LG PAHCMR000 User manual

INSTALLATION MANUAL
FOR LG AIR HANDLER UNIT (AHU)
COMMUNICATIONS KIT
AHU Model Number: PAHCMR000

For continual product development, LG Electronics U.S.A., Inc. reserves the right to change specifications without notice.
© LG Electronics U.S.A., Inc.
PROPRIETARY DATA NOTICE
This document, as well as all reports, illustrations, data, information, and other materials are the property of
LG Electronics U.S.A., Inc., and are disclosed by LG Electronics U.S.A., Inc. only in confidence.
For more materials such as submittals, catalogs, engineering,
installation, owner’s, and service manuals, visit www.lghvac.com.
Do not throw away, destroy, or lose this manual.
Please read carefully and store in a safe place for future reference.
Content familiarity required for proper installation.
The instructions included in this manual must be followed to prevent product malfunction, property damage, injury, or death to the user or
other people. Incorrect operation due to ignoring any instructions will cause harm or damage. The level of seriousness is classified by the
symbols described by the summary list of safety precautions on page 3.

3
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
TABLE OF CONTENTS
Safety Precautions ..........................................................................................................................................................................4
AHU Kit Introduction.......................................................................................................................................................................7
Specications, Components List...................................................................................................................................................8
AHU Communications Kit Installation...........................................................................................................................................9
Selecting the Best Location�����������������������������������������������������������������������������������������������������������������������������������������������������������9
DIP Switch Settings ���������������������������������������������������������������������������������������������������������������������������������������������������������������������10
AHU Communications Kit Parts���������������������������������������������������������������������������������������������������������������������������������������������������12
AHU Communications Kit Mounting �������������������������������������������������������������������������������������������������������������������������������������������13
Wiring Diagram����������������������������������������������������������������������������������������������������������������������������������������������������������������������������14
Power Wiring �������������������������������������������������������������������������������������������������������������������������������������������������������������������������������16
Communications Wiring���������������������������������������������������������������������������������������������������������������������������������������������������������������17
Connection for Fan Signal�����������������������������������������������������������������������������������������������������������������������������������������������������������18
Thermistor Installation �����������������������������������������������������������������������������������������������������������������������������������������������������������������19
Solutions Overview����������������������������������������������������������������������������������������������������������������������������������������������������������������������21
External Connection Diagrams����������������������������������������������������������������������������������������������������������������������������������������������������29
Control Functions ������������������������������������������������������������������������������������������������������������������������������������������������������������������������34
EEV Kit Installation........................................................................................................................................................................35
Introduction, Specications, and Design Parameters������������������������������������������������������������������������������������������������������������������35
Parts ��������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������36
Mounting the EEV Kit ������������������������������������������������������������������������������������������������������������������������������������������������������������������37
Preparing the Pipes���������������������������������������������������������������������������������������������������������������������������������������������������������������������38
Brazing and Insulating the Piping������������������������������������������������������������������������������������������������������������������������������������������������39
PRLK048A0 and PRLK096A0 Wiring������������������������������������������������������������������������������������������������������������������������������������������40
PRLK396A0 Wiring����������������������������������������������������������������������������������������������������������������������������������������������������������������������41
Testing ............................................................................................................................................................................................42
Troubleshooting ............................................................................................................................................................................43

