Inverter Aircon Repair and Diagnostics Course

Lesson 1 • Capacitors, Inductors, and Transformers

Explains passive component behaviour in AC circuits and their roles in inverter systems. Students test and evaluate these components during board-level diagnostics.

Lesson 2 • Reading Electrical Schematics

Teaches interpretation of wiring diagrams, ladder diagrams, and PCB layout symbols. Accurate schematic reading is critical for tracing faults in inverter control boards.

Lesson 3 • Grounding and Electrical Safety Standards

Establishes grounding principles and compliance with electrical safety requirements. Proper grounding prevents shock hazards and protects sensitive inverter electronics.

Lesson 4 • DC and AC Circuit Theory

Reviews Ohm's law, series and parallel circuits, and AC waveform characteristics. Provides the electrical foundation for analysing inverter drive circuits.

Lesson 1 • Refrigeration Cycle Basics

Covers the vapour-compression cycle, refrigerant states, and heat transfer principles. Establishes thermodynamic context required for all subsequent diagnostic work.

Lesson 2 • System Component Identification

Identifies indoor and outdoor unit components and their functional roles. Provides the component vocabulary needed for accurate fault diagnosis.

Lesson 3 • Refrigerants Used in Inverter Systems

Surveys common refrigerants, their properties, and safe handling requirements. Connects refrigerant selection to system design and diagnostic interpretation.

Lesson 1 • IGBT Inverter Bridge Operation

Details how insulated-gate bipolar transistors switch DC bus voltage to produce variable-frequency AC. Students identify IGBT failure signatures and test procedures.

Lesson 2 • Sensor Inputs and Feedback Circuits

Identifies current, voltage, and temperature sensors that feed data to the control board. Faulty sensor signals are a leading cause of nuisance shutdowns and misdiagnosis.

Lesson 3 • Communication Interfaces on Control Boards

Explains serial communication protocols linking indoor and outdoor control boards. Students use protocol knowledge to isolate communication-related fault codes.

Lesson 4 • Power Supply and Rectifier Stage

Examines AC-to-DC conversion, bridge rectifiers, and bulk capacitor filtering. Understanding this stage is prerequisite for diagnosing drive input faults.

Lesson 1 • Fault Code Libraries and Interpretation

Teaches systematic decoding of alphanumeric and numeric fault codes across major platforms. Students map codes to subsystems and prioritise investigation paths.

Lesson 2 • Vibration and Noise Diagnostics

Identifies abnormal mechanical sounds and vibration patterns linked to specific component failures. Acoustic diagnosis complements electrical and refrigerant-side testing.

Lesson 3 • Systematic Troubleshooting Methodology

Introduces structured diagnostic frameworks to avoid random-part replacement. Applying a repeatable process reduces diagnostic time and improves first-call resolution.

Lesson 4 • Manufacturer Diagnostic Interfaces

Covers wired and wireless diagnostic ports, service software, and handheld tools. Connecting correctly and reading live data accelerates fault isolation significantly.

Lesson 1 • Electrical Testing of Compressor Motors

Covers winding resistance, insulation resistance, and back-EMF tests for three-phase compressor motors. These tests distinguish motor faults from drive-board faults.

Lesson 2 • Inverter Compressor Operating Principles

Reviews scroll and rotary compressor mechanics as applied in inverter systems. Understanding internal operation guides accurate interpretation of electrical test results.

Lesson 3 • Post-Replacement Commissioning and Verification

Establishes leak testing, recharging, and operational verification steps after compressor replacement. Confirms system performance meets manufacturer specifications before handover.

Lesson 4 • Refrigerant Recovery and System Evacuation

Details certified refrigerant recovery procedures and deep vacuum evacuation before compressor replacement. Proper recovery protects the environment and prevents contamination.

Lesson 1 • Soldering and Desoldering Techniques

Develops through-hole and SMD soldering skills required for component-level board repair. Quality solder joints are critical for long-term reliability of repaired boards.

Lesson 2 • In-Circuit Component Testing

Covers in-circuit testing of diodes, transistors, capacitors, and resistors without full board removal. Efficient in-circuit testing minimises disassembly time during diagnosis.

Lesson 3 • IGBT and Power Module Replacement

Details safe removal and installation of IGBT modules and power transistors on inverter boards. Correct thermal interface application prevents premature power module failure.

Lesson 4 • Visual Inspection and Board Assessment

Teaches systematic visual inspection for burn marks, swollen capacitors, cracked traces, and corrosion. Visual findings guide the sequence of subsequent electrical tests.

Lesson 1 • Thermistor Testing and Replacement

Covers NTC thermistor resistance-temperature curves and substitution testing methods. Accurate thermistor readings are essential for correct inverter speed and protection logic.

Lesson 2 • Pressure Sensor Diagnostics

Tests high-side and low-side pressure transducers and compares output to manifold gauge readings. Pressure sensor faults cause incorrect compressor speed commands and false shutdowns.

Lesson 3 • Four-Way Reversing Valve Service

Tests and replaces the four-way valve and its solenoid coil in heat pump systems. Valve failures cause heating or cooling mode loss and refrigerant bypass symptoms.

Lesson 4 • Electronic Expansion Valve Operation and Testing

Explains stepper-motor EEV operation, coil testing, and valve position verification. EEV faults directly affect superheat control and overall system efficiency.

Lesson 1 • System Performance Benchmarking

Measures actual system capacity, EER, and COP against manufacturer specifications. Benchmarking identifies degraded performance before it escalates to component failure.

Lesson 2 • Power Quality and Electrical Supply Issues

Analyses voltage imbalance, harmonics, and supply fluctuations that damage inverter drives. Identifying power quality issues prevents repeat failures after component replacement.

Lesson 3 • Intermittent and Multi-Fault Diagnosis

Develops strategies for diagnosing faults that do not appear consistently or involve multiple failed components. Intermittent faults require data logging and pattern recognition skills.

Lesson 4 • Preventive Maintenance Programmes

Designs scheduled maintenance routines that reduce unplanned downtime and extend system life. Preventive maintenance is the highest-value service a technician can deliver.