The high-voltage network (HV, in Poland with a voltage of 110 kV) is used to transmit electricity over long distances between the power plant and the distribution networks. High-voltage electrical installations use specialized power cables with a large surface area and low resistance. Various technologies are used to connect HV power cables. In this article, we focused on the correct connection and protection of high-voltage wires.
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Selection of connection type depending on the cable type
The energy system in Poland is based on:
- overhead lines - wires for overhead lines are run above ground level on special poles;
- cable lines – insulated cables are run underground, often in pipes or cable ducts; multi-core cables, bundles of single-core cables and sets of various cables and wires connected in parallel are used here.
What are the rules for selecting wires for a given electrical installation? You need to consider: voltage, material and purpose. High-voltage cables and wires come in different types. The most popular variant is power cables. They are divided into underground, submarine and overhead cables.
Depending on:
- type of cable (power, current, electric, etc.),
- wire cross-section,
- number of strands (wire, strand),
- appropriate cable connections must be used.
Screw connections of high voltage cables
Screw connections are a way to connect high-voltage cables in power plants, substations or transmission line connections with strength and stability. The adjustable screw allows for precise adjustment of the connector to the cable diameter, which translates into reliability and safety of the connection in the event of high voltage. Screw connection systems often include a steel or copper alloy clamp with a copper alloy current path. The resulting connection is durable.
The use of cable joints and the connection of high-voltage cables
Cable joints (resin) are popular, versatile elements used to connect and repair cables. They provide reliable, electrical and mechanical connections with properties equal to those of the cable. They are extremely easy to install. The design of the joint varies depending on the rated voltage, cable type, number and cross-section of cores and manufacturing technology. In practice, the most commonly used joints are through joints that connect sections of the same type of cable and transition joints that connect different types of cables. Cable joints can be made using various technologies: tape, heat shrink, cold shrink or cast. Slip-on models are also available on the market.
Resin joints are used in both high and low voltage installations. Thanks to the polyurethane resin, the cable joint is resistant to weather conditions, UV radiation and aggressive chemicals. It often offers an increased degree of tightness, providing maximum protection against water and moisture - even in the event of continuous immersion. Using a resin cable joint, you can connect various cables and wires, including power, current and electrical, including insulated ones with a wide range of cross-sections, with any number of cores.
Connecting wires using a cable joint involves inserting them into a special connector and filling them with resin. When the resin hardens, a solid, durable and tight electrical connection is created, allowing for safe and efficient operation of the electrical installation - even in difficult environmental conditions. The installation of the resin joint is quick and easy, which allows specialists to save a lot of time when performing high-voltage electrical installations.
Application of strip connectors
Rail connectors (also known as bus connectors) are used to connect copper and aluminum conductors of power cables, both wire and stranded. Their body is usually made of self-extinguishing plastic with high breakdown voltage. This material is characterized by excellent durability and resistance to thermal aging and vibration. Rail connectors enable thoughtful segregation of wiring in switchboards and control cabinets, ensuring order within the installation, and consequently - its trouble-free inspections, service and possible modifications. Depending on the color of the rail connector, it will have a different purpose.
We invite all professionals who deal with designing, implementing or servicing electrical installations, as well as owners of shops and small electrical wholesalers and construction and renovation companies to familiarize themselves with the offer of the Onninen electrical wholesaler. In our assortment you will find everything you need to create a modern, durable and reliable electrical installation. We supply various types of cables and wires - a total of over 50 thousand products! We offer electrical installation equipment from leading Polish and foreign manufacturers. Onninen specialists are available to help you select high-voltage wires.