4
PRCKAM AHU Communication Kit Installation Manual
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
TABLE OF SYMBOLS
This symbol indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury�
This symbol indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury�
This symbol indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury�
This symbol indicates situations that may result in equipment or property damage accidents only�
This symbol indicates an action should not be completed�
DANGER
CAUTION
The instructions below must be followed to prevent product malfunction, property damage, injury or death to the user or other people. Incor-
rect operation due to ignoring any instructions will cause harm or damage. The level of seriousness is classified by the symbols described
below.
Installation
All electrical work must be performed by a licensed electri-
cian and conform to local building codes or, in the absence
of local codes, with the National Electrical Code, and the
instructions given in this manual.
If the power source capacity is inadequate or the electric work is not
performed properly, it may result in re, electric shock, physical injury or
death�
Do not touch the communications and EEV kits’ wir-
ing, terminals, or other electrical components with tools or
exposed skin when the power is connected. Only qualied
technicians should install, remove, or re-install the kits.
Improper installation or use may result in re, electric shock, physical
injury or death�
Do not install, remove, or re-install the communications
and EEV kits by yourself (end user). Ask the dealer or a qual-
ied technician familiar with safety procedures and equipped
with the proper tools and test instruments to install the kits.
Improper installation by the user may result in re, electric shock, physi-
cal injury or death�
For replacement of an installed communications and EEV
kits, always contact a qualied LG service provider familiar
with safety procedures and equipped with the proper tools
and test instruments.
There is risk of re, electric shock, and physical injury or death.
Do not install the communications and EEV kits in a loca-
tion where the kits can be exposed to rain, snow, etc.
There is risk of physical injury or death due to electric shock�
Safely dispose of the packing materials.
Tear apart and throw away plastic packaging bags so that children may
not play with them and risk suffocation and death�
Wear protective gloves when unpacking, installing, and han-
dling the kits. Sharp edges may cause personal injury.
Do not install the communications and EEV kits in loca-
tions where either kit could fall down.
There is risk of physical injury�
Use the appropriate parts and connectors.
There is risk of physical injury or death due to re and / or electric shock.
Replace all control box and panel covers on the communica-
tions and EEV kits.
If cover panels are not installed securely, dust, water, and animals may
enter the kits, causing re, electric shock, and physical injury or death.
Failure to carefully read and follow all instructions in this
manual can result in physical injury or death.
Only qualied technicians familiar with safety procedures
and equipped with the proper tools and test instruments
should install, remove, or re-install the communications and
EEV kits.
Improper installation or use may result in product malfunction�
Do not install the communications and EEV kits in a
location where the kits can be exposed to rain, snow, etc.
There is risk of product malfunction�
Do not drop the communications and EEV kits.
It may damage the products�
Failure to carefully read and follow all instructions in this
manual can result in property damage and equipment mal-
function.
SAFETY PRECAUTIONS

5
Safety Precautions
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
SAFETY PRECAUTIONS
Do not supply power to the communication and EEV kits
until all electrical wiring, controls wiring, piping, installation,
and refrigerant evacuation are completed for the entire air
conditioning system.
The information contained in this manual is intended for use
by a trained, licensed electrician familiar with the U.S. Nation-
al Electric Code (NEC) and equipped with the proper tools
and test instruments.
Failure to carefully read and follow all instructions in this manual can
result in equipment malfunction and property damage�
The information contained in this manual is intended for use
by a trained electrician familiar with the U.S. National Electric
Code (NEC) who is equipped with the proper tools and test
instruments.
Failure to carefully read and follow all instructions in this manual can
result in personal injury or death�
All electric work must be performed by a licensed electrician
and conform to local building codes or, in the absence of
local codes, with the National Electrical Code, and the
instructions given in this manual.
If the power source capacity is inadequate or the electric work is not
performed properly, it may result in re, electric shock, physical injury or
death�
Use power wires of sucient current capacity and rating.
Refer to local, state, and national codes.
Wires that are too small may generate heat and cause a re resulting in
physical injury or death�
Secure all eld wiring connections with appropriate wire
strain relief.
Improperly securing wires will create undue stress on equipment power
lugs. Inadequate connections may generate heat, cause a re and result
in physical injury or death�
Verify that all power wiring, plugs, and sockets are not loose
or damaged.
Loose wiring may overheat at connection points causing a re or electri-
cal shock and result in physical injury or death�
WIRING
DANGER
High voltage electricity is required to operate the commu-
nications and EEV kits. Adhere to the NEC code and these
instructions when wiring.
Improper connections and inadequate grounding can cause accidental
injury or death�
Always ground the communications and EEV kits following
local, state, and NEC codes.
There is risk of re, electric shock, and physical injury or death.
Turn the power o at the nearest disconnect before servicing
the equipment.
Electrical shock can cause physical injury or death�
Properly size all circuit breakers or fuses.
There is risk of re, electric shock, explosion, physical injury or death.
Communication kit requires its own power source (EEV kit
is powered o of Communication kit). Do not share the
power source with other equipment.
There is risk of heat generation which may cause re, electric shock,
explosion, physical injury or death�

