LG Multi V Water V ARWM072CAS5 User manual

Outdoor Unit
SERVICE MANUAL
CAUTION
Before Servicing the unit, read the safety precautions in General SVC manual.
Only for authorized service personnel.
R410A
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modification, copying or transmission of this Service Manual is STRICTLY PROHIBITED unless you have obtained
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covered by this prohibition includes, without limitation, any text, graphics or logos in this Service Manual.
Copyright © 2020 LG Electronics Inc. All rights reserved. Only training and service purposes.

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Copyright © 2020 LG Electronics. Inc.
All right reserved. Only for training and service purposes
Air Conditioner Service Manual
TABLE OF CONTENTS
Safety Precautions .....................................................................................................3
Part 1 General Information ........................................................................................8
Part 2 Outdoor units.................................................................................................16
Part 3 HR Units ........................................................................................................44
Part 4 PCB Setting and Test Run ........................................................................... 55
Part 5 Trouble shooting guide................................................................................ 87

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Copyright © 2020 LG Electronics. Inc.
All right reserved. Only for training and service purposes
Safety Precautions
Safety Precautions
To prevent injury to the user or other people and property damage, the following instructions must
be followed.
nIncorrect operation due to ignoring instruction will cause harm or damage. The seriousness is
classified by the following indications.
nMeanings of symbols used in this manual are as shown below.
WARNING
CAUTION
This symbol indicates the possibility of death or serious injury.
This symbol indicates the possibility of injury or damage to properties only.
Be sure not to do.
Be sure to follow the instruction.
WARNING
nInstallation
Have all electric work done by a licensed
electrician according to "Electric Facility
Engineering Standard" and "Interior Wire
Regulations" and the instructions given in
this manual and always use a special circuit.
• If the power source capacity is inadequate or
electric work is performed improperly, electric
shock or fire may result.
Ask the dealer or an authorized technician to
install the air conditioner.
• Improper installation by the user may result in
water leakage, electric shock, or fire.
Always ground the product.
• There is risk of fire or electric shock.
Always intstall a dedicated circuit and breaker.
• Improper wiring or installation may cause fire or
electric shock.
For re-installation of the installed product,
always contact a dealer or an Authorized
Service Center.
• There is risk of fire, electric shock, explosion, or
injury.
Do not install, remove, or re-install the unit
by yourself (customer).
• There is risk of fire, electric shock, explosion, or
injury.

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Copyright © 2020 LG Electronics. Inc.
All right reserved. Only for training and service purposes
Safety Precautions
Do not store or use flammable gas or
combustibles near the air conditioner.
• There is risk of fire or failure of product.
Use the correctly rated breaker or fuse.
• There is risk of fire or electric shock.
Prepare for strong wind or earthquake and
install the unit at the specified place.
• Improper installation may cause the unit to top-
ple and result in injury.
Do not install the product on a defective
installation stand.
• It may cause injury, accident, or damage to the
product.
When installing and moving the air condition-
er to another site, do not charge it with a
different refrigerant from the refrigerant
specified on the unit.
• If a different refrigerant or air is mixed with the
original refrigerant, the refrigerant cycle may
malfunction and the unit may be damaged.
Do not reconstruct to change the settings of
the protection devices.
• If the pressure switch, thermal switch, or other
protection device is shorted and operated
forcibly, or parts other than those specified by
LGE are used, fire or explosion may result.
Ventilate before operating air conditioner
when gas leaked out.
• It may cause explosion, fire, and burn.
Securely install the cover of control box and
the panel.
• If the cover and panel are not installed securely,
dust or water may enter the Outdoor unit and fire
or electric shock may result.
If the air conditioner is installed in a small
room, measures must be taken to prevent the
refrigerant concentration from exceeding the
safety limit when the refrigerant leaks.
• Consult the dealer regarding the appropriate
measures to prevent the safety limit from being
exceeded. Should the refrigerant leak and cause
the safety limit to be exceeded, harzards due to
lack of oxygen in the
room could result
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 gas es.
Otherwise, it may cause fire or explosion.
• There is the risk of death, injury, fire or explo-
sion.

