How to Avoid Circuit Breaker Overload in Your Home

If you’ve ever noticed the lights dim when you switch on the hair dryer, you’ve experienced your breaker approaching the overload point. In modern homes with 200amp electrical service, it’s difficult to overload the breaker. But homes weren’t always built with the capacity to handle the electrical needs of a 2017 household, and many older homes commonly have 100amp or even 60amp service. So how do you avoid circuit breaker overload in an older home without upgrading your electrical service?

When we talk about “overloading” a breaker, what we mean is that the electrical demands on the circuit are coming close to tripping the circuit breaker. Most circuit breakers can tolerate using 80% of their amperage without tripping. If you start to approach the 80% mark, you may notice signs that the circuit is reaching its tripping point, such as flickering lights.

To determine what the tripping point of your circuit is—and thereby avoid overloading it—you need to work backwards from its amperage. Most home circuit breakers provide 15amp service. That means that the total electrical load used by the devices you plug into the circuit should not exceed 12amps.

Calculating how many amps you’re pulling on one circuit is simple once you know how to do it. The formula is watts/volts=amps. That majority of home electrical wires use 120volt power, so to calculate the amperage load of each device, simply divide the device’s wattage by 120.

Add up the amps from each device you have plugged into a single circuit. Does it exceed the 80% capacity of the circuit? Then don’t plug them all in at once! Splitting plugs among multiple circuits will reduce the load on each circuit and reduce the likelihood of circuit breaker overload.

Of course, in order to accurately calculate how many amps are being loaded onto one circuit, you first have you know which and how many outlets are plugged into a single circuit. Splitting up the number of outlets attached to each circuit will also help prevent overloads. That, however, is a job for a licensed electrician.

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