Demystifying Air Circuit Breakers: Ensuring Electrical Safety and Efficiency

A circuit breaker is the only piece of switchgear that activates in the event of an overcurrent, earth fault, or short circuit in an electrical system, separating the malfunctioning circuit from the healthy circuit. Switchgear is switching hardware used in many applications within an electrical system. Operating voltage, nominal current, making and breaking capacities, and duty cycle make up the circuit breaker’s basic technical requirements.

Meaning Of Air Circuit Breakers

A circuit breaker is a specific type of electric equipment that may normally be used to manually or remotely interrupt any circuit. A circuit breaker, often known as a CB, serves the primary purpose of interrupting a circuit under certain fault circumstances such as a short circuit, over-current, etc. A circuit breaker often switches or safeguards the system. Relays and other devices, like as switches, fuses, and so on, are often used in conjunction with circuit breakers.

Places Where Circuit Breakers Are Used

Circuit breakers are primarily used in power systems and industrial settings to safeguard and manage different circuit components such transformers, switch gears, motors, alternators, and generators. The air circuit breaker is one of several types of circuit breakers used in many sectors.

As needed in an electrical system, circuit breakers can also be controlled manually or remotely. Depending on its intended use, circuit breakers can handle a range of voltage and current ratings. According to the arc quenching medium used to put out an arc during the opening of a circuit breaker.

In typical functioning, a switch is one of the electrical parts that is utilised to open and close the circuit. During defective currents, a circuit breaker is employed to either open or close the circuit.

A fixed and moving set of contacts make up an air circuit breaker, which is housed in a chamber with an arc  that uses air to quench the arc.

The Air Circuit Breaker’s Component Parts

These circuit breakers are often employed in low voltage (up to 1000 V) applications. It can handle current ratings of 500 amps to 10,000 amps.

Construction of Air Circuit Breakers (ACB)

 Compact in design is the low voltage Air Circuit Breaker (ACB). An arc chute assembly houses each pole of an ACB that has both fixed and movable contacts. Through a triggering mechanism, these breakers can be controlled physically or electrically. These breakers have sliding and guiding rail assemblies as well as rack-in and rack-out functions. On the ACB are installed push buttons for its manual functions.

Additionally, CTs, relays, and trip unit provisions are integrated into ACBs.

Construction and Operation of an Air Circuit Breaker (ACB). For arc extinction, the air circuit breaker uses a high resistance interruption mechanism.

When a circuit breaker is opened in a malfunctioning or regular working situation, the resistance of the arc increases quickly to a high amount, rendering the source voltage unable to sustain the arc voltage.

Air Circuit Breaker Arc Resistance’s Operation Ra may be raised in a variety of ways, including:

l  the arc being cooled

l  expanding the arc

l  decreasing the arc’s cross-section

l  breaking the arc

Types Of Air Break Circuit Breakers In The Air Break Circuit

Breaker Graph

ü  Simple Break Type Cross-Blast or ACB ACB

ü  ACB with Magnetic Blowout

ü  ACB with Magnetic Blowout

ü  Magnetic Blowout Type ACB

Uses For Air Circuit Breake

l  The majority of applications for air circuit breakers are low voltage and low/high current ones.

l  Most indoor low- to medium-voltage electrical systems, such power control cubicles and motor control cubicles, employ air circuit breakers.

l  Because ACBs have a very quick arcing period, they are suited for situations where there is a significant danger of fire risks.

l  As they are best suited for frequent and high-speed operations, air circuit breakers are employed for motor and capacitor starting and protection applications.

l  Circuit breakers of the air blast type are frequently employed in railway electrification.

A circuit breaker that uses the air as an arc-extinguishing medium at a specific atmospheric pressure is known as an air circuit breaker. Today’s market offers a variety of air circuit breakers and switching gears that are strong, efficient, simple to install, and maintain. Completely taking the role of oil circuit breakers are air circuit breakers.

 Building Air Circuit Breakers

The following list of internal and exterior components can be used to build an air circuit breaker.

The ON/OFF button, an indication for the primary contact position, an indicator for the energy storage mechanism, LED indicators, the RST button, the controller, the rated nameplate, the handle for energy storage, displays, shaking, and fault codes are the key exterior components of the ACB.

Building of the ACB

The main steel-sheet supporting structure, the current transformer used to protect the trip unit, the pole group insulating box, the horizontal terminals, the arcing chamber, the trip unit for protection, the terminal box, the closing springs, the control for opening and closing the CB, the plates to move the arcing and main contacts, and the plates for fixed main & arcing contacts are the internal components of the ACB.

Working Theory

When compared to other types of CBs, the functioning concept of an air circuit breaker is unique. We are aware that the primary purpose of a CB is to prevent the return of arcing in situations when the space between contacts will cause the system’s recovery voltage to be insufficient.

The air circuit breaker operates similarly yet differently. It makes an abrupt turn in an arc.

Post time: Jun-27-2023