LG MULTI V ARNU363DDA4 Installation Manual page 47

Connecting the Power Wiring
DANGER
High voltage electricity is required to operate this system. Adhere to the National Electrical Codes and these instructions
when wiring. Always ground the unit following local, state, and National Electrical Codes. Read the safety summary at the
beginning of this manual.
• Secure all field wiring connections with appropriate wire strain relief. Improperly securing wires will create undue stress on equipment
power lugs. Inadequate connections will generate heat, cause a fire and physical injury or death.
• Properly tighten all power connections. Loose wiring will overheat at connection points, causing a fire, physical injury or death.
• Connect the RTU input power cable but
Inappropriate power connection can result in equipment damage and will void the LG limited liability warranty.
• When connecting the communications bus between the outdoor unit and RTU(s), it does not matter what physical path or route the wire
takes. The installer can use discretion when choosing the order the components are connected to the communications bus, but must main-
tain the daisy chain and polarity configuration.
• Failure to follow any of these power and communications wiring guidelines or instructions will cause communications errors and unit mal-
function.
Never use wire caps and never splice communications cables.
Never connect zone controllers or other central controllers or LG building management system gateways to the RTU / outdoor unit com-
munications cable.
Connection Procedure
RTU installation best practices are to connect control wiring (low voltage) and then connect power wiring (high voltage).
power to the RTU or any Multi V system component until authorized to do so by the system commissioning agent.
1. Ensure the input power is disconnected and there is no power on the power input cable.
2. Remove the knockout plugs from the control box. Remember the communications cable and the power cable must enter the control box
through different knockouts.
3. Install a field provided plastic or rubber grommet in the knockout holes to prevent wire chaffing.
4. If using conduit, connect the conduit to the control box using field provided fittings and industry best-practice procedures.
5. Ensure the power wiring is routed separately from the communications cable to the RTU's terminal block (see figures on the preceeding
pages). Do not route the communications cable near the power cable. Provide at least three (3) to four (4) inches of slack cable at each
RTU.
Power wiring is field supplied. Wire size is selected based on the larger MCA value, and must comply with the applicable local and national
codes.
6. Connect the power wiring to the terminal block connections. Ensure the screws securely connect the wire to the terminals and are not
loose.
7. Polarity matters on the outdoor unit to RTU communications bus, and must be maintained throughout the entire system.
Be sure to connect
• IDU-A terminals (outdoor unit) to ODU(IDU)-A (RTU unit) terminals and connect IDU-B terminals (outdoor unit) terminals to ODU(IDU)-B
(RTU unit) terminals.
• Central-A terminals (outdoor unit) to ODU(CEN)-A (RTU unit) terminals and connect Central-B terminals (outdoor unit) to ODU(CEN)-B
(RTU unit) terminals.
do not apply power to the RTU until authorized to do so by the system commissioning agent.
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.
ELECTRICAL
Connection Procedure
Do not apply
47