Circuit breakers protect your home by preventing electricity from leaking outside the electrical system if there’s a wiring or power supply problem.
There are different circuit breakers, but they all serve the same primary purpose of protecting people and property from electrical fires and explosions due to excess voltage and amperage levels.
In a power system, it is often necessary to switch on or off various electrical devices and circuits like generating plants, transmission lines, distribution systems, etc., either in normal operating conditions or under abnormal situations.
Initially, this task is performed by a switch and a fuse connected in series with the electrical circuit.
Here are some details about different types of circuit breakers to help you choose the right one to install in your home.
Introduction to Circuit Breakers
A circuit breaker is an electrical device used to protect an electrical circuit from damage caused by excess current.
Circuit Breakers are unique devices because they are mechanical devices connected to an electrical system.
Since the first electrical systems were utilized, there is always a need for a mechanism or a device that can initiate and interrupt the flow of electric current.
Each with a unique design, several different circuit breakers are intended to perform a specific task. Understanding each type will help you choose which circuit breaker would be best for your application.
Below, we’ll cover the different types of circuit breakers and explain how they work, but first, let’s review some key terms you need to know:
- Break current: The amount of current that needs to flow through a system before it trips a breaker; also known as trip current or rated current
- Current transformer: Also called CT or CCT. Converts alternating current (AC) into direct current (DC). AC comes in two flavors – 1) Polyphase — Three wires running at 120 degrees out of phase 2) Single-phase — Two wires running at 180 degrees out of phase.
- Timer: Starts after a trip operation has been activated when no fault exists on the primary coil(when the secondary coil cannot be energized).
- Trip indication: Indicates if the tripping operation has been initiated due to short circuits, overload, and earth faults.
Different Types of Circuit Breakers
1. MCBs (miniature circuit breakers)
The most different types of circuit breakers are the Miniature circuit breakers, or MCBs as they’re often called, which are designed to protect small equipment and installations from large current surges caused by overloads.
A miniature circuit breaker (MCB) is a fuse that contains an electronically operated switch instead of a physical fuse.
When excess current flows through an MCCB, it quickly blows a high-speed fuse inside, cutting off the power until it can be reset.
These devices work very much like fuses in your home; once they open up, you need to repair or replace them before you can use them again.
Miniature circuit breakers are available in many shapes and sizes depending on how much amperage they can control.
2. Trip-free circuit breaker
Trip-free circuit breakers contain thermal-magnetic switches that sense abnormal current flow through a conductor.
Unlike miniature circuit breakers, trip-free breakers don’t contain any moving parts because they don’t rely on mechanical components to function correctly.
Instead, their sensing mechanism involves sensitive materials and design elements that enable them to sense changes in heat levels at specific points along a wire’s length without being affected by movement or vibration.
If these materials detect abnormal heat buildup in a wire, they generate electrical pulses within milliseconds that are strong enough to trigger the trip mechanism without fail.
3. MCCBs (main circuit breaker)
Main circuit breakers (MCCBs) are large circuit breakers designed to protect an entire home or building.
MCCBs typically trip at 30,000 amps (almost 300 tons). Although MCCBs can be installed on either 120/240-volt or 480-volt circuits, it’s common for a 240-volt MCCB to protect an enormous load. One 240-volt leg offers more protection than two 120-volt legs.
Since homeowners rarely have 240-volt appliances, multi-pole main circuit breakers (MCCBs) generally serve as your first line of defense against outages and overloads.
If they fail to trip when needed, you could face significant electrical damage due to overheating, fire or shock.
When buying a main circuit breaker, please pay attention to its amperage rating (usually indicated in amps or kA), which tells you how much current it can safely handle.
If there’s any doubt about whether your installation requires a 240-volt MCCB, always consult with an electrician before installing.
4. Thermal Magnetic Breaker
A thermal-magnetic breaker, or TM breaker, is a circuit breaker used in many household appliances.
Unlike most breakers found in homes today, it only breaks a circuit when it gets too hot. The advantage to having one is that when something short circuits, it will trip before there’s a chance for damage to occur.
However, suppose you need to reset your breaker often due to frequent short circuits. You might consider replacing your current model with another type of circuit breaker that won’t have any trouble keeping up with demand.
Thermal Magnetic breakers are designed for slowly applied (non-impulsive) fault conditions. You can easily recognize a thermal-magnetic circuit breaker by its brown-tinted glass window on top; other types have clear glass windows.
Unlike most breakers found in homes today, it only breaks a circuit when it gets too hot.
The advantage of these different types of circuit breakers at home is that when something short circuits, it will trip before there’s a chance for damage to occur.
However, suppose you need to reset your breaker often due to frequent short circuits.
You might consider replacing your current model with another type of circuit breaker that won’t have any trouble keeping up with demand.
5. Silicon Controlled Rectifier
Using a combination of silicon diodes, germanium diodes, signal diodes, and thyristors, a silicon-controlled rectifier is one part of an electronic circuit designed to handle an incredible amount of power in short bursts.
The technology was first used in radios during World War II and had to be hand-made in tiny labs—hence its name.
In contrast to standard diode (or one-way current) flow, electricity can travel through both directions using a rectifier.
This might sound not very clear, but it’s pretty simple: A Silicon Controlled Rectifier turns on when the voltage on its terminals reaches a certain level, and it stays on until those same terminals are depleted.
For example, if you have three batteries connected in series and your desired output voltage is 12 volts, you could use a single silicon-controlled rectifier with three inputs to get what you want out of each battery cell.
Because of their unique properties and ability to work with high voltages, these devices are commonly used as switchable half-wave or full-wave converters.
These switches allow you to use two batteries simultaneously rather than just one like other converter circuits do.
In addition, they can also isolate sections of larger circuits from each other—beneficial if there’s any chance they could interact with each other while powered up.
The fundamental aspects of circuit breakers are their interrupting ratings, when they open and close, how they reset themselves automatically, and a few others.
So with different types of circuit breakers, there will be different characteristics that differentiate one product from another that would suit your need.