n Error Diagnosis and Countermeasure Flow Chart

Part 5. Trouble Shooting

- 77 -

Only for training and service purposes

LGE Internal Use Only

< Inverter PCB>

< CT Sensing Check Point >

36,42kBtu/h class

Vdc

18,24,30kBtu/h class

Vdc

2.5V

GND

Red

Black

INV_Cur

INV_Curr

ent

INV_Current

Part 5. Trouble Shooting

- 78 -

Only for training and service purposes

LGE Internal Use Only

Display

code

Title Cause of error Check point & Normal condition

41 D-pipe sensor (Inverter)

• Open / Short

• Soldered poorly

• Internal circuit error

1. Bad connection of thermistor connector

2. Defect of thermistor connector (Open/Short)

3. Defect of outdoor PCB

44 Air sensor

• Open / Short

• Soldered poorly

• Internal circuit error

1. Bad connection of thermistor connector

2. Defect of thermistor connector (Open/Short)

3. Defect of outdoor PCB

45

Condenser Mid-pipesen-

sor

• Open / Short

• Soldered poorly

• Internal circuit error

1. Bad connection of thermistor connector

2. Defect of thermistor connector (Open/Short)

3. Defect of outdoor PCB

46 Suction Pipe sensor

• Open / Short

• Soldered poorly

• Internal circuit error

1. Bad connection of thermistor connector

2. Defect of thermistor connector (Open/Short)

3. Defect of outdoor PCB

48

Condenser Out-pipe sen-

sor

• Open / Short

• Soldered poorly

• Internal circuit error

1. Bad connection of thermistor connector

2. Defect of thermistor connector (Open/Short)

3. Defect of outdoor PCB

Ω

Check Point

1. Estimate the resistance of each sensor.(Unplugged)

2. Check the value of the resistor of thermistor.

D-pipe sensor (Inverter) : Normal Value of the resistor is 200kΩ at 25℃

Air sensor : Normal Value of the resistor is 10kΩ at 25℃

Cond. Mid-pipe sensor : Normal Value of the resistor is 5kΩ at 25℃

Suction pipe sensor : Normal Value of the resistor is 5kΩ at 25℃

Condenser Out-pipe sensor : Normal Value of the resistor is 5kΩ at 25℃

Is sensor connected

to PCB correctly??

Is sensor value correct?*

Connect sensor to PCB correctly

Replace sensor

Replace corresponding

outdoor unit PCB

Yes

No

Yes

n Error Diagnosis and Countermeasure Flow Chart

Part 5. Trouble Shooting

- 79 -

Only for training and service purposes

LGE Internal Use Only

Display

code

Title Cause of error Check point & Normal condition

43

Sensor error of high

pressure

Abnormal value of sensor

(Open/Short)

• Bad connection of connector PCB

• Bad connection high pressure connector

• Defect of high pressure connector (Open/Short)

• Defect of connector PCB (Open/Short)

• Defect of outdoor main PCB.

Is sensor connected

to PCB correctly?

Connect sensor to PCB correctly

Replace corresponding

pressure sensor

Yes

No

Replace the pressure sensor

Yes

No

Yes

END

After replacement of outdoor

unit main PCB is the system

also abnormal?

Is pressure sensor OK?

(Check the value of

pressure sensor.

Cf. Output voltage is about

1.4V at 1500kPa)

Part 5. Trouble Shooting

- 80 -

Only for training and service purposes

LGE Internal Use Only

Check Point

1. Check the indoor unit capacity.

2. Check the combination table.

Display

code

Title Cause of error Check point & Normal condition

51 Over capacity

• Over capacity Combination

• Check the indoor unit capacity.

• Check the combination table.

Model Gross max.capacity Max.single indoor unit capacity

A2UW18GFH0 24k 15k

A3UW24GFH0 33k 24k

A4UW30GFH0 40k 24k

A5UW36GFH0 48k 24k

A6UW42GFH0 56k 36k

Part 5. Trouble Shooting

- 81 -

Only for training and service purposes

LGE Internal Use Only

53

Title

Communication

(Indoor ’ Outdoor)

• Communication poorly

• Power input AC 230V. (Outdoor, Indoor)

• The connector for transmission is disconnected.

