Incoming line part: Displays the incoming line source of the distribution box, which may be a single-line incoming line or multiple-line incoming lines (such as normal power supply and backup power supply), and marks the model and rated breaking current of the incoming line. Incoming line part: Displays the incoming line source of the distribution box, which may be a single-line incoming line or multiple-line incoming lines (such as normal power supply and backup power supply), and marks the model and rated breaking current of the incoming line. That cable running from your main service entrance to your distribution box isn't just another wire – it's the critical link that determines how safely and efficiently power flows through your entire building. And all the switching and protective devices are installed in the. The Distribution box system diagram mainly includes the following parts: Incoming line part: Displays the incoming line source. A distribution box is a low-voltage electrical enclosure that receives incoming power and distributes it safely to multiple outgoing circuits through protective and switching devices such as MCBs, RCDs, RCBOs, fuses, isolators, busbars, neutral bars, earth bars, and surge protective devices. It contains safety mechanisms like circuit breakers, neutral and ground bars, and wiring. High and low voltage switchgear is a key distribution equipment in the power system, and the selection of its incoming line method directly affects the reliability of power supply, equipment safety, convenience of operation and maintenance, and optimization of the layout of the entire distribution.