How many wires can be connected to each other

Connect lines and cables

Electrical installation Lines and cables: The right connection is what counts

There are numerous possibilities for a permanent and secure connection between two lines or cables. However, they are linked to various factors. At this point it must be mentioned that there are clear regulations within the existing electrical installation of a house or apartment. Anyone who connects, extends or replaces cables interferes with the existing electrical installation and must observe the regulations of DIN VDE 0100. In addition, work on the electrical installation is taboo for laypeople. This is what Paragraph 13 of the “Low Voltage Connection Ordinance” says. This ban applies to all electrical systems in the house.

Anyone who connects lines or cables in permanently installed electrical systems (DIN VDE 0100-520 "Installation of low-voltage systems" in Part 5-52: "Selection and installation of electrical equipment - cable and line system") must always do so in a suitable junction box to do. There the two lines are to be connected with detachable clamps. For cross-sections up to 2.5 mm², loose, insulated individual terminals can be used as connecting means in junction boxes. For cross-sections of 4 mm² or more, only clamps that are fixed in their position in their junction boxes are permitted. The label on the inside of the box about the conductor cross-section, the maximum number of terminals and the conductors must be observed. Basically, detachable connections must always remain accessible.

In the case of systems with flexible connection cables that are not permanently installed, connection sleeves and crimped connections with shrink tubing are permitted. Underground cables are usually connected with corresponding cable junction boxes or connection sleeves.

Electrical installation is required to master

It is not without reason that the installation of electrical systems is one of the master crafts in Germany. This means that the electrical installation must be carried out by a master company. Anyone who, as a skilled do-it-yourselfer, still wants to carry out some of the work from the electrician's trade should do so be sure to coordinate with a specialist company in advance.

Rigid or flexible line?

When connecting lines or cables, pay attention to the design. Is it a rigid or flexible line or a rigid or flexible cable?

Rigid designs have a monolithic vein that consists of only a single strand.

Flexible designs have a twisted braid made of many thin wires.

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Before you connect flexible cables or lines permanently and safely, the stripped wire ends must be provided with wire end sleeves. They are available in the common core cross-sections and can be pressed into place with crimping or crimping pliers. The flexible wire has been turned into a rigid wire that can now be safely connected to other lines or cables in terminals.

Safety rules for electrical installation

Electric current is extremely dangerous and can be fatal. Therefore:

  1. Before working on electrical devices, pull out the power plug.
  2. Always switch off the power before installation work. Switch off the fuse belonging to the relevant circuit.
  3. Attach the information label to the fuse box to prevent the fuse from being accidentally switched on again.
  4. Check whether the system concerned is de-energized.
  5. Hands off house connections as well as sealed meters and main fuses!
  6. Only carry out electrical work for which specialist knowledge is available!
  7. Do not use, disconnect or remove the protective conductor for other functions.
  8. Check the protective conductor function after the work is finished!

Clamp connections

Various components are available for connecting cables and lines. The most popular clamp connection in households is still the Luster terminal. Its name is derived from "luster", which was used to describe the "chandelier" that was connected to the power supply with luster terminals. Luster terminals are still a popular and very simple solution for connecting lamps and lights. However, their installation is somewhat complex, which is why other, faster solutions are preferred in house installation today.

The individual luster terminal consists of a stainless steel sleeve into which two small screws are screwed transversely. The sleeve is also encased in a characteristic plastic cover. This plastic cover isolates the luster terminal from the outside and also protects the screws from contact. Because the screws are energized after connection.

A luster terminal guarantees a permanent connection. However, it must be protected from moisture. This is because it does not offer any protection against a short circuit that can result from moisture. In addition, they must be protected against mechanical influences. They do not offer any resistance to tensile forces. Therefore, luster terminals must always be mechanically decoupled from possible pull. That is why hanging lamps must never be connected with just the clamp! A power line that is subject to tension ALWAYS includes a ceiling hook with a matching eyelet on the cable.

Electricians today use plug-in terminals that consist of a reusable sleeve. They create the connection through a spring-loaded blade inside. When the cable is inserted, this blade cuts into the copper wire and becomes stuck.

When using Plug-in terminals the wire is stripped so far that the copper wire disappears completely into the sleeve and is no longer visible from the outside. Plug-in terminals are available with different connection variations.

So-called Spring-loaded terminals. They combine the advantages of the plug-in terminal with the luster terminal. They work like plug-in terminals. The inner connection of the lines is made by a hinged bracket, which makes the handling of this clamp much easier and makes it usable for longer.

Screw cable connector

In the case of cables and lines that are not permanently installed in an existing electrical installation in a house or apartment, there are other options for establishing a permanent and permanent connection. The simplest method is to use a screw cable connector.

Cap and tail of the Screw cable connector are pulled over the ends of the two lines or cables to be connected. Then the stripped copper wires are connected in the connector. Make sure that each wire is brought together with the corresponding color coding. Flexible wires are to be fed into the appropriate wire end sleeves and squeezed tightly. Then the screw connections are pushed onto the ends of the cable and tightened. They are used to insulate the connection in a watertight manner and to provide strain relief.

An alternative is to squeeze the wire ends together. Before doing this, however, a shrink tube is pulled over the cable or line. Then the wires are pushed into a receptacle and pressed into place with crimping or crimping pliers. Once the connections are tight, the shrink tubing is pulled over the exposed connection. The shrink tubing is heated with a heat gun until it contracts and forms a unit with the two lines and the connection is optimally insulated. The plug connections are robust and can withstand even greater tensile loads.

Connecting sleeves

Connecting sleeves are primarily created for the connection of underground cables. The connector ensures that the connected cable ends are completely insulated. The connection is made either by screwing the wire ends or they are connected with a crimp connection. Purely mechanical sleeves isolate the connected cables through their housing and well-sealed cable entries. There are narrow sealing grommets at the entries, which can also be fixed with cable ties.

So-called gel sleeves are filled with a silicone-based gel inside. The gel securely seals and isolates the connection points when the sleeve is closed. There are also sleeves that are filled with a casting resin after the cabling has been completed. This hardens after a short time and permanently surrounds the cables. These sleeves protect extremely well.

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