• The connecting wires are misconnected.

• The communication line is shorted at GND.

• Transmission circuit of outdoor PCB is abnormal.

• Transmission circuit of indoor PCB is abnormal.

Display

code

Title Cause of error Check point & Normal condition

WARNING

Before checking PCB or each outdoor electric parts, wait for 3 minutes after the power is off. When measuring at standby state

of power supply, after checking the measurement mode of the meter, be careful of the short-circuits with other parts.

Check Point

1. Check the input power AC230V. (Outdoor, Indoor unit)

2. Check the communication wires are correctly connected.

Adjust the connection of wire Confirm the wire of "Live", "Neutral"

3. Check the resistance between communication line and GND. (Normal :

Over 2MΩ)

4. Check the connector for communication is correctly connected.

5. If one indoor unit is operated normally, outdoor PCB is no problem.

Check the another indoor unit.

* CH05 is displayed at indoor unit, CH53 is displayed at

outdoor unit.

6. If all indoor unit is displayed CH05 but outdoor PCB not

display

CH53 : Check the CN_COM and CN_POWER is correctly connected.

• 18,24,30kBtu/h class

1. In Case of CH53, Check the Connection

’ L1,L2 at the terminal block

• 36,42kBtu/h class

1. In Case of CH05, Check the Connection ’ CN_POWER,

CN_COMM at the Main PCB

2.

In Case of CH53, Check the Connection ’ CN_COMM at the

Main PCB ’ L1, L2 at the terminal block

< TERMINAL BLOCK >

L1

L2

< MAIN PCB >

N

CN-Power

CN-COMM

L1

L2

L1

L2

Part 5. Trouble Shooting

- 82 -

Only for training and service purposes

LGE Internal Use Only

60

Inverter PCB & Main

EEPROM check sum error

EEPROM Access error

and Check SUM error

1. EEPROM contact defect/wrong insertion

2. Different EEPROM Version

3. ODU Inverter & Main PCB assembly damage

Display

code

Title Cause of error Check point & Normal condition

n Error Diagnosis and Countermeasure Flow Chart

Is EEPROM insertion normal?

No

Yes

Recheck power and installation condition

1.Check EEPROM insert direction/connection condition

2.Check EEPROM Check SUM

→ Replace if abnormality found

Is inverter PCB assembly normal?

No

Yes

Replace inverter PCB assembly

Yes

MAIN PCB assembly normal?

No

Replace MAIN PCB assembly

Check Point

- Check the EEPROM Check sum & Direction

18,24,30kBtu/h class

EEPROM

WARNING

Before checking PCB or each outdoor electric parts, wait for 3 minutes after the power is off. When measuring at standby state

of power supply, after checking the measurement mode of the meter, be careful of the short-circuits with other parts.

Part 5. Trouble Shooting

- 83 -

Only for training and service purposes

LGE Internal Use Only

36,42kBtu/h class

Part 5. Trouble Shooting

- 84 -

Only for training and service purposes

LGE Internal Use Only

Display

code

Title Cause of error Check point & Normal condition

61

High temperature in out-

door Cond. Pipe

• Overload operation (Out-

door fan constraint,

screened, blocked)

• Outdoor unit heat ex-

changer contaminated

• EEV connector displaced

/ poor EEV assembly

• Poor Cond. Pipe sensor

assembly / burned

• Check outdoor fan constraint / screened / flow

structure

• Check if refrigerant overcharged

• Check the status of EEV assembly

• Check the status of sensor assembly / burn

CN- C/PIPE

(Violet 3Pin Connector)

Replace the Thermistor

Yes

WARNING

Before checking PCB or each outdoor electric parts, wait for 3 minutes after the power is off. When measuring at standby state

of power supply, after checking the measurement mode of the meter, be careful of the short-circuits with other parts.

