If they need to be placed outdoors, especially in high humidity, you must ensure their waterproofness. If necessary, equipping a rain cover, cooling fan or dehumidifier will be better. Remember to leave enough space around the box for better ventilation and maintenance. Another important consideration when choosing the location for a power distribution box is the environment in which it will be placed. Unlike standard junction boxes, these distribution systems must. Primary distribution systems consist of feeders that deliver power from distribution substations to distribution transformers.