Self-clamping terminal blocks: types and scope of application + recommendations for buyers

The rapid development of electrical engineering has been marked by a mass of innovations, affecting even simple but extremely necessary connecting elements - terminals.Among the existing variety of such devices, self-clamping terminal blocks occupy a special place, thanks to which electrical installation is significantly simplified.

You will learn all about the innovative type of connectors from our article. We will introduce you to the range currently available to the novice electrician. Let's look at the most popular connectors of this kind, which are in high demand.

Device of self-clamping connectors

Technically, the designs of self-clamping terminals are not particularly complex, despite the promising name.

As a rule, the main working component of this type of product is a spring element. It is due to the spring action that the self-clamping property of the terminal is obtained.

The range of self-clamping terminals on the market provides potential electrical installers with extensive options for creating reliable circuit connections.

The design of the terminal involves the concentration of force in a specific area, limited, for example, by the wire cross-section parameter. Therefore, self-clamping connectors of various form factors are supplied to the market, providing the ability to work with various electrical wires.

The clamping element of the terminal block is traditionally made on the basis of a copper alloy, which has a sufficient level of rigidity. The contact area of ​​the clamping element is treated with a tin-lead coating.

This approach to processing guarantees reliable protection against possible corrosion and ensures the durability of the product.

Treatment of the surfaces of the terminal block design elements allows you to preserve the durability of the mechanism, the properties of reliable contact, and the overall functionality of the device

The self-clamping effect is ensured by a spring made of durable steel. The spring “backs up” the clamping element with a calculated force almost equal to the force that the user must apply to the operating lever before inserting the wire into the groove.

According to technical information, self-clamping terminals are designed to work with conductors with a cross-section of 0.08-95 mm at operating voltages up to 1000 volts. Operating current parameters are allowed in the range of 6-320A. The main area of ​​application is household, but industrial units are also produced.

Types of self-clamping terminals

Actually, there are two types of products of this type:

1. Lever.
2. Push.

The first type is a design that uses micro-levers. The potential user lifts or presses such a lever, and then inserts the end of the wire into the socket. After releasing the lever, the copper or aluminum core is firmly pressed by a spring-loaded plate.

One of the common designs of a self-clamping terminal block, where an auxiliary control element is used - a micro-lever.It works simply: raising the lever opens the terminal, lowering it closes it, clamping the conductor

The second type usually involves additional action with a screwdriver or similar tool. The blade of the screwdriver is inserted into an additional slot, usually located above the conductor entry slot, and gentle pressure is applied. Holding the screwdriver in this position, insert the end of the wire into the input hole until it stops.

Self-clamping push-type terminal blocks work in approximately the same way, where the use of a screwdriver is not required. In this option, the end of the conductor is simply inserted into the input window with some pressure until it stops. Typically this type of terminal is designed for single-core copper wires.

The design of the terminal block is self-clamping, where the use of a screwdriver or similar tool is necessary. To operate the tool on such structures, a special groove is made

The two varieties noted are complemented by a mass of subspecies, to some extent, modernized terminals.

A striking example in this regard is provided by the products of the famous German company Wago. The connectors of which are reliable, simple and easy to use. It is not surprising that most electricians choose these terminals. Let's get to know them better.

Features of using various terminals

The German manufacturer Wago offers an extensive range self-clamping type terminals, among which, from the point of view of subspecies, the following stand out:

• cage clamp — flat configuration;
• fit clamp — mortise configuration;
• leaf-spring configurations.

For ease of selection and configuration, Wago products are divided into series.Let's consider what serial modifications of self-clamping terminals exist.

Subtype #1 - series 222 for stranded wire

Products in this series are of a lever type design. As a rule, these are painted terminals for electrical wires bright orange color, which allows you to quickly detect the connection object in conditions of mass electrical installation.

A product of the German company Wago, designated series 222 in the catalog. Lever type design, convenient for use when installing networks of relatively low power

Despite its specific purpose, the 222 series is equally successfully used for connecting single-core conductors. The calculated operating voltage is limited to 380 volts with a maximum permissible current of 32A.

Self-clamping terminal blocks of the 222 series are used to create connections inside distribution boxes. At the household level, they are often used when installing lighting networks.

Subtype #2 - series 243 for micro-clamp design

Considering the micro-design of this product series, the design voltage for the connection is allowed no higher than 100 volts at a rated current of 6A. The manufacturer declares the use of this type wire clamps only for single-core wire. Both copper and aluminum based conductors are supported.

The design of the 243 series is another product from the range of the German manufacturer. Compact miniature housing allows you to easily use terminal strips in hard-to-reach places

This is one of the subtypes of self-clamping terminal blocks, where the use of auxiliary levers is not provided.

