Metal boxes are used in many electrical systems. These metals are strong and last a long time. It is best for places that need extra protection, like. Engineering thermoplastics like polycarbonate and epoxy-coated steel are very safe and strong. Types of electrical distribution boxes Regardless of the classification criteria based on materials. They are (i) substations, (ii) transmission poles and towers, and (iii) electricity conductors. Substations transform voltage from high to low, or the reverse, or perform any. Electrical enclosures are electro-protective housings that look a lot like a box.