The safety of all its inhabitants depends on the quality of work on laying electrical wiring in a residential building. Connecting electrical wires with the help of twisting has long been a forgotten past. Today, self-clamping terminal blocks are increasingly used for this. What it is and how it works, you can find out in our short review.
Description
Terminal - a special device that provides a reliable connection of electrical wires. The method of connecting the two ends of the wire using a terminal is regulated by the rules for electrical installations and is the most reliable and safe. Connecting devices, including self-clamping terminal blocks, are used to connect the two ends of the electrical wire in the mounting nodes of electrical networks, as well as in junction boxes. They differ in design, manufacturer, connection mechanism.
Types of terminal blocks
There are two types on the market todayelectrical terminals: screw and self-clamping terminal blocks. Germany is the leading country in their production. They prevent heating of the junction of two wires and, as a result, failure of the insulation and short circuit of the wiring.
Screw terminals are a device with a plastic shell, inside of which there is a metal capsule with two holes. The ends of the wire without insulation are inserted into these holes. 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 terminal blocks are a device for connecting the two ends of an electrical wire, which has a special mechanism that 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 set in two positions. Self-clamping terminal blocks for electrical wiring can be disposable and reusable. Connectors of this type are the easiest to use, as there is no need to use additional tools to connect the two ends of the electrical wire.
Advantages of self-clamping terminals
Self-clamping terminal blocks, although they are the easiest way to connect the ends of the electrical wire, nevertheless they have their advantages and disadvantages. Their benefits include:
- ease and speed of installation;
- repeated use, evendisposable terminals can be reused;
- possibility of connecting copper and aluminum conductors.
As for the disposable terminal, its only difference from the reusable device is the absence of a lever. In this case, you can disconnect the ends of the wire that fasten the electrical terminal block of a self-clamping design using an ordinary thin flat screwdriver.
Flaws
Every barrel of honey has its own fly in the ointment, and this case is no exception. In addition to all the visible advantages, such a connector has its drawbacks:
- It is not recommended to use self-clamping terminal blocks for connecting large diameter and high voltage wires due to their low pressing capacity.
- disposable connectors are not suitable for attaching flexible wires.
- when the temperature fluctuates greatly, there is a possibility that the spring will weaken, which may cause the conductors to disconnect.
However, the last point is just a guess. During the tests, this statement was not confirmed.
Scope of application
These devices are used in all wiring diagrams with a maximum voltage level of up to 1000 V. They are equally reliable both in domestic and industrial conditions. But they are most popular when installing electrical wiring in everyday life due to the rather high cost compared to others.connection methods.
The choice of connector is carried out depending on the power of the electrical circuit. On the body of each self-clamping terminal block, the maximum level of its bandwidth is indicated. As a rule, such terminals are installed in junction boxes or shields on a DIN rail.
Terminal selection
Given that the self-clamping terminal block is part of the electrical wiring, its choice must be taken with the utmost responsibility. Conditions to consider when buying a connector:
- The maximum possible conductor power. It can be found out from the passport of the electric cable or guided by the diameter of its section.
- Place of attachment of the connector. If the space for mounting the connecting terminal is limited, then it is necessary to choose more miniature models of the self-clamping connector or stop at the screw terminal.
- Producer. When choosing a terminal, you should not save and purchase cheap analogues of dubious quality, because they may not be able to cope with the power of the electrical circuit, which will lead to overheating of the conductor and, as a result, a short circuit.
Electrical connector manufacturers
Today, quite a lot of large and recognizable companies are engaged in the production of electrical connectors. The most popular brands can be found according to the table.
| Terminal type | Brand | Country of production |
| Self-clamping | Wago | Germany |
| Self-clamping | Spelsberg | Germany |
| Self-clamping | DKC | Italy |
| Screw/Self-clamping | Hager | Germany |
| Self-clamping | ContaClip | Germany |
| Screw/Self-clamping | E-NEXT | China |
| Screw/Self-clamping | IEK | China |
| Screw/Self-clamping | ABB | Germany |
In the domestic market, self-clamping terminal blocks from Wago and ABB are in greatest 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-clamping terminal blocks have three types of clamps: semi-spring clamps, CAGE CLAMP clamps and FIT CLAMP clamps. Each of them has a special marking on the body of the connector, which indicates the number of the series to which it belongs. When choosing a connector, be sure to consider all the characteristics of the device.
ABB is one of the world's leading manufacturers of terminalconnectors. One of its largest clients is Gazprom, which undoubtedly speaks of the high quality and reliability of its products. The ABB self-clamping terminal block has high spring force built into it, high temperature resistance, as well as ease and ease of installation.
Installing the connection terminal
When self-assembling a self-clamping electrical terminal, all recommendations must be strictly followed. The connector application step by step guide includes the following steps:
- Remove voltage from the electrical circuit and make sure it is off.
- Determine the required pair of conductors. Please note that there must be at least as many clamps in the terminal as there are lines to be connected. It is strictly forbidden to connect several power cables to one clamp at once.
- If the ends of the wire were twisted before installation, then it is necessary to cut off their damaged parts with wire cutters.
- Clean the ends of the electrical cable from carbon deposits and insulation so that they fit freely into the holes of the terminal block.
- Place the ends of the conductor in the self-clamping terminal block and connect.
- Make sure the connection is secure and can withstand mechanical stress.