The standard design of the 243 series terminal block is a rectangular module for placing four conductors inside four contact holes. Products in this series are usually painted in dark gray tones. They are used in the installation of video surveillance systems and in the assembly of other systems and networks that require miniature connectors.

Subtype #3 - series 2273 for lighting installation

2273 or Compact are a kind of self-clamping specialized terminal blocks, that is, designed for use in constructing a lighting network circuit. True, the manufacturer does not impose strict restrictions. As the documentation indicates, it is allowed to work with conductors measuring 0.5-2.5 mm² by section.

A design variant of the self-clamping terminal block produced by Wago as a product of the 2273 series. This type is distinguished, first of all, by the specific application recommended by the manufacturer.

The peculiarity of this series is the presence of products containing paste inside and those without. As a rule, a special conductive paste is used on the installation of aluminum wires in order to create optimal conditions against the appearance of metal oxides on the clamped conductors and the terminal blocks themselves.

Subtype #4 - series 773 for distribution boxes

The main purpose of this series of terminal blocks is to work with copper-based conductors (single-core/multi-core) of class 3 flexibility.

It is allowed to insert cores with a cross section of 1-6 mm² depending on the design configuration for a specific section. The terminals are classified as vibration-resistant products. Operating current 25-40A.

The execution is almost the same as the previous one, with the exception of a technical feature.The peculiarity is that this design is more powerful and allows you to work with a higher current load

The body of such Wago products is made of transparent insulating material, which allows you to control the depth of penetration of the core into the contact groove. Also on the case there is a “control” contact - points where it is possible to connect the probes of measuring instruments.

Subtype #5 - series 862 with presser foot

This series provides the connection of single-core and multi-core wires. In this case, it is allowed to connect up to 4 wires of one and another type with a diameter of no more than 4 mm per terminal. Series 862 terminals are suitable for use at voltages up to 500 volts.

A light pressure on the terminal block’s unique control element, the tab, is enough to easily insert the working conductor into the groove. Releasing the button foot is, accordingly, accompanied by clamping the wire

The uniqueness of the product is that it does not require the use of an electric tool when making the connection. The design has a special button - a fixation tab, which makes it easy and simple to connect/disconnect the conductor manually or with a screwdriver.

The design is also distinguished by the presence of a fixing leg for attaching this connector.

Rules for choosing self-clamping terminals

The main rule for a potential buyer of self-clamping terminal blocks is, perhaps, the mandatory checking the product for authenticity. On the commercial market there are a lot of counterfeit goods marked with the German brand - the manufacturer Wago itself warns about this.

The cost of such products is reduced, which naturally attracts the buyer.However, this kind of savings can result in troubles when operating the assembled circuits.

Meanwhile, without unnecessary warnings, it should be obvious that a counterfeit product is a significant reduction in quality. How to choose correctly wire connectorswithout fear of getting a fake? In principle, everything is quite simple. You just need to be more careful when choosing self-clamping terminals for installation.

A branded product traditionally has the Wago logo printed in a clear font, usually on the top or side of the case. Also on the side are the main parameters - voltage and current.

This is what a branded product released under the Wago brand looks like. Counterfeit terminal blocks, as a rule, do not contain such a seal, or contain a partial one applied with low quality

The color of the insulating material of branded products is distinguished by a uniform, clear color. There is a mini connection instruction on the back/side of the terminal block.

When compared with Chinese counterfeit goods, terminal blocks, as a rule, do not have any of the above-mentioned differences. In addition, the fake is immediately distinguished by the blurred color of the insulator, often multi-colored.

Of course, the main points of choice are the purely technical parameters of self-clamping terminal blocks. In particular, operating voltage And permissible conducted current.

If the mounted circuits are designed for operating voltages that exceed the capabilities of the terminal blocks, then the application becomes impractical and, moreover, dangerous.

You can find out what color the wires to be connected are marked in next article, the contents of which we advise you to familiarize yourself with.

Conclusions and useful video on the topic

The video below demonstrates a comparative analysis of branded terminal blocks with products that are a complete fake and are quite widely represented on the market.

The point being considered is how to distinguish a branded self-clamping terminal from a fake:

Self-clamping devices, with the help of which the electrical connection is organized, are convenient and practical. But despite all the advantages of such accessories, their use is somewhat limited by technical and operational parameters.

But the development of such devices continues actively. It would not be surprising if in the near future some kind of universal terminals for working in different conditions will appear.

Tell us about how you repaired or upgraded your electrical system using push-in connectors. Share some technological nuances that novice electricians should take advantage of. Please leave comments in the block below, post photos and ask questions about the topic of the article.