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 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. 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. Make poor choices here, and you're potentially looking at: Electrical systems are like a. This technical article describes single line diagrams of two typical power substations 66/11 kV and 11/0. 4 kV and their power flow, principles of incoming lines (incomers) and outgoing lines (feeders), busbar arrangement functionality and so on. Single Phase Distribution Box generally consists of Double Pole MCBs, Single Pole MCBs, and RCCBs. Both these lines can be loaded simultaneously to share the.