Self-clamping terminal blocks: how to use, description

From the quality of work on laying electrical wiring in a residential house depends the safety of all its inhabitants. Connecting electrical wires with twists is a long-forgotten past. Today, self-clamping terminals are increasingly being used for this purpose. What this and how it works, you can find out in our brief review.

Description

A terminal is a special device that provides a reliable connection of electric wires. The method of connecting the two ends of the wire with a terminal is regulated by the rules for the installation of electrical installations and is the most reliable and safe. Connecting devices, including self-clamp terminals, are used to connect the two ends of the electrical wire in the power grid assembly units, as well as in junction boxes. They differ among themselves in the design, the manufacturer, the mechanism of connection.

Types of terminal blocks

Today, there are two types of electrical terminals on the market: screw and self-clamping terminals. Germany is a leading country in their production. They prevent the heating of the junction of the two wires and, as a consequence, the failure of the insulation and the short-circuit of the wiring.

Screw terminals are a device with a plastic sheath inside which is a metal capsule with two holes. In these holes, the ends of the wire are inserted without insulation. The connection is made with a screw, which is clamped with a simple screwdriver. Screw terminals can be used, both in low-current circuits, and in power circuits.

Self-clamping terminals are a device for connecting two ends of an electric wire, which has a special mechanism, which consists of a housing, power elements and a control lever. The connection and disconnection of the wire is carried out using a special lever, which can be installed in two positions. Self-clamping terminals for wiring can be disposable and reusable. Connectors of this type are the easiest to use, since it is not necessary to use additional tools to connect the two ends of the electrical wire.

Advantages of the self-clamping terminal block

Self-clamping terminals, although they are the easiest way to connect the ends of the electrical wire, but nevertheless they have their advantages and disadvantages. Their advantages include:

• Simplicity and speed of installation;
• Reuse, even one-time terminals can be reused;
• The possibility of connecting copper and aluminum conductors.

As for the disposable terminal, the only difference from the one-way device is the lack of a lever. In this case, you can use the usual thin flathead screwdriver to disconnect the ends of the wire that secure the electrical terminal block to an electrical self-clamping structure.

disadvantages

Each barrel of honey has its own fly in the ointment, and this case is no exception. In addition to all visible advantages, such a connector has its drawbacks:

• It is not recommended to use self-clamping terminals for connecting large diameter wires and high voltage because of their low pressure capacity.
• Single-use connectors are not suitable for fastening flexible wires.
• At high temperature fluctuations, there is a possibility of a weakening of the spring, which can lead to disconnection of the conductors.

However, the last point is just an assumption. During the tests, this statement was not confirmed.

Application area

These devices are used in all wiring diagrams with a maximum voltage level of up to 1000 V. They are equally reliable in both domestic and industrial environments. But they are most popular when installing electrical wiring in the home due to the relatively high cost compared to other connection methods.

The choice of the connector is carried out depending on the power of the electrical circuit. The maximum level of its capacity is indicated on the body of each self-locking terminal block. Typically, these terminals are installed in junction boxes or flaps on a DIN rail.

Terminal selection

Given that the self-clamping terminal block is part of the wiring, it should be taken with utmost responsibility to its selection. Conditions to consider when buying a connector:

1. The maximum possible power of the conductor. It can be recognized from the passport of the electrical cable or guided by the diameter of its section.
2. The place of attachment of the connector. If the space for mounting the connection terminal is limited, it is necessary to choose more miniature models of the self-clamp connector or completely stop at the screw terminal block.
3. Manufacturer. When choosing a terminal, you should not save and buy cheap analogs of doubtful quality, because they can not cope with the power of the electrical circuit, which will cause the conductor to overheat and, as a result, short circuit.

Manufacturers of electrical connectors

To date, the production of electrical connectors engaged in quite a lot of large and recognizable companies. The most popular brands are available on the basis of the table.

In the domestic market, the greatest demand is for self-clamping terminals of Wago and ABB.

The products of the German company Wago are distinguished by a special degree of reliability and safety. This company represents a wide range of electrical equipment and additional accessories at affordable prices. Wago self-clamping terminals have three types of clamps: semi-spring clamps, CAGE CLAMP clamps and FIT CLAMP clamps. Each of them has a special marking on the connector body, which indicates the number of the series to which it refers. When choosing a connector, it is necessary to take into account all characteristics of the device.

ABB is one of the world's leading manufacturers of terminal connectors. One of its biggest customers is Gazprom, which undoubtedly speaks of the high quality and reliability of the products. The ABB self-clamping terminal block has a high spring force built into it, resistant to high temperatures, and easy and simple installation.

Mounting of the connection terminal

When installing the self-clamping electrical terminal by yourself, all recommendations must be strictly followed. The step-by-step guide to using the connector includes the following steps:

1. Remove the voltage from the electrical circuit and make sure that it is not present.
2. Determine the required pair of conductors. Note that the terminals in the terminal must be no less than the connected lines. It is strictly forbidden to connect several feeding cables to one terminal at once.
3. If the ends of the wire were twisted before installation, then it is necessary to cut their damaged parts with the help of wire cutters.
4. Strip the ends of the electrical cable from soot and insulation so that they fit freely into the holes of the terminal block.
5. Place the ends of the conductor in the self-clamping terminal block and connect.
6. Ensure that the connection is made securely and withstands mechanical stress.