High Voltage Circuit Breaker – Air, Oil, SF6 & Vacuum Types

A High Voltage Circuit Breaker (HVCB) is a crucial component in power transmission and distribution networks. Its primary role is to protect electrical equipment by interrupting fault currents within the system. Beyond safeguarding equipment, HVCBs are vital for maintaining the integrity of the power grid. They isolate faults effectively, ensuring that adjacent systems remain unaffected … Read more

Rated Short Circuit Making Current and Breaking Current 

Definition of Making Current The rated short circuit making current of a circuit breaker is the maximum peak current that the circuit breaker can close without any damage. It is the maximum peak current that a circuit breaker can make safely.  Definition of Breaking Current The rated short circuit breaking current, on the other hand, … Read more

Zero Current Crossing Method in A Circuit Breaker

This zero current crossing method is only applicable to alternating current circuit breaker. We all know that an alternating current naturally passes through zero at regular intervals (every half-cycle of the AC waveform). This method safely interrupts the alternating current at the natural zero-crossing of its waveform. Working Principle of a CB based on Zero … Read more

Small Inductive Current Interruption by Circuit Breakers

Normal Short Circuit Rating of Circuit Breaker Engineers design high voltage circuit breakers to handle very high short-circuit currents. Manufacturers build these breakers to interrupt extremely high fault levels effectively. They typically rate circuit breakers for short-circuit breaking capacities such as 25kA, 31.5kA, 40kA, or even 50kA and more. Such ratings define their ability to … Read more

Arc Voltage, Recovery Voltage, Restriking Voltage, RRRV

We will discuss here in details the concept of Arc Voltage, Recovery Voltage, Restriking Voltage, RRRV Basic Concept of Arc Voltage, Recovery Voltage, Restriking Voltage, RRRV When contacts of a circuit breaker open under current carrying condition, electric arcs form in the gap between the contacts. This is due to ionization of the surrounding medium. … Read more

Shunt Trip Mechanism Vs Series Trip Mechanism

Circuit breakers are essential protective devices of electrical power systems. A circuit breaker safeguards electrical circuits from abnormal conditions such as overloads and faults. Among different tripping arrangements, the shunt trip mechanism is the most popular method for ensuring safe and reliable operation in high-voltage systems. In this article, we will explain the theoretical working … Read more

Details Current Ratings of a Circuit Breaker

In addition to the normal current rating of a circuit breaker (which is the current it can handle continuously during regular operation), there are two important categories of short-circuit current ratings that define how the circuit breaker performs during fault conditions: Rated Short Circuit Breaking Current The short-circuit breaking current of a circuit breaker consists … Read more

First Pole to Clear Factor of Circuit Breaker

Discover the First Pole to Clear Factor. How does the highest restriking voltage in the first-clearing pole, divided by phase-to-ground recovery voltage, impact circuit breaker performance?123 characters (approx) In an AC system, the phase difference between the currents of each phase is \(120^\circ\). This means the current of one phase is \(120^\circ\) apart from the … Read more

Rated Transient Recovery Voltage of a Circuit Breaker

A high voltage circuit breaker plays a crucial role in power systems by protecting electrical equipment from damage due to electrical faults in the system. One of the key challenges in circuit breaker design is dealing with the transient recovery voltage (TRV), a phenomenon that occurs immediately after current interruption. When a fault current gets … Read more

M2 Class Circuit Breakers as per IEC 62271‑100

Introduction to M2 Class Circuit Breakers The M2 class of circuit breaker belongs to a special class defined by IEC 62271-100. This means these circuit breakers require minimal maintenance and can operate mechanically for an extended lifespan. If a breaker performs at least 10,000 mechanical operations without any even minor damage, it comes under M2 … Read more