6
PRCKAM AHU Communication Kit Installation Manual
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
Do not install the communications and EEV kits in loca-
tions exposed to open ame or extreme heat. Do not touch
the kits with wet hands.
There is risk of re, electric shock, physical injury or death.
Do not modify or extend the power supply cords.
There is risk of re, electric shock, physical injury or death.
Do not step or place anything on the communications
and EEV kits.
If the product falls, there is risk of physical injury�
Do not place heavy objects on the communications and
EEV kits’ power cables.
There is risk of re, electric shock, physical injury or death.
Only authorized persons should operate the communications
and EEV kits.
If the kits are not operated properly, there is a risk of physical injury�
Do not provide power to or operate communication and
EEV kits if the kits are ooded or submerged. Always have
the dealer or an authorized technician to service the kits.
There is risk of re, electric shock, physical injury or death.
Do not store or use ammable gas or combustibles near
the communications and EEV kits.
There is risk of re, explosion, and physical injury or death.
Unplug the communication and EEV kits if either kit emits
strange sounds, smells, or smoke.
There is risk of re, electric shock, physical injury or death.
Do not let the communication and EEV kits get wet.
There is risk of product failure or malfunction�
Only authorized persons should operate the communication
and EEV kits.
There is risk of product failure or malfunction�
Do not drop the communications and EEV kits.
There is risk of product failure or malfunction�
Do not step or place anything on the communications
and EEV kits.
If the product falls, there is risk of product damage�
OPERATION
DANGER
CAUTION
SAFETY PRECAUTIONS

7
General Specifications
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
Introduction
The PAHCMR000 AHU Communications Kit bridges LG’s air conditioning outdoor unit to a third party Air
Handling Unit (AHU). Its function is based on the return air temperature control. In installations where
the AHU is designed with Direct Expansion (DX) Coil, the PAHCMR000 will control the return air tem-
perature by measuring the inlet and outlet temperatures of the DX coil and changing the operation of the
outdoor unit and the expansion unit. PAHCMR000 AHU Communications Kit features are:
• It can be used with LG Multi V air or water source outdoor units and LG Single Zone outdoor units.
• It supports AHU coil capacities from 12 - 396 kBtu/h.
• It controls the Electronic Expansion Valve (EEV, required, sold separately)
• It measures the return air temperature through the enclosed temperature sensor and controls the
outdoor unit to secure the demanded return air temperature.
• It can be directly connected to direct digital control (DDC) without a separate control module, so DDC
can receive product control and status information through Modbus communication.
• The PAHCMR000 AHU Communications Kit consists of a chassis, communication module, pipe-in
thermistor, pipe-out thermistor, and room (return) air thermistor.
Figure 1: PAHCMR000 AHU
Communications Kit.
Figure 2: AHU Communications Kit System Schematic.
AHU KIT INTRODUCTION
* BACnetTM is a trademark of ASHRAE; LonWorksTM is a trademark of Echlelon Corporation.
Control Signal (field supplied)
Pipe
Thermistor Signal
Air flow
Refrigerant flow (cooling)
Refrigerant flow (heating)
LG Wired
Controller1
LG AHU
EEV Kit
LG Multi V
Air Source or
Water Source Unit2
3rd Party
Air Handling
Unit
1LG wired controller is required.
2Compatible units are Multi V and Single Zone.
3Compatible central controllers are AC Smart IV and ACP IV.
LG Central Controller3
Max
Length 32ft.
LG
AHU Comm Kit
PAHCMR000
Return Air
Thermistor
Pipe In
Sensor
(Liquid)
Pipe Out
Sensor (Vapor)

