The power distribution box incoming and outgoing line structure is configured as the following manners that: the box body of the power distribution box is divided into an independent incoming line switch room, an independent watt hour meter room and an independent outgoing. The power distribution box incoming and outgoing line structure is configured as the following manners that: the box body of the power distribution box is divided into an independent incoming line switch room, an independent watt hour meter room and an independent outgoing. 400V Distribution When tunnel distribution is carried out at 400V, Cable Link Boxes can be provided which will typically accept incoming and outgoing SWA cables with a cross section of 95mm2 4C and switchgear rated up to 250A. The main switch can control the outgoing feeder cable only, with. The utility model discloses a power distribution box incoming and outgoing line structure. The power. Power supply and distribution in a tunnel Tunnels are home to a variety of applications that need to be supplied with power in a high-availability configuration. Particularly critical subsections, such as ventilation and lighting, must continue to work even in emergency situations, for example. The Tunnel Distribution & Lighting Box provides tunnel contractors with a complete solution for temporary electrical installation that complies with competent local authorities. 9km (not connected as a single circuit). A wide variety of factors afect the. Most of the tunnel equipment and systems require electrical energy to operate. Therefore, equipment for supplying power to the tunnel must be installed. This installation has to satisfy two essential requirements: Meet the needs under all operational situations (normal, degraded, critical.