Waterproof distribution box manufacturers tell you that the way to waterproof an outdoor distribution box is to first choose a distribution box made of waterproof material, seal the cable entry points, apply silicone sealant, install a weatherproof cover, use outdoor rated sockets. Waterproof distribution box manufacturers tell you that the way to waterproof an outdoor distribution box is to first choose a distribution box made of waterproof material, seal the cable entry points, apply silicone sealant, install a weatherproof cover, use outdoor rated sockets. Selecting and installing the right protective enclosure ensures long-term electrical safety in demanding environments. A robust waterproof distribution box shields sensitive components from moisture, dust, and mechanical impacts. 9 Waterproofing and drainage measures should be taken for the cable mezzanines, cable trenches and cable rooms located below the outdoor floor of substations and power distribution stations ; waterproofing measures should also be taken for the cable inlets, outlets and cable protection pipes. If water gets into the distribution box, it can cause anything from equipment failure to serious safety accidents. Many people are wondering how to make these boxes completely waterproof even in heavy rain. Built with durable materials, CE & ROHS certified. For outdoor outlets, use a gfci outdoor outlet with.