Self-locking terminal blocks: how to use, description

The safety of all its inhabitants depends on the quality of work on laying electrical wiring in a residential building. The connection of electrical wires by means of twisting has long been a forgotten past. Today, self-clamping terminal blocks are increasingly used for this. You can find out what it is and how it works in our brief review.

Description

The terminal is a special device that provides a reliable connection of electrical wires. The method of connecting the two ends of the wire using the terminal is regulated by the rules of the electrical installation and is the most reliable and safe. Connecting devices, including self-clamping terminal blocks, are used to connect the two ends of the wire in the mounting nodes of the electrical networks, as well as in junction boxes. They differ among themselves in design, manufacturer, connection mechanism.

Types of terminal blocks

There are two types of electrical terminals on the market today: screw and self-locking terminal blocks. Germany is the leading country in their production. They prevent heating of the junction of the two wires and, as a result, failure of the insulation and short circuit of the wiring.

Screw terminal blocks are a device with a plastic shell, inside of which there is a metal capsule with two holes. The ends of the wire are inserted into these openings without insulation. The connection is made using a screw, which is clamped with a simple screwdriver. Screw terminal blocks can be used both in low-current circuits and in power ones.

Self-locking terminal blocks are a device for connecting two ends of an electric wire, which has a special mechanism, which consists of a body, power elements and a control lever. Connection and disconnection of the wire is carried out using a special lever that can be installed in two positions. Self-locking terminal blocks for electrical wiring can be disposable and reusable. Connectors of this type are the easiest to use, since there is no need to use additional tools to connect the two ends of the electric wire.

Advantages of the self-clamping terminal block

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

• simplicity and speed of installation;
• repeated use, even disposable terminals can be reused;
• the ability to connect copper and aluminum conductors.

As for the disposable terminal, its only difference from the reusable device is the lack of a lever. In this case, it is possible to disconnect the ends of the wire, which the terminal block is fastened by the self-clamping design, using an ordinary thin flat screwdriver.

disadvantages

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

• It is not recommended to use self-clamping terminal blocks for connecting wires of large diameter and high voltage due to their low pressing ability.
• Disposable connectors are not suitable for attaching flexible wires.
• at high temperature fluctuations, there is the possibility of a spring loosening, which can lead to separation 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 equally reliably manifest themselves both in domestic and industrial conditions. But they are most popular in the installation of electrical wiring in everyday life because of the relatively high cost compared to other connection methods.

The choice of connector is carried out depending on the power of the circuit. On the case of each self-clamping terminal block the maximum level of its throughput is indicated. As a rule, such terminals are installed in junction boxes or panels on a DIN rail.

Terminal block selection

Given that the self-clamping terminal block is part of the wiring, its choice should be taken with maximum responsibility. Conditions to consider when purchasing a connector:

1. The maximum possible power of the conductor. It can be found out from the passport of the electric cable or according to its diameter.
2. Connector mounting location. If the space for mounting the connection terminal is limited, then it is necessary to choose more miniature models of the self-locking connector or to stop completely at the screw terminal block.
3. Manufacturer. When choosing a terminal, you should not save money and purchase cheap analogues of dubious quality, because they can not cope with the power of the electrical circuit, which will entail overheating of the conductor and, as a result, a short circuit.

Electrical Connector Manufacturers

To date, the production of electrical connectors is involved in a lot of large and recognizable companies. The most popular brands can be found according to the table.

In the domestic market, Wago and ABB self-clamping terminal blocks are most in demand.

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-locking terminal blocks have three types of clamps: semi-spring, CAGE CLAMP clamps and FIT CLAMP clamps. Each of them has a special marking on the connector housing, which indicates the series number to which it refers. When choosing a connector, be sure to consider all the characteristics of the device.

ABB is one of the world leaders in terminal connector manufacturing. One of its largest customers is Gazprom, which undoubtedly indicates the high quality and reliability of its products. The ABB self-clamping terminal block has a high spring force built into it, resistance to high temperatures, as well as ease and ease of installation.

Mounting terminal block

When installing the self-clamping electrical terminal yourself, you must strictly follow all the recommendations. A step-by-step guide for using the connector includes the following steps:

1. Remove voltage from the circuit and make sure that it is missing.
2. Identify the required pair of conductors. Please note that there should be no less clamps in the terminal than there are connected lines. It is strictly forbidden to connect several power cables to one terminal at once.
3. If the ends of the wire were twisted before installation, it is necessary to cut off 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. Make sure that the connection is reliable and withstands mechanical stress.