In this article, you will learn everything about junction boxes, including their definition, junction box working principle, types, components, applications, advantages and disadvantages, selection guide, and common problems. Plastic Junction Boxes Materials: PVC, ABS. Learn about the importance of junction boxes in electrical systems, how they protect wire connections, and their role in commercial electrical setups. These installations help us with our daily lives and make us productive. We may be compensated if you purchase through links on our website.