What Are Circuit Breakers And How Do They Work

Posted on Dec 15 2016 - 1:10pm by admin

One of the most important and useful devices that can be found in today’s world of electronics is the circuit breaker. It is a safety mechanism that is utilized to cut the flow of electricity to prevent fires and other possible problems that are caused by electricity, such as wiring problems for example. When electrical current goes beyond the safety levels, a circuit breaker functions to automatically protect an electrical circuit from getting damaged whenever a short circuit or overload occurs. As soon as it detects a fault in the system, it interrupts the continuity of electrical flow. It can be reset either manually or automatically in order to resume normal operation.

Circuit Breakers

As a matter of fact, circuit breakers are essential parts of any structure. They are made in varying sizes depending on where they are used – from small devices suitable for individual household settings and large switchgears designed to protect an entire city that depends on high voltage circuits. These are integral parts of any large infrastructure such as shopping malls, sports arenas, factories, schools and even airplanes. Technological consistency and innovation by companies that provide circuit breaker solutions, like those offered by ABB.com, are both of enormous importance as even certain minor innovations have the power to radically improve the efficiency of a client company.

The types of circuit breakers according to criteria are the following:

According to arch quenching media

Oil circuit breaker – One of the oldest types of circuit breakers, it uses oil as an insulating medium and when a fault occurs in the system or when there is separation of current that carries contacts in the oil, the arc in the circuit breaker initializes at the same time that the separation happens.

Air circuit breaker – This uses compressed air as arc quenching medium and when faults occur, it opens the circuit automatically and dampens or quenches the arcing during overloading.

  1. SF6 circuit breaker – This kind of circuit breaker operates by using sulphur hexafluoride or SF6 gas. It has an optimum insulating property and high electro-negativity.
  2. Vacuum circuit breaker – A type of circuit breaker where the arc quenching occurs in vacuum. This kind of technology is adapted mainly for medium voltage application.

According to their services

Outdoor circuit breaker – Designed to use only outside without the coverings of any roof, these circuit breakers’ external closure arrangement is strong enough to withstand destruction.

Indoor circuit breaker – Designed only for use inside buildings or weather-resistant enclosures, these circuit breakers that have a metal cad switchgear enclosure operate at medium voltage.

According to operating mechanism

Spring-operated circuit breaker – This uses a motor to charge or compress one or more closing springs. The springs push against a mechanism to force the breaker contacts closed.

Pneumatic circuit breaker – In this system, an air compressor replaces the charging motor while a piston and a storage tank replace the closing springs.

Hydraulic circuit breaker – This kind of circuit breaker replaces the air compressor and tank with a hydraulic pump and an accumulator to function.

According to the voltage levels of installation types

High voltage circuit breaker – This circuit breaker is used by electrical power transmission networks wherein 72.5 kV or higher is controlled.

Medium voltage circuit breaker – Rated between 1 and 72, they are commonly used for indoor use or installed outdoors in a substation.

Low voltage circuit breaker – Commonly utilized d in domestic, industrial and commercial applications, this circuit breaker is used with less than 1000 VAC.