Control Box And Connecting Position Of Wiring; Communication And Power Cables - LG Multi V IV PRHR041 Installation Manual

24
CAUTION
!
• Use the 2-core shield cables for communication cables. Never use
them together with power cables.
• The conductive shielding layer of cable should be grounded to the
metal part of both units.
• Never use multi-core cable
• As this unit is equipped with an inverter, to install a phase leading
capacitor not only will deteriorate power factor improvement effect,
but also may cause capacitor abnormal heating. Therefore, never in-
stall a phase leading capacitor.
• Make sure that the power unbalance ratio is not greater than 2%.
If it is greater the units lifespan will be reduced.
Precautions when laying power wiring
Use round pressure terminals for connections to the power terminal
block.
Round pressure terminal
When none are available, follow the instructions below.
- Do not connect wiring of different thicknesses to the power terminal
block. (Slack in the power wiring may cause abnormal heat.)
- When connecting cable which is the same thickness, do as shown in
the figure below.
- For wiring, use the designated power cable and connect firmly, then
secure to prevent outside pressure being exerted on the terminal
block.
- Use an appropriate screwdriver for tightening the terinal screws. A
screwdriver with a small head will strip the head and make proper
tighterning impossible.
- Over-tightening the terminal screws may break them.
CAUTION
!
When the 400 volt power supply is applied to "N" phase by mistake,
check damaged parts in control box and replace them.

Control box and connecting position of wiring

- Remove all of the screws at front panel and remove the panel by
pulling it forward.
- Connect communication cable between main and sub outdoor unit
through the terminal block.
- Connect communication cables between outdoor unit and indoor
units through the terminal block.
- When the central control system is connected to the outdoor unit, a
dedicated PCB must be connected between them.
- When connecting communication cable between outdoor unit and in-
door units with shielded cable, connect the shield ground to the earth
screw.
Power cable
Front Panel
WARNING
!
The temperature sensor for outdoor air should not be exposed to
direct sunlight.
- Provide an appropriate cover to intercept direct sunlight.
UX2
Main PCB
Noise Filter
External PCB
Take care of the
phase sequence of
3-phase 4-wire
power system

Communication and Power Cables

Communication cable
- Types : shielding cable
2
- Cross section : 1.0~1.5mm
- Maximum allowable temperature: 60°C
- Maximum allowable cable length: under 1000m
Remote control cable
- Types : 3-core cable
Central control cable
Product type
ACP&AC Manager 2-core cable (Shielding cable)
AC Smart 2-core cable (Shielding cable)
Simple central controller 4-core cable (Shielding cable)
Separation of communication and power cables
- If communication and power cables are run alongside each other then
there is a strong likelihood of operational faults developing due to in-
terference in the signal wiring caused by electrostatic and electro-
magnetic coupling.
The tables below indicates our recommendation as to appropriate
spacing of communication and power cables where these are to be
run side by side
Current capacity of power cable
100V or more
Exceed 100A
UX3
Cable type Diameter
1.0~1.5mm
1.0~1.5mm
1.0~1.5mm
Spacing
10A 300mm
50A 500mm
100A 1000mm
1500mm
2
2
2