Bud offers thousands of models of box electrical enclosures suited for use as junction boxes, both indoors and outdoors. Choose a box in the size you need based on the type of material (steel, diecast aluminum, plastic, or fiberglass) you prefer. Consider features such as hinged covers, screw-down covers, transparent covers, and knockouts.
An electrical junction box is an enclosure made of plastic or metal that protects people from contacting the electrical equipment inside it. Traditionally, junction boxes are used as a secure place to connect electrical wires (a junction) and access those connections, but today they are also used for things like mounting security cameras and for housing industrial controls.
A junction box is a type of enclosure. Many junction boxes have knockouts that simplify installation. Some also have clear covers that let users inspect for moisture without opening the enclosure. In truth, almost any small box enclosure can be used as a junction box, so the difference is more in the application than in the construction of the box.
If you are using metal-sheathed cables that must be grounded, then you must use a metal junction box or ensure that the plastic enclosure has proper grounding provisions, can withstand the heat generated, and meets local codes. If the cables are not metallic, then you may use a plastic junction box. Often plastic boxes are less expensive, while metal boxes offer greater strength and durability.
Plastic junction box. Plastic boxes are naturally corrosion resistant and are popular for outdoor locations. Any plastic box used outdoors should carry a proper UV rating, so you know it will stand up to sunlight. Also, it is a good idea to choose a plastic enclosure with a high flammability rating.
A junction electrical box made of polycarbonate plastic is stronger than one made of ABS plastic or the PVC plastic used in residential applications. A relatively new material is polycarbonate plastic infused with 10% glass fibers. The fibers add strength without the cost of a fully fiberglass box.
Metal junction box. Most metal junction boxes are fabricated from sheet steel and are intended for indoor use unless they are properly coated. Die-cast aluminum enclosures may be used as sturdy outdoor junction boxes, although they won’t have knockouts. Metal has the advantage of being totally non-flammable.
Outdoor junction boxes protect electrical connections from wetness, wind, and weather. They accomplish this with a tightly fitting cover and a continuously poured gasket. The degree to which a box is waterproof and dustproof is identified by its rating, called NEMA ratings or IP ratings. A NEMA 4x or NEMA 6P rated box is a good choice for outdoor applications. Weatherproof IP ratings include IP67 and IP68. IP68 means the box will not leak even if it is submerged for short periods of time. Our website has a whole section of NEMA/IP rated boxes.
Options include screw-down covers or hinged covers with latches. Some styles come with knockouts. Optional clear covers are available in some models. Some styles have mounting flanges for easy wall installation. Mounting brackets are available as accessories for wall or pole mounting. Another option is an internal mounting panel, made of aluminum, steel, or plastic, to which components are secured before installing the panel inside the box. Of course, for outdoor and wet locations, remember to include cable glands with your order.
Bud offers a wide variety of junction boxes for indoor and outdoor applications. Here are some of our favorites:
