LG DOAS, ARND20BDAT2, ARND20BDAR2 Installation And Operation Manual

DEDICATED OUTDOOR AIR SYSTEM (DOAS)

INSTALLATION AND OPERATION MANUAL

Variable Refrigerant Flow DOAS Units

ARND20BDAT2

ARND20BDAR2 (no preheat)

Do not throw away or destroy this manual.

Please read carefully and store in a safe place for future reference.

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 below.

TABLE OF SYMBOLS

This symbol indicates a potentially hazardous situation which, if not avoided, may result in death, serious injury, property damage or equipment damage.

This symbol indicates additional helpful information such as an explanation, a comment, or a clarication

about the subject. This symbol indicates a recommendation or tip. Recommendations instruct the user to apply the suggested

practice to ensure the best operating results to achieve the maximum benet of the product. Tips contain

practical information that may help the user solve a problem or describe actions that may save time.

A list of safety precautions begins on page 4.

Dedicated Outdoor Air System (DOAS) Installation and Operation Manual

Due to our policy of continuous product innovation, some specifications may change without notification.

TABLE OF CONTENTS

Table Of Symbols ..................................................................................2

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

Location Selection .................................................................................8

General Installation Instructions .........................................................11

Piping ....................................................................................................12

Electrical ...............................................................................................15

Low Voltage Communications ...........................................................16

Duct Connections ................................................................................17

Wiring Diagrams ..................................................................................18

Start-Up ................................................................................................22

DOAS Start-Up Checklist ....................................................................50

Operation ..............................................................................................51

Maintenance .........................................................................................52

Maintenance Log .................................................................................53

Who To Call For Assistance ............................................................... 55

SAFETY PRECAUTIONS

The instructions below 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 below.

This symbol indicates a potentially hazardous situation which, if not avoided, may result in death, serious injury, property damage or equipment damage.

This symbol indicates additional helpful information such as an explanation, a comment, or a clarication

about the subject. This symbol indicates a recommendation or tip. Recommendations instruct the user to apply the suggested

practice to ensure the best operating results in order to achieve the maximum benet of the product. Tips

contain practical information that may help the user solve a problem or describe actions that may save time.

Roughing-In

All electric work must be performed by a licensed electrician and conform to local building codes or, in the absence of local

Failure to do so may result in dust or water infiltration, causing fire, electric shock, physical injury and/or death.

codes, with the National Electrical Code NFPA 70/ANSI C1-1993 or current edition, and the instructions given in this manual.

If the electrical work is not performed properly, it may result in fire, electric shock, physical injury and/or death.

Always wear safety glasses and work gloves when installing the product. A rapid release of R410A refrigerant may cause frostbite.

The customer should not install, remove, or re-install the unit.

There is risk of fire, electric shock, physical injury and/or death.

Do not use oxygen, acetylene or air in place of refrigerant and dry nitrogen for leak testing.

The dealer or an authorized technician should install the unit.

There is a risk of explosion resulting in physical injury and/or death. Improper installation by the user may result in water leaks, fire, electric shock, physical injury and/or death.

Properly insulate all cold surfaces when installing this product.

Uninsulated cold surfaces may generate condensate that may drip

For re-installation of an installed unit, always contact the dealer

and cause water damage to wall and floors.

or an authorized technician.

There is risk of fire, electric shock, physical injury and/or death.

Be very careful when transporting the product. DOAS weight and size preclude one person carrying the unit. Use

two or more people to transport the product without the assistance of mechanical transport equipment. There is a risk of personal injury.

Do not handle DOAS without the use of gloves and protective clothing. The product may have sharp edges.

This product is engineered to be used for conditioning of

outdoor air only. It is not to be used in applications that require

precision cooling or heating such as data centers, food preser-

vation, wine coolers, refrigeration and / or freezer applications.

There is risk of property damage.

Provide field-installed electrical isolation devices to protect

sensitive equipment sharing a power source with this product.

There is a risk of personal injury.

