Cable lugs. types and types. work and application

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Crimping lugs for cables ensure a reliable and tight connection of cables, which is one of the conditions for the safe connection of household appliances to the electrical network. From this article you can learn in detail about all the features of these products, including their types, sizes and markings. The text provides an overview of double and single ferrule crimping technology, as well as products designed for connecting power cables.

Terminations for crimping are necessary for a reliable and safe connection

Clamping wires of different sections into a common terminal

The most difficult task during installation (especially for novice craftsmen) is combining conductors of different cross-sections in one connector. To avoid problems, you should adhere to the following rules:

• Wires of larger and smaller cross-sections are diverted from each other. This can be done thanks to different insulation of the conductors, as well as a reserve in diameter at the tip skirt. The thinner product is stripped a greater distance, after which it is moved forward so that it ends up in the end first.
• At the second stage, the main wire is inserted into the tip all the way and crimping is performed.

A similar principle should be followed in the case of double NSHVIs - first the thin conductor is inserted, and then the main