LG Arnu Service Manual

The LG Arnu is a high-performance air conditioning unit featuring advanced cooling technology, energy efficiency ratings, smart connectivity options, and user-friendly controls. This service manual provides comprehensive information for installation, maintenance, troubleshooting, and repair procedures for certified technicians. Below are key sections covering technical specifications, installation guidelines, operational procedures, maintenance schedules, and diagnostic troubleshooting.

1. Product Overview 2. Technical Specifications 3. Installation Procedures 4. Electrical Connections 5. Control System Operation 6. Refrigerant System 7. Maintenance Schedule 8. Diagnostic Codes 9. Troubleshooting Guide 10. Parts Replacement 11. Safety Precautions

Product Overview

Key components: Compressor unit, evaporator coil, condenser unit, control board, remote controller, temperature sensors, refrigerant lines.

ComponentDescription
CompressorHigh-efficiency rotary compressor with inverter technology
Evaporator CoilCopper tubing with aluminum fins for optimal heat exchange
Condenser UnitOutdoor unit with fan motor and heat exchanger
Control BoardMain PCB with microprocessor and safety circuits
Remote ControllerWireless remote with LCD display and programming functions
Temperature SensorsRoom and coil temperature monitoring sensors
Refrigerant LinesCopper piping for refrigerant flow between units
Drain SystemCondensate removal with pump option
Air FiltersWashable and replaceable filtration system
Electrical ConnectionsPower input and communication terminals

Technical Specifications

Installation Procedures

Proper installation is critical for optimal performance and safety.

  1. Select installation location: Ensure adequate clearance (min 50cm around units)
  2. Mount indoor unit: Secure to wall with provided bracket at minimum 2.2m height
  3. Install outdoor unit: Place on stable surface with vibration pads
  4. Connect refrigerant lines: Flare connections, ensure no leaks
  5. Connect drain hose: Ensure proper slope for water drainage
  6. Electrical connections: Follow wiring diagram precisely
  7. Vacuum and charge: Evacuate system, charge with specified refrigerant amount

WARNING! Only certified technicians should perform installation. Incorrect installation may void warranty.

Electrical Connections

Power supply requirements and connection specifications.

TerminalSpecificationWire Size
L1, L2, N230V AC Power Input2.5 mm² minimum
CommunicationIndoor-Outdoor SignalShielded cable 0.75 mm²
GroundProtective Earth2.5 mm² green/yellow
Control WiringRemote/External Control0.75 mm² multi-core

CAUTION! Disconnect power before servicing. Verify voltage matches unit specifications.

Control System Operation

Operating modes and control functions available.

Refrigerant System

Refrigerant circuit specifications and service procedures.

  1. Refrigerant Type: R410A
  2. Charge Quantity: 850g ± 20g
  3. Operating Pressure: High side: 2.8-3.2 MPa, Low side: 0.8-1.0 MPa
  4. Oil Type: POE oil, 350ml capacity
  5. Service Ports: High and low pressure service valves
  6. Leak Testing: Use nitrogen at 3.0 MPa maximum
  7. Vacuum Procedure: Evacuate to 500 microns or less

WARNING! R410A operates at higher pressures than R22. Use appropriate gauges and tools.

Maintenance Schedule

ComponentFrequencyProcedure
Air FiltersEvery 2 weeksClean with water, dry completely
Outdoor UnitEvery 3 monthsClean coil fins, check for debris
Indoor UnitEvery 6 monthsClean evaporator, check drain
ElectricalAnnuallyCheck connections, measure voltage
RefrigerantAs neededCheck pressure, leak test if required
Fan MotorsAnnuallyLubricate bearings if applicable

Diagnostic Codes

Common error codes and their meanings.

CodeDescriptionPossible Cause
E1Room temp sensor faultSensor disconnected or faulty
E2Evaporator temp sensor faultSensor wiring or connection issue
E3Communication errorIndoor-outdoor communication failure
E4System abnormalityRefrigerant pressure or flow issue
E5Over current protectionCompressor or fan motor overload
E6Compressor drive errorInverter board or compressor fault
E7Outdoor fan errorFan motor or driver circuit
E8Voltage errorPower supply voltage out of range

Troubleshooting Guide

SymptomPossible CauseCorrective Action
Unit not startingPower supply, remote batteriesCheck circuit breaker, replace batteries
Poor coolingDirty filters, low refrigerantClean filters, check refrigerant charge
Water leakageClogged drain, improper slopeClear drain line, adjust slope
Unusual noiseLoose parts, fan obstructionTighten mounting, clear obstructions
Remote not workingBatteries, signal obstructionReplace batteries, ensure line of sight
Error code displayedSensor or system faultRefer to diagnostic codes section
Unit cycles on/offThermostat, dirty coilsCheck sensor placement, clean coils

Parts Replacement

Common replacement parts and procedures.

NOTE: Use only genuine LG replacement parts for optimal performance.

Safety Precautions

Essential safety guidelines for service technicians.

  1. Always disconnect power before servicing
  2. Use proper personal protective equipment
  3. Follow refrigerant handling regulations
  4. Ensure proper ventilation when brazing
  5. Verify electrical isolation before touching components
  6. Use calibrated instruments for measurements
  7. Follow local electrical and building codes
  8. Dispose of components according to environmental regulations

WARNING! Failure to follow safety procedures may result in injury or equipment damage.

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