Fujitsu AOU48RLXFZ Installation Manual

The Fujitsu AOU48RLXFZ is a high-performance outdoor unit for split-type air conditioning systems with R32 refrigerant, designed for residential and commercial applications. This unit features inverter technology for energy efficiency, quiet operation, weather-resistant construction, and compatibility with various indoor units. Below are key sections covering safety precautions, technical specifications, installation procedures, electrical connections, commissioning, and maintenance guidelines.

Features at a Glance

Key components: Weather-resistant outdoor unit, inverter compressor, R32 refrigerant system, fan motor, heat exchanger, electrical terminal block, service valves, and drainage port.

Safety Precautions

Read all instructions before installation. Use proper personal protective equipment.

1. Disconnect power before servicing or installation.
2. Use certified refrigerant handling equipment and follow local regulations.
3. Ensure proper grounding of electrical components.
4. Install unit on stable, level surface with adequate clearance.
5. Verify refrigerant type (R32) before charging.

WARNING! R32 refrigerant is flammable; no smoking or open flames during installation. Ensure adequate ventilation.

Technical Specifications

• Model: AOU48RLXFZ
• Cooling Capacity: 48,000 BTU/h
• Heating Capacity: 51,000 BTU/h
• Power Input: Cooling: 4.8 kW, Heating: 5.2 kW
• Current Rating: 25 A max
• Refrigerant Charge: Factory pre-charged: 4.41 lbs (2.0 kg)
• Max Piping Length: 98 ft (30 m) between indoor and outdoor units
• Max Height Difference: 49 ft (15 m) outdoor above/below indoor unit
• Drain Connection: 3/8" PVC pipe
• Operating Ambient: -13°F to 115°F (-25°C to 46°C)

Installation Requirements

Select appropriate location and prepare necessary tools and materials.

1. Location: Well-ventilated area, away from direct sunlight, minimum 12" clearance on all sides.
2. Mounting: Concrete pad or sturdy wall bracket, level surface.
3. Tools: Torque wrench, flaring tool, vacuum pump, manifold gauge, leak detector.
4. Materials: Copper piping (ACR grade), insulation, electrical cable, conduit.
5. Permits: Check local building codes and obtain necessary permits.

CAUTION! Do not install in confined spaces or areas with combustible gases.

Mounting Procedures

Proper mounting ensures stability and optimal performance.

1. Position unit: Place on concrete pad or secure wall bracket with vibration isolators.
2. Level unit: Use spirit level to ensure unit is perfectly horizontal.
3. Secure fasteners: Use appropriate bolts and anchors for mounting surface.
4. Clearance: Maintain minimum clearances - 12" sides, 48" front, 24" top.
5. Drainage: Ensure proper slope for condensate drainage away from unit.

Tip: Use rubber vibration pads to reduce noise transmission.

Refrigerant Piping

Proper piping installation is critical for system performance.

1. Pipe sizing: Use recommended diameter (liquid: 1/4", gas: 1/2") for maximum efficiency.
2. Flaring: Create 45° flare connections using proper flaring tool.
3. Bending: Use tube bender to avoid kinks; minimum bend radius 4x pipe diameter.
4. Insulation: Apply closed-cell foam insulation to both pipes; seal joints with tape.
5. Routing: Keep pipes straight and supported every 6-8 feet.
6. Connections: Tighten flare nuts to specified torque (25-30 ft-lbs).

WARNING! Never use pipe thread sealant on flare connections.

Electrical Connections

Follow electrical codes and use proper wiring methods.

1. Power disconnect: Install weatherproof disconnect within sight of unit.
2. Wiring: Use copper conductors only; follow NEC guidelines for wire sizing.
3. Grounding: Connect equipment grounding conductor to terminal block.
4. Terminal connections: Match wire colors to terminal markings; torque to 15 in-lbs.
5. Communication cable: Use shielded 2-conductor cable for indoor-outdoor communication.
6. Conduit: Use liquid-tight conduit for outdoor wiring connections.

CAUTION! Turn off power at main breaker before making electrical connections.

Vacuum Drying & Leak Testing

Essential steps to ensure system integrity and performance.

1. Pressure test: Use dry nitrogen to pressurize system to 150 psi; hold for 24 hours.
2. Leak check: Apply bubble solution to all connections; use electronic leak detector.
3. Evacuation: Connect vacuum pump to service ports; pull vacuum to 500 microns.
4. Hold test: Isolate vacuum pump; verify vacuum holds below 1000 microns for 15 minutes.
5. Charge refrigerant: Open service valves to release factory charge into system.

Tip: Use core removal tool for better vacuum performance.

Commissioning & Startup

Final checks and system activation.

1. Visual inspection: Verify all connections, clearances, and mounting.
2. Electrical check: Measure voltage at terminal block; verify proper grounding.
3. Startup: Turn on power; set indoor unit to cooling mode.
4. Operation check: Listen for abnormal noises; verify fan operation.
5. Performance: Measure operating pressures and temperatures.
6. Settings: Configure thermostat and remote control settings.

WARNING! Do not operate system if unusual sounds or smells are detected.

Maintenance & Service

Regular maintenance ensures optimal performance and longevity.

• Monthly: Clean air filters on indoor unit.
• Seasonal: Clean outdoor coil with soft brush and water.
• Annual: Professional inspection of refrigerant charge, electrical components.
• As needed: Clear debris from around outdoor unit.
• Winter: Install protective cover if unit will not be used.

CAUTION! Only qualified technicians should service refrigerant circuit.

Troubleshooting

Reset: Turn power off for 5 minutes, then restart.

Service: Contact authorized Fujitsu service center; 1-800-853-8573