8
PRCKAM AHU Communication Kit Installation Manual
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
Specifications
Table 1: PAHCMR000 AHU Communications Kit Specications Table.
AHU Communications Kit Components
Table 2: PAHCMR000 AHU Communications Kit Components Table (factory supplied).
Kit Model Number PAHCMR000
For Use With Multi V and Single Zone systems
Power Supply Requirements 208-230VAC, 60Hz, 1Ph
Rated Current 0.1A
Ambient Operating Temperature Range -4 to +149°F
Ambient Operating Humidity Range 0 to 98% (Non-condensing)
Dimensions (in., W x H x D) 11-13/16 x 6-3/32 x 11-13/16
Net Weight (lbs.) 13.7
Shipping Weight (lbs.) 16.4
Communications RS-485 (Connects to Indoor Unit A / B Terminals on Air-Source / Water-Source Unit PCB;
Master unit in multi-frame systems)
Communications Cable AWG 18 x 2 Stranded, Shielded Copper Wire
Part Quantity Image
AHU
Communications Kit One (1)
Return Air (Room)
Thermistor One (1)
Pipe Thermistor
Two (2)
(One [1] Pipe In,
One [1] Pipe Out)
AHU COMMUNICATIONS KIT SPECIFICATIONS,
COMPONENTS LIST

9
Installation
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
AHU COMMUNICATIONS KIT INSTALLATION
Selecting the Best Location
Selecting the Best Location
Do
• Install the AHU Communications and EEV Kits with the access panels facing outward.
• Install in a location that can support the weight of the kits.
• Install the EEV kit on the AHU as close as possible to the heat exchanger.
Don’t
• Don’t install or operate the unit in an area where mineral oils, sulphuric gases, acidic or alkaline vapors or spray are present.
• Don’t install in an area where the air contains high levels of salt (oceanside locations).
• Don’t install in vehicles or vessels.
• Don’t install in an area where voltage fluctuates significantly (factories), or near machines that generate electromagnetic waves.
AHU Operation Range
Range of the heat exchanger inlet air temperature is 64.4 to 104°F for cooling, and 41 to 86°F for heating. If the temperature is <64.4°F
for cooling and >86°F for heating, the system might cycle on and off because of the system’s protection logic.
Application Conditions
100% outside air intake: The AHU(s) is (are) the only indoor unit(s)
connected to the air-source / water-source unit(s).
The total capacity of 100% outside air intake AHU(s) should be
50~100% of the air-source / water-source unit(s).
Combination of indoor unit(s) and 100% outside air intake AHU(s) is (are)
connected to the air-source/water-source unit(s)
The combination ratio should be 50~100%
The total capacity of the 100% outside air intake AHU should be less
than 30% of the air-source/water-source unit capacity
To measure room temperature accurately, install the room thermistor in the heat exchanger inlet� If the room thermistor is not installed
properly, the AHU may not operate properly�
Table 3: AHU Applications and Conditions.
AHU Communications Kit Design Parameters
• Minimum coil entering air temperature is 41°F when system is operating in heating mode.
• AHU coil sizing parameters:
• Suction (evaporating) temperature for coil sizing is 41°F, Condensing (liquid) temperature for coil sizing is 110°F.
• Recommended coil tube sizes: 3/8 or 1/2 inches.
• Coil volume is needed to calculate additional refrigerant charge amount.
• Coils larger than 8 tons on heat recovery systems or 32 tons on heat pump systems should be divided into multiple circuits to allow EEV
Kit connection (EEV Kit sold separately).
• Pipe sizing rules are same rules as the connected air-source or water-source unit (see respective Engineering and Installation Manuals for
more information).
• Maximum recommended combination ratio is 100%.
• AHU Communications Kits and EEV Kits (sold separately) are not weatherproof and must be protected from rain, snow, etc.

