LG MULTIV III User manual

Heat Recovery Unit
SERVICE MANUAL
MODEL : PRHR041/PRHR041A
PRHR031/PRHR031A
PRHR021/PRHR021A
CAUTION
Before Servicing the unit, read the safety precautions in General SVC manual.
Only for authorized service personnel.
Internal Use Only
http://biz.lgservice.com
R410A

Air Conditioner Service Manual
TABLE OF CONTENTS
Safety Precautions .....................................................................................................3
Part 1 General Information ........................................................................................5
Model Names ...............................................................................................................................6
External Appearance ...................................................................................................................7
Nomenclature ...............................................................................................................................8
Part 2 HR Units ...........................................................................................................9
Part 3 PCB Setting....................................................................................................19
Part 4 Trouble shooting guide................................................................................ 35
Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
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Safety Precautions
Safety Precautions
To prevent injury to the user or other people and property damage, the following instructions must
be followed.
■Incorrect operation due to ignoring instruction will cause harm or damage. The seriousness is
classified by the following indications.
■Meanings 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
■Installation
Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
- 3 -
When installing and moving the air conditioner to
another site, do not charge it with a different refrig-
erant 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.
R22
R407C
R410A
■Operation
Do not damage or use an unspecified power
cord.
• There is risk of fire, electric shock, explosion, or
injury.
Do not touch the power switch with wet
hands.
• There is risk of fire, electric shock, explosion, or
injury.

Safety Precautions
Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
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CAUTION
■Operation
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.
Avoid a place where rain may enter since the
HR unit is for indoor
• There is risk of property damage, failure of prod-
uct or electric shock.
Install the HR unit at a place in which it is not
affected by operation mode changing noise.
• Installation within cell such as meeting room etc,
may disturb business due to noise.

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Part 1
General Information
1. Model Names ..................................................................6
2. External Appearance.......................................................7
3. Nomenclature...................................................................8

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Power Supply 2 branches 3 branches 4 branches
1Ø, 220-240V, 50Hz / 1Ø, 220V, 60Hz PRHR021 PRHR031 PRHR041
1Ø, 208/230V, 60Hz PRHR021A PRHR031A PRHR041A
1. Model Names
1.1 HR Unit
Model Names

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
External Appearance
2. External Appearance
2.1 HR Unit
2 branches 4 branches
123
124
3 branches
123
PRHR021/PRHR021A PRHR031/PRHR031A PRHR041/PRHR041A

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Serial Number
No. of Connected branches
02 : For 2 branches
03 : For 3 branches
04 : For 4 branches
Indicates that this is System
HR Unit using the R410A
PRHR 04 1
Serial Number
No. of Connected branches
02 : For 2 branches
03 : For 3 branches
04 : For 4 branches
Indicates that this is System
HR Unit using the R410A
PRHR 04 1 A
Nomenclature
3. Nomenclature
3.1 HR Unit

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Part 2
HR Units

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
1. Specifications ................................................................................................................11
2. Parts Functions .............................................................................................................12
3. Dimensions ....................................................................................................................13
4. Piping Diagrams ............................................................................................................14
5. Wiring Diagrams............................................................................................................15
6. Electric Characteristics ................................................................................................16
7. Functions .......................................................................................................................17
HR Units

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Specifications
1. HR Unit
Specifications
Notes:
1. Voltage range : Units are suitable for sue on electrical systems where voltage supplied to units terminals is not below or
above listed range limits.
2. Maximum allowable voltage unbalance between phases is 2%
Model
Max. Connectable No. of Indoor Units
Max. Connectable No. of Indoor Units of a branch
Net. Weight kg
lbs
Dimensions mm
(WxHxD) Inch
Casing
Connecting Pipes Indoor Liquid Pipe [mm/inch]
Gas Pipe [mm/inch]
Outdoor Liquid [mm/inch]
Low Pressure [mm/inch]
High Pressure [mm/inch]
Sound Absorbing Insulation Material
Power Supply
PRHR021/PRHR021A PRHR031/PRHR031A PRHR041/PRHR041A
16 24 32
888
18 20 22
39.7 44.1 48.5
801x218x617 801x218x617 801x218x617
31.5x8.6x24.3 31.5x8.6x24.3 31.5x8.6x24.3
Galvanized steel plate
Ø9.52[3/8]
Ø15.88[5/8]
Ø9.52[3/8] Ø12.7[1/2] Ø15.88[5/8]
Ø22.2[7/8] Ø28.58[1 1/8] Ø28.58[1 1/8]
Ø19.05[3/4] Ø22.2[7/8] Ø22.2[7/8]
Polyethylene Foam
1Ø, 220-240V, 50Hz / 1Ø, 220V, 60Hz(PRHR041, PRHR031, PRHR021)
1Ø, 208/230V, 60Hz(PRHR041A, PRHR031A, PRHR021A)