Provide sufficient protection against the effects of Dispose the packing materials safely.

Destroy the structure of plastic packaging and boxes to prevent children from playing with them. There is a risk of injury, suffocation

Dedicated Outdoor Air System (DOAS) Installation and Operation Manual

and / or death to humans, animals and wildlife.

electromagnetic fields (EMF) and electrical noise.

Inverter equipment, private power generators, high-frequency

medical equipment, or radio communication equipment may cause

the air conditioner to malfunction.

Do not install the unit on an unstable structure.

It may result in the failure of the structure, property damage, equipment damage, and / or personal injury or death.

R410A refrigerant creates toxic gases when burned. Do not store or use flammable products near the unit.

There is risk of product failure, fire, and physical injury and/or death.

Replace all control box and panel covers after completing work.

Due to our policy of continuous product innovation, some specifications may change without notification.

Provide sufficient electrical system protection against

lighting strikes.

The risk is loss of warranty, product damage, and / or complete loss

of the product.

Ductwork and other installed airflow restriction devices such as

filters shall not exceed the rated maximum static pressure limits

of the DOAS fan assembly.

Doing so may cause product malfunction.

Roughing In, Continued

Do not store or use gasoline or other flammable vapors and liquids in the vicinity of the DOAS unit.

Doing so could result in fire, physical injury and/or death.

Do not work in a closed area where refrigerant or nitrogen gases may be leaking.

Vapors may be present and can result in physical injury and/or death.

Always use a pressure regulator to control incoming pressures when pressure testing.

Excessive pressure may result in product damage, physical injury or death.

Do not install this product outdoors or where it will be directly exposed to coastal conditions.

Air from the ocean may cause the condenser and evaporator fins to

SAFETY PRECAUTIONS

corrode, which may cause product malfunction.

Do not install this product in a location that is noise sensitive.

Provide additional acoustical treatment as needed.

The risk may be occupant discomfort.

When installing refrigerant piping, consider pipe expansion and

use flare connections.

Improper pipe installation may lead to pipe fatigue, failure, and a

rapid release of refrigerant, frostbite, suffocation, physical injury, and

/or death.

Verify the piping system has been properly evacuated (<500

ppm), and the system’s refrigerant charge is correct before

commissioning and after any repair is made.

Improper system evacuation and / or an improper refrigerant charge

may cause product malfunction.

Safety Precautions

Power Wiring

The information contained in this manual is intended for use by a qualified, experienced service technician familiar with safety procedures, and who is equipped with the proper tools and test instruments.

Failure to carefully read and follow all instructions in this manual can result in equipment malfunction, property damage, personal injury and/or death.

This equipment uses high voltage electricity. Only a qualified, experienced electrician should wire this system. Never assume that the electrical power has been disconnected. Verify with a meter.

Failure to follow all guidelines, properly respect electricity, use industry best grounding practices, follow suggested wiring instructions, local, and NEC codes can lead to electrical shock, physical injury, seizures, and/or death.

Use a properly sized circuit protective device. Using an undersized protective device will lead to equipment malfunction. Installing an oversized protective device may cause burns, fire, and death.

There is risk of fire, electric shock, explosion, physical injury and/or death.

Verify all power, ground, and communications wires and cables are properly terminated before applying power to the product. Securely tighten all wire terminations.

Improper and/or loose wire and communications cable terminations may cause product malfunction, fire, physical injury and/or death.

Turn power off at the unit disconnect before servicing.

Electrical shock can cause physical injury and/or death.

When servicing controls, ensure all wires are labeled properly prior to disconnecting.

Wires labeled incorrectly could cause product malfunction, fire, physical injury and/or death.

Properly replace all controls.

Failure to replace controls could result in fire and/or explosion.

Do not overload the VFD motor. The overload ampere setting must not exceed 115% of the electric motors FLA rating as shown on the motor nameplate.

There is risk of fire, electric shock, explosion, physical injury and/or death.

Properly secure power wires and communications cables at connectors to eliminate wire strain.

