How do Circuit Breakers Work?

Circuit breakers are an essential component of the electrical systems in our Edmonton and Sherwood Park homes and businesses. They are designed to protect us from electrical overloads and short circuits that could lead to fires, electrocution, and other hazards. In this article, we will explore how circuit breakers work and why they are so important.

What are Circuit Breakers?

A circuit breaker is an electrical device that automatically cuts off power to a circuit when there is too much current flowing through it. When too much current flows through a circuit, it can cause the wires to overheat, which can lead to electrical fires. Circuit breakers are designed to trip or turn off the power when this happens, preventing any further flow of electricity and protecting the circuit and the connected devices from damage.

How Do Circuit Breakers Work?

Circuit breakers work by using an electromechanical mechanism to sense the current flowing through a circuit. They have a spring-loaded switch that is connected to a bimetallic strip or an electromagnetic coil. When the current flowing through the circuit exceeds the rated capacity of the circuit breaker, the bimetallic strip or the electromagnetic coil becomes heated, which causes the switch to open, interrupting the flow of electricity.

When the switch opens, it disconnects the circuit from the electrical supply, cutting off the flow of electricity. This prevents the wires from overheating and causing electrical fires. Circuit breakers are designed to trip quickly to prevent any significant damage to the circuit or the connected devices.

Types of Circuit Breakers

There are several types of circuit breakers, each designed for a specific application. Here are some of the most common types:

1. Thermal Circuit Breakers

Thermal circuit breakers are the most common type of circuit breaker. They use a bimetallic strip to sense the current flowing through a circuit. The bimetallic strip is made up of two different metals that expand at different rates when heated. When the current exceeds the rated capacity of the circuit, the bimetallic strip becomes heated, and the two metals expand at different rates, causing the strip to bend and open the switch, interrupting the flow of electricity.

2. Magnetic Circuit Breakers

Magnetic circuit breakers use an electromagnetic coil to sense the current flowing through a circuit. The coil generates a magnetic field, which becomes stronger as the current flowing through the circuit increases. When the current exceeds the rated capacity of the circuit, the magnetic field becomes strong enough to pull the switch open, interrupting the flow of electricity.

3. Ground Fault Circuit Interrupters (GFCI)

Ground fault circuit interrupters (GFCI) are designed to protect against electrocution. They work by sensing the current imbalance between the hot and neutral wires in a circuit. When the current
imbalance exceeds a certain threshold, the GFCI trips, interrupting the flow of electricity. GFCIs are commonly used in bathrooms, kitchens, and other areas where there is a risk of electrocution.

4. Arc Fault Circuit Interrupters (AFCI)

Arc fault circuit interrupters (AFCI) are designed to protect against electrical fires caused by arcing. Arcing occurs when the electricity jumps from one wire to another, creating a spark. AFCIs use a combination of thermal and magnetic sensing to detect the unique waveform of an electrical arc. When an arc is detected, the AFCI trips, interrupting the flow of electricity and preventing a fire.

Why Circuit Breakers are Important

Circuit breakers are an essential component of the electrical systems in our homes and businesses. They protect us from electrical overloads and short circuits that could cause fires, electrocution, and other hazards. Without circuit breakers, the electrical system in our homes and businesses would be much more dangerous and prone to accidents.