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Copyright © 2020 LG Electronics. Inc.
All right reserved. Only for training and service purposes
nOperation
Safety Precautions
Do not damage or use an unspecified power cord.
• There is risk of fire, electric shock, explosion, or
injury.
Use a dedicated outlet for this appliance.
• There is risk of fire or electrical shock.
Be cautious that water could not enter the product.
• There is risk of fire, electric shock, or product
damage.
Do not touch the power switch with wet hands.
• There is risk of fire, electric shock, explosion, or
injury.
When the product is soaked (flooded or
submerged), contact an Authorized Service
Center.
• There is risk of fire or electric shock.
Be cautious not to touch the sharp edges
when installing.
• It may cause injury.
Take care to ensure that nobody could step
on or fall onto the Outdoor unit.
• This could result in personal injury and product
damage.
Do not open the inlet grille of the product
during operation. (Do not touch the electro-
static filter, if the unit is so equipped.)
• There is risk of physical injury, electric shock, or
product failure.
CAUTION
nInstallation
Always check for gas (refrigerant) leakage
after installation or repair of product.
• Low refrigerant levels may cause failure of
product.
Do not install the product where the noise or
hot air from the Outdoor unit could damage
the neighborhoods.
• It may cause a problem for your neighbors.
Keep level even when installing the product.
• To avoid vibration or water leakage.
Do not install the unit where combustible gas
may leak.
• If the gas leaks and accumulates around the
unit, an explosion may result.

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Copyright © 2020 LG Electronics. Inc.
All right reserved. Only for training and service purposes
Safety Precautions
Use power cables of sufficient current
carrying capacity and rating.
• Cables that are too small may leak, generate
heat, and cause a fire.
Do not use the product for special purposes,
such as preserving foods, works of art, etc. It
is a consumer air conditioner, not a precision
refrigeration system.
• There is risk of damage or loss of property.
Keep the unit away from children. The heat
exchanger is very sharp.
• It can cause the injury, such as cutting the finger.
Also the damaged fin may result in degradation
of capacity.
When installting the unit in a hospital, com-
munication station, or similar place, provide
sufficient protection against noise.
•
The inverter equipment, private power generator,
high-frequency medical equipment, or radio com-
munication equipment may cause the air condition-
er to operate erroneously, or fail to operate. On the
other hand, the air conditioner may affect such
equipment by creating noise that disturbs medical
treatment or image broadcasting.
Do not install the product where it is exposed to sea wind (salt spray) directly.
• It may cause corrosion on the product. Corrosion, particularly on the condenser and evaporator fins,
could cause product malfunction or inefficient operation.
nOperation
Do not use the air conditioner in special
environments.
• Oil, steam, sulfuric smoke, etc. can significantly
reduce the performance of the air conditioner or
damage its parts.
Do not block the inlet or outlet.
• It may cause failure of appliance or accident.
Make the connections securely so that the
outside force of the cable may not be applied
to the terminals.
• Inadequate connection and fastening may gen-
erate heat and cause a fire.
Be sure the installation area does not deteri-
orate with age.
• If the base collapses, the air conditioner could
fall with it, causing property damage, product
failure, or personal injury.