Inadequate connections may generate heat, cause a fire and physical injury and/or death.

Due to our policy of continuous product innovation, some specifications may change without notification.

Verify the DOAS unit is operational after servicing. Secure all doors with a door latch or nut and bolt.

GENERAL DATA

Table 1: Dedicated Outdoor Air System General Data

Dedicated Outdoor Air System

ARND20BDAT2 ARND20BDAR2

Cooling Mode Performance

Capacity (Btu/h)

Heating Mode Performance

Capacity (Btu/h) (Main Coil) Capacity (Btu/h) (Reheat Coil)

Entering Air

Cooling Max (°F DB/WB) Heating Min (°F DB)

Unit Data

Refrigerant Type

Refrigerant Control Sound Power dB(A) Net Unit Weight (lbs) Shipping Weight (lbs) Communication Cable

Fan

Type

Backward Curved Plenum Backward Curved Plenum

Motor Motor/Drive Airflow Rate (CFM) External Static Pressure (in wg) Airflow Range (CFM)

Piping (Main Coil)

Liquid Line (in, OD) Vapor Line (in, OD)

Piping (Reheat Coil)

Liquid Line (in, OD) Vapor Line (in, OD)

Condensate

Dedicated Outdoor Air System (DOAS) Installation and Operation Manual

Condensate Line (in, OD)

EEV - Electronic Expansion Valve ECM - Electronically Commutated Motor Power wiring is field supplied and must comply with the applicable local and national codes. This data is rated 0 ft. above sea level, with 25 ft. of refrigerant piping per coil. Main Coil Cooling capacity rating obtained with entering air of 95°F DB/75°F WB and leaving air of 52.9°F

DB, 52.5°F WB. Main Coil Heating capacity rating obtained with entering air of 44°F DB and leaving air of 75°F DB. Reheat Coil Heating capacity rating obtained with entering air of 54°F DB and leaving air of 86°F DB.

143,100 143,100

59,900 59,900 45,900 45,900

122/78 122/78

2.5 41

R410A R410A

EEV EEV

84 84 725 600 825 700

4 x 18 4 x 18

1 1

ECM/Direct ECM/Direct

2000 2000

1.65 1.65

1200 - 2000 1200 - 2000

1/2 1/2

1-1/8 1-1/8

1/2 1/2

1-1/8 1-1/8

1 NPT 1 NPT

Take appropriate actions at the end of HVAC equipment life to recover, recycle, reclaim or destroy R410A refrigerant according to applicable regulations (40 CFR Part 82, Subpart F) under section 608 of CAA.

All communication cable to be minimum 18 AWG, 4-conductor, stranded, shielded and must comply with applicable and national code. Power Supply (V/Hz/Ø): 208-230/60/3.

Actual discharge air temperatures may vary from discharge air temperature set-point due to changes in outdoor air processing loads.

Due to our policy of continuous product innovation, some specifications may change without notification.

REFRIGERANT SAFETY

ASHRAE Standards 15-2010 and 34-2010 offer guidelines that address refrigerant safety and the maximum allowable concentration of refrigerant in an occupied space. Refrigerant will dissipate into the atmosphere, but a certain volume of air is required for this to occur safely. For R410A refrigerant, the maximum allowable concentration of refrigerant is twenty-six (26) lbs. per 1,000 cubic feet of an occupied space. Buildings with twenty-four (24) hour occupancy allow half of that concentration.

ASHRAE Standards 15 and 34 assume that if a system develops a leak, its entire refrigerant charge will dump into the area where the leak occurs. To meet ASHRAE Standards 15 and 34, calculate the refrigerant concentration that may occur in the smallest room volume on the system, and compare the results to the maximum allowable concentration number. Also consult state and local codes in regards to

refrigerant safety.

Verify the maximum refrigerant concentration level for spaces served by DOAS meets the concentration limit for the application.

Installation Instructions

Due to our policy of continuous product innovation, some specifications may change without notification.

