Crimping twisted pair cables: step-by-step instructions and color schemes for 4 and 8 cores

Despite the proliferation of optical networks, copper lines remain the main type of cable at distances up to 100 meters. Easy to install and maintain, reliable and very economical. Yes, some manufacturers are trying to change the situation, but we can’t expect serious progress in this area in the next 15 years.

The most common copper cable today is twisted pair - four pairs of copper or copper-aluminum conductors with a diameter of 0.52 mm. There isn't a network engineer who hasn't encountered this cable. Let's look at the main types of twisted pair cables and how to handle them.

Twisted pair categories

Alexander Bell is considered the creator of the twisted pair cable, who proposed a twisted pair wire to protect a telephone line from interference caused by adjacent telegraph wires or power lines. This twisted pair of wires was used successfully for almost 100 years until it was replaced by modern types of copper cable.

Twisted pair. General form

Like any telecommunications equipment, international standards have been developed for copper cables. In this case, ISO/IEC 11801. In addition, there is the EIA/TIA 568 standard, which is valid in the United States and its satellites. These standards have been supplemented several times and today there are 8 categories of twisted pair cables:

• Category 1 (Cat1). The same twisted pair of Alexander Bell wires. Used only in analog telephony.
• Category 2 (Cat2). A two-pair cable designed for Arcnet and TokenRing networks and providing transfer speeds up to 4Mbps. Discontinued in the early 2000s.
• Category 3 (Cat3). The first cable is 4 pairs. Designed for 10Base-T Ethernet networks. Out of production in the 2000s.
• Category 4 (Cat4). 4-pair cable for Token Ring networks, 10/100Base-T. Out of production, but found on older networks.
• Category 5 (Cat5). The first cable capable of transmitting information at speeds up to 100 Mbps. Almost completely supplanted by its successor.
• Category 5e (Cat5e). Improved version of cat5. The most popular category today. The cable is capable of transmitting data at speeds up to 1 Gbit/s. It is found in two versions: two-pair and four-pair.
• Category 6 (Cat6). Introduced in 2002. The throughput of twisted pair is 10Gbps. The first cable capable of operating at 10Gbps, albeit over a short distance. Considered as a possible alternative to cat5e.
• Category 6A (Cat6a). Modification of the Cat6 standard, introduced in 2008. The throughput of twisted pair Cat6a - 10Gbps is maintained at distances of up to 100 meters. The actual analogue of Cat5e for 10GE networks.
• Category 7 (Cat7). Introduced in 2002 along with Cat6. The standard was initially positioned as a more powerful version of Cat6, capable of transmitting 10Gbps over a distance of over 50 m, but with the advent of Cat6A it lost its relevance.
• Category 7A (Cat7a). Deep modernization of Cat7, designed to work with 25GE. The bandwidth of this cable also allows you to transmit a 40GE signal, but only over a distance of 1-15 meters.
• Category 8 (Cat8). The newest standard, introduced in 2016. This four-pair cable is capable of transmitting a 40GE signal over a distance of up to 42 meters. Cat8 is divided into 2 categories: Cat8.1 - standardized to work with RJ-45 connectors and is backward compatible with Cat6A cables.
• Cat8.2 – designed for connectors such as TERA (developed by Siemens Company), GG45 (developed by Nexans), and ARJ-45 (developed by Bei Fuse Ltd). These connectors are proprietary and the prospects for their use are still vague.

Types of twisted pair

In addition to categories, copper cables are distinguished by design. The following types of cable are distinguished:

• UTP is a cable with a simple sheath, without armor or protective shield (unshielded twisted pair). Usually installed indoors.
• FTP – shielded twisted pair (foil shield).
• STP - Here each pair of wires is placed in a protective shield and a wire mesh armor is laid between the two shells.
• S/FTP, also known as SSTP, is a double shielded cable. The first one braids each pair separately, the second one covers the entire bunch.
• U/STP – similar to STP, but without external armor.
• SFTP - This shielded twisted pair cable has the thickest cable of all. It has three screens: an internal one covering paired wires and two external ones. One is made of foil, the other is made of wire mesh.

