{"id":117634,"date":"2026-07-02T07:30:00","date_gmt":"2026-07-02T05:30:00","guid":{"rendered":"https:\/\/www.reichelt.com\/magazin\/?p=117634"},"modified":"2026-07-01T15:39:59","modified_gmt":"2026-07-01T13:39:59","slug":"the-comprehensive-guide-to-cables-understanding-choosing-and-using-them-correctly","status":"publish","type":"post","link":"https:\/\/www.reichelt.com\/magazin\/en\/guide\/the-comprehensive-guide-to-cables-understanding-choosing-and-using-them-correctly\/","title":{"rendered":"The Comprehensive Guide to Cables: Understanding, Choosing and Using Them Correctly"},"content":{"rendered":"\n

<\/span>Choose the wrong cable, and you\u2019re left with a tangled mess: devices don\u2019t work, connections are unstable, and, in the worst-case scenario, it can even pose a safety risk. For beginners, apprentices or DIY enthusiasts, it\u2019s not always easy to keep track of everything. This guide explains what matters when choosing cables, and helps you make the right decision.<\/p>\n\n\n\n

How a cable is constructed<\/h2>\n\n\n\n

A cable consists of several layers, each with a specific function. The conductor [1] is at the heart of the cable: this is where the current flows, usually through copper. It is surrounded by an insulating, protective layer [2], usually made of plastic, which prevents short circuits or electric shocks. Not every cable has shielding [3]. This protects against electromagnetic interference, which is particularly important for data cables. The outer jacket is called the sheath [4], and protects against mechanical damage, moisture, or external substances.<\/p>\n\n\n\n

\"Structure<\/a>
Structure of a cable<\/figcaption><\/figure>\n\n\n\n

Solid or stranded conductors?<\/h3>\n\n\n\n

Solid conductors<\/a><\/strong> consist of a single, solid copper wire and are stable and break-resistant. This makes them ideal for fixed installations, for example, within walls. Stranded conductors (strands)<\/strong><\/a>, on the other hand, are made up of many thin copper wires, and are therefore considerably more flexible. This makes them better suited to applications involving movement: for example, in extension leads or within appliances and machinery.<\/p>\n\n\n\n

\"A<\/a>
A comparison of conductor types: Rigid or flexible \u2013 depending on the application<\/figcaption><\/figure>\n\n\n\n

Types of sheathing and materials<\/h3>\n\n\n\n

The sheathing makes a big difference: PVC is inexpensive and flexible, making it perfect for indoor use, such as in the home or office. Rubber, on the other hand, is more robust, heat-resistant, and remains flexible even in cold conditions; perfect for the workshop and outdoor use. PUR sheathing, made of polyurethane, is oil- and abrasion-resistant, making it the most durable choice for industry and machinery.<\/p>\n\n\n\n

In addition, a sequence of letters is printed on every cable, for example, \u2018H03VV-F\u2019. Each letter stands for a specific property. H means that the cable complies with a standard that is uniform across Europe, and may therefore be used anywhere in Europe. The number that follows indicates the voltage: 03 stands for 300\/300 volts, 05 for 300\/500 volts, and 07 for 450\/750 volts. The higher the number, the higher the voltage the cable is rated for. The first letter describes the inner conductor insulation, the second the outer sheath; here, V stands for a PVC sheath, R for standard rubber and N for a special, heavy-duty rubber. The final letter \u2013 F for fine-stranded, or U for rigid \u2013 indicates whether the conductors are flexible or rigid. An H03VV-F cable is therefore: compliant with European standards, designed for low voltage, PVC-insulated and sheathed, and flexible. This type of cable is well suited to light domestic appliances.<\/p>\n\n\n\n

<\/div>\n\n\n\n

Meaning of cable marking<\/strong><\/p>\n\n\n\n

Character sequence<\/th>Symbol<\/th>Meaning<\/th>Explanation<\/th><\/tr><\/thead>
1st character<\/td>H<\/strong><\/td>Harmonised cable<\/td>Complies with European standards (HAR system)<\/td><\/tr>
2nd character<\/td>03<\/strong><\/td>Rated voltage 300\/300 V<\/td>For low voltages and light-duty applications<\/td><\/tr>
2nd character<\/td>05<\/strong><\/td>Rated voltage 300\/500 V<\/td>For medium-duty applications<\/td><\/tr>
2nd character<\/td>07<\/strong><\/td>Rated voltage 450\/750 V<\/td>For higher voltages and installations<\/td><\/tr>
3rd character<\/td>V<\/strong><\/td>PVC core insulation<\/td>PVC insulation on individual conductors<\/td><\/tr>
3rd character<\/td>R<\/strong><\/td>Rubber sheath<\/td>Rubber core insulation<\/td><\/tr>
4th character<\/td>V<\/strong><\/td>PVC sheath<\/td>Outer sheath made of PVC<\/td><\/tr>
4th character<\/td>R<\/strong><\/td>Rubber sheath<\/td>Outer sheath made of rubber<\/td><\/tr>
4th character<\/td>N<\/strong><\/td>Special rubber<\/td>Heavy-duty rubber sheath (e.g. neoprene)<\/td><\/tr>
5th character<\/td>U<\/strong><\/td>Solid conductor<\/td>Solid copper conductor (Class 1)<\/td><\/tr>
5th character<\/td>R<\/strong><\/td>Multi-strand conductor<\/td>Rigid conductor consisting of several strands (Class 2)<\/td><\/tr>
5th character<\/td>K<\/strong><\/td>Fine-strand conductor<\/td>Flexible conductor (Class 5), e.g. for control cabinets or installation conduits<\/td><\/tr>
5th character<\/td>F<\/strong><\/td>Flexible cable<\/td>Indicates a flexible cable for applications involving movement<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Beispiele:<\/strong><\/p>\n\n\n\n