MCCB – Molded Case Circuit Breaker | Working Principle | Ratings

An MCCB or Molded Case Circuit Breaker is a modular device used to protect a piece of low voltage equipment or circuit from overload and short circuits. Apart from overloads and short circuits, specially designed MCCBs can protect against ground faults or residual currents. They can be used for power distribution, motor protection, and as … Read more

Drawout circuit breaker positions and indications explained

Several operating indications can be seen on the front of an ACB or MCCB. Being an electrician or an engineer it is important that one must understand those indication and circuit breaker positions. Each of those indications has some critical information regarding the current state of the circuit breaker. The following are the three most … Read more

Ultimate breaking capacity (Icu) and Service breaking capacity (Ics) – IEC 60947-2

Circuit breakers are devices that can protect circuits or loads during overloads and short circuit. The reliability of the circuit breakers during short circuits is determined by Ultimate breaking capacity (Icu) and Service breaking capacity (Ics) ratings. These ratings are mentioned in IEC/EN 60947-2. Definition of Ultimate breaking capacity (Icu) The term Ultimate breaking capacity … Read more

Earth Leakage Relay (ELR)

An earth leakage can represent a danger to life or property if it is not located and mitigated. Studies have revealed that at least 500 people experience electrocution every year in the US alone. Earth leakage relays can be helpful in sensing and mitigating such incidents. What is earth leakage? Earth leakage is an unindented … Read more

Top 3 causes behind a circuit breaker trip | MCB Trip

Circuit breakers are employed to automatically switch off a circuit or a load whenever any abnormalities in current flow are detected. This functionality of the circuit breakers is known as ‘Trip’. By doing so, circuit breakers are preventing fire or other damages caused to the circuit. Here are the major reasons behind your circuit breaker … Read more

Top 5 differences between fuses and circuit breakers

Short circuits and overloads are abnormal conditions that cause heavy current flow in a circuit. Heavy currents are capable of damaging a device or a circuit and may end up with electrical hazards. Fuses and circuit breakers are protection devices that ensure the safety of the equipment or circuit in which they are used. This … Read more

What is an arc chute?

Definition of arc chute Arc chute is a set of metal plates that are arranged in parallel and mutually insulated from each other, which can divide, cool and safely extinguish an electric arc. They are also known as arc splitters and arc dividers. Arc chutes can be found inside circuit breakers, contactors, isolators and other … Read more

Difference between over-current and overload

Over-current and overload are abnormal conditions occurring in a circuit. This article well explains the difference between over-current and overload. Difference between over-current and overload Over-current Any situation in which the current flow through a device or conductor exceeds the desired value is known as over current. Both overload and short circuit can cause excessive … Read more

Difference between Short circuit and overload

Short Circuit A short circuit occurs when two or more current-carrying conductors of different phases or different voltage levels or different terminal (in DC circuits) come in contact with each other or with the ground. It is an abnormal condition during which current shoots up several times the permissible limits. Read about short circuits in … Read more

Miniature circuit breaker (MCB) – Principle of operation

Miniature circuit breakers commonly known as MCB, are mechanically operated switches cum circuit protection devices. It is an electro-mechanically operated automatic circuit protection device and is used to interrupt a circuit during overload and short circuits. It can be used as an alternative to fuses for domestic applications. They can be reused even after the … Read more