LOCATION SELECTION

(

Clearance Requirements

Selecting the Best Location

Placement of the unit relative to ductwork, electrical and plumbing must be carefully considered. Use flexible gasket material to seal the duct to the unit.

Verify floor, foundation or suspension support can sustain the total unit weight, including accessories. The unit must be level on both horizontal axis to support the unit and reduce noise and vibration.

Allow adequate space for piping access and panel removal. To ensure proper access for field service, maintain minimum clearances for field piping and other obstructions. Refer to Table 2 and Figure 1. Condensate drain connections are located on the access side of the unit. Follow local building codes for additional service clearance requirements.

Table 2: Dedicated Outdoor Air System Clearances

Access Side Clearance

Dimension X on Figure 1.

Figure 1: Minimum Clearance Required for Unit Access

36 inches 6 inches

All Other Sides

Front

Left

Right

See Table 2)

Back

Suspended Unit Mounting Details

DOAS units are equipped for suspended installations. The unit should be lifted into position by supporting the unit with skid used for shipping. Carefully install the DOAS unit to prevent damage to the cabinet and ensure the unit is installed level. Additional installation provisions may be necessary depending on the job specifications. The specifying engineer or installing contractor are responsible for ensuring the installation of the DOAS is structurally sound. Refer to Figure 2 and Figure 3 for recommended suspended installation methods.

Dedicated Outdoor Air System (DOAS) Installation and Operation Manual

Due to our policy of continuous product innovation, some specifications may change without notification.

LOCATION SELECTION

Mounting Details

DOAS unit can be installed using either platform suspension (Figure 2) or parallel beam suspension (Figure 3) as shown below.

Figure 2: Series Platform Suspension Installation

Field-Provided Isolation as Required

Air

Flow

Field-Provided Suspension Rods (as required). Avoid Interference with Access Doors.

Installation Instructions

Avoid Interference with Condensate Drain

Figure 3: Series Parallel Beam Suspension Installation

Field-Provided

Air

Flow

Isolation as Required

Secure to Field-Provided Metal Plate

Field-Provided Suspension Rods (as required). Avoid Interference with Access Doors.

Avoid Interference with Condensate Drain

Due to our policy of continuous product innovation, some specifications may change without notification.

Secure to Field-Provided Beams

LOCATION SELECTION

Unit Orientation and Control Component Location

Figure 4: Unit Orientation

DOAS TOP VIEW

Left Hand Side

Outdoor Air (Back)

Connections and Service Access on Right Side for RightHand Orientation

Filter, coil and wiring access doors are on the right side as designated by the unit orientation and fan access door is on the left side. The back will always be the same side as the lter and outdoor air opening. The front will always be the side opposite the lter and outdoor air opening.

AIR FLOW

Right Hand Side

Supply Air (Front)

Dedicated Outdoor Air System (DOAS) Installation and Operation Manual

Due to our policy of continuous product innovation, some specifications may change without notification.

GENERAL INSTALLATION INSTRUCTIONS

Failure to observe the following instructions will result in premature failure of the DOAS and possibly void your warranty.

Receiving the Unit

• Check the unit for damage that may have occurred during transit.

• If damage is found, note it on the carrier’s freight bill and request an inspection by the carrier’s agent immediately.

• Check the name plate to ensure the correct model sizes and voltages were received and match and satisfy the job requirements.

• In order to protect the warranty, if repairs need to be made to damaged goods then the factory should be notified before any repair action is taken. Certain equipment alterations, repairs and manipulation of equipment without consent from the manufacturer may void the product warranty.

Upon receipt, check the shipment for items that ship loose such as lters and remote sensors. Review

order and shipment documentation to identify potentially loose shipped items. These items may have been placed inside the unit cabinet for security. Installers and owners should secure all doors with locks or nuts and bolts to prevent unauthorized access.

Storage

The DOAS cannot be stored outdoors. If installation does not occur immediately following delivery, store the equipment in a dry protected area away from construction traffic and in the proper orientation as marked by the packaging. Prior to storing the unit, secure all loose-shipped items.

