Views: 3 Author: Site Editor Publish Time: 2022-11-17 Origin: Site
Low-voltage cables are power cables with an operating voltage of less than 1kv. Low-voltage cables consist of a core, insulation and a protective layer. They are used to connect cables from the distribution cabinet to the equipment end. Compared to high-voltage cables, low-voltage cables are technically more structured and used. The range is also different, both are also carriers for conducting electrical energy and are used everywhere.
Several common types of cables and their characteristics
1. Copper-core power cable
At present, the domestic low-voltage power cables are common cores stranded together into a cable. This structure of the cable poor anti-interference ability, poor lightning resistance, cable three-phase impedance imbalance, zero sequence impedance, line protection appliances difficult to operate reliably.
2. Cross-linked polyethylene insulated power cable
XLPE cable for short, is the use of chemical or physical methods to transform the cable insulation material polyethylene plastic molecules from a linear structure into a three-dimensional network structure, that is, from the original thermoplastic polyethylene into thermosetting cross-linked polyethylene plastic, thereby greatly improving the heat resistance and service life of the cable, but still maintain its excellent electrical properties.
3. PVC Insulated PVC Sheathed Power Cable
The long-term working temperature of PVC insulated PVC sheathed power cable does not exceed 70℃, and the maximum temperature of the cable conductor does not exceed 160℃. The longest duration of short circuit is not more than 5s, and the minimum temperature of construction and laying is not less than 0℃.
Low-voltage power cable insulation layer is planned into a double layer, the total thickness of insulation is not increased, the inner layer of insulation is planned to give primary
consideration to the electrical function, the outer layer of insulation is given primary consideration to low smoke halogen-free flame retardant function; in the extrusion process is selected double layer co-extrusion skills, seamless bonding of the inner and outer layers, further enhancing the electrical function of the cable and waterproof function; insulation, sheathing. The insulation and sheath are irradiated and cross-linked to improve the temperature resistance of the cable, which can reach 90 ~ 125 ℃. Low-voltage power cables are mainly used for power distribution projects in intelligent green construction, hospitals, stadiums, sports centers and other large occasions.
With the continuous development of science and technology and economic changes, the process of vigorously building modern cities and towns has accelerated a lot. In the process of building modern cities, with the addition of various electrical appliances, the laying of power grids is essential. Because the system of power grid engineering is relatively messy, so the operation and maintenance of cable lines has been a huge and messy project. One from the beginning, the operation and maintenance of power cable lines is also a relatively important operation in the power grid system.
Low-voltage power cable is currently more widely used, the amount of larger power cable, power cable models are diverse, many standards, what is used in our daily lives?
Wire and cable products used in the power system mainly include overhead bare wire, busbar (convergence bar), power cable (plastic cable, oil paper cable (basically replaced by plastic power cable), rubber sheathed cable, overhead insulated cable, branch cable (instead of part of the convergence bar), electromagnetic wire, power equipment wire and cable.
2、Information transmission system
Information transmission system used in the low-voltage power cables and wires mainly include local cables, television cables, electronic cables, radio frequency cables, fiber optic cables, data cables, electromagnetic lines, power communications or other composite cables.
3, Mechanical equipment, instrumentation system
In addition to overhead bare wire, almost all products are used in this part, but the primary low-voltage power cables and electromagnetic cables, data cables, instrumentation cables, etc.