The incoming and outgoing lines under the rainproof distribution box shall meet the requirements of "one machine, one gate, one leakage and one box", the door and lock shall be perfect, rainproof and dust-proof measures shall be taken, there shall be no sundries in the. The incoming and outgoing lines under the rainproof distribution box shall meet the requirements of "one machine, one gate, one leakage and one box", the door and lock shall be perfect, rainproof and dust-proof measures shall be taken, there shall be no sundries in the. Requirements for IP Rain and Spraying Test Methods of Distribution Boxes a. Swing pipe water spraying test Sample Placement: Select an appropriate radius for the oscillating arm so that the height of the sample support surface is at the diameter position of the oscillating arm. Place the sample on. (1) Waterproof distribution box engineered for harsh outdoor and industrial environments, providing IP65–IP68 sealing against dust, rain, and UV. In order to ensure that these distribution boxes can effectively prevent the intrusion of moisture and dust, international standards for protection levels (IP. That's where NEMA-rated enclosures come in. They help protect your equipment and keep everything running smoothly. In this article, we'll explain the differences between NEMA 3, NEMA 4X, and NEMA 6P enclosures.