Description of Electrical Components Used in Split Air Conditioner

In a split air conditioning system, electrical components play a vital role in controlling, protecting, and ensuring the efficient operation of the unit. Understanding these components is essential for installation, servicing, and troubleshooting in the Refrigeration and Air Conditioning (RAC) trade. This chapter describes the various electrical components used in split AC systems and their functions.

Introduction

A split air conditioner consists of indoor and outdoor units, both of which contain several electrical components. These components help in starting the compressor, controlling temperature, regulating airflow, and protecting the system from faults such as overload and short circuits.

Main Electrical Components

Compressor Motor

The compressor motor is the most important electrical component in the outdoor unit. It drives the compressor, which circulates refrigerant throughout the system.

• Operates on single-phase or three-phase supply
• Consumes maximum electrical power
• Protected by overload devices

Fan Motors

Split AC systems use two types of fan motors:

• Indoor Fan Motor: Circulates air over the evaporator coil
• Outdoor Fan Motor: Helps in heat dissipation at condenser

These motors ensure proper airflow and heat exchange.

Capacitor

Capacitors are used to start and run motors efficiently. They improve the power factor and provide the necessary phase shift for motor operation.

• Start Capacitor: Provides high starting torque
• Run Capacitor: Ensures smooth operation of motors

Contactor / Relay

Contactors or relays are used to control the power supply to the compressor and fan motors. They act as switches that open or close the circuit based on control signals.

• Operated electrically or electronically
• Used in outdoor unit

Thermostat

The thermostat senses room temperature and controls the operation of the compressor. When the desired temperature is reached, it switches off the compressor and restarts it when needed.

• Maintains comfort conditions
• Available in mechanical or electronic type

Printed Circuit Board (PCB)

The PCB is the control center of a split AC system. It manages all functions such as temperature control, fan speed, compressor operation, and protection features.

• Receives signals from remote control
• Controls system operations automatically
• Includes microcontroller and sensors

Sensors (Thermistors)

Sensors are used to measure temperature at different points in the system. These include:

• Room temperature sensor
• Evaporator temperature sensor
• Condenser temperature sensor

These sensors provide input to the PCB for proper system control.

Overload Protector (OLP)

The overload protector protects the compressor motor from overheating and excessive current.

• Disconnects power during overload
• Automatically resets after cooling

Fuse and Circuit Breaker

These components provide protection against short circuits and overcurrent conditions.

• Fuse melts when current exceeds limit
• Circuit breaker trips during fault

Transformer

A transformer is used to step down the voltage for control circuits and electronic components.

• Provides low voltage supply to PCB
• Ensures safe operation of electronics

Solenoid Valve (in some systems)

Solenoid valves are used to control refrigerant flow in advanced systems such as heat pump ACs.

• Operates electrically
• Used in reversing cycle systems

Display Panel and Remote Control

The display panel shows system status, while the remote control allows the user to operate the AC from a distance.

• Controls temperature, mode, and fan speed
• Sends signals to PCB

Functions of Electrical Components

The electrical components collectively perform the following functions:

• Start and run compressor and fan motors
• Control temperature and airflow
• Provide safety and protection
• Ensure automatic and efficient operation

Common Electrical Faults

Some common issues related to electrical components include:

• Faulty capacitor causing motor failure
• PCB malfunction leading to improper operation
• Sensor failure affecting temperature control
• Overload protector tripping due to overheating

Proper diagnosis and maintenance are required to resolve these issues.

Safety Precautions

• Switch off power before servicing
• Use proper tools and instruments
• Ensure proper earthing
• Avoid direct contact with live circuits

Conclusion

Electrical components are essential for the proper functioning of split air conditioning systems. They control, protect, and regulate the entire operation of the system.

Understanding these components helps RAC technicians perform installation, maintenance, and troubleshooting effectively. Proper handling and regular inspection ensure safe and efficient operation of split AC systems.