The Importance Of Circuit Breakers

Circuit Breaker Types & Replacement Guide

Circuit breakers are essential safety devices for every building, warehouse and all edifices that use electricity. They act as the third party or arbitrators within complicated and otherwise dangerous electrical wiring systems. When met with excessive current, wiring systems can cause fires, power surges and explosions. But before such dangerous reactions can occur, circuit breakers step in by cutting the electrical power.

These box-like contraptions work by limiting the current in a single circuit. Without circuit breakers, your facility would be under constant danger and disorder.

How many types of breakers are there?

There are three main types of circuit breakers: standard, AFCI circuit breakers and GFCI breakers.Here’s what you need to know about them

Standard Circuit Breakers

Standard circuit breakers come in two varieties: single-pole breakers and double-pole breakers. These are simpler breakers that monitor the cadence of electricity as it circulates an indoor space. It keeps track of electricity in electrical wiring systems, appliances and outlets. This kind of breaker stops the current during overloads and short circuits to prevent wires from overheating. This can take place when a hot wire contacts a ground wire, another hot wire or a neutral one. This current shutoff prevents electrical fires.

Here’s a little bit more about both single-pole and double-pole breakers:

Single-Pole Breakers

The more common breaker

Protects one energized wire

Supplies 120V to a circuit

Handles 15-20 amps

Double-Pole Breakers

Has two single-pole breakers with a handle and a shared trip mechanism

Protects two wires

Supplies 120V/240V or 240V to a circuit

Comes in 15-200 amps

Used for large appliances like water heaters


A Basic Guide to Circuit Breaker Types

Modern machines of all types are setting aside fuses in favor of circuit breakers. Circuit breakers have quite a few virtues; they’re more durable, they’re easier to reset and replace, and they can be ordered in types that fit in where most fuses were used on vehicles. Still, it’s important to know the different circuit breaker types and their uses.

Circuit Breakers: An Overview

A circuit breaker’s function is right there in the name; when it detects high amperage or another electrical problem, usually by a circuit heating up, it flips and cuts off the circuit, protecting sensitive electrical systems from damage. Generally, they come in three broad categories: auto, manual, and push-to-trip, and in three different types: I, II, and III. These can overlap somewhat depending on the design of the breaker.

The broad categories describe how the breakers reset. Auto means the breaker self-resets without help from the user, manual requires the user to reset the circuit themselves, and push-to-trip allows you test the circuit by pressing a button and breaking the circuit. Push-to-trip, also called “switchable,” is an especially important breaker type because it allows you to force anybody accessing certain vehicle systems to cut those off from power before opening. Generally, systems wired directly to batteries and other heavy shock risks will have push-to-trip breakers that make it impossible to put current through the system while repairing it.

Types Of Circuit Breakers

In automotive, circuit breakers generally fall into three types. Type I breakers are, without exception, automatic. They’ll either cycle or keep resetting until the issue is resolved. Generally, you’ll use Type I in applications where you have relatively low voltage and reaching the breaker for a manual reset will be difficult, and which will only occasionally deal with overload situations. That includes systems like wiper motors, headlamps, and non-essential systems like device charges. In short, if it doesn’t draw much power and needs to be buried deep in the vehicle where it’s hard to get to, it’s probably a Type I.

Type II is also automatic in a sense. Most Type II breakers will reset when the ignition is turned off, or the overload is removed, making them perfect for systems that only need breakers when the engine is on. That generally includes systems like power windows, and situations where you don’t want to deal with replacing fuses that blow on a regular basis.


Circuit Breaker

Types of Circuit Breakers

Circuit breakers are essentially switches installed inside a breaker box that protect your home’s electrical components from overheating or catching fire. When an electrical short or overload occurs, a circuit breaker mitigates the problem by interrupting the flow of electricity. There are three basic circuit breaker varieties: standard breakers (which include both single-pole and double-pole circuit breakers), ground fault circuit interrupter circuit breakers (GFCIs) and arc fault circuit interrupter circuit breakers (AFCIs).


Installing or replacing a circuit breaker is a job for a licensed electrician and may require a permit. Failure to take proper precautions and observe electrical codes when working with electrical components can result in fires, serious electrical shock or death. An electrician can best determine the circuit breaker type required for your home.

Single-Pole Circuit Breakers

Single-pole circuit breakers are the type most often found in homes today. They’re named single-pole because they’re designed to monitor the current of a single wire and trip in the event of a short or electrical overload. Single-pole breakers are intended to accommodate between 15 and 30 amps and deliver 120 volts to the circuit.

Double-Pole Circuit Breakers

Double-pole circuit breakers monitor the flow of electricity through two wires simultaneously. They’re easily recognized as a single breaker with two interlinked, side-by-side switches. This type of breaker will trip if one or both of the wires short out or becomes overloaded. Double-pole circuit breakers deliver either 240 volts or 120/240 volts to an electrical circuit and can accommodate anywhere from 15 amps to 200 amps. Circuits that supply power to appliances that require a substantial amount of energy, such as washing machines and dryers, demand double-pole breakers.

GFCI Circuit Breakers

GFCI circuit breakers are designed to protect against a line-to-ground fault. This is when a dangerous electrical path occurs between a grounded element and an electrical current. GFCI breakers also offer protection against an electrical short or overloaded current. These breakers are required by some electrical codes for areas in the home that can become wet such as bathrooms, laundry rooms and outdoor areas.


Circuit breakers

Circuit breakers limit the electrical current flowing through the various circuits of your home’s electrical system, prevent electrical fires, and protect you from electrical shock hazards. Keep reading this buying guide to determine the products that are best for your home’s electrical system.

Before You Shop

Before beginning any electrical project, make sure to consult your local building codes and acquire any necessary permits. Local building and electrical codes may influence which types of circuit breakers you can use for specific projects and how you can install them. Consult with your local inspector for more information.

Amperage Rating

All circuit breakers have an amperage rating, which is the maximum amount of electrical current the breaker will allow before automatically “tripping,” thereby shutting off power to the circuit. The amperage of the circuit breaker must not be greater than the amperage of the circuit conductors. In addition, the amperage of the circuit conductors must not be less than the amperage required for the circuit.

Standard Circuit Breakers

Standard circuit breakers are the most commonly used type of circuit breakers. They control the flow of electricity on each circuit. If the circuit becomes overloaded (e.g., too many devices are being used at once) or a short circuit occurs (when a “hot” wire comes into contact with a grounded wire or object), the circuit breaker immediately “trips,” or breaks the current. This prevents overheating and electrical fires. Standard circuit breakers are available in three varieties.

  • 1-Pole: Protects one energized wire
  • 2-Pole: Protects two energized wires
  • 3-Pole: Protects three energized wires

GFCI Circuit Breakers

Like standard circuit breakers, GFCI (ground fault circuit interrupting) breakers cut the power in the event of a short circuit or overload. However, GFCI breakers will also cut the power when a ground fault occurs. A ground fault is an unintended electrical path between a power source and the earth or a grounded item. If a person’s body provides a path to the ground, electrocution will occur. GFCI circuit breakers protect people from accidental electrical shock. They are required for all areas that are likely to be wet, such as bathrooms, kitchens, garages, unfinished basements, and all outdoor areas.


A Quick Guide to Circuit Breakers

Circuit breakers, we’ve all seen one. Whether the application is in your home or an industrial factory, breakers have become the standard. Until now you may have never had to learn more about them besides what to do when one is tripped but let’s take a look at some of the details of a circuit breaker and how that will guide your purchase.

Starting with the basics, we know a circuit breaker is a device that will interrupt the flow of current in an electrical circuit. This interruption protects the surrounding electrical components and wiring from damage caused by either electrical overloads or short circuits. Great, now that we know that; let’s explore the next step in figuring out what kind of circuit breaker you’re looking for.

MCCB Circuit Breaker:

Rated current up to 1000-2,500 Amps (depending on series and brand)

Trip current may be adjustable

Thermal or thermal-magnetic operation

Interruption current rating of up to 200,00 Amps (Depending on series and brand)

MCB Circuit Breaker:

Rated current of no more than 100 Amps

Trip current is usually not adjustable

Thermal or thermal-magnetic operation

Interruption current rating of up to 18,000 Amps (Depending on series and brand)

Considered to be the standard according to the National Electrical Code, UL489 Listed circuit breakers are considered “any listed circuit breaker that has an interrupting rating other than 5,000 Amps.” Overload tests are performed at six times the current rating of the device or 150A minimum. Devices rated up to 600V and 6,000A are covered in this standard. Beyond overload protection the UL489 rated circuit breaker must offer short circuit protection, switching functionality as well as disconnection function. Lastly, most UL489 devices are used in electrical distribution panels; therefore, the minimum current ratings available are seldom less than 15A