10
PAHCMR000 AHU Communication Kit Installation Manual
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
Switch
Number
SW1
ODU Type
On
Single Comm.
Using Single Zone outdoor unit
Off
MULTI V Comm.
Using MULTI V outdoor unit
Control Type
On
Communication
Controlled by DDC through Modbus or LG centralized controller
Off
Contact signal
Controlled by DDC through Contact signal (AI, DI)
LG Centralized controller can only monitor status
DO Type
On
DO1 : High, DO2 : Middle, DO3 : Low
Off
DO1 : On/Off, DO2 : Defrost, DO3 : Alarm
4Fan Speed
(TH. On/Off)
On
Fan Speed doesn’t change when TH. On/Off (Cooling/Heating)
Off
Change
Fan Speed change to LOW when Th. Off in Cooling Mode
Fan Speed change to STOP when Th. Off in Heating Mode
SW2
Reserved
-
--
Reserved
-
--
UI Setting
Off/Off
UI Setting #1 UI1 : Operation On/Off, UI2 : Heating/Cooling
UI3 : Forced Thermo On/Off, UI4 : Target air temperature
Off/On
UI Setting #2 UI1 : Operation On/Off, UI2 : Cooling only/Off
UI3 : Heating only/Off, UI4 : Forced Thermo On and Off
On/Off
-devreseR
On/On
-devreseR
SW3
Master/Slave
On
Slave mode
Off
Master mode Master mode is default for single AHU Controller installation.
2/3 Operation mode
setting
Off/Off
Cooling or Heating operation mode is available
Off/On
Operation mode is Heating only (Heating / Fan)
On/Off
Operation mode is Cooling only (Cooling / Fan)
On/On
-devreseR
Reserved
--
SW4 Capacity
Setting --
Refer to the capacity DIP switch setting table for details
Communication Module
The default setting of all DIP switches is “off”
Notes :
1) Do not change reserved switches. Changing reserved switches may cause equipment malfunction.
2) If using group control, the maximum length of the group control cable is 164ft including remote controller wiring.
Fan speed
Status
Fixed
-
1
2
3
1
2
3/4
1
4
Heat Pump
Heating Only
Cooling Only
DIP Switch Item Setting Note
1~4
Setting the AHU DIP Switches
For the AHU Communications Kit to function properly, set the DIP switches as required by your system.
Figure 3: DIP Switches
Table 4: DIP Switch Settings.
AHU COMMUNICATIONS KIT INSTALLATION
DIP Switch Settings

11
Installation
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
AHU COMMUNICATIONS KIT INSTALLATION
DIP Switch Settings
Setting the AHU DIP Switches
Set DIP switch SW4 as appropriate for the capacity of your air handing unit.
Table 5: SW4 DIP Switch Settings for AHU Capacity.
SW4 DIP switches
Capacity (kBTU/h)
MULTI V
5211
7512
9813
21424
51825
81636
42247
03848
63459
246701
846911
0651121
0743131
5835141
devreseR27151
devreseR29161
Single Zone
Switch
Number
Notes:
1. PAHCMR000 AHU can be connected to the PRLK048A0, PRLK096A0, or PRLK396A0 EEV kits only.
2. If connecting the PRLK396A0 EEV kit to a Multi V outdoor unit, set DIP switches 1, 2, 3, and 4 to ON
to set capacity to 192 kBtu/h.

12
PAHCMR000 AHU Communication Kit Installation Manual
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
Diagram Label Part Name Quantity
1Thermistor Assembly,NTC Three (3)
2Controller Assembly One (1)
3 Bracket One (1)
4Panel Assembly,Control Three (3)
AHU COMMUNICATIONS KIT INSTALLATION
AHU Communications Kit Parts
Figure 4: AHU Communications Kit Parts Diagram.
Table 6: AHU Communications Kit Parts Table.
1
2
3
4

