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What Is a Branch Circuit Breaker? (An Expert’s Explanation)

Written by Edwin Jones / Fact checked by Andrew Wright

What Is A Branch Circuit Breaker

You’re trying to set up your home’s electrical network and came across a branch breaker. But what is a branch circuit breaker?

The definition of a branch circuit breaker is a tool that delivers and guides the appropriate current to a connected electronic device. It also comes in different types and amperage ratings to fit different electrical demands. 

Continue reading to gain additional insight into branch breakers.

What Is a Branch Electrical Circuit Breaker?


Generally, a branch breaker manages the electrical power output of specific locations in a property. It usually connects to outlets with relatively light power requirements but may serve appliances with high current demands as well.

Take note that other circuit breakers in the same electrical panel won’t become affected if one branch circuit breaker trips. Also, it’s important to mention that an electrical branch circuit comes in different variations.

1. Amperage

An individual branch circuit typically provides the appropriate electrical demands based on the assembly. These requirements often follow the voltage rating of each particular branch circuit breaker.

Upon looking at this voltage reading, you’d be one step closer to identifying the unit’s amperage rating. However, it’s also possible to verify the amperage by looking at an electrical diagram.

For instance, 120-volt branch breakers often come in 15- to 20-amp ratings. On the other hand, 240-volt branch circuit breakers usually have amperage readings ranging from 30 amps and higher.

2. Types

According to the National Electrical Code (NEC) Article 100 Section 210.3, branch wiring generally has four types:

  • General purpose: 120-volt circuit breakers are used to supply and control electricity for relatively small and/or portable electronics like lighting fixtures.
  • Appliances: As their name implies, branch circuits under this type are ideal for providing and managing power to dedicated appliances.
  • Individual: An individual branch circuit sends and oversees the flow of electricity to one piece of electronic equipment (e.g., motor or heater).
  • Multi-wires: This type of branch circuit wiring often has multiple ungrounded conductors connected to another grounded or neutral conductor.

3. Purposes

Typically, the function of a circuit breaker, particularly a branch one, is to control and supply power to connected electrical devices in a residence or business establishment. However, branch breakers also have other functions.

For instance, single-pole branch circuits can provide protection against fires, lightning, and power surges.

Frequently Asked Questions


1. What Are The Components Of A Branch Circuit Breaker?

Branch circuit breakers generally consist of five main parts, which are:

  • Frame or shell
  • Interrupting structure
  • Terminal connections
  • Tripping unit
  • Operating assembly

Take note that each component has its main function. For instance, the operating assembly is in charge of opening and closing the contacts. On the other hand, the tripping unit closes the circuit upon detecting an abnormality in the current.

2. What’s The Difference Between A Main Circuit Breaker And A Branch Breaker?

You can typically find the main circuit breaker sitting at the top of the electrical service panel. This device supplies and controls the current running through the branch circuits.

So, you can turn off the main circuit breaker to remove power deliverance to branch breakers in the same panel. But you can turn off a branch breaker without significantly affecting the main breaker.

3. Why Does Main Breaker Trip And Not The Circuit Breaker?

The main breaker tripping before branch circuit usually happens if the fault current falls below or equal to 6,000 amps. If so, the branch circuit breaker will open or remain functional while the main breaker will close.

4. Can You Split A Branch Circuit?

It’s possible to split a branch circuit by forming a letter “T” with the wiring. You may need to splice the existing wires in the branch circuitry to accommodate your property’s specific electrical demands. 


Now that you’re at the end of this post, you should have a better idea than before as to what is a branch circuit breaker. Remember, branch breakers are responsible for the electrical deliverance and management of connected electronic devices.

Also, keep in mind that different CBs are available on the market. For example, you can purchase a 120-volt branch breaker with a 20-amp rating, but you can also buy and install a 240-volt 50-amp model.

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