So, how are bus ducts and power distribution cabinets connected? One of the most commonly used connection methods is through a plug-in box. Busbar Systems Medium voltage busbar systems consist of two general arrangements. The connection method between them directly impacts the efficiency and safety of power transmission. As an efficient power transmission solution, bus ducts transfer electrical energy from the power source. This article aims to shed light on the importance of proper busbar connections, the different materials used in busbars, the types of busbars, the techniques employed for their connections, and their current carrying capacity. 3 What is the. Power Distribution Equipment is a term generally used to describe any apparatus used for the generation, transmission, distribution, or control of electrical energy.