Part 5. Trouble Shooting

- 85 -

Only for training and service purposes

LGE Internal Use Only

62

Heatsink High error

Inverter PCB heatsink

temperature is over 85°C

1. ODU fan locking

2. Heatsink assembly of INV PCB assemble condi-

tion abnormal

3. Defect of temperature sensing circuit part defect

of INV PCB

Display

code

Title Cause of error Check point & Normal condition

n Error Diagnosis and Countermeasure Flow Chart

Is Installation

Condition Normal?

No

1. Check Pipe Clogging/ Distortion

2. Check Covering (Outdoor/Indoor Unit)

3. Check EEV Connector Assemble Condition/Normal Operation

4. Check Refrigerant Pressure

5. Check Power Wire/ Connection Condition

Reassemble or Manage if abnormality Found

1. Check Inv. PCB Screw Connection Condition

Reassemble or Manage if abnormality Found

No

Inv. PCB IGBTM Connection

Condition Normal?

Yes

1. Check Outdoor Unit Fan Motor Operation or Lock

Reassemble or Manage if abnormality Found

No

Is ODU Fan Motor Normal?

Yes

1. Reset

Replace Inv. PCB Assembly

No

Is Inv. PCB assembly

Normal?

Yes

Recheck Power and

Installation Condition

Yes

Check Point

1. Check resistance between No.19 pin and NO.20 pin of PCB PFC module

2. Resistance value should be in 7kΩ ±10%.(at 25°C).

3. Check Inv. PCB Screw Connection Condition – only 36,42kBtu/h class

Part 5. Trouble Shooting

- 86 -

Only for training and service purposes

LGE Internal Use Only

Check Screw Connection Condition

36,42kBtu/h class

18,24,30kBtu/h class

PFCM :

Measuring resistance

between No.19,20 pin

Red

Black

10

9~11KΩ

Part 5. Trouble Shooting

- 87 -

Only for training and service purposes

LGE Internal Use Only

65

Heatsink Sensor error

Inverter PCB heatsink

sensor is open or short

1. ODU fan locking

2. Heatsink assembly of INV PCB assemble

condition abnormal

3. Defect of temperature sensing circuit part defect

of INV PCB

Display

code

Title Cause of error Check point & Normal condition

Is installation

condition normal ?

No

Yes

1. Check fan locking

2. Check covering of heat exchanger

3. Check distance between ODU and obstacles

4. Check pipe distortion and abnormality

5. Check service valve is opened

→ Eliminate causes for abnormal condition

Check resistance between NO.19 pin and NO.20 pin

of PFC module

Check resistance between NO.24 pin and NO.25 pin

of PFC module

→ 7KΩ 10%(at 25°C)

→ Replace PCB if abnormality found

Is assemble condition

of INV PCB heatsink normal ?

Is PCB temperature

sensing part normal ?

No

Yes

Check assemble condition between INV PCB heatsink and

IGBTM Module

→ Reassemble if abnormality found

Recheck installation condition

and connection of Heat sink

Yes

n Error Diagnosis and Countermeasure Flow Chart

Check Point

1. Check resistance between No.19 pin and NO.20 pin of PCB PFC module

2. Resistance value should be in 7kΩ ±10%.(at 25°C).

3. Check the PFC Module No.19, 20.

Part 5. Trouble Shooting

- 88 -

Only for training and service purposes

LGE Internal Use Only

67

Fan Lock Error

Fan RPM is 10RPM or

less for 5 sec. when ODU

fan starts or 40 RPM or

less after fan starting.

1. ODU fan locking

2. Heatsink assembly of INV PCB assemble condi-

tion abnormal

3. Defect of temperature sensing circuit part defect

of INV PCB

Display

code

Title Cause of error Check point & Normal condition

Is ODU Fan Motor Assemble

condition normal?

No

Yes

Recheck power and installation condition

Check ODU Fan Motor assemble condition and fan locking

→ Reassemble or replace if abnormality found

Is ODU Fan Motor normal?