Handling the Unit

Before lifting the unit, ensure all shipping material has been removed. If spreader bars, blocking or other lifting devices are used, take extra care to ensure the cabinet, coil and fans are not damaged.

Figure 5: Lockable Handle

Installation Instructions

Due to our policy of continuous product innovation, some specifications may change without notification.

PIPING

Condensate Drain Piping

Condensate drain trapping and piping must conform to all applicable codes. A p-trap and drain line must be installed. The p-trap cannot exceed 6 inches from the drain connection. The lines need to be the same pipe size or larger than the drain connection, include a p-trap, and pitch downward toward the drain. An air break should be used with long condensate line runs.

Figure 6: Drain Trap

Failure to install p-traps can result in an overow of condensate water. This can lead to product

damage or property damage. Draw-through cooling coils will have a negative static pressure in the drain pan area. This can cause an un-trapped drain to back up due to the air being pulled up through the condensate drain piping.

The value of pressure in the drain pipe should be at least equal to the absolute value of the negative static pressure in the drain pan plus one inch. Follow the procedure below to calculate the static pressure.

Calculating Static Pressure

1. Add the pressure drops of all components upstream of the drain plan. This includes the cooling coil.

2. Add the return duct static pressure. Include the dirt allowance pressure drop for the filters to account for the worst-case scenario.

The absolute value of the fan inlet pressure will always be greater than or equal to the absolute value of the static pressure in the drain pan or draw-through units so the fan inlet pressure is a safe value to use for the drain pan static pressure.

Table 3:DOAS Drain Trap Dimensions

Draw-Through

Drain Pan Pressure Trap Dimensions

Negative Static X Y

(inches of water) (inch) (inch)

-0.50 1.50 0.75

-1.00 2.00 1.00

-1.50 2.50 1.25

-2.00 3.00 1.50

-2.50 3.50 1.75

-3.00 4.00 2.00

-3.50 4.50 2.25

-4.00 5.00 2.50

Dedicated Outdoor Air System (DOAS) Installation and Operation Manual

Due to our policy of continuous product innovation, some specifications may change without notification.

PIPING

A + B ~ 12" – 19"

Max. 12"

~ 12" – 19"

Piping Guidelines

Refrigerant Piping

The installing contractor is responsible for piping the condensing unit to the air handling unit. Acceptable piping sizes can be determined by using LATS software.

Refrigerant Piping Guidelines

• Pipe sizes must be selected to meet installation conditions and not based on the connection sizes at the evaporator or condensing unit.

• Only clean ACR tubing should be used and all piping should follow any applicable codes.

• The air handling unit coils are pressurized and the copper caps must be punctured to permit a gradual escape of pressure prior to unsweating the caps.

• To avoid exposing the coils to moisture, immediately couple the tubing to the DOAS unit.

• When making solder connections, ensure the dry nitrogen flows through the lines when the copper is heated to prevent oxidization inside of the copper.

• When piping is complete, the interconnecting piping and the air handling unit must be leak checked and evacuated to 500 microns or less. This will allow condenser shutoff valves to open and allow refrigerant to flow to the air handling unit.

• The DOAS should be charged based on the manual calculation of refrigerant charge, based on coil refrigerant volumes.

• The refrigerant reheat coil is to be connected to a separate outdoor unit than the main coil outdoor unit. Ensure not to cross circuits in the reheat systems.

A properly installed pipe system will have sufficient support so that pipes will not sag during the life of the system. As necessary, place supports closer for segments where potential sagging could occur. Maximum spacing of pipe supports shall meet local codes.

Figure 7: Pipe Support at DOAS Unit

Figure 8: Typical Pipe Support Location - Change in Pipe Direction

Refrigerant Pipe Connections

• DOAS units come with brazed connections.

Refrigeration system components contain very small capillary tubes, small orices, electronic expansion valves, oil separators, and heat exchangers that can easily become blocked.

