LG MULTI V ARNU073TUD4 Installation Manual page 48

WIRING
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 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
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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.
Figure 40: Correct Master Outdoor Unit to Indoor Unit / Heat Recovery
Master Outdoor Unit
-
Heat Recovery Unit
(For Heat Recovery
Systems Only)
Indoor Unit Indoor Unit
Wired Controllers
Figure 41: Incorrect Master Outdoor Unit to Indoor Unit / Heat Recovery
HR unit
Do not ground the
Indoor Unit Indoor Unit Indoor Unit Indoor Unit
Wired Controllers Wired Controllers