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. 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. Waterproof distribution box moisture typically originates from condensation, gasket degradation, or cable entry leakage. Moisture inside a waterproof distribution box almost always traces back to one of three root causes: seal degradation, condensation buildup, or mechanical breach. Identifying. Selecting and installing the right protective enclosure ensures long-term electrical safety in demanding environments. Via these enclosures, you're able to protect the most sensitive electrical components from eco-hazards, such as humidity, water jets, and dust, which your. In order to ensure the waterproof performance of distribution boxes, manufacturers will strictly seal the joints of the box. Usually, rubber sealing rings or sealants are used for sealing to effectively prevent the intrusion of rainwater, sand and dust.