The differences in performance are by no means limited to cable design. The materials from which it is made also play a role. Thus, conductors made of pure copper have better conductivity characteristics compared to their counterparts made of copper-plated aluminum. Another thing is that copper conductor is much more expensive than aluminum.

Shell materials should also be differentiated. The most popular shell today is polyvinyl chloride (PVC). A cable with such a sheath is marked with the letters PVC and is most often painted gray. It is intended for installation indoors. This casing is very cheap, but burns well and has limited resistance to heat and cold.

Another popular cable sheath material is polyethylene (designated PE). It is used in cables for outdoor installation. Outdoor twisted pair cables withstand temperature changes well and are not afraid of dampness. In a number of options it is equipped with a support cable. This allows you to stretch the cable between the supports without the risk of damaging the conductors.

Street twisted pair cable with cable

In recent years, twisted pair cables with a sheath made of a low-smoke, halogen-free compound (LSZH marking) for indoor installation have been gaining popularity. It burns poorly and does not emit harmful substances. Therefore, if strict fire safety requirements are imposed on lines or premises, this should be chosen. Yes, it is more expensive than PVC, but it is more durable and safer.

There are also rarer cable sheaths. For example, the FRNC marking means that the cable sheath is fireproof and corrosion resistant. The polyurethane (PUR) shell offers excellent resistance to oil and repeated bending. Such cables are used in robotics and other areas with special requirements for conductors.

Instructions

Various wires are used for wiring telephone communications indoors. The most widespread, especially in old houses, is the telephone distribution wire (TDW), or “noodle”. The low reliability and noise immunity of this wire are compensated by its low price, which explains its widespread use. A more modern and convenient option is a flat line telephone cord (SHTL). Each of the four conductors is individually insulated with multi-colored plastic, which makes wiring easier. All the wires are sealed in a plastic sheath, which prevents mechanical damage. When purchasing a new wire, preference should be given to SHTPL or its analogues.

Crimping twisted pair

The main advantages of copper cable compared to optical cable are its low cost and ease of deployment. All that is required for termination is a twisted pair crimping tool (twisted pair crimping pliers) and an RJ45 connector. In this case, the installer does not require special equipment or training. Laying copper cable indoors does not require the use of protective covers or corrugated pipes, like optical patch cords. And if the connector gets dirty, you can easily clean it or install a new one.

For use, copper cables must be terminated with appropriate connectors. The most commonly used is 8P8C, better known as RJ-45. The latter, by the way, is a popular misconception. A real RJ-45 connector has a slightly different shape and is incompatible with the connectors of its namesake.

Crimpers for installing modular RJ-45 connectors:

Jonard Tools UC-864

• Crimping RJ22, RJ11, RJ12 and RJ45 connectors
• Cable type: Twisted pair STP/UTP 0.32 - 0.64 mm
• Two-component rubberized handles
• Knife for cutting cables or conductors
• Stripper for stripping insulation from round cables
• Flat cable stripper
• Steel structure, oxide coating
• High carbon steel dies
• Finger safety clips

Jonard UC-4569 - crimper for through connectors

• Crimping of Through and Standard RJ45 Connectors
• Guillotine for removing protruding wire
• Crimping RJ22, RJ11, RJ12 and RJ45 connectors
• Cable type: Twisted pair STP/UTP 0.32 - 0.64 mm
• Two-component rubberized handles
• Knife for cutting cables or conductors
• Stripper for stripping insulation from round cables
• Flat cable stripper
• Steel structure, oxide coating
• High carbon steel dies
• Finger safety clips

Greenlee PA1561

• Crimping RJ22, RJ11, RJ12 and RJ45 connectors
• Non-slip handles
• Knife for cutting cables or conductors
• Stripper for stripping insulation from round cables
• Mechanism for releasing the crimp connector
• Weight: 390 g

