What Is A Junction Box?

As you’re likely now aware, based on our first two blogs, the Flux Connectivity team prides itself on providing manufacturing solutions that both enable high performance and extreme safety. You’ll notice that in each of our definitions for wire harnesses and cable assemblies respectively, we highlighted the significance of the materials used to promote safety. As you can imagine, protecting people from the flow of electrical current is of paramount importance. An industrial junction box can be defined as an electrical enclosure that securely unites multiple wires and cables through various ports of entry. Junction boxes can come in many different sizes depending on the number and type of connections required. Standard junction boxes for simple power distribution applications can measure 2 x 3 x 2.5 inches and can hold up to three wires. Larger junction boxes used in industrial applications are often custom built to support many different types of wire and cable entering and exiting the box. The junction box is mounted to a structural point on either a building or on machinery.

So what are the main purposes of a junction box?

A junction box performs several important functions. We would argue that safety is its primary purpose because it serves to keep people and animals away from live electrical connections. With that being said, the primary function of the enclosure is to shield the inside terminations from the outside elements like dirt and moisture. Other purposes of the junction box are based on the application. One of these applications is to distribute power from one location to multiple other locations. A second application is the collection of control signals from various input and output devices, such as sensors and buttons, which are then brought back to a central control cabinet or control panel. In either application, they provide a test point and are usually labelled in reference to a schematic in order to assist with maintenance. As Newark points out on their site, "maintenance and safety are of great importance in keeping and preserving equipment and the facility in a functional state."

What are the main characteristics of a junction box?

A junction box consists of the enclosure and a set of terminal blocks or wire connectors. The enclosure and the types of entry and exit points are typically composed of either plastic or metal depending on the environmental considerations of where it will be mounted. These conditions consist of the level of humidity and  presence of dust or gas. The entry and exit points can be a simple knock-out hole or a more robust cable gland. This gland prevents most external environmental conditions from getting inside the enclosure and causing harm to the connections. The entry and exit points can also take the form of the mating side of a connector from a cable assembly to help simplify the connectivity for the field technician or electrician. We imagine that you may have more questions about junction boxes. Please know that the Flux Connectivity team would only be too happy to answer them for you! For more information, please don’t hesitate to give us a call at 1-800-557-FLUX or email us at connect@fluxconnectivity.com.