Crimping of wires with sleeves

Now there is a huge amount of technology that allows you to quickly and reliably connect electrical wires and cables. Each of the methods has both pluses and minuses. Wires and cables are connected by welding or soldering. It is possible to use twisting or fixing of conductors by terminal blocks, PPE. All these methods are good and effective. But when it is necessary to get a really good connection, the crimping of the causes will help.

The result of this method is a good contact, protected from oxidative processes and a particularly strong connection. The only drawback - inextricability. Disconnect the two cables will not work. I'll just have to cut it. The crimping of wires is carried out with the use of special handpieces - sleeves. They can be purchased at any construction store or market. The cost of these elements is about $ 1 per unit.

In them, veins are inserted. And the sleeve itself is then deformed with the help of a hand press, thereby creating a reliable electrical connection.

Why is crimping reliable?

Connecting the wires by crimping is the most robust way to connect. This reliability can not be provided by any existing mounting option. In order to obtain a qualitative connection, a sufficient contact area and strength must be provided. Popular twins of two guides do not give either one or the other. When twisting conductors are often oxidized (even in the presence of an electrical tape). And this does not have a good effect on the electrical contact. The use of insulating clamps or PPE allows improving some strength characteristics for simple twisting.

However, there is no one hundred percent guarantee of reliability of such a connection. The terminal blocks are an ideal solution, but in the case of high current, they are not suitable. A good contact can be lost by soldering. Here, both strength and excellent contact. But there are disadvantages of such a connection. The solder can be heated if a large current flows through the conductors. Also soldering wires is not always convenient and safe.

Ideal contact can be achieved by welding. However, the tools for creating such a connection are quite expensive and not available to everyone. Also, working with these devices requires certain skills. The crimping of the wires makes it possible to obtain an ideal electrical contact, and the connection itself will be as reliable as possible in terms of strength. It is very difficult to break such fasteners.

Connection Features

The technology implies two variants of crimping. This is a method of local indentation and continuous crimping. Copper or aluminum wires are used for operation. The sleeve must also be made of these materials. There are also elements made of copper-aluminum alloy.

Since aluminum cables are prone to the appearance of oxidizing films on them, the sleeve must be pre-cleaned and treated with special lubricants. Copper wires are also pre-processed. The use of lubricants in the process reduces the risk of possible damage to the cores. The frictional force also decreases noticeably. Crimping is performed by a manual or hydraulic tool. In the latter case, a figurative press. Usually it is used in large industries.

How it works? The two ends of the cable are crimped before they take a round shape. Then the vein is inserted into the sleeve until it stops. You can connect not exactly to the butt. But in this case the cross-section of all veins does not exceed the bushing. In the case of local compression, contact directly depends on the depth of the pits. The latter can be measured with a caliper. If a continuous reduction is used, then check the cross-sectional area. Then, when the crimping of the wires is done successfully, it is necessary to treat the outer layer with an insulating tape or with a weeping. Next, the wire and cable are neatly laid in the distribution box.

Required Tools

In order to connect the wires or cores of the cable in this way, a special tool is needed. These are mechanical press pliers. They allow to tighten the ends of the sleeve quite tightly over its entire length.

The hand tool allows to squeeze the tip, the cross section of which is less than 120 mm ² . The larger sleeve is compressed with a hydraulic tool. If the task is to connect several cable cores of different sizes, then it is better to use a tool for crimping wires of a different type. Such pliers are equipped with replaceable punches and matrices for different sections.

Sleeves for wires under pressure and their varieties

To get the perfect connection, it is necessary to choose the sleeve or tip correctly. In technical documents, sleeves for crimping wires have certain designations. So, there are the following types of tips:

• Copper.
• Aluminum.
• Combined.
• Insulated handpieces.

GM and GML

Copper parts are used to work purely with copper cables and conductors. They are divided into two types - GM and HML. The first are ordinary copper connecting sleeves. They are not protected in any way, they do not have protective coatings, they have not been processed beforehand. The appearance resembles nothing more than an ordinary tube. GML is also a copper sleeve, but it is tin-plated.

The surface of such a tip is covered with a layer of special tin-bismuth alloy. This protective layer prevents oxidative and corrosive processes. Copper quickly oxidizes, and a protective alloy avoids this. After the connection with the use of GML, copper wires do not enter into oxidation reactions. Some specialists use copper tin-plated sleeves for crimping wires along with aluminum conductors. According to the masters, the tin layer does not give direct contact between the conductor and the copper sleeve. But this is not recommended. In the process of deformation, the integrity of the protective layer is disturbed, and corrosion is only a matter of time.

Aluminum sleeves

In technical documents they are designated as "GA" and are suitable only for working with aluminum. Do not use them for wires from other materials.

Combined sleeve

These are aluminum-copper tips. They are denoted in documents as GAM.

With their help, crimping copper wires with butt-ends with aluminum is carried out. These devices are perfect when you need to build a new cable with old wiring. On the one hand, a copper core is inserted into the cartridge, on the other - aluminum. Two parts of such a cartridge are interconnected by friction welding.

GSI Sleeve

These are isolated tips for the wires under the crimping. This sleeve is a conventional tip with a tin alloy. The top part is covered with PVC insulation. With the help of such a device, multicore cables with copper components are perfectly connected. GSI is good and convenient in the work - there is no need to remove its isolation before the process.

Dimensions of tips, structural features

The minimum available cross-sections for GML are 1.5 mm ² . Further the sizes grow - 2, 4, 6, 10 mm ² and above. From these values it can be said that the cross sections of the sleeves are equal to what wires and cables have. Decipher the designations of the tips is quite simple. For example, GML-6 is a copper tip, tinned. The cross section is 6 mm ² . In the case of combined sleeves, two sizes are indicated in the marking - for an aluminum wire and for a copper wire. For example, GAM 16/10 - 16 for aluminum, and 10 - for copper.

By design, the sleeves can be through in the form of a hollow tube or with a septum. The second ones are applied if the crimping of the wires is carried out with the butt-ends. These partitions are in the middle of the cartridge case. With their help you can adjust the depth of the cable. If it is necessary to increase it, both ends will come into the tip at the same length.

Errors when working on crimping

Often, beginners in the work with an electrician can make mistakes. Especially they are made by house masters in the process of repairing a house or apartment. Let's consider the most typical of them, which are allowed in the process of joining by the method of crimping. The cross section of the sleeve is smaller than the wire. Never at connection it is not necessary to try to reduce a cable and to adjust it under the size of a tip.

This can lead to increased electrical resistance and reduced throughput. In the places of such connections, the vein will become very hot, and in time it will simply collapse. The second popular mistake is a sleeve, whose diameter is larger than necessary. In this case, it will not be possible to obtain the necessary mechanical strength of the joint. Even bending the core several times, a good connection still does not get.

Sleeve cutting

When pressure testing of copper wires or any other is carried out in conditions of shortage of cartridge cases, many try to cut the tip into several parts. It is connected with saving money. But such an action will only increase resistance and heat. Also, the wire will not crimp well. The connection is made only by the instrument intended for this purpose. Do not try to perform the task of crimping and crimping with hammers, pliers or some other tool. The element does not take the desired shape and does not secure the wire. So you can damage the sleeve and cable.

Summary

Crimping is a reliable way to connect two wires or cores and get good contact. But it is necessary to use only the devices intended for this purpose. As a result, you will get a quality all-in-one connection that will not oxidize.