Primary distribution box without a roof size

Radial operation is the most widespread and most economic design of both MV and LV networks. It provides a sufficiently high degree of reliability and service continuity for most customers. In American (120. [pdf]

Manual switch on the side of the secondary distribution box

A manual transfer switch is installed next to the main service panel to override the normal electrical service with power from a backup generator during a power outage. Manual transfer switchesrequire an oper. [pdf]