Industry
Fact-checked

At AboutMechanics, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is a Circuit Breaker?

D Frank
D Frank

A circuit breaker is an electrical device used in an electrical panel that monitors and controls the amount of amperes (amps) being sent through the electrical wiring. Circuit breakers come in a variety of sizes. For instance, 10, 15 and 20 amp breakers are used for most power and lighting needs in the typical home. Some appliances and specialty items (washers, dryers, freezers, whirlpools, etc.) will require a larger circuit breaker to handle the electrical load required to run that appliance.

If a power surge occurs in the electrical wiring, the breaker will trip. This means that a breaker that was in the "on" position will flip to the "off" position and shut down the electrical power leading from that breaker. Essentially, a circuit breaker is a safety device. When a circuit breaker is tripped, it may prevent a fire from starting on an overloaded circuit; it can also prevent the destruction of the device that is drawing the electricity.

Fuses do the same thing as circuit breakers.
Fuses do the same thing as circuit breakers.

While a number of older homes and buildings still use fuses to monitor the electrical load, almost every newer home has circuit breakers in the electrical panel. Fuses perform much the same duty as circuit breakers. However, circuit breakers are safer to use than fuses and easier to fix. If a fuse blows, oftentimes a homeowner will not know which fuse controls which specific power areas of the house. The homeowner will have to examine the fuses to determine which fuse appears to be burned or spent. The fuse will then have to be unscrewed from the fuse box and a new fuse will have to be installed.

Screw-in plug fuses are an alternative way to protect an overloaded electrical circuit.
Screw-in plug fuses are an alternative way to protect an overloaded electrical circuit.

Circuit breakers are much easier to fix than fuses. When the power to an area shuts down, the homeowner can look in the electrical panel and see which breaker has tripped to the "off" position. The breaker can then be flipped to the "on" position and power will resume again. Please note that if a breaker continues to trip after you flip it, you may have a faulty breaker, a wiring problem, or there may be an issue with an electrical device that relies on that breaker. You should leave the breaker off and consult an electrician.

A glass fuse.
A glass fuse.

The typical house these days carries either a 100 amp or 200 amp electrical service. Accordingly, the circuit breakers can be used to distribute the power properly throughout the house. Most old-time fuse boxes allotted 60 amps for an entire house. Factories, offices, and assorted other business facilities will have far greater electrical capacities. However, the power will still be distributed to a number of electrical panels (probably 200 amp panels) throughout the place of business and then distributed through 15 and 20 amp breakers to the lighting fixtures and electrical outlets.

Discussion Comments

Krati

After a period of time, the breaker can wear out and excessive load will break it down. Replacement breakers can be found online, along with specification charts as well that show amps and various other properties.

klh0320

Does it use more electricity to power circuit breakers off when the corresponding unit is not in use, such as the stove/oven?

anon164535

Yes,that which disturb the assembly, i.e., physical parameters will change.

anon151281

What causes circuit breaker to be hot when in use for more than an hour?

anon111330

Article 4: In my point of view, a C/B weeks when tripped time to time, due to electric arc that up surge on its contacts, so it may weak the as built properties.

anon94317

It is a "mechanical" item made of plastic/metal components thus excessive wear is possible. However, if it is tripping and resetting continuously there is a greater problem.

anon38969

Does a circuit breaker weaken over a period of time after going off and then resetting?

lisatag

Does it weaken a circuit breaker if you flip it on and off?

Post your comments
Login:
Forgot password?
Register:
    • Fuses do the same thing as circuit breakers.
      By: Willee Cole
      Fuses do the same thing as circuit breakers.
    • Screw-in plug fuses are an alternative way to protect an overloaded electrical circuit.
      By: George Kelly
      Screw-in plug fuses are an alternative way to protect an overloaded electrical circuit.
    • A glass fuse.
      By: Willee Cole
      A glass fuse.
    • Circuit breakers are safety mechanisms that can help prevent electrical fires or overloading a circuit.
      By: FirstBlood
      Circuit breakers are safety mechanisms that can help prevent electrical fires or overloading a circuit.
    • Circuit breakers control the amount of amperes sent through electrical wiring.
      By: Lisa F. Young
      Circuit breakers control the amount of amperes sent through electrical wiring.
    • Most homes have a breaker box, where the circuit breakers are located.
      By: auremar
      Most homes have a breaker box, where the circuit breakers are located.