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Parts Functions
Prevent liquid chargingLBVLiquid bypass valve
Control the subcoolingSCEEVSubcooling EEV
Control the pressure between High and Low
pressure pipe during operation switching
BLVBalancing valve
Gas pipe connected with indoor unitGSPGas pipe
Liquid pipe connected with indoor unitLP2Liquid pipe 2
Control the path for heating or coolingSOL1, 2Solenoid assembly 1, 2
Liquid pipe connected with outdoor unitLP1Liquid pipe 1
Pipe for high pressure gasHPGVHigh pressure gas pipe
Pipe for low pressure gasLPGVLow pressure gas pipe
Major functionSymbolParts name
Balancing valve
Low pressure gas pipe
High pressure gas pipe
Liquid bypass valve
Solenoid assembly 1
Solenoid assembly 2
Liquid pipe1
Gas pipe
Liquid pipe2
Subcooling EEV
Parts Functions
1. Parts Functions

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
1. HR Units
Dimensions
480(18-29/32) 137(5-13/32)
345(13-19/32)
481(18-15/16)
218(8-19/32)
38(1-1/2)
60(2-3/8)30(1-3/16)
174(6-27/32)
453(17-27/32)204(8-1/32)
98(3-27/32)
CHASSIS CODE:
Outdoor Unit
PRHR041/PRHR041A PRHR031/PRHR031A PRHR021/PRHR021A
76, Seongsan-dong, Changwon City, Gyeongnam,
641-713, Korea
Dimensions

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Piping Diagrams
s
s
s
ss
sss
s
s
s
s
s
Low pressure gas pipe
Liquid pipe
High pressure gas pipe
Liquid pipe Gas pipe Liquid pipe Gas pipe Liquid pipe Gas pipe Liquid pipe Gas pipe
sSolenoid
EEV
Sensor
A
B
C
D
1. HR Unit
Piping Diagrams
Ⓐ: To be switched operation between cooling and heating by two Solenoid valve
Ⓑ: To be used decreasing noise according to sub-cooling of inlet and outlet of indoor unit
(Simultaneous operation)
Ⓒ: To prevent liquid charging between high pressure gas valve and HR unit at cooling mode
Ⓓ: To be controlled the pressure between high and low pressure pipe during operation switching

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
1Ø 220V-240V, 50Hz
/ 220V, 60Hz
1Ø 208/230V,60Hz
Wiring Diagrams
1. HR Units
Wiring Diagrams
CN04 Solenoid valve 01L/H(For room1)
CN05 Solenoid valve 02L/H(For room2)
CN06 Solenoid valve 03L/H(For room3)
CN07 Solenoid valve 04L/H(For room4)
CN08 Solenoid valve 01 (Bypass for room1)
CN09 Solenoid valve 02 (Bypass for room2)
CN10 Solenoid valve 03 (Bypass for room3)
CN11 Solenoid valve 04 (Bypass for room4)
CN12 Solenoid valve bypass
CN14 Sub cooling EEV
CN16(SC Out) Sensor, sub cooling out
CN16(SC In) Sensor, sub cooling in
CN18(Liquid) Sensor, liquid receiver
SW01M Solonoid valve number Setting(When manual address)
SW02M(1) Selecting, auto address() or manual address()
SW02M(2~3) Setting, total number of indoor connected
SW03M Setting, the address of indoor_10(When manual address)
SW04M Setting, the address of indoor_1(When manual address)
SW05M Setting, HR unit number

