The busbar compartment is located in the middle section of the switchgear. The switchgear is pre set for easy extensions on both sides. ) The multi-function relay. In 2017, UL 508 harmonized with IEC 60947 for low voltage switchgear and control gear to become UL 60947 - further cementing IEC devices as the industry standard for years to come. In most assemblies you will find horizontal main bars, vertical risers, neutral and equipment-ground buses, and purpose-designed. In electric power distribution, a busbar (also bus bar) is a metallic strip or bar, typically housed inside switchgear, panel boards, and busway enclosures for local high current power distribution, transmission, or switching substations.