For the specifications and application methods of terminal line lines, high-voltage lines and low-voltage lines, first of all, the cable section should be selected according to a certain economic current density to minimize the annual operation cost of the line, save electric energy and non-ferrous metals, and verify other conditions

For general low-voltage lighting circuits, because higher voltage levels are required, the section is usually selected according to the allowable voltage loss conditions, and then the heating conditions and mechanical strength are checked

For low-voltage power line, due to its large load current, the section is selected according to the heating conditions, and the voltage loss and mechanical strength UL terminal line are verified

Generally speaking, the lighting level provided by terminal lines, wires and cables, road and bridge lighting equipment is low, and the human eye is in the middle vision state. At this time, the difference object is not completed by the color difference between them, but depends on the brightness difference between the object and the scene. Taking distance lighting as an example, the distance lighting load on the bridge is uniformly distributed, regardless of whether it is single side distribution lamp, interlaced distribution lamp, symmetrical distribution lamp or base distribution lamp. When calculating the voltage loss, it can be assumed that the dispersive load will gather at the midpoint of the dispersive line segment, and calculated according to the convergent load

According to the requirements of bridge power supply quality, the completed voltage of bridge lighting load line shall not be less than 90% of the additional voltage, and shall not be greater than 105% of the additional voltage; The finished voltage of the power load line on the bridge shall not be less than 90% of the additional voltage; Low voltage power supply shall meet the following requirements: Cctor cos_ It shall be higher than 0.85

Terminal line specifications are divided into ul terminal line, PVC terminal line, PE terminal line, shielded terminal line, rainbow line terminal line, gray line terminal line, Teflon high temperature terminal line, silica gel high temperature terminal line, etc. The products are widely used in machinery, electronic products, toys, household appliances, computers, electrical equipment, military, shipbuilding and other industries