a fuse being tested with a multimeter

Fuses

Originally contributed by • last updated 3/17/2021

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Did you know that Thomas Edison patented the first fuse in 1890 when he invented his electric distribution system? Since then, there have been a lot of advancements in electrical systems and many newer safety designs and features have been implemented. Nowadays, there are so many different kinds of these little electricity stoppers, it’s hard to choose one without knowing the basics first. 

Definition

In general, fuses are sacrificial electrical safety devices that are designed to stop the flow of electricity if there is a problem. These safety devices are commonly found in automobiles, home electronics and appliances, and in older home electrical panels. They can come in a variety of shapes, sizes, and capacities, depending on their application. Fuses are similar to circuit breakers because they both stop electricity when there is a problem. However, unlike circuit breakers that can be reset, these little trippers are designed for single use and must be replaced.

What’s The Best Way To Fix A Blown Fuse?

Fuses are commonly used as electrical safety features in automobiles and in many modern home appliances and electronic devices. They are typically used in smaller places where a resettable breaker switch will not work, such as under the dashboard in a car or inside a home audio system. Sometimes, they need to be replaced if they are unfortunate enough to blow or trip. There are a couple of ways you can tell if a one is blown:

  • In many cases, you’ll be able to see a visible gap in the wire or a dark metallic smear inside the fuse if it is blown. If you see either, you’ll probably need to replace it as they are typically not repairable.
  • If you are unsure if one is blown, you can test it by using a multimeter. By measuring for continuity, you can determine whether or not the circuit is complete or open. If you’re unsure how to do this, it’s probably best to call a professional.
  • Replacing a fuse is typically an easy task. In most cases, it requires removing the old one and simply replacing it with one that isn’t blown. Often, the hard part is identifying the one that needs to be replaced.