Computer networks are the traditional reality of modern digital technology. Similar structural elements are used universally and on a large scale. Meanwhile, the design of networks involves the massive use of a special cable, through which individual points (nodes) are connected to each other.
Such a cable is technologically seen as the standard version of products of this type, and a peculiar feature of the product is twisted pair - two conductors. These conductors are twisted with one another along the entire length, being insulated. In this case, a certain twisting step is observed.
We will talk about how twisted pair crimping is performed to organize reliable contact. The article we presented describes the connection for a four-core (2 pair) and eight-core (4 pair) cable. Based on our advice, you can carry out the entire front of work yourself without any problems.
Features of crimping a conductor of 8 and 4 cores
Before considering the crimping technology of copper conductors that make up the internal contents of a network cable, it is logical to familiarize yourself with the options for connecting the terminals.
Network cable lug crimping schemes
Ferrule - standard plastic plug of 8P8C series connector. Such a connector (plug + socket) is often classified by computer network experts as an RJ45 connector.
However, such a classification is incorrect. But this is for general information.
The appearance of the lugs (eights) of the network cable, the contacts of which are subject to the crimping procedure, when used for the first time. Once crimped tips are not reusable
As can be seen from the designation of the series (8P8C), the plastic plug and socket are also 8-pin. These eight contacts can be connected in a different schematic form, depending on the type of cable connection.
Actually, there are two standards for the wiring of the conductors of the T568A and T568V plugs and two options for crimping them:
- Straight.
- Cross.
For convenience, the pinout of the twisted pair cable and subsequent crimping, each core is marked with a certain color. Moreover, the veins of one pair are close in color. For example, the classic coloring of the first pair for the T568A standard for direct crimping of the first twisted pair: 1 - green-white; 2 - green.
The standard for coloring the cores of the eight-core network cable: the upper figure is the T568A standard; The bottom figure is the T568B standard. As can be seen from the pictures, the difference in standards is noted by the color designation of some paired veins. 1 and 8 - core numbers
Direct and cross configuration
The difference between the direct and cross crimping schemes of copper conductors, should be obvious. The direct configuration provides a circuit solution when the two conductor numbers (colors) coincide at the two opposite ends of the network cable.
The cross configuration, respectively, provides a circuit solution, when at the opposite ends of the network cable there is a slightly changed scheme for the correspondence of conductors by numbers (colors) relative to each other. In particular, 1,2,3 and 6 conductors are interchanged.
Cross crimp configuration for use in conditions of a transmission speed of 100 Mbps: 1 - white-orange / white-green; 2 - orange / green; 3 - white-green / white-orange; 4 - green / orange
Both crimping schemes provide for the location of conductors on opposite end plugs, taking into account the numbering, when the first wire is opposite the eighth and vice versa - the eighth wire is opposite the first.
In addition to these two schemes, there is another, called the "console". In this case, the conductors along the end plugs are arranged in reverse order upside down.
That is, the first conductor of one plug corresponds to the first conductor of the other plug and, accordingly, the eighth wire at one end corresponds to the eighth wire at the opposite end.
Cantilever crimping scheme for copper conductors of network cable. It differs in that the end plugs are located relative to one another in an inverted position when the wire 1 = 1; wire 8 = 8
The purpose of a particular scheme
The specific application of the considered twisted-pair crimping schemes is determined by the options for connecting computer equipment. As a rule, direct configuration is used for connecting a network card and a switch (hub).
Cross configuration is usually used when there is a need to connect two network cards of personal computers. The same scheme was used for communications of outdated models of communicators (hubs).
An important detail is worth noting: at the present stage of the development of digital technology, the cross-configuration has practically lost its significance. This is due to the development and implementation of technology for automatic detection of signal circuits of network terminals.
The cable configuration with crimp “console” purpose is traditionally used for official purposes. For example, through such a scheme, a communicator (router) is configured using a personal computer
Step-by-step instructions for crimping the network cable
Given that cable connections are used quite often in a variety of conditions, including domestic, the question of how to compress a cable into 8 cores is quite relevant. Especially if not experts are taken into account, but ordinary users - owners of personal computers.
Consider this uncomplicated workflow to ease the task for potential creators of home networking.
A special tool is required for crimping cable twisted pairs:
- crimper;
- stripper;
- ordinary knife.
The first two tools with exotic names are a special press reminiscent of ordinary electrician's pliers and a cutter for removing cable insulation.
In fact, the cutter is an ordinary knife, with the only difference being that it is equipped with additional notches for removing the insulation coating.
Professional press used for crimping copper cores of a network cable. This tool configuration allows you to work with the 8P8C and 6P6C series plugs
Step # 1 - preparing the cable
Here you will need to select the desired option according to the number of cores and the desired length. For home use, it is often necessary to crimp 4 veined copper twisted pair cables, that is, you need a piece of cable for four wires.
In principle, the use of an eight-core cable version is also possible. In this case, idle pairs are simply not used. Another issue is saving, because the price of four-pair products is higher than two-pair ones.
A fragment of a network cable, where eight copper conductors are placed under the sheath - four twisted pairs. This option is often suitable for solving connection problems in the domestic environment.
Step # 2 - trimming insulation
Having prepared a piece of the required length, it is necessary to carefully remove the insulation on the short end sections of the network cable. It is enough to step back 40-50 mm from the edge of the end cut, then cut the cable sheath with a light circular passage.
Trimming the sheath of the network cable with the help of a uniform cutter specially created for such purposes. As you can see from the picture, the tool is endowed with different shaped cutouts, giving the best quality cut
It is recommended to carefully perform this action so as not to touch the insulation of the internal conductors. Usually, the sheath is not cut to the full depth, but only partially. Then, with a smooth movement of the hands, the cable is bent in the incision area, so that the shell is torn in a circle.
It is quite convenient and high-quality to remove the cable sheath with a stripper. However, first you will have to spend some time mastering this tool. From the first call, it is rarely possible to perform a high-quality stripper removal even by professionals.
Step # 3 - preparing the cores for loading the plug
The opened, twisted-pair conductors in the area freed from the insulating cable sheath should be untwisted (untwisted) and smoothed. The thin-walled copper conductors are quite soft, so it’s easy to perform such actions.
Then all wires should be aligned relative to each other and cut exactly perpendicularly, departing from the end of 2-3 mm. This operation is conveniently performed with ordinary paper scissors. As a result, an even end row of four (or eight) copper insulated cores should form.
The built-in row of conductors must be cut before loading into the body of the plastic plug to obtain an even end line of the entire row. It is convenient to trim with ordinary scissors
Next, a plastic new eight-pin plug (8P) will be used, on which crimping will be performed - contact fastening of copper conductors. It is worth considering that there are no 4-pin plugs for computer networks. Therefore, in any case, a 8-pin plug is used.
Step # 4 - crimping pads
The back of the plug (8P) is technically an input gateway for loading copper conductors. A kind of gateway contains eight rectangular cells, where the corresponding color conductors are loaded.
The loading of copper conductors of the network cable into the “gateway” of the contact plug is carried out without removing the insulation. Wires are simply inserted into the channels until they stop.
Then a standard press is used for 8P8C connectors. The press block is superimposed on a plastic fork, after which the tool handles are squeezed until a characteristic click occurs.
The moment of crimping the contacts of the plastic end plug by means of a special tool - crimper. It is recommended that you press the cable toward the plug with your free hand until the process is completed.
Step # 5 - press quality testing
After crimping, the press is removed, the connection is checked for strength by attempting to physically pull the conductors out of the plug. If everything is done exactly according to the technology, the crimping strength will not allow you to remove the cores from the pressed slots.
On this crimping procedure is considered complete. A similar process is carried out at the opposite end of the cable.
The end of the crimping of the two ends of the cable is usually followed by a subsequent electrical test. For this, a special tester is used, including a transmitter and a receiver of the test signal. The processed cable is included in the device and, using control LEDs, is tested for connection integrity.
The device is a specialized test for the quality of electrical communication of crimped conductors. It is usually used on a professional level. In everyday life, you can apply a simple method of cable proverbs
Application of non-standard pressing methods
Given that acquiring a special tool (the same crimper) requires money, some craftsmen practice a non-standard method of crimping wires. Use an ordinary electrician screwdriver with a flat tip of suitable width and thickness.
Such a screwdriver makes the pressing of the contact rods, successively pressing one into the body of the plug one at a time.
The method with a screwdriver, it should be noted "barbaric", but it works. True, good quality pressing is not always obtained, as a result of which instability of the network cable is noted
If it is required to perform twisted pair extension, the work is carried out in the manner described in detail in the next article. We recommend that you familiarize yourself with useful informative material.
The video below demonstrates the household version of working with cable crimping, the use of a special tool and a step-by-step process.
This video, although not entirely correct in technical terms, will help to understand the essence of the process more fully.
The procedure for crimping copper cores of a network cable can be studied theoretically without much difficulty. Meanwhile, even with theoretical knowledge, a practical skill is required.
In fact, this skill is developed quickly enough even when you have to face work for the first time. True, in order not to spoil a couple of plastic forks, the novice master can not do - you will have to first practice. This is the law of practice.
Please leave comments, post a photo and ask questions in the block below. Tell us about how you crimped a twisted pair with your own hands. Perhaps you know the tricks and techniques that will be useful to site visitors.