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Electric Characteristics
1. HR Units
Electric Characteristics
Symbols:
MCA: Minimum Circuit Amperes (A)
MFA : Maximum Fuse Amperes(see note 5)
kW : Fan Motor Rated Output(kW)
FLA : Full Load Amperes(A)
IFM : Indoor Fan Motor
Note :
1. Voltage Range
Units are suitable for use on electrical system where voltage supplied to unit terminals is not below or above the
listed range limits.
2. Maximum allowable voltage unbalance between phase is 2%.
3. MCA/MFA
MCA = 1.25 x FLA
MFA ≤ 4 x FLA
(Next lower standard fuse rating. Minimum 15A)
4. Select wire size based on the MCA.
5. Instead of fuse, use Circuit Breaker.
Units Power Supply IFM Input(W)
Model Hz Volts Voltage Range MCA MFA kW FLA Cooling Heating
PRHR021
50 220 Max: 242
Min: 198
0.115- -1414
PRHR031 0.15 15 - - 21 21
PRHR041 0.2 15 - - 28 28
Units Power Supply IFM Input(W)
Model Hz Volts Voltage Range MCA MFA kW FLA Cooling Heating
PRHR021A
60 208/230 Max: 252
Min: 187
0.115- -1414
PRHR031A 0.15 15 - - 21 21
PRHR041A 0.2 15 - - 28 28

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
1.1 Normal Operation
1.2 Starting Control(Heating Mode Only)
If the system is operated in the heating mode, all high pressure gas valves are opened
1.3 Valve Control
Mode change timer is calculated as Table 1, and valves are controlled by Mode change timer according to
Table 2.
1. Basic Control
Open
Open
Close
Cooling
operation Stop state
Heating
operation
Power onActuator
KeepOpenCloseHigh pressure gas valve
KeepClose
After 30 sec.
Open
Low pressure gas valve
CloseCloseCloseLiquid valve
Mode change timerChanging modePrevious mode
180 secHeatingCooling mode
120 secCoolingHeating mode
During heating : 60 sec
During cooling : 0 sec
Stop or ventilationCooling or heating
120 secCooling or heatingStop or ventilation
Balancing
valve
L/P gas
valve
H/P gas
valve
Mode change
timer
Operating
mode
CloseKeepKeep180 ≤timer
Heating CloseCloseClose0 < timer < 180
CloseCloseOpentimer = 0
Keep
Open
Close
Keep
Close
Keep Close
Close
Open
Close
Closetimer = 0
Close0 < timer < 120
Cooling mode :
Close
Heating mode :
Low pressure
gas valve
➠Close
0 < timer ≤5
Timer = 0
Stop or
ventilation
Keep120 ≤timer
Cooling
Table 2. Valve control by mode change timer
Table 1. Mode change timer calculation
Functions
Functions

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Functions
2.1 Oil Return/Defrost Control
2.2 Liquid Bypass Control
2.3 Subcooling EEV Control
Target : about 25°C
Subcooling EEV works with Fuzzy rules to keep the degree of subcooling at the outlet of subcooler during
simultaneous operation
The degree of subcooler = T outlet of subcooler – T inlet of subcooler
Open or CloseCloseKeepHigh pressure gas valve
Close
Open
60 Hz
Running EndingStartingComponent
40 HzStopInverter compressor
Open or CloseKeepLow pressure gas valve
CloseOpen for 30sBalancing valve
Are whole indoor units
operating
cooling mode?
Solenoid valve open
for liquid bypass
(High pressure gas →
Low pressure gas valve)
Indoor units operating
Yes
No
2. Special Control

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Part 3
PCB Setting

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Copyright ©2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
HR Unit PCB ........................................................................................................................21
1. Switch for Setup of HR Unit ..................................................................................21
2. Method for Addressing of Indoor and HR Unit....................................................26
3. Flow Chart for Auto-Addressing of Indoor and HR Unit ....................................28
4. Example of Manual Valve Addressing(Non-Zoning setting) ..............................31
5. Example of Manual Valve addressing(Zoning setting) .......................................32
6. Example of Checking Valve Address ...................................................................33
7. Identification of Manual Valve ID (Address) ........................................................33
8. Method of checking the pipe detection result at outdoor unit ..........................33
9. Setting method of Master indoor unit in zoning .................................................34
PCB Setting