42 | ELECTRICAL CONNECTIONS
ELECTRICAL CONNECTIONS | 43
Electrical Connections
MUL
TI V W
ater V W
ater Source Unit Engineering Manual
© LG Electronics Canada, Inc., North York, ON Canada. All rights reserved. “LG” is a registered trademark of LG Corp.
© LG Electronics Canada, Inc., North York, ON Canada. All rights reserved. “LG” is a registered trademark of LG Corp.
Figure 10: Example of a Typical Heat Recovery Configuration Power Wiring and Communications Cable Schematic.
WARNING
SYSTEM FOR HEAT RECOVERY
CONFIGURATION, 575V
• Ground wiring is required to prevent accidental electrical shock during current leakage, communication problems from electrical noise, and
motor current leakage.
Do not connect the ground line to the pipes. There is risk of fire, electric shock, explosion, physical injury or death.
• Install a main shutoff switch that interrupts all power sources simultaneously. There is risk of fire, electric shock, explosion, physical injury
or death.
• Communication cable between Master ODU to Slave ODU(s), and Master ODU to IDUs / HRUs to be 18 AWG, 2-conductor, twisted, strand-
ed, shielded. Ensure the communication cable shield is properly grounded to the Master ODU chassis only. Do not ground the ODU to
IDUs / HRUs communication cable at any other point. Wiring must comply with all applicable local and national codes. Inadequate connec-
tions may generate heat, cause a fire, and physical injury or death.
• The GND terminal at the main PCB is a negative terminal for dry contact, not a ground. Inadequate connections may generate heat, cause
a fire, and physical injury or death.
• Make sure that the terminal numbers of master water source unit and slave water source unit(s) match (A to A, B to B). The system will
malfunction if not properly wired.
• Maintain polarity throughout the communication network. The system will malfunction if not properly wired.
• If the system operates in reversed phase, it may break the compressors and other components.
• If there is a possibility of reversed phase, phase loss, momentary blackout, or the power goes on and off while the system is operating, install
a field-supplied phase loss protection circuit. Operating the system in reverse phase may break the compressor and other unit components.
Master WSU
Indoor Units
Main Switch
Slave 1 WSU
Slave 2 WSU
Pull Box
(Installer option)
R
(L1)
L1
L2
Switch
Fuse
Switch
Fuse
Switch
Fuse
S
(L2)
T
(L3)
R
(L1)
S
(L2)
T
(L3)
R
(L1)
S
(L2)
T
(L3)
Power Supply
3 Phase, 60Hz
575V
Power Supply
1 Phase, 60Hz
208/230V
Heat
Recovery
Unit
Pull Box
(Installer
option)
Pull Box
(Installer
option)
Pull Box
(Installer
option)
Power Cable:
Communication Cable:
Heat Recovery Unit
3(A) 4(B)
A
B
3(A) 4(B)
B
ODU
IDU
CENTRAL
DRY1 DRY2 GND 12 V
A
B
A
B
A
B
DRY1 DRY2 GND 12 V
A
B
A
B
A
B
DRY1 DRY2 GND 12 V
A
B
A
B
A
Heat Recovery Operation
Communications Cable Between Master Outdoor Unit and
Heat Recovery Units / Indoor Units
Communications Cable Between Master Outdoor Unit and Slave Outdoor Unit(s)
B
ODU
IDU
CENTRAL DRY1 DRY2 GND 12 V
A
B
A
B
A
Master Outdoor Unit Communication Terminal Block
Master Outdoor Unit Communication Terminal Block
Slave 1 Outdoor Unit Communication Terminal Block
Slave 2 Outdoor Unit Communication Terminal Block
Indoor Unit
Indoor Unit
ODU
IDU
CENTRAL
ODU
IDU
CENTRAL
For Heat Recovery Unit information, refer
to the applicable Engineering Manual on
www.lghvac.com
.
Figure 9: Example of a Typical Heat Pump Configuration Power Wiring and Communications Cable Schematic.
SYSTEM FOR HEAT PUMP
CONFIGURATION, 575V
• Ground wiring is required to prevent accidental electrical shock during current leakage, communication problems from electrical noise, and
motor current leakage.
Do not connect the ground line to the pipes. There is risk of fire, electric shock, explosion, physical injury or death.
• Install a main shutoff switch that interrupts all power sources simultaneously. There is risk of fire, electric shock, explosion, physical injury
or death.
• Communication cable between Master ODU to Slave ODU(s), and Master ODU to IDUs to be 18 AWG, 2-conductor, twisted, stranded,
shielded. Ensure the communication cable shield is properly grounded to the Master ODU chassis only. Do not ground the ODU to IDUs
communication cable at any other point. Wiring must comply with all applicable local and national codes. Inadequate connections may
generate heat, cause a fire, and physical injury or death.
• The GND terminal at the main PCB is a negative terminal for dry contact, not a ground. Inadequate connections may generate heat, cause
a fire, and physical injury or death.
WARNING
• Make sure that the terminal numbers of master water source unit and slave water source unit(s) match (A to A, B to B). The system will
malfunction if not properly wired.
• Maintain polarity throughout the communication network. The system will malfunction if not properly wired.
• If the system operates in reversed phase, it may break the compressors and other components.
• If there is a possibility of reversed phase, phase loss, momentary blackout, or the power goes on and off while the system is operating, install
a field-supplied phase loss protection circuit. Operating the system in reverse phase may break the compressor and other unit components.
Master WSU
Indoor Units
Main Switch
Slave 1 WSU
Slave 2 WSU
Pull Box
(Installer option)
R
(L1)
Switch
Switch
Switch
Fused
Disconnect
S
(L2)
T
(L3)
R
(L1)
S
(L2)
T
(L3)
R
(L1)
S
(L2)
T
(L3)
Power Supply
3 Phase, 60Hz
575V
Power Supply
1 Phase, 60Hz
208/230V
Pull Box
(Installer
option)
Pull Box
(Installer
option)
Pull Box
(Installer
option)
Power Cable:
Communication Cable:
Fused
Disconnect
Fused
Disconnect
L1
L2
Heat Pump Operation
Communications Cable Between Master Outdoor Unit and Indoor Unit
B
ODU
IDU
CENTRAL DRY1 DRY2 GND 12 V
A
B
A
B
A
Master Outdoor Unit Communication Terminal Block
B
ODU
IDU
CENTRAL
DRY1 DRY2 GND 12 V
A
B
A
B
A
B
DRY1 DRY2 GND 12 V
A
B
A
B
A
B
DRY1 DRY2 GND 12 V
A
B
A
4(B)
3(A)
4(B)
3(A)
B
A
Communications Cable Between Master Outdoor Unit and Slave Outdoor Unit(s)
Master Outdoor Unit Communication Terminal Block
Slave 1 Outdoor Unit Communication Terminal Block
Slave 2 Outdoor Unit Communication Terminal Block
Indoor Unit
Indoor Unit
ODU
IDU
CENTRAL
ODU
IDU
CENTRAL