The frequency is 60Hz and the working voltage is about 660V. It is suitable for the use of motor control or lighting equipment. This manual on electric power distribution systems is one of a series developed to aid utility supervisory personnel at shore establishments in the performance of their duties. It includes information obtained from extensive research of current literature on the subject and preferred practices. A distribution box, also known as a distribution board, electrical panel, or breaker box, is an enclosure that houses electrical components responsible for distributing electricity throughout a building. It receives power from the main electrical supply and divides it into separate circuits, each. ides information on the measurement and improvement of distribution system reliability. Standard indices to measure system eliability, outage rate goals, types of faults, and types of outages will be discuss d. This guide provides industrial customers with a comprehensive understanding of distribution boards, their importance, types, and key considerations. For procurement professionals, electrical contractors, and project managers, choosing the right Distribution Box (DB Box) is a critical decision that directly impacts system safety, reliability, and long-term operating costs.