Detailed Information on Circuit Breaker

Author: Michael Neil

Residential and commercial electrical systems are made up of many sophisticated components. From each electrical component to your fuse box and other circuits, each part of your electrical system serves important functions. So, what is a circuit breaker? A miniature circuit breaker Schneider is a switching device that can be well operated both manually and automatically for an efficient protection of an electrical power system. It was created to provide security to the wires from carrying excessive amounts of current. It is able to immediately discontinue electric flow. Unlike a new fuse, which operates & as soon as it gets overloaded, it blows up, and the fuse must be needed to replace, a circuit breaker may be just reset to be able to resume normal operation as before.

As modern power systems are known to deal with huge currents, special attention should be provided during the designing phase of the circuit breaker so as to ensure that it is able to safely interrupt the arc produced during the closing of a circuit breaker. The very demand and need for circuit breakers have gone up considerably with an added increase in concern for safety in all sectors, not to exclude electronic, electrical, automotive, telecommunications, and whatnot. This level of advancement and expansion of the transmission network is paving a way to set the fuel to the upcoming growth of the global circuit breaker market.

For example - Suppose a Siemens circuit breaker online is rated at 12 Amps. So, if any current circulation above 12 Amps goes through the circuit breaker, it will immediately open the circuit breaker so as to break the connection. It acts as a safety net to defend all electrical products and homes.

Components of a Circuit Breaker:

The majority of circuit breakers are made up of five below mentioned components-

  • Molded Case (Frame) - The sole function of the frame is to offer an insulated housing to incorporate every circuit breaker component. The material of the frame most of the time is glass polyester material.
  • Arc Extinguisher - When the current flow is interrupted by a circuit breaker, an arc is created. Thus, the function of an arc extinguisher is to divide that arc, hence extinguishing it.
  • Operating Mechanism - The work of the operating mechanism is to open and close the contacts. The handle position tends to tell us about the status of the contacts, whether it is closed, open, or tripped. The handle is in the mid-way position when the contacts are in the tripped position.
  • Trip Unit - The trip unit is considered as the brains of the circuit breaker. The function of a trip breaker is to trip the entire operating mechanism in any event of a short circuit or overload of current. Even electronic trip units are available that provide much more sophisticated monitoring along with effective protection.

Function and Working Principle of a Circuit Breaker:

Low voltage circuit breakers come loaded with a wide variety of protection functions such as adjustable action value, convenient operation, high breaking capacity, safety. It is composed of an efficient operating mechanism, protection devices, arc extinguishing systems, contacts.

When a short circuit happens, which is created by the larger current tends to overcome reaction force springs; the trip unit pulls the operating machine and switch trips instantaneously. So, when overloaded, the current tends to become larger, the generation of heat increases, and the bi-metal gets deformed to a certain extent. When the circuit is short-circuited or gets severely damaged, the armature of the over-current release takes charge in, resulting in a free tripping mechanism to act the main contact disconnects the main circuit.

Parameters of Circuit Breaker:

  • Rated working voltage (Ue) - This is the voltage at which a circuit breaker works under uninterrupted conditions.
  • Short circuit breaking capacity (Ics) - The rated breaking capacity of a circuit breaker is divided into two types - the rated ultimate short-circuit breaking capacity and the rated operating short-circuit breaking capacity.
  • Rated Current (In) - This is the maximum current value that a circuit breaker can withstand under ambient temperature and will not exceed the temperature limit mentioned by the current bearing component.
  • Short-circuit relay trip current setting value (Im) - It is used to quickly trip the circuit breaker when a high fault current occurs, and the trip gets limited.

Various Types of Circuit Breakers:

According to their services, the circuit breakers can be put into categorization as:

1. Outdoor circuit breaker.2. Indoor breaker.

According to the operating mechanism, it can be varied as:

(i) Spring-operated circuit breaker.(ii) Pneumatic circuit breaker.(iii) Hydraulic circuit breaker.

Depending upon the voltage level of installation types of circuit breaker:

(i) High voltage circuit breaker.(ii) Medium voltage circuit breaker.(iii) Low voltage circuit breaker.