Junction box installation costs $100 to $300 for parts and labor, depending on the installation location, accessibility, and the electrical box size, material, and indoor or outdoor rating. The distribution box cost encompasses not only the initial purchase. Safely conduct, connect and distribute energy in hazardous areas with R. We offer bespoke, custom-made terminal boxes and terminal box combinations, as well as standard products with short delivery times. Discover our high-quality products now. Whether you are an electrical contractor or a construction brigade, knowing how to properly and safely install distribution boxes is the basis of ensuring the safe operation of the entire system.