Greenlee 45553

• Installing RJ-11 and RJ-45 connectors
• Reliable ratchet mechanism
• Strictly perpendicular course of the matrix
• Guaranteed long tool life
• High crimp quality
• Knife for cutting cables or conductors
• Stripper for stripping insulation from round cables

Hobbes Tooltest - crimper with LAN tester

• Crimping RJ22, RJ11, RJ12 and RJ45 connectors
• Knife for cutting cables or conductors
• Stripper for stripping insulation from round cables
• Built-in RJ-45 cable tester
• Testing the cable for continuity, breakage, mixed-up conductors, short circuit.
• Low battery indicator.
• Crimping tool and cable tester in one

Examination

After connecting the device to other devices or connecting to the local network, you need to check how the created line works. The simplest way is to connect the Ethernet connector to the PC and make sure everything is functioning.

Professionals use cable testers or LAN testers. They include two blocks and allow you to diagnose cables distributed in different rooms. Both blocks have ports for installing connectors. After connection, the device starts up and checks each wire, as indicated by LEDs with serial numbers. If there is a break, then you can see where the damage is or where the crimping was done poorly.

At home, a multimeter is used instead of a tester. It is set to ringing or low resistance (200 Ohms). After this, each wire of the same color is diagnosed on two connectors placed next to each other. Thin probes are needed to accurately touch the contacts. To do this, you need to sharpen them or install wire tips.

It is also easy to check the cable with plugs in different rooms with a multimeter. In the ports of the connected devices there is an induction coil connecting the wires of one pair, so there is conductivity between them. You need to insert a connector into the port of one of the switched off devices, and check the conductivity on the second connector. For private lines (up to 100 Mbit/s), only two pairs need to be dialed.

Couples tend to have similar resistance. If the difference is large or the value is very high, if the line cannot be dialed, this indicates that the wires were crimped incorrectly.

Twisted pair crimping circuits

There are two main crimping schemes:

• Straight. Both ends of the cable are crimped equally. It is used when connecting computers to modems, switches or routers, as well as when connecting switches to routers.
• Cross (crimping twisted pair computer to computer). The first and second pairs of wires are swapped. Used for computer-to-computer connection, as well as for connecting router to router. Today it is practically not used, because devices have already learned to “rearrange” the contacts in the connector programmatically.

Twisted pair pinout for direct crimping and cross crimping

When terminating the cable, it is necessary to use a special tool - crimpers, which are also often called pliers. But if you urgently need to mount one or two connectors, but there is no crimper, you can use a flat-head screwdriver. But be careful. It is very easy to damage the connector or injure your hands.

Crimping procedure

Now let's move on to the correct way to crimp the cable. Be careful when working - the main thing is not to damage yourself, and the connectors are cheap)

Step 1. Remove the insulation

First, remove the insulation from the wire - you can carefully pry it off with scissors or use a stripper on a crimper - insert it, turn it, and the wrapper comes off. It is fragile and can be removed quite easily. You don't need to remove much insulation - a couple of centimeters from the end is enough. If anything happens, you can trim everything later. The pliers have special marks indicating at what level the coating should be cut.

Step 2. Straighten the wires

Now we take our wires, straighten them and arrange them according to the pinout diagram. From the recommendations - try straightening them with a pencil or hand - they become smooth and closely spaced to each other - which is what we need.

Step 3. Trim

Now is the time to cut and straighten our wires. We cut it either with wire cutters, or with the same pliers, or even with a knife. Leave about a centimeter of clean wire. With practice, you will learn to accurately check the distance.

Step 4. Getting into the connector

The hardest part. Now we need to insert our design into the connector. When inserted, the connector is positioned with the leg down. Why is it difficult - the wires try not to fall into their grooves, they crawl into neighbors, bend, and get tangled. Here the recommendation - patience and once again paying attention to the pencil treatment - helps.

Step 5. Insert all the way

After the hit, we press on the cable so that the wires go all the way. In this case, the wrapper will be hidden in the connector itself. If the wrapper does not fit into the connector, fractures are possible in the future. If the opposite turns out to be short, the wires will not reach the knives. So everything is done with experience and by eye.

