In this case, a bus coupler is used to switch the busbar power supply. Refer to this article for more details on understanding a busbar and a bus coupler. Click Here to. In Simple words, a bus-bar is a common connection point or a node for multiple incoming and outgoing circuits such as power lines or feeders. Hence we use bus bars, where these connections can be done spaciously and. Special busbar systems for all electrical connections in switchgear, control cabinets and low-voltage systems. In most assemblies you will find horizontal main bars, vertical risers, neutral and equipment-ground buses, and purpose-designed.