Electrical Box Installations and Uses

Types and Uses For Electrical Boxes Around the Home

Electric cables and terminal gang box inside a dry wall
daoleduc / Getty Images

There are many different types of electrical boxes. Some are designed to house switches and outlets, while others are used for hanging light fixtures. Still others are designed for outdoor and weatherproof installations, not to mention low-voltage installations. If you're installing electrical boxes in concrete or bricks, there are special boxes for this also. If you know what type of box to use, how to install it, and what to use to cover them, you'll be on your way to successfully working with electrical boxes.

Here are all the different types of electrical boxes you might need to identify.

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    Types Of Electrical Boxes:

    Photo of an Electrical Box
    Electrical Bracket Box Tim Thiele

    Plastic electrical boxes have their pluses and minuses. Because they are plastic, there is no need to attach a ground wire to it. Since it is made of a non-conductive material, switches and outlets cannot short out if they touch the side of the box.

    Plastic boxes usually come with tapped screw holes for easy attachment of switches and outlets. These boxes come in a single-gang, double-gang, and even multiple-gang configurations.

    You can choose between plastic boxes with nail-on brackets, complete with nails, or a cut-in version that has tabs that spin out when tightened to hold the box securely to the wall.

    The disadvantages of plastic boxes are their brittleness and wire support brackets. Let me explain. If you look at the box, you'll notice that the device screw holes are also plastic. If the screw is lined up when installing the device, you're fine. But get the screw cross-threaded and you have a problem.

    Electrical boxes come in many shapes and sizes. These boxes are used for outlets, switches, ceiling fixtures, junction boxes, and for keeping wires splices dry. Depending on the size and shape of the box, electrical boxes hold different amounts of wires. There are round, square, retangular, shallow, weatherproof, and extension boxes.

    Electrical boxes come in plastic and metal varieties. Plastic boxes are non-conductive and are relatively inexpensive. They come in different styles that either nail on or are the cut-in variety. These cut-in boxes come equipped with wings that hold the box in place tightly against the drywall.

    Metal or steel boxes are more durable than plastic boxes and some, like gangable boxes, can be joined to add more devices. These boxes are used in garages and basements where they are likely to be exposed and require more wear and tear traffic. Unlike plastic boxes that crack easily, metal boxes are built to last.

    In order to join two or more gangable boxes together, you must first remove one set screw from each of the boxes that hold on the side plates. Use a screwdriver to remove the screws and set them aside for the reconnection process.

    There are a couple of methods of connecting a receptacle on the outside of your home. One is to cut a regular junction box into the interior of the wall and only expose the box opening to the outside. Then, after you add a ground fault circuit interrupter outlet, cover the outlet with a gasket and a cover plate to seal the connection to the wall. Another method is to attach a weatherproof box to the wall using the mounting brackets provided within the box and a couple of screws to attach it firmly to the wall. These mounts are external so there are no holes through the interior of the box.

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