Communications Cable Specifications - LG MULTI V ARNU073M1A4 Installation Manual

Ducted indoor units

Table of Contents

Communication Cable Specifications From Outdoor Unit to Indoor Units /

Heat Recovery Units

• Communication cable from Master Outdoor Unit to Indoor Units / Heat Recovery Units is to be LG supplied or field supplied 18 AWG,

2-conductor, twisted, stranded, shielded. Never splice communications cable. Ensure the communication cable shield is properly grounded

to the Master Outdoor Unit chassis only.

any other point. Wiring must comply with all applicable local and national codes.

• Cable shields between the connected devices must be tied together and continuous from the master outdoor unit to the last component

connected and insulated to prevent grounding against the IDU/HRU electrical enclosures.

• Start the communication cable at the master outdoor unit and route to the indoor units / heat recovery units in a daisy chain configuration.

Do not install in a starburst configuration.

• Indoor Unit / Heat Recovery Unit Communication Bus: The communication terminals are labeled differently among the indoor units, de-

pending on type (currently for indoor units: A / B, 3[A] / 4[B], or 3 / 4; for heat recovery units: A / B). Refer to the wiring diagram schematic

found in the indoor unit itself, or to the indoor unit wiring diagrams for more information. Match IDU A and B terminals on outdoor unit to A

(3) and B (4) terminals on indoor units / heat recovery units.

• Insulation as required by NEC and local codes.

• Rated for continuous exposure of temperatures up to 140°F.

• Maximum allowable communication cable length is 3,281 feet.

WARNING

• Ground wiring is required to prevent accidental electrical shock dur-

ing current leakage, communication problems from electrical noise,

and motor current leakage.

the pipes. There is risk of fire, electric shock, explosion, physical

injury or death.

•

Never ground the shield of the communications cable to the

indoor unit frame or other grounded entities of the building. Inad-

equate connections will generate heat, cause a fire, and physical

injury or death.

• Always verify the communication cable is connected to a com-

munications terminal on the outdoor unit(s).

voltage power to the communication cable connection. If contact is

made, the PCBs will be damaged.

•

Never use a common multiple-core communications cable.

Each communications bus shall be provided a separate cable (i.e.,

between outdoor unit(s) and indoor units, outdoor units and central

controller(s)). If communications cables of separate systems are

wired using a common multiple-core cable, it will result in a poor

communications signal and unacceptable system operation.

Do not ground the Outdoor Unit to Indoor Units / Heat Recovery Units communication cable at

Do not connect the ground line to

Never apply line

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