13
Installation
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
1. Use the key to open the AHU Communication Kit door.
2. Remove the four nuts from the four captive bolts at the corners of the control panel assembly.
3. Carefully remove the control panel assembly from the AHU Communication Kit.
4. Use the AHU Communication Kit as a template and mark the locations of the screw holes on the mounting surface.
NOTE: Do not drill holes without removing the control panel assembly.
Metal shavings can collect on the control panel assembly and damage the equipment when power is applied�
5. Drill the four holes for the field-supplied screws. Ensure the drill bit does not damage any equipment or components.
6. Carefully replace the control panel assembly and secure with the four nuts on the four captive bolts.
7. Position the AHU Communications Kit at the mounting location and secure with four field-supplied screws. Ensure the screws do not
damage any equipment or components.
Figure 5: AHU Communications Kit Installation
AHU COMMUNICATIONS KIT INSTALLATION
AHU Communications Kit Mounting
Model
PAHCMR000 11-13/16 6-3/32 11-13/16 10-1/4 10-1/4
11/32 Holes (4)
BackFrontSide
Size (inch)
W D H A B
D W A
B
H

14
PAHCMR000 AHU Communication Kit Installation Manual
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
AHU COMMUNICATIONS KIT INSTALLATION
Wiring Diagram
Figure 6: PAHCMR000 AHU Communications Kit Wiring Diagram.
* Set the UI1, UI2, UI3, and UI4 ports DIP switches as appropriate for your system
** Set the DO1, DO2, and DO3 ports DIP switches as appropriate for your system
SW1 DO Type
On
DO1 : High
DO2 : Middle
DO3 : Low
Off
DO1 : On/Off ***
DO2 : Defrost
DO3 : Alarm
Fan speed
Status
3
SW2 UI Setting
Off/Off
UI Setting #1
UI1 : Operation On/Off
UI2 : Heating/Cooling
UI3 : Forced Thermo On/Off
UI4 : Target air temperature
Off/On
UI Setting #2
UI1 : Operation On/Off
UI2 : Cooling only/Off
UI3 : Heating only/Off
UI4 : Forced Thermo On and Off
3/4
UI1* UI2*
UI3*
UI4*
DO1** DO2** DO3**
*** This output can be used to start/stop an AHU single-speed fan

15
Installation
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
19
Name Port Contents Electrical Spec.Function
Thermistor Room NTC RI1/G
Room (Return) air thermistor
NTC10 kΩ,16.4 ft
Return air temperature sensor
Thermistor Pipe in NTC RI3/G Pipe in (Liquid) thermistor
NTC5kΩ,16.4ft
Inlet pipe (Liquid) Temp. sensor
Thermistor Pipe out
NTC RI4/G Pipe out (Gas) thermistor
NTC5kΩ,16.4ft
Outlet pipe (Gas) Temp. sensor
Name Port Contents Electrical Spec.Function
Module Comm. RS485 CH1
DDC(Modbus)
Comm.
Max 1640ft,
2C x 18~16 AWG
(shield wire)
Communication with DDC or Main
module of PAHCMS000 model
through Modbus protocol
MULTI VIDU
Comm.RS485 CH2
MULTI VIDU Comm.
Max 3280ft,
2C x 18~16 AWG
(shield wire)
Communication with MULTI V
Outdoor unit
Single IDU
Comm.
SINGLE N/SIG
Single IDU Comm.
Max 246 ft,
2C x 18~16 AWG
(shield wire)
Communication with Single Split
Outdoor unit
AHU COMMUNICATIONS KIT INSTALLATION
Wiring Diagram
Table 7: RS485/Single Communications Port.
Table 8: NTC Thermistors.

16
PAHCMR000 AHU Communication Kit Installation Manual
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
Figure 7: Power Wiring Connection.
Power Wiring
AHU COMMUNICATIONS KIT INSTALLATION
General Power Wiring Guidelines
All electrical work must be performed by a licensed electrician and conform to local building codes or, in the absence of
local codes, with the National Electrical Code, and the instructions in this manual.
Inadequate power source capacity or improper electric work may result in re, electric shock, physical injury or death.
All eld-supplied parts, materials, and electric work must conform to local codes.
Improper components and installation may result in re, electric shock, physical injury or death.
A main switch or disconnect, in accordance with relevant local and national codes, and having a contact separation in
all poles, must be incorporated in the wiring.
Improper installation by the user may result in re, electric shock, physical injury or death.
Refer to the air-source / water-source heat pump unit installation manual for power wiring sizes, circuit breaker and
switch capacities, and wiring instructions.
If the power source capacity for the air-source unit / water-source unit is inadequate or the electric work is not performed properly, it may result
in re, electric shock, physical injury or death.
Use copper wire only and connect wires tightly to the terminals. Install wiring so that other equipment is not obstructed.
Improper or incomplete connections could result in overheating, re, electric shock, physical injury or death.
Ensure the power source is disconnected before performing this procedure.
If the power source is connected during this procedure, it could result in electric shock, physical injury, or death�
1. Carefully pull the power cable through the cable nut and grommet.
2. Connect the power cable to the power
terminal block.
3. Pull enough cable through
the nut and grommet to
allow enough slack for
strain relief.
4. Tighten the cable nut.
Power Terminal Block
Cable
Insert
Front View with Cover Open

17
Installation
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
AHU COMMUNICATIONS KIT INSTALLATION
Communications Wiring
• Communications wiring must be 18 gauge, shielded, and stranded�
• The thermistor cable, remote controller wires, and communications wires should be positioned at least two (2) inches away from
power supply wires� If these wires are installed too closed together, it may result in product malfunction due to electrical interference�
All electrical work must be performed by a licensed electrician and conform to local building codes or, in the absence
of local codes, with the National Electrical Code, and the instructions in this manual.
If the electrical work is not performed properly, it may result in re, electric shock, physical injury or death.
All eld-supplied parts, materials, and electric work must be conform to local codes.
Improper components and installation may result in re, electric shock, physical injury or death.
Ensure the power source is disconnected before performing this procedure.
If the power source is connected during this procedure, it could result in electric shock, physical injury, or death�
1. Carefully pull the communications cable through the cable nut and grommet.
2. Refer to the wiring diagram in Figure 6 and connect the communications cable to the appropriate communication terminals for your
system: Single IDU, DDC (RS485 Ch1), or Multi V IDU (RS485 Ch2).
3. Pull enough cable through the nut and grommet to allow enough slack for strain relief.
4. Tighten the cable nut.
Figure 8: Communications Wiring Connection
Comm Cable to:
• Single IDU, or
• DDC (RS485 Ch1), or
• Multi V IDU (RS485 Ch2)
Cable
Insert
Front View with Cover Open

18
PAHCMR000 AHU Communication Kit Installation Manual
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
L
HI
MED
LO W
AHU Communication Kit
H EX
Motor Control (MCC) Panel
M
N
Air Handler Unit
Motor Input Power
1Ø, 208/230 V ~ 60 Hz
MMotor
Relay
Field Wiring
Factory Wiring
L1 L2
Control Power
1Ø, 208/230 V ~ 60 Hz
Cable : Over CV 15AWG
220-240 V ~ 50/60 Hz
R-LOWR-MED
R-HI
LOW (L)
MED (L)
HI (L)
DO1 DO2 DO3
L1(L) L2(N)
AHU Communications Kit to Air Handler Unit Connection (Fan Motor Control)
AHU COMMUNICATIONS KIT INSTALLATION
• AHU manufacturer-supplied relays must be used
to connect the LG AHU Communications Kit to the
AHU fan motor.
• MCC panel means motor control panel.
Connection for Fan Signal
Figure 9: AHU Communications Kit to AHU Connection (For Fan Signal).
AHU Communications Kit Hi/Med/Low wires should
not be connected directly to the AHU fan motor�
Improper connections could result in re, electric
shock, physical injury or death�
• AHU Communications Kit Hi/Med/Low
wires should not be connected directly
to the AHU fan motor� Improper connec-
tions could result in product damage�
• If the third-party AHU fan motor is the On/Off
type, the HI/MED/LOW wires from the motor
control panel to the AHU have to connect as
one common wire� Example: If just the Hi wire is
connected, the fan motor will not operate using
the LG AHU Communications Kit control logic�

19
Installation
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
Thermistor Locations
All thermistors (one [1] return air [room] thermistor and two [2] pipe thermistor) must
be correctly installed to ensure proper AHU Communications Kit operation.
1. Return Air (Room) Thermistor: Install it at the AHU heat exchanger inlet in the
return air stream.
2. Pipe In Thermistor: Install it ahead of the distributor on the coldest area in the heat
exchanger (contact the heat exchanger manufacturer for the precise location).
3. Pipe Out Thermistor: Install it on the vapor line outlet of the heat exchanger as
close as possible to the heat exchanger.
Pipe In (Liquid)
Thermistor
Pipe Out (Vapor)
Thermistor
Air Handler Unit
Tie
Thermistor
45°
Step 1 Step 2
Thermistor Installation
AHU COMMUNICATIONS KIT INSTALLATION
System operation must be evaluated to determine if the AHU evaporator is
protected against freezing up� Run a system test, and see if the AHU evaporator
is freezing up�
Thermistor
Air Flow
Air Handler Unit
AHU Communications Kit
Return Air
Thermistor
T
Figure 10: Location of the Return Air (Room) Thermistor.
Figure 11: Locations of the Pipe Thermistors.
Thermistor Cable Installation
• Place the thermistor cables in a separate protective tube.
• Always add a pull-relief to the thermistor cable to avoid strain on
the thermistor cable and loosening of the thermistor.
Strain on the thermistor cable or loosening of the thermistor may
result in a bad contact and incorrect temperature measurements�
Thermistors must be securely attached for proper operation�
Figure 12: Securing the Thermistor Cable.

20
PAHCMR000 AHU Communication Kit Installation Manual
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
Tips for Attaching the Pipe In / Pipe Out Thermistors
• Put the thermistor cable in a separate protective tube.
• Always add a pull-relief to the thermistor cable to avoid strain on
the thermistor cable and loosening of the thermistor. Strain on the
thermistor cable or loosening of the thermistor can result in bad
contact with the pipe and incorrect temperature measurement.
Water
Attaching the Pipe Thermistors
Thermistor Installation
AHU COMMUNICATIONS KIT INSTALLATION
Figure 13: Attach Pipe Thermistors.
• To avoid water accumulating on the thermistor tip, position
the thermistor cable slightly below the thermistor tip, or
install the thermistor tip parallel with the cable.
Do not include a 90° angle or a kink in the thermistor
cable, nor install the thermistor tip upside down.
Figure 14: Thermistor and Cable Installation.
1. Securely attach the thermistor to the pipe with a field-supplied pipe strap.
2. Insulate the thermistor with a field-supplied insulation sheet that is >5t.
Thermistors must be securely attached with a pipe strap� The equipment will
not operate properly if thermistors are not making good physical contact in the
appropriate installation location�
Step 1
Step 2
Figure 15: Positioning the Thermistor Cable and Tip.
2Tie wrap
Thermistor
45°
1
Other manuals for PAHCMR000
2
Table of contents
Other LG Air Handler manuals
Popular Air Handler manuals by other brands

Klimor
Klimor EVO-T Plus Operation and maintenance manual

Ruck
Ruck ETA K 600 V W Assembly and operating manual

Bosch
Bosch BWA Series installation instructions

Lennox
Lennox VVCB installation instructions

McQuay
McQuay Skyline OAC Series Installation and maintenance manual

Allied
Allied 4SCU16LE Service manual

Trane
Trane Horizon OADG Series Installation, operation and maintenance

Trox Technik
Trox Technik X-CUBE compact installation manual

Swegon
Swegon WISE Adriatic Prisma Instructions for use

Trane Technologies
Trane Technologies Foundation BAYCCHT306 Series installation guide

BLAUBERG
BLAUBERG FRESHBOX E120 Operation manual

RDZ
RDZ WHR 400 Installation & technical manual