Step 6. Crimping

Now is the time to tighten our knives - the methods were discussed above, but it is better to use pliers. Take it and live it.

Step 7. Check and refinement

Be sure to check the connection on your computer or router before putting away your tools. Sometimes it may not work out the first time. The easiest way to correct the situation before getting upset is to squeeze the knives again, but harder. It helps a lot.

If there is no connection, pay attention to this:

• Are the wires routed exactly according to the diagram? Didn't they fly out? Look through the connector.
• Have the wires reached the stop of the connector? Were the knives able to reach them?

The rest can only be attributed to cable failure.

Initially, before crimping the network cable, you can install these casings. They perfectly protect against bending near the connector, but in practice everything works without them. There are a lot of species, that’s not what the article is about. For reference.

Crimping twisted pair 8 cores (4 pairs): color scheme

Crimping a twisted pair cable into 8 cores occurs as follows:

Remove the sheath, outer shields and armor from the cable. The best thing is to have a tool at hand for cutting the cable sheath - a stripper. But if you don’t have one, a utility knife will do.

Unwind the pairs, straighten the cable cores and place them in the order of the color scheme in the photo

Trim all conductors to a length equal to approximately the width of your thumb from the edge of the cable sheath

Install the twisted pair connector. Make sure that all wires are fully seated and that the cable jacket fits into the connector.

Insert the connector into the socket of the crimping pliers and smoothly squeeze their handles until they stop.

The result of crimping a twisted pair into 4 pairs (8 cores)

Crimping twisted pair 4 cores diagram

The arrangement of conductors in the connector for a cable with 4 cores (2 pairs) stands out. In this case, the first 3 cores are placed similarly to the 4-pair circuit, and the last one takes place in the sixth pin (position) of the connector.

Crimping diagram for twisted pair 4 cores

The main problem here is not to make a mistake with the placement of the last wire. One way to avoid this is to insert it after the previous three.

Types of connectors

Below are the types of new connectors:

1. RJ 9 is one of the connectors that is necessary to connect the handset to a stationary device.
2. RJ 11 – connects one telephone, the most common option, used, as a rule, in multi-apartment residential buildings where there is one telephone line.
3. RJ 12 - they are not popular in residential buildings, as they have contacts with 4 wires, which makes it possible to connect a separate line to 2 telephones. For private houses and apartments this is not necessary, so this telephone socket is popular in office premises.
4. RJ 14 is considered universal, as it allows connection to both one line (lines are connected to contacts 2 and 3) and several lines (connection to contacts 1 and 4).
5. RJ 25 - differs from the previous type in that it has 3 pairs of working contacts. Installing and connecting such a connector is very complex and requires specialist skills. It is difficult to install it yourself.

Connecting a twisted pair cable to an outlet

Wiring a cable to a power outlet is a little easier due to the fact that the wiring diagram is printed directly on the contact panel of the outlet. The main thing is not to confuse anything. When installing sockets, it is recommended to use a tool for sealing twisted pair cables, for example, a jointing knife-eskractor. Some modern sockets allow you to do without it - after distributing the conductors, simply close the socket cover and it will fix the connections.

Connecting a twisted pair cable to an outlet using a connector

A special case of connecting to a socket is connecting twisted pair cables through a coupling. Here everything is similar to a socket, only the operation is repeated twice: first for the first cable, and then for the second. Perhaps the easiest way to connect two patch cords is with a special RJ-45 twisted-pair connector made from two sockets placed in one box.

