Circuit breakers are a type of mechanical device that are connected to different electrical systems. systems, there is a need to switch different circuits and electrical devices on and off.
Initially, the task was left to fuse switches connected to electrical circuits.The main issue with this setup is the possibility of the fuse getting blown and replacement of the same can take a long time.This may mean a longer time before the power supply is Using a fuse also means that heavy fault currents cannot be interrupted.
It is such limitations that made the use of fuse and switch combinations inadequate and could only make sense in small capacity and small voltage circuits. For larger current and high voltage systems, one would need a better method than this. achieve this.
What are they?
Circuit breakers can be defined as mechanical switching devices capable of making, breaking, or carrying circuits either automatically or manually under abnormal or normal circuit conditions. a specified time and also breaks currents.
There are miniature circuit breakers or MCBs that are meant to prevent any damage to the electrical circuit in case of excess current.
Characteristics
A circuit breaker is capable of breaking or making circuits in normal conditions using a remote control or manually
In fault or abnormal conditions, the circuit breakers break circuits automatically
These characteristics make circuit breakers very useful devices for protection and switching power systems.
Operations
Circuit breakers must switch electrical circuits on and off in abnormal or normal operating conditions.This should be possible once or severally.The principle behind how the circuit breaker panel works is quite simple. Usually, the contacts remain closed in normal conditions of operation.
When a system is faulty, contacts open automatically, or as an alternative, they can be manually opened as desired, like when maintenance is needed, or when there are faulty conditions. There is a mechanism used to pull moving contacts away because of the energization of the trip coil, which ends up opening the circuit.
Circuit breaker classification
It is now clear why circuit breaker installation is so important in different scenarios.
These include:
· Medium and method used to interrupt current or arc extinction
Installation location
The intended voltage applications
There are different ways that can be used to classify circuit breakers.
Based on the voltage class
This logical circuit breaker classification is based on the operating voltage. There are two voltage-based options here:
i. Low voltage circuit breakers: this type of circuit breaker can be used at a maximum of 1000 V
ii. High voltage circuit breakers can be used in voltages greater than 1000V.
The high voltage options can be further divided into 123kV and above and 72.5kV and below.
Based on the installation type
The circuit breakers, such as indoor or outdoor installations, may be classified according to the installation location. made of metal.
The difference between outdoor and indoor options is the way they are packaged and their enclosures. location of installation.
Based on the interrupting Medium
This important and significant classification is based on the arc extinction method and interruption medium. The two are the main factors used in designing of circuit breakers, and they dictate the design parameters of the circuit breaker. as the Medium.
Types
The common classification is based on arc extension, which dictates the circuit breakers we see today. The most common extinction medium is a vacuum, sulfur hexafluoride, oil, and air. The types of breakers based on these include:
- Oil circuit breakers: In this case, insulating oil is used as the extinguishing Medium of the arc.
- Air blast circuit breakers: High-pressure air is used as an extinguishing medium. If there is a fault, an air blast opens contacts and cools the arc controlled by the blast valve.
- Vacuum circuit breakers: Here, the extinguishing Medium is a vacuum, and it is one of the most incredible choices and has the best insulating strength.
- Sulfur hexafluoride circuit breakers: In this case, sulfur hexafluoride acts as the extinguishing medium. and absorbed by the gas, causing the formation of negative ions, which are immobile, which increases the insulation and extinguishes the arc.
How to replace a circuit breaker
If a breaker fails, then it may be necessary to replace it. With some understanding of electrical issues, you can easily; handle the project. type of breaker than needs to be replaced and find an ideal replacement.
i. Turn off the power
ii. Remove the cover plate
iii.Remove the defective circuit breaker
iv. Disconnect all wires
v. Attach wires to the circuit breaker (new)
vi.Insert the new circuit breaker
vii. Replace the cover plate and switch the power on.
If replacement is too complicated or you are not conversant with electric systems, call in a professional.
How to reset a circuit breaker in 4 easy steps
It is possible to reset a circuit breaker in some easy steps.
i. Turn the lights off and unplug all appliances that are related to the breaker
ii. Find the circuit breaker panel.
iii. To reset, switch it off, wait for a few seconds, and then switch it on again.
iv. Plug the appliances and then test whether they are working well.