Wiring Direction: Wiring between the main circuit breaker and each branch circuit breaker in the box generally goes on the left, and the wiring out of the distribution box generally goes on the right. Binding Requirements: The wires should be bound with plastic ties. Choose the right box based on environment (indoor/outdoor), load capacity, and durability. Check for proper IP/NEMA ratings and material quality. A distribution switchboard is divided into a number of functional units, each comprising all the. Distribution Board or DB is an electricity supply system or a common enclosure that distributes the electrical power feed into subcircuits. The hub distributes electrical power from a single input source to various circuits throughout a building.