Spacers for installing RJ-45 sockets:

Palladin Tools PT-1913 - UTP/STP stripper with 110 spacing

• Stripping UTP/STP cable categories CAT-5, 5e, 6
• Connecting twisted pair cables to cross-connect 110
• High quality performance
• Easy to use
• Self-regulation of cable stripping depth

Jonard Tools ENI-110 - cable terminations for cross-connect 110

• Purpose: connecting wires to 110 cross
• Two blades: with wire cutter and without cutter
• Handle color: light blue
• Weight: 64 g

Jonard EPD-9Krone - impact tool for cutting cables KRONE

• Includes blade for cross-country knife type KRONE
• Durable impact mechanism
• Two driving force modes Hi and Low: 18.14 kg and 13.6 kg
• Hook for removing the conductor from the cross
• Two-color handle for mode identification
• Blade storage compartment with locking mechanism
• Tool life: 100,000 operations in Hi driving mode (18.14 kg / 178 N)
• Weight without blade: 127 g

How to make twisted pair installation easier: secrets from practice

It is worth noting some other subtleties of twisted pair installation:

• To measure 1 meter of cable it is not necessary to look for marks on it. A length of 1 meter is the distance from the fingertips to the opposite shoulder along the chest line of a person of average height.
• The cable sheath must fit into the connector and be crimped. This helps prevent accidental disconnection of the connector. If you remove too much casing, try stretching the rest. Please note that this does not always work in cables with a thick sheath.
• After installing the twisted pair connector, make sure that all wires are inserted into the connector until they stop. Gaps lead to poor contact.
• Use twisted pair testers to monitor the quality of connector installation. Often the simplest models are sufficient. More advanced devices allow you to collect the maximum available information and even draw up a small report.

LAN tester for twisted pair: advanced model from Softing

• If the situation requires connecting cable cores using twisted pair tapes, it is advisable to stock up on a special tool - crimpers for push-button connectors. Unlike pliers, they do not harm the connectors and significantly speed up the installation of adhesive tapes.
• If you are crimping an FTP/STP cable with shielded twisted pair connectors, it is recommended that you first prepare the wires for installation as for a UTP cable, and then cut off more of the sheath and crimp the intact shield.
• Remember that although the cross-section of the twisted pair core is about 0.5 mm, its use as a conductor is allowed only in low-current systems. It is strictly prohibited to use twisted pair cables to power active equipment.

A set of tools for working with twisted pair cables

And one last thing. If you often have to work with twisted copper cable, collect your own set of tools or take a ready-made set of tools for the system administrator. You can take a ready-made one or assemble the components of the kit at your discretion.

Kinds

Twisted pair is a cable made of twisted copper or brass wires in a braid. It is designed to transmit signals between equipment and is connected via Ethernet connectors. Maybe with protection. The latter is made of foil or wire braiding and can be shared or paired. The first covers the cable completely, the second covers separate pairs.

Twisted pair cables are divided into several types:

An unshielded cable (UTP) is not inferior to others in terms of signal transmission quality, but under the influence of electromagnetic interference, the connection deteriorates significantly. It should not be placed near electrical wiring.

In individually shielded (FTP) cable, the individual pairs are protected by foil, making the signal impervious to external interference or crosstalk between pairs. May be located near electrical wiring.

STP (S/UTP) – shielding occurs due to copper braiding over all pairs.

Explanation:

• U – no screen;
• F – foil is used;
• S – metal braid of the outer screen.

A cable with a common shield (F/UTP, S/UTP, SF/UTP) provides good protection from external electromagnetic influences.

An Internet cable with both types of screens protects both from external influences and from cross influences between pairs. These are the types of cable F/FTP, S/FTP, SF/FTP.

Number of cores

The cable includes one core (single-core) or a series of wires (multi-core). The first type bends poorly, but has better properties responsible for the signal transmission range. It is easier to press it, fix it, it practically does not bend. Optimal for connecting internet outlets.

A wire with many cords bends better, but has high attenuation when transmitting a signal. It does not crimp well because there is a risk of breaking the insulation. It is difficult to fit into the connector and is used where flexibility is required, for example, when connecting a router and a PC or two computers.

Selecting a cable for a local network

The main task when planning structured cabling networks (SCN) is to create an infrastructure that will be used for many years. Therefore, the first thing you need to decide is the purpose of the local network. What devices will connect to it? Where will the cable be laid?

