Fujitsu AOU24RLXFZ Service Manual

The Fujitsu AOU24RLXFZ is a 24,000 BTU split-type air conditioning unit with R410A refrigerant, designed for residential and light commercial applications. This service manual provides comprehensive technical information for qualified service technicians, including specifications, installation procedures, troubleshooting, maintenance, and repair guidelines. Below are key sections covering technical data, installation, operation, maintenance, and troubleshooting.

1. Technical Specifications 2. Installation Requirements 3. Wiring Diagrams 4. Refrigerant System 5. Control System 6. Maintenance Procedures 7. Troubleshooting Guide 8. Error Codes 9. Parts List 10. Safety Precautions

Technical Specifications

Key technical parameters and performance data for the AOU24RLXFZ unit.

Specification	Value
Cooling Capacity	24,000 BTU/h (7.0 kW)
Heating Capacity	26,000 BTU/h (7.6 kW)
Power Supply	208-230V, 60Hz, 1Phase
Refrigerant	R410A
Refrigerant Charge	2.65 lbs (1.2 kg)
Operating Current (Cooling)	10.5A
Operating Current (Heating)	11.2A
Sound Pressure Level (Indoor)	34 dB(A)
Sound Pressure Level (Outdoor)	52 dB(A)
Dimensions (Indoor Unit)	35.4" x 12.6" x 8.7"
Dimensions (Outdoor Unit)	33.1" x 25.6" x 13.4"

Installation Requirements

Proper installation procedures and requirements for safe operation.

Select installation location: Ensure adequate clearance around indoor and outdoor units.
Mount indoor unit: Secure to wall with proper brackets, level unit.
Install outdoor unit: Place on stable surface or mounting brackets.
Connect refrigerant piping: Use flare connections, ensure proper insulation.
Connect electrical wiring: Follow wiring diagram, use proper gauge wires.
Connect drain hose: Ensure proper slope for water drainage.
Vacuum and charge system: Evacuate to 500 microns, charge with R410A.

WARNING! Only qualified technicians should perform installation. Follow all safety procedures and local codes.

Wiring Diagrams

Complete electrical schematics for indoor and outdoor units.

Indoor Unit Wiring: Power supply, control board, fan motor, thermistor connections.
Outdoor Unit Wiring: Compressor, fan motor, 4-way valve, control board connections.
Inter-unit Wiring: Communication cable between indoor and outdoor units.
Remote Control Wiring: Connection to indoor unit control board.

CAUTION! Disconnect power before servicing electrical components.

Refrigerant System

Refrigerant circuit components and service procedures.

Compressor: Rotary type, 3-phase DC inverter controlled.
Condenser: Copper tubes with aluminum fins.
Evaporator: Copper tubes with hydrophilic coated aluminum fins.
Expansion device: Electronic expansion valve.
4-way valve: For heating/cooling mode changeover.
Service ports: High and low pressure gauge connections.

Service Notes: Use R410A compatible tools and gauges. Never mix refrigerants.

Control System

Electronic control system and operation modes.

Control Board: Microprocessor controlled with fault detection and protection circuits.

Operation Modes: Cooling, Heating, Dry, Fan Only, Auto.

Fan Speeds: Auto, Low, Medium, High, Quiet.

Temperature Control: Digital thermistor sensing, ±1°C accuracy.

Timer Functions: 24-hour on/off timer, weekly programming available.

Maintenance Procedures

Routine maintenance tasks and schedules.

Clean air filters: Remove and wash every 2 weeks during operation.
Clean indoor coil: Use soft brush and vacuum annually.
Clean outdoor coil: Remove debris, clean with coil cleaner annually.
Check drain pan and hose: Clear obstructions, ensure proper drainage.
Check electrical connections: Tighten terminals, inspect for corrosion.
Check refrigerant charge: Measure superheat/subcooling as needed.
Check fan motors: Lubricate bearings if required.

Tip: Keep detailed maintenance records for warranty compliance.

Troubleshooting Guide

Common problems and diagnostic procedures.

Symptom	Possible Cause	Corrective Action
Unit not starting	Power supply, fuse, breaker	Check voltage, reset breaker, replace fuse
Poor cooling/heating	Dirty filters, low refrigerant	Clean filters, check refrigerant charge
Water leakage	Clogged drain, improper slope	Clear drain line, adjust slope
Unusual noise	Loose parts, fan hitting	Tighten components, check fan clearance
Error code displayed	System fault detected	Refer to error code section

Error Codes

Diagnostic codes and their meanings.

Code	Description	Action
E0	Protection device activated	Check sensors, wait for reset
E1	Indoor PCB error	Replace indoor control board
E2	Communication error	Check wiring between units
E3	Outdoor PCB error	Replace outdoor control board
E4	High pressure protection	Check condenser, refrigerant charge
E5	Low pressure protection	Check for leaks, refrigerant charge
E6	Compressor overload	Check compressor, electrical connections

Parts List

Major components and replacement part numbers.

Compressor: Part #KHB4510FMC
Indoor Fan Motor: Part #FXY-24G192
Outdoor Fan Motor: Part #FXY-38G268
Indoor Control Board: Part #PCB-A241RLX
Outdoor Control Board: Part #PCB-A241ROX
Thermistor Set: Part #THS-A241RLX
4-Way Valve: Part #V4W-A241RLX
Capacitor Set: Part #CAP-A241RLX

Safety Precautions

Important safety information for service technicians.

Electrical Safety: Always disconnect power before servicing. Use lockout/tagout procedures.

Refrigerant Safety: Wear gloves and safety glasses when handling refrigerant. Use in well-ventilated areas.

Lifting Safety: Use proper lifting techniques for heavy components.

Working at Heights: Use fall protection when working on rooftop installations.

Emergency Procedures: Know location of fire extinguishers and emergency exits.