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Copyright © 2020 LG Electronics. Inc.
All right reserved. Only for training and service purposes
Safety Precautions
Install and insulate the drain hose to ensure
that water is drained away properly based on
the installation manual.
• A bad connection may cause water leakage.
Be very careful about product transportation.
• Only one person should not carry the product if it weighs
more than 20 kg.
• Some products use PP bands for packaging. Do not use any
PP bands for a means of transportation. It is dangerous.
• Do not touch the heat exchanger fins. Doing so may cut
your fingers.
• When transporting the Outdoor unit, suspending it at the
specified positions on the unit base. Also support the
Outdoor unit at four points so that it cannot slip sideways.
Safely dispose of the packing materials.
•
Packing materials, such as nails and other metal or
wooden parts, may cause stabs or other injuries.
• Tear apart and throw away plastic packaging bags
so that children may not play with them. If children
play with a plastic bag which was not torn apart,
they face the risk of suffocation.
Turn on the power at least 6 hours before
starting operation.
• Starting operation immediately after turning on
the main power switch can result in severe
damage to internal parts. Keep the power switch
turned on during the operational season.
Do not touch any of the refrigerant piping
during and after operation.
• It can cause a burn or frostbite.
Do not operate the air conditioner with the
panels or guards removed.
• Rotating, hot, or high-voltage
parts can cause injuries.
Do not directly turn off the main power
switch after stopping operation.
• Wait at least 5 minutes before turning off the
main power switch. Otherwise it may result in
water leakage or other problems.
Auto-addressing should be done in condition of
connecting the power of all indoor and outdoour
units. Auto-addressing should also be done in
case of changing the indoor unit PCB.
Use a firm stool or ladder when cleaning or
maintaining the air conditioner.
• Be careful and avoid personal injury.
Do not insert hands or other objects through
the air inlet or outlet while the air conditioner
is plugged in.
• There are sharp and moving parts that could
cause personal injury.

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Copyright © 2020 LG Electronics. Inc.
All right reserved. Only for training and service purposes
Part 1
General Information
1. Model Names ..................................................................................9
1.1 Indoor Unit.................................................................................9
1.2 Outdoor unit.............................................................................10
1.3 HR Unit....................................................................................10
2. External Appearance .....................................................................11
2.1 Indoor Unit ...............................................................................11
2.2 Outdoor unit.............................................................................12
3. Combination of Outdoor units .....................................................13
4. Nomenclature.................................................................................14
4.1 Indoor Unit...............................................................................14
4.2 Outdoor unit.............................................................................14
4.3 HR Unit....................................................................................15