No

Yes

1. Set the multi tester to diode mode.

2. Check voltage between 1pin and 4pin of Fan Motor

(1Ţ0.2V)

3. Replace Inverter PCB if abnormality found.

Is wire connection of

ODU Fan Motor wire normal?

No

Yes

Check wiring between OUD fan motor and Inverter PCB

( Check if Hall Senor and Motor output terminal color is

matched)

→Reassemble if abnormality found

Is Inverter PCB assembly normal?

No

Yes

Replace Inverter PCB assembly

n Error Diagnosis and Countermeasure Flow Chart

Check Point

1. Check voltage between 1pin and 4pin of Fan Mortor connector (Tester diode mode)

2. Voltage value should be in 1V ±0.2V.

3. Do not replacing all of fan motor and PCB at once.

Check error code again, after replacing the abnormal part (Fan Motor or PCB) first.

Part 5. Trouble Shooting

- 89 -

Only for training and service purposes

LGE Internal Use Only

36,42kBtu/h class

18,24,30kBtu/h class

Tester

Fan motor

connector

Check voltage betwen

1pin and 4pin of fan motor

-. Checking wire

terminals for

possible short

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ᴬᴬ

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d@Ẹ

@Ẹ

d@Ẹ

@Ẹ

d@Ẹ

@Ẹ

ڽڻ

ᴬᴬ

ھڻ

ڸڻڼڽھ

Part 5. Trouble Shooting

- 90 -

Only for training and service purposes

LGE Internal Use Only

73

AC input instant over cur-

rent error

(Matter of software)

Inverter PCB input power

current is over 48A(peak)

for 2ms

1. Overload operation (Pipe clogging/Covering/EEV

defect/Ref.overcharge)

2. Compressor damage

(Insulation damage/Motor damage)

3. Input voltage abnormal (L, N)

4. Power line assemble condition abnormal

5. Inverter PCB assembly damage

(input current sensing part)

Display

code

Title Cause of error Check point & Normal condition

n Error Diagnosis and Countermeasure Flow Chart

No

1.Check Pipe clogging/distortion

2.Check Covering (Indoor/Outdoor Unit)

3.Check EEV connector assemble condition/normal operation

4.Check refrigerant pressure

→ Reassemble or manage if abnormality found

Is installation

condition normal?

Is compressor

Wire connection

condition normal?

1.Check inverter PCB assembly U,V,W connector connection condition

2.Check wire disconnection and wiring

3.Check compressor terminal connection condition(bad contact)

→ Reassemble if abnormality found

Is AC input Wire connection

condition normal?

1.Check L1,L2 connection condition

2.Check wire disconnection and wiring

→ Reassemble if abnormality found

Is inverter PCB assembly

normal?

Yes

No

Recheck power and

installation condition

Yes

No

Yes

No

Check

L1~L2 phase voltage is 230V ± 15%

→ Check connection condition and wiring if power is abnormal

Is input voltage normal?

Check inverter PCB assembly IPM normality

→ Replace inverter PCB assembly

Part 5. Trouble Shooting

- 91 -

Only for training and service purposes

LGE Internal Use Only

< Input Power Source Check Point >

< Main PCB wiring Check Point >

< Noise Filter wiring Check Point >

OUT

IN

18,24,30kBtu/h class

IN

OUT

L1

L2

Part 5. Trouble Shooting

- 92 -

Only for training and service purposes

LGE Internal Use Only

< Noise Filter wiring Check Point >

< Main PCB wiring Check Point >

< Input Power Source Check Point >

< Inverter PCB wiring Check Point >

L2

L1

L2

L2 L1

L1

36,42kBtu/h class

L1 L2L2 L1 L2 L1

L1 L2

L1

L2

LG Electronics LG3ZMSS288 Quad Zone Mini Split System

Product's Documents

Owners Guide

Specifications

LG Electronics LG3ZMSS288 Questions and Answers