Purpose
The purpose of this guideline is to minimize incidental failures, prolong the service life of VRF (Variable Refrigerant Flow) systems, and reduce operating costs. Proper maintenance ensures optimal performance and reliability in commercial applications such as hotels and offices.
This document follows the periodic inspection recommendations set by JRAIA (Japan Refrigeration and Air Conditioning Industry Association) and Fujitsu General’s own maintenance schedules.
Maintenance Frequency
To ensure long-term efficiency and reliability, the following periodic maintenance should be performed:
- Quarterly Maintenance: Basic inspections and cleaning.
- Annual Maintenance: More thorough inspections before peak usage seasons (e.g., summer/winter).
- Component-Specific Maintenance: As per the lifespan and operational hours specified.
The replacement / repair period is an average and does not indicate the life of the product or part.
Outdoor Unit Maintenance
Component | Inspection Frequency | Conservation Period (Replacement or Repair) | Inspection Method | Conservation Method |
Cabinet (Panel), Guard | Once a year | Cleaning: 8 years | Visual inspection | Cleaning, touch-up paint |
Vibration Rubber | Annually | Parts change: 10 years | Visual, sound check | Parts replacement |
Fan, Fan Guard | Annually | Parts change: 10 years | Visual, sound check | Parts replacement |
Fan Motor | Annually | Parts change: 20,000 hours | Insulation resistance test | Replacement if necessary |
Compressor | Annually | Parts change: 20,000 hours | Sound, vibration check | Replacement if needed |
Heat Exchanger | Annually | Cleaning: 5 years | Visual inspection | Cleaning |
Pipes | Annually | Parts change: 20,000 hours | Leak detection | Replacement if necessary |
Refrigerant Valves (4-way, Expansion) | Annually | Parts change: 20,000 hours | Leak check, function test | Replacement if needed |
Protective Devices (Pressure switch, Capacitors) | Annually | Parts change: 25,000 hours | Voltage check | Replacement if necessary |
Electrical Components | Annually | Parts change: 25,000 hours | Resistance test | Replacement |
Condenser coil | Quarterly | Cleaning | Visual inspection | Cleaning |
Indoor Unit Maintenance
Component | Inspection Frequency | Conservation Period (Replacement or Repair) | Inspection Method | Conservation Method |
Decoration Panel | Once a year | Cleaning: 8 years | Visual inspection | Cleaning |
Air Filters | Monthly | Cleaning: Weekly; Change: 5 years | Visual inspection | Cleaning, replacement |
Fan & Fan Casing | Annually | Parts change: 13 years | Sound check | Replacement if needed |
Drain Pan | Annually | Parts change: 8 years | Visual inspection | Cleaning, replacement |
Drain Pump | Annually | Parts change: 20,000 hours | Functional test | Replacement if needed |
Heat Exchanger | Annually | Cleaning: 5 years | Visual inspection | Cleaning |
Pipes | Annually | Parts change: 20,000 hours | Leak detection | Replacement if necessary |
Temperature Sensor | Annually | Parts change: 5 years | Resistance test | Replacement |
Remote Controller | Annually | Parts change: 25,000 hours | Function test | Replacement if needed |
General Inspection Procedures
- Electrical System: Check voltage, terminal connections, and insulation resistance (>1MΩ).
- Refrigerant System: Inspect refrigerant levels, leaks, and pressure readings.
- Drainage System: Ensure proper drainage and check for clogs.
- Noise & Vibration: Identify any abnormal sounds or excessive vibrations.
- Coils & Heat Exchangers: Inspect for dirt buildup and corrosion; clean if necessary.
- Transmission wiring: Measure the resistance of the signal amplifier terminal and the terminal of the indoor and outdoor units connected farthest away from the device where terminal resistor is measured.
A value from the table is displayed, depending on the distance from the signal amplifier and the device where the terminal resistor is set. The resistance between the terminals of the transmission cable is 45-60Ω. This value is an estimate.
Checking Air On and Air Off Temperatures
- Measure the air temperature entering (Air On) and exiting (Air Off) the evaporator coil.
- Compare the temperature difference (Delta T) with manufacturer specifications.
- Ensure proper airflow and confirm that the system is cooling or heating efficiently.
- Identify any discrepancies that may indicate refrigerant issues, airflow obstructions, or component malfunctions.
Special Maintenance Considerations
- Harsh Environments: If the system operates in areas with excessive dust, humidity, or corrosive substances, more frequent maintenance is required.
- Power Quality: Check for voltage fluctuations, unbalanced phase voltage, and power surges that can affect system longevity.
- Operating Hours: Systems running more than 10 hours per day (e.g., hospitals, factories) may require earlier part replacements.
- Restarting after a long period of being powered down: Leave the breaker on for at least 12 hours before starting operation when it is to be used again.