LG Multi V Water IV - Electrical System Installation: Communication Cable; Communication Cable Specifications; WSU Communications Schematic Diagram; WSU to Central Control Communication Cable

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MULTI V Water IV System Installation Manual
Due to our policy of continuous product innovation, some specifications may change without notification.
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• Use two-conductor, 18 gauge, stranded and shielded cable
between the water source unit and the indoor units.
• Insulation material as required by local code
• Rated for continuous exposure of temperatures up to 140°F
• Maximum allowable cable length is 984 ft.
• Use copper-bearing ring or spade terminals to terminate
communication cables.
• Firmly attach the cable; provide slack, but secure in a way to
prevent strain on the cable and terminal block connections.
• Connect and terminate communications cable connecting the
water source unit to indoor unit(s) in a daisy chain (bus) con-
figuration starting at the water source unit.
• Terminate the cable shield to a grounded surface at the water
source unit only. Cable shields between connected devices
shall be tied together and continuous from the water source
unit to the last device connected.
• Refer to the installation manual for the specific model of IDU for
detailed communication cable installation instructions.
• Ring and spade terminals used to connect communications
cables MUST be copper bearing. Do NOT use terminals that are
galvanized or nickle plate over steel.
• Always verify the communication cable is connected to the proper
communications terminals on the WSU(s). Never apply line voltage
power to the communication cable connection. Line voltage can
damage the circuit boards in the WSU(s) and the IDU(s).
• The shield of the communications cable connecting the water
source unit to the indoor units should be grounded only to the water
source unit frame. Tie the shield of each cable segment together
using a wire nut at each indoor unit.
• Never ground the shield of the communications cable to the indoor
unit frame or any other ground point.
• Position the WSU communication cables away from power wiring.
Refer to minimum spacing requirements in Table 62.
• Never use a common multiple-conductor communications cable.
Each communications bus must be a separate cable (i.e., one bus
between WSU(s) and indoor units, and one bus between WSU(s) and
central controller(s). If communications cables of separate systems
are wired using a common multiple-conductor cable, it will result in a
poor communications signal and unacceptable system operation.
Note:
Figure 72: Water Source Unit Communications Schematic Diagram.
Required Conguration—18 Gauge, Two Conductor, Stranded
and Shielded Cable in a Daisy Chain Conguration
Communication Cable
ELECTRICAL SYSTEM INSTALLATION
General Communication Cable Specifications
CEN B
IDU AIDU B
SODU A
Connect 2-Wire Communication Cable
to IDU B and IDU A Terminals in WSU
Communication Cable Between the WSU and the Central Control Device
• This communications cable is field provided, 18 gauge, two conductor, stranded and shielded.
• Use cable with insulation material as required by local code.
Connect all central control devices such as AC Smart II, AC Smart Premium, ACP, BACnet and LonWorks gateways, and energy recovery venti-
lators all on the same cable. Order does not matter, but polarity does. Keep “A” terminals with “A” terminals, and “B” terminals with “B” terminals.
Starting at the water source unit, terminate the cable on terminals CEN A and CEN B. Route the cable as needed between each device. Follow
the cable routing parameters described in “Separating Power Wires and Communication Cables” on page 84,
Improperly Terminated Communications Cable—Multiple Core
Cable in a Starburst Conguration