For example, twisted pair cable with 4 cores of category 5e remains an excellent choice for the “last meter” in FTTx networks, where 100 Mbps of throughput is quite enough, and a smaller number of pairs significantly saves the budget. In addition, the average lifespan of such a cable is about 3 years, and putting an ultra-reliable cable there is unprofitable.

Cat5e is still in demand in the world

On the other hand, the local network of a modern business center will be in operation for a long time. Here it is much more promising to use twisted pair cable of category 6.

In general, the main criteria for choosing a twisted pair are as follows:

• Twisted pair category 5e for 2 pairs (4 cores) - low-current systems (alarm, access control), cable networks with a throughput of no more than 100Mbps.
• Category 5e twisted pair for 4 pairs (8 cores) - local networks for home and small offices, video surveillance networks and access control systems. Using Cat 5e for GE networks is undesirable because... These speeds can only be achieved with high quality cables that are comparable in price to Cat6.
• Twisted pair category 6/6A - access level for local networks of an office or administrative building at speeds up to 3-5 Gbit/s.
• Twisted pair category 7/7A - internal networks of data centers and communication centers, aggregation level of corporate local networks with a bandwidth of up to 10GE inclusive. It should be borne in mind that the use of twisted pair cable of category 7 is justified only in small areas of up to 50 meters.
• Category 8 twisted pair cable—internal data center connections at distances from 5 to 15 meters. At shorter distances, it becomes more profitable to use direct-attach cables (SFP modules connected by cable).

Don't forget about the cable design. Unshielded twisted pair UTP is great for connecting workstations or telephone jacks. In a word, places where the presence of external interference is not critical.

In turn, shielded twisted pair FTP is more suitable for connecting office Wi-Fi access points, thin client workstations that require constant connection to the data center and other lines that are sensitive to interference.

Last, but not least, is the price of the issue. The difference between the nearest cable categories can reach 100%. But a lot of cable is required. In addition, modernizing the cable network in most cases means the need for cosmetic repairs to the premises. Yes, the problem is often solved by using cable boxes. But they do not always fit into the interior.

For office Wi-Fi it is better to use Cat6A

Today, the most promising access cable is Cat6. The throughput of twisted pair cables in this category fully covers the needs of an office data transmission network for the next 5-7 years.

If we are talking about access points, then it is better to use a shielded Cat6A/7 cable. Wi-Fi speeds are growing by leaps and bounds, and in recent years there has been a trend towards creating wireless office networks. And here the requirements for throughput become more stringent.

What kind of twisted pair will there be tomorrow?

Despite serious competition from optical cable, twisted pair continues to firmly hold the “last meter” segment. An important role here is played by the price and dimensions of optical transceivers, which do not allow their use in personal computers and laptops.

Indeed, in many cases, optical cables turn out to be more promising than copper cables, due to greater reliability and a huge margin for modernization. The same pair of fibers can transmit both 1GE and 40GE. At the same time, the optical cable is absolutely not subject to electromagnetic interference and is more resistant to bad weather and humid environments. Yes, installing a fiber optic cable is much more complicated than copper lines, but if the distance between network nodes exceeds 70 meters, take optics - you won’t go wrong.

However, the twisted pair market will continue to grow in the coming years. As ResearchAndMarkets experts expect, [12] by 2023, more than 90% of the data cable market will be UTP copper twisted pair. Cat5e cable is already losing ground to more modern Cat6/6A cables, and Cat7 cable will expand its market presence, filling the niche currently occupied by Cat6A.

As for exotics like twisted pair with 6 pairs of conductors, it is rapidly becoming a thing of the past, not least thanks to the spread of IP telephony. IP devices have already caught up in price with their analog counterparts, so today it is easier and cheaper to transfer both data and telephony over a single UTP than to use combined solutions.

In fact, the main competitor of twisted pair in its “last meter” niche is not optical, but wireless lines. The introduction of the Wi-Fi 6 standard can seriously change the balance of power in this area, and how events will develop will become clear very soon, after 2022.