Piping

While brazing, ALWAYS follow these guidelines:

• Keep pipe supplies capped, clean, and store in a dry location.

• Use a tubing cutter, do not use a saw to cut pipe. De-burr and clean all cuts before assembly. Blow clean the pipe with dry nitrogen prior to assembly.

• Do not use flux, soft solder, or anti-oxidant agents. Use a 15% silver phosphorous copper brazing alloy to avoid overheating and produce good flow.

• Protect refrigerant shut-off valves electronic expansion valves, unit case, insulation, and control components from excessive heat by using a wet rag or a heat barrier spray product while brazing.

• While brazing, always use a dry nitrogen purge operating at a minimum pressure of three (3) psig and maintain a steady flow.

Due to our policy of continuous product innovation, some specifications may change without notification.

PIPING

Piping Insulation

Figure 9: Typical piping Diagram

Pipe Insulation

• Insulate all cold surfaces sufficiently to prevent moisture from forming. All pipes must be insulated and each pipe must be wrapped separately.

• Use field-provided half (1/2) of an inch thick (or better) closed cell insulation. The thickness may need to be increased based on ambient conditions and local codes.

• All refrigerant and condensate piping including field-provided isolation ball valves and flexible pipe connection kits provided by LG should be wrapped.

• All insulation joints should be glued with no air gaps between insulation segments, and between insulation segments and the unit case. Insulation material shall fit snugly against the refrigeration pipe with no air space between the pipe surface and the surrounding insulation.

Dedicated Outdoor Air System (DOAS) Installation and Operation Manual

Due to our policy of continuous product innovation, some specifications may change without notification.

ELECTRICAL

Electrical

• Verify the unit name plate matches the power supply.

• The unit is provided with a single point power wiring connection. The connection terminals are made to the main terminal block. A complete wiring diagram including factory and field wiring can be found inside the control compartment door.

• Route power and control wiring separately. Do not run the power and control signal wires in the same conduit.

• All units require field supplied electrical overcurrent and short circuit protection. The device must not be sized larger than the maximum overcurrent protection (MOP) shown on the nameplate.

• Local codes may require a disconnect switch to be within sight of the unit. The disconnect switch should not be installed on the DOAS unit.

• The electrical supply can enter the unit through the bottom or the side of the controls compartment.

• A single point connection to a terminal block is provided with the unit. High voltage conductors must be placed in the control panel in a separate opening and separate conduit from low voltage conductors.

• To pass a wire through the wall or roof of the unit, cut an opening and pass the conduit through it. Follow the procedure below to safely cut an electrical opening.

Table 4: Dedicated Outdoor Air System Electrical Data

Model

ARND20BDAT2

ARND20BDAR2 (no preheat)

MCA = Minimum Circuit Ampacity MOP = Maximum Overcurrent Protection Power wiring cable is field provided and must comply with the applicable local and national codes.

Voltage

Range

187-253 96 100 60 208-230 3 187-253 8 15 60 208-203 1

MCA MOP

Power Supply

Hz Volts Phase

Cutting an Electrical Opening

1. Select the location for the opening. Ensure the conduit will not interfere with the operation of any components, prevent door access or prevent a panel from being removed.

Field cut openings must be a minimum of 6 inches away from all components and wiring to prevent damage caused by drilling or cutting.

2. Drill a pilot opening all the way through the foam panel.

3. Using a hole saw, cut the opening through the metal on both sides of the foam area.

If a reciprocating saw is used to make the cut-out, ensure that the metal shavings from the foam part do not separate from the foam. If the foam is separated, it can result in structural damage of the part.

4. Using a knife, cut the foam from the opening.

5. Install the conduit.

6. After the conduit is installed in the opening, caulk the sides with an industrial grade silicone sealant or a duct seal compound.

If a larger opening is needed for additional duct connections not provided by the factory, it is imperative that the foam be completely sealed. Insulation covers must be fabricated from sheet metal to cover the foam at the cut. The edges and corners that are not covered need to be sealed using silicone caulking or a duct seal compound.

