This handbook covers the complete maintenance and troubleshooting framework for metal-enclosed busbar systems — IPB, NSPB, SPB, and busway — from daily monitoring obligations through to major overhaul and spares management. In this type, maintenance activity of any bay or equipment such as a transformer is not possible without service interruption of the particular bay or equipment. Single Bus with Bus. The purpose of this method is to verify the functionalities of a Metal Enclosed Busb ar. How do you check and maintain busbars? What are the faults of busbar? What is bus bar in DB? For complete safety instructions and precautions, always refer to the test equipment instruction manual. High exposure to bus faults: a single point of failure.