Secondary distribution boxes, also known as sub-distribution boxes, generally serve specific power supply areas. These boxes have inner and outer doors, powder-coated exteriors, and are designed for safety and aesthetic appeal, with rainproof tops for outdoor work. A feeder usually begins with a feeder breaker at the distribution substation. Many feeders leave substation in a concrete ducts and are routed to a nearby pole. From the transformer's low-voltage side (0. 4kV), power is distributed to a main distribution panel. In this guide, we'll break down the 12 main types of distribution boxes in a way that's easy to understand. We'll chat about what each one does, where it shines, and then dive into how to choose the perfect box for your needs.