Model Names
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Copyright © 2020 LG Electronics. Inc.
All right reserved. Only for training and service purposes
1. Model Names
1.1 Indoor Unit
h*Wall Mounted - L : Basic, R : Mirror
*Ceiling Cassette - A : Basic, C : Plasma
*Ceiling Concealed Duct - A : Basic, Z : FAU
Category Chassis
Name
Capacity[Btu/h(kW)]
5.5
(1.6)
7.2
(2.2)
9.6
(2.8)
12.3
(3.6)
15.4
(4.5)
19.1
(5.6)
24.2
(7.1)
28.0
(8.2)
30.0
(8.8)
36.2
(10.6)
42.0
(12.3)
48.1
(14.1)
54.0
(15.8)
76.4
(22.4)
96.5
(28.0)
Wall Mounted
SJ
ARNU053SJ*4 ARNU073SJ*4 ARNU093SJ*4 ARNU123SJ*4 ARNU153SJ*4
SK ARNU183SK*4 ARNU243SK*4
SV ARNU303SVA4 ARNU363SVA4
ART
COOL SF
ARNU093SFA4 ARNU123SFA4
Ceiling
Cassette
1 Way
TU
ARNU073TUC4 ARNU093TUC4 ARNU123TUC4
TT ARNU183TTC4 ARNU243TTC4
2 Way TL ARNU183TLC4 ARNU243TLC4
4 Way
TR
ARNU053TRC4 ARNU073TRC4 ARNU093TRC4 ARNU123TRC4
TQ ARNU153TQC4 ARNU183TQC4
TP ARNU243TPC4 ARNU283TPC4
TN ARNU073TNA4 ARNU093TNA4 ARNU123TNA4 ARNU153TNA4 ARNU183TNA4 ARNU243TNA4 ARNU363TNA4
TM ARNU243TMA4 ARNU283TMA4 ARNU363TMA4 ARNU423TMA4 ARNU483TMA4
Ceiling
Concealed
Duct
High
Static
BH
ARNU073BHA4 ARNU093BHA4 ARNU123BHA4 ARNU153BHA4 ARNU183BHA4 ARNU243BHA4
BG ARNU073BGA4 ARNU093BGA4 ARNU123BGA4 ARNU153BGA4 ARNU183BGA4 ARNU243BGA4 ARNU283BGA4 ARNU363BGA4 ARNU423BGA4
BR ARNU283BRA4 ARNU363BRA4 ARNU423BRA4 ARNU483BR*4 ARNU543BRA4
B8 ARNU363B8A4 ARNU423B8A4 ARNU483B8A4 ARNU763B8*4 ARNU963B8*4
Low
Static
L1
ARNU073L1G4 ARNU093L1G4
L2 ARNU123L2G4 ARNU153L2G4 ARNU183L2G4
L3 ARNU243L3G4
Middle
Static
M2 ARNU073M2A4 ARNU093M2A4 ARNU123M2A4 ARNU153M2A4 ARNU183M2A4 ARNU243M2A4 ARNU283M2A4 ARNU363M2A4 ARNU423M2A4
M3 ARNU283M3A4 ARNU363M3A4 ARNU423M3A4 ARNU483M3A4 ARNU543M3A4
Built
In
B3
ARNU073B3G4 ARNU093B3G4 ARNU123B3G4 ARNU153B3G4
B4 ARNU183B4G4 ARNU243B4G4
Ceiling & Floor VE ARNU093VEA2 ARNU123VEA2
Ceiling Suspended VJ ARNU183VJA2 ARNU243VJA2
Floor
Standing
With
Case
CE
ARNU073CEA4 ARNU093CEA4 ARNU123CEA4 ARNU153CEA4
CF ARNU183CFA4 ARNU243CFA4
Without
Case
CE
ARNU073CEU4 ARNU093CEU4 ARNU123CEU4 ARNU153CEU4
CF ARNU183CFU4 ARNU243CFU4
Vertical AHU
NJ
ARNU123NJA4 ARNU183NJA4 ARNU243NJA4 ARNU303NJA4 ARNU363NJA4
NK ARNU423NKA4 ARNU483NKA4 ARNU543NKA4

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Copyright © 2020 LG Electronics. Inc.
All right reserved. Only for training and service purposes
Model Names
1.2 Outdoor Unit
1.3 HR Unit
Heat Pump ARWM
Heat Recovery
Power Supply 24 HP
(20 Ton)
28 HP
(24 Ton)
34 HP
(28 Ton)
43 HP
(36 Ton)
46 HP
(16 Ton)
54 HP
(48 Ton)
3 Ph, 575 V, 60 Hz 240CAS5 288CAS5 336CAS5 432CAS5 480CAS5 576CAS6
Power Supply 8 HP
(6 Ton)
10 HP
(8 Ton)
12 HP
(10 Ton)
14 HP
(12 Ton)
20 HP
(16 Ton)
3 Ph, 575 V, 60 Hz 072CAS5 096CAS5 121CAS5 144CAS5 192CAS5
Power Supply 2 branches 3 branches 4 branches
1 Ph, 208/230 V, 60 Hz PRHR022A PRHR032A PRHR042A
Power Supply 2 branches 3 branches 4 branches
1 Ph, 220-240 V, 50 Hz / 1 Ph, 220 V, 60 Hz PRHR023 PRHR033 PRHR043
1 Ph, 208/230 V, 60 Hz PRHR023A PRHR033A PRHR043A
Power Supply 6 branches 8 branches
1 Ph, 220-240 V, 50 Hz / 1 Ph, 220 V, 60 Hz PRHR063 PRHR083
1 Ph, 208/230 V, 60 Hz PRHR063A PRHR083A