Communication Cable Specifications - LG ARUM072BTE5 Installation Manual

ELECTRICAL

Communication Cable Specifications

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 18 AWG, 2-conductor, twisted, stranded,
shielded. Ensure the communication cable shield is properly grounded to the Master Outdoor Unit chassis only.
Outdoor Unit to Indoor Units / Heat Recovery Units communication cable at 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.
• 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, depend-
ing 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 in the Engineering Manuals 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
during current leakage, communication problems from electrical
noise, and motor current leakage.
line to 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 may generate heat, cause a fire, and physical
injury or death.
• Always verify the communication cable is connected to a commu-
nications terminal on the outdoor unit(s). Never apply line voltage
power to the communication cable connection. If contact is made,
the PCBs may 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.
106
Do not connect the ground
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. "LG" is a registered trademark of LG Corp.
Correct Master Outdoor Unit to Indoor Unit / Heat Recovery Unit Com-
munication Wiring—Daisy Chain Configuration.
Master Outdoor Unit
Heat Recovery Unit
(For Heat Recovery
Systems Only)
Indoor Unit Indoor Unit
Wired Controllers
Incorrect Master Outdoor Unit to Indoor Unit / Heat Recovery Unit Com-
munication Wiring—Starburst Configuration.
HR unit
Do not ground the
Indoor Unit Indoor Unit Indoor Unit Indoor Unit
Wired Controllers Wired Controllers