Electrical

• Size supply conductors based on the unit minimum current ampacity (MCA). Supply conductors must be rated at a minimum of 75°C.

• Wire power leads to the unit’s terminal block or main disconnect. All wiring beyond this point has been completed by the factory and cannot be modified without effecting the unit’s agency and/or safety certification.

• The supply voltage must be within the minimum and maximum range displayed on the unit nameplate. The available short circuit current should not exceed the short circuit current rating (SCCR) shown on the unit nameplate.

Three phase voltage imbalance will cause motor overheating and premature failure. The maximum allowable imbalance is 2.0%. Voltage imbal-

ance is dened as 100 times the maximum deviation from the average voltage divided by the average voltage.

• Check the voltage imbalance at the unit disconnect. Contact your local power company for line voltage corrections.

• The installing contractor must check for proper motor rotation and check blower motor amperage listed on the motor nameplate is not exceeded.

Due to our policy of continuous product innovation, some specifications may change without notification.

LOW VOLTAGE COMMUNICATIONS

Outdoor/DOAS Unit Communications Cable Installation Guidelines

Three phase voltage imbalance will cause motor overheating and premature failure. The maximum allowable imbalance is 2.0%. Voltage imbal-

ance is dened as 100 times the maximum deviation from the average voltage divided by the average voltage.

Polarity matters. When connecting the communications cable conductors at each Multi V system component, be careful the conductor connected to the DOAS (A) terminal on the outdoor unit is connected to the 10 terminals at each AHU control terminal. Likewise, the conductor connected to the DOAS (B) terminal on the outdoor unit must be connected to the 11 terminals at each AHU control terminal. Cross connecting between the “A” and “B” terminals will cause a communications error and the system will not run (see Figure 10).

The minimum distance required between power wires and the communications cable is voltage/amperage dependent and in cases where either are relatively high the minimum distance may be more than two (2) inches. Refer to the respective LG Multi V Outdoor Unit Engineering Manual on www.lg-vrf.com for detailed information.

• Keep communications cables away from line voltage wiring, lighting ballasts, and other devices emitting EMF energy. Maintain a minimum of two (2) inches between line voltage wires and communications cables.

• Field provide a minimum of 18-4 AWG, stranded and shielded, PVC or vinyl jacket communications wiring between the DOAS units and outdoor units.

• The outdoor/DOAS unit communications cable must be run between components in a daisy chain configuration.

• Ground the shield of the communications cable at the OUTDOOR UNIT END ONLY.

Don’ts

• Star and Wye communications cable configurations are not acceptable

• Never splice communication cables

• Never use wire caps

Figure 10: DOAS Wiring Connection to Outdoor Unit

COMM1(2)

Dedicated Outdoor Air System (DOAS) Installation and Operation Manual

COMM2(2)

RS485A(2)

RS485B(2)

RS485A(2)

RS485B(2)

ODU Connected to DOAS Reheat Coil

Due to our policy of continuous product innovation, some specifications may change without notification.

CEN B SODU B

CEN A IDU AIDU BSODU A

ODU Connected to DOAS Main Coil

CEN A IDU AIDU BSODU ACEN B SODU B

DUCT CONNECTIONS

Duct Connections

• Attach duct to flanges provided on the unit. The installer is responsible for sealing ducts to the flanges to prevent water leaks.

• Ductwork should be sized in accordance with the ASHRAE Handbook. Ductwork should be installed in accordance with NFPA Standard 90A.

• When attaching duct to the unit, use a flexible/compressible material rated for duct connections. A three inch flexible connector for both outdoor air and supply duct connections is recommended.

Electrical

Due to our policy of continuous product innovation, some specifications may change without notification.

+ 39 hidden pages

LG DOAS, ARND20BDAT2, ARND20BDAR2 Installation And Operation Manual

Specifications and Main Features

Frequently Asked Questions

User Manual