The Difference between DC Breaker and AC Breaker

Publish Time: Author: Site Editor

A circuit breaker is an electrical safety device. When an overload or short circuit occurs, a breaker trips and interrupts power to that section of the circuit. The breaker will reset automatically unless there is another overload or short-circuit in that same circuit section.

These devices are typically found in homes and businesses, where they protect against overloading of power outlets, light fixtures, and other appliances.

A circuit breaker that uses alternating current is called an ac circuit breaker, while a circuit breaker that uses direct current is called a dc circuit breaker. This article will discuss the difference between AC circuit breakers and DC circuit breakers.

The Difference between DC Breaker and AC Breaker

What is a DC Circuit Breaker?

A DC breaker is a device that protects equipment from damage caused by accidental contact with direct current. It is an important safety mechanism in electrical systems.

They play an essential role in safeguarding battery banks, solar PV arrays, inverters, and other electronic devices. DC breakers are used for high-voltage systems where it’s not practical to use ac breakers. The DC breakers are usually found on high-voltage circuits, and they interrupt power because they have an open-close contact that a switch or motor can operate.

A DC circuit breaker works by measuring the current flowing through the conductor and comparing it to the predetermined level. If too much current flows, the circuit breaker will open up and break the circuit. Moreover, DC circuit breakers work based on magnetic and thermal safety. The thermal protection mode is activated when the DC circuit breaker receives an overload current. When a strong fault current is present, the magnetic protection system functions as a protective barrier to protect the circuit.

What is an AC Circuit Breaker?

AC circuit breakers are used to protect the electrical system from overloading. Circuit breakers for AC circuits are more prevalent than for DC circuits. The voltage applied to AC circuit breakers will not be constant. Because the electrons are free, they have the ability to flow back and forth. The circuit disables itself from the primary energy source when sufficient power is detected to safeguard the wiring system from heating.

AC is useful for long-distance transmission or to power large motor loads. While DC breakers are most typically used in manufacturing environments, AC circuit breakers can also be found in homes. 

AC Breakers vs DC Breakers

AC breakers are more popular than DC breakers. They are used in homes and businesses to stop the current flow when there is a power outage. On the other hand, DC breakers are also used to control the current flow, but they are often employed in industrial settings where they can be used as a switch or circuit breaker.

A significant distinction between breaking alternating current and breaking direct current is that a DC circuit breaker’s arc extinguishing point is higher. The electric arc is more durable to disruption in direct current because the voltage is constant.

There are also differences in the number of primary contacts between these two. For DC, there are two mina connections, and for AC, there are three. On the other hand, specific breakers are made so that they can be used in both AC and DC circuits.

The Difference between DC Breaker and AC Breaker

Which Type of Breakers are Used in Homes?

AC breakers provide a more reliable and safer way to protect your home from power surges. An AC breaker is much more reliable because it will trip as soon as a power surge. On the other hand, a DC breaker will only trip when the voltage exceeds the threshold set by the breaker’s manufacturer.

AC breakers are also safer because they come with an automatic reset mechanism that resets them after a power surge has passed. Whereas DC breakers don’t have this safety feature, if you forget to reset them manually, they will stay off until someone turns them back on again.


In this article, we have seen the difference between AC circuit breakers and DC circuit breakers in detail. We found out that AC breakers are more common in homes and offices, while in solar PV system, DC circuit breaker is a must.