Crimping a network cable: diagrams of using the RJ-45 connector, pinout

A network cable or twisted pair is a special wire that consists of four pairs of copper conductors twisted together. Such a number of cores and the design itself help to reduce the influence of all kinds of interference. Crimping a network cable is necessary to fix special connectors (connectors) on it for connecting to a computer. With its help, a local network is created and devices are connected to each other.

RJ45 connector

When crimping, 8P8C connectors with 8 pins are most often used. They are most commonly referred to as RJ45. Crimping the cable itself is not difficult, but you need to choose the connector carefully - some of them are only used by professionals. They are of two types:

• Unshielded, which are used for UTP wires;
• Shielded - for STP or FTP.

There are also plug-in connectors, but they are only intended for soft stranded wires. If the wire is solid, it will be extremely inconvenient to use them.

Inside the connector there are eight grooves for wires. Metal contacts are located above them. The cores of the cord need to be located in these grooves, and when the connector is closed, they will connect to the contacts. You need to put the connector with the latch towards you, with the contacts up, so that the numbering is correct. In this position, the first recess will be on the right, the eighth on the left. It is recommended to start laying with the first contact.

There are two main distribution schemes: EIA / TIA-568A and EIA / TIA-568B. The veins are arranged in different ways. There are only four pairs of them in the power cord, rarely two. For such wires, the circuit will be different.

Crimp options

There are several schemes for crimping RJ 45 twisted pair: crossover and direct. Difference for purposes of use:

• Direct is used when the cable will be used to connect network equipment (with a computer or among themselves), and connect client equipment. This method is used most often.
• Cross-connect is used to connect computers to each other. No other equipment should be used. Less commonly, this method is used to connect devices via up-link ports.

Any method can be used, but both ends must be crimped equally. Typically, for direct crimping, a 568B circuit is used.

Recently, cables are gaining popularity, in which instead of four twisted pairs there are only two. Only two devices can be connected with them. If the local traffic is high, it is not advisable to use this method, because the data transfer rate will decrease from 1 Gb / s to 100 Mb / s.

Either orange and green or blue and brown are used. Contacts are connected in the same way as in the case of using all 8 wires.

To make a crossover cable, one end of the cord is crimped according to the 568 V scheme, the other - 568A. You need to use all the wires. This method provides a relatively low speed.

To ensure a higher speed, a special scheme is used: one end of the cable is crimped according to the 568B color scheme, and the pinout of the network cable at the other end should be like this:

1. white with green;
2. green;
3. white with orange;
4. white with brown;
5. Brown;
6. Orange;
7. blue;
8. white with blue.

To create a network of two or more computers without using other equipment (switches, routers, etc.), a different twisted pair pinout is used.

The color scheme for 8 wires allows you to connect two devices by simply plugging a cable into their network ports. At the same time, different ends are crimped according to different schemes.

Required tool

To crimp an RJ-45 twisted pair, you need a special tool called a crimping pliers. Its other name, which is used by experts, is crimper.

There are two types of crimpers: lever and press. Lever arms (on the left in the picture) are cheaper, but they are more difficult to work: you need to exert physical effort, but the compression is still uneven. The design of the latter implies the presence of a comb, which moves perpendicular to the connector, placing contacts in it.

To crimp the cable, you first need to separate and strip the twisted pairs, insert them into the grooves on the RJ-45 and the entire structure into the groove on the crimper. After that, bring its handles all the way. Then you need to press the connector latch to the body and remove it from the tongs.

Crimping method without crimper

There is a method that allows you to crimp the cable without a crimper. To do this, you need a vise (or other device that will allow you to fix the RJ-45 plug), a screwdriver, a hammer. You must first insert the wiring into the contact, then fix it with a vice on the side parts. Then, with the tip of a screwdriver and a hammer, carefully deepen the lamellas, snap in the cable clamp - and you're done.

In this way, it is importantso that the tip of the tip is no more than 55 mm, otherwise it will crush the insulating sides, because the lamellas in the connectors are 56 mm thick. If this happens, then you need to cut off the hanging edges with a sharp knife, otherwise the contacts of the socket will cling to the edges, and there will be no contact.

Application of used connectors

If you need to crimp the cable urgently, and the new connector is not at hand, then you can use the old one. To do this, clamp the connector retainer with a vice and gently pry the lamellas with an awl, pulling them out 1 mm. Then, with a knife, cut the latch from the side of the cable, remove it and the old twisted pairs. In this case, the cable retainer is removed, and in order to fix a new one, you need to drop silicone or sealant into the resulting space.

Crimping after removing the old power cord is the same as if the connectors were new. If you need to repair damage to the cord, or if you can lengthen it, use a twist or solder instead of crimping a new cable. The spike is much more reliable.