How Circuit Breakers Work

Circuit breakers prevent millions of electrical fires every year. They cut off the power (“break the circuit”) when they detect problems such as an electricity overload, keeping occupants of the home safe from potential electrical fires. Every modern home comes equipped with circuit breakers, some of which may trip frequently and require resets. Learning how circuit breakers work can help you calculate safe electrical loads, take care of minor issues on your own, and know when to call an electrician.

Circuit Breakers, Overloads, and Electrical Fires

When a power company delivers electricity from a power grid into your home, the electricity enters via a circuit breaker box or fuse box. The box divides the incoming electricity into multiple circuits to power different outlets and appliances. The circuit breaker and its switches are in charge of organizing and monitoring circuits as you use your electricity. Although the main power grid consistently delivers the same voltage to a home, different appliances have certain amounts of resistance, or load.

A breaker, or fuse, protects each circuit in your home. It is the breaker’s job to monitor electricity currents and loads, and to break the circuit if a problem occurs. Pushing more current than a circuit is designed to hold, for example, could cause a dangerous overload and an electrical fire if the circuit does not detect and respond to the issue right away. An overload may happen when you plug too many energyconsuming devices into a single circuit. This causes the circuit to heat up from the burden of too much electrical current.

Without a properly working breaker, the heat could melt the wire’s insulation and start a fire. You can prevent circuit overloads by calculating how much current a circuit can handle. First, find out the capacity of your circuit and its breaker. Then, add up the amps your appliances are demanding from the circuit. A capacity of 15 amps (or 1,800 watts), for example, cannot safely handle a 10-amp space heater and a six-amp coffee maker. Calculate your acceptable amps to prevent overload or unplug items until your circuit breaker stops tripping.

Long-Term Circuit Breaker Solutions

Tripping a circuit breaker generally isn’t a big deal, as you can remedy the overload and prevent future trips. You may encounter bigger problems, however, if you have a “nuisance trip” or if you need your circuit to handle a greater number of amps. A nuisance trip describes a circuit breaker that continuously trips, even when you know you aren’t causing a current overload. This problem could indicate a defective or broken circuit breaker that requires replacement. It could also be due to wiring problems, such as damaged or worn cords.

If you need your circuit breaker to handle a higher electricity load (i.e., if you’re installing floodlights in your yard), the answer might be to install a new circuit and outlet. Installing a new circuit dedicated to powering your flood lights, space heater, or other appliance that’s causing an overload can be a great longterm solution. Electricians will generally recommend installing a dedicated circuit if an appliance is going to require more than half the amp capacity of a circuit. Talk to an electrician for more information about how circuit breakers work.