An MDB is a panel or enclosure that houses the fuses, circuit breakers and ground leakage protection units where the electrical energy, which is used to distribute electrical power to numerous individual circuits or consumer points, is taken in from the transformer or an upstream panel. An MDB typically has a single or multiple incoming power sources and includes main circuit breakers and residual current or earth leakage protection devices.

A MDB is comprised of a free standing enclosure, a bus bar system, MCCB’s, metering and support equipments and required current transformers. Panels are assembled in a systematic manner such as incomer section and outgoing section.