The fuse box is a metal box installed somewhere on the inside or outside of the home. It is installed by an electrician and has a hinged cover to keep the fuses protected. Most homes built before 1960 will have a fuse box, those built after have a circuit breaker box.

This box controls the electrical flow to your home. In the event of an overload, the fuse attached to that circuit will blow. This will cut power to every device on that circuit in the house. Most boxes have a main switch that will control power to the entire house.

There are three important things that you need to know about your box. You need to know where it is, what type of fuses your box uses, and if your main switch works properly. You should test your main switch at least three times annually to make sure it works correctly.

The inside of your box has several threaded spaces that resemble light sockets. These are called Edison sockets, and your fuses screw into them. Some fuses have an adapter called a rejection base snapped inside of them. The rejection base will only allow an S type fuses to be placed in that spot, whereas the larger T type fuses are screwed into the non-adapted sockets.

The most common fuses in homes nowadays are fuse types SL and TL. The SL fuse is a fuse with a rejection base already installed. The TL type fuse is a fuse with a regular Edison base. These work well for home use because they are designed to handle momentary power overloads caused by turning on household appliances.

When you blow a fuse, you need to unplug everything connected to that circuit. Go to the box and place a dry rubber mat on the floor to stand on to create insulation for your body. Put on a pair of thick leather gloves to avoid possible electrocution, open the hinged door and turn off the main switch for the house.

Using a flashlight, examine the top of each fuse. The top is made of glass. A blown fuse will either have the metal wire broken in pieces inside the glass, or glass that appears cloudy so you can’t see in. Remove this fuse, being careful not to touch the metal parts with your bare hands. Replace this with a fuse of matching amps. Turn the main power switch back on.

If you don’t want to mess with fuses, you can install mini breakers into the box. These turn each fuse into its own circuit breaker with a button on top. When a fuse blows, push the button to reset it. Your other option is to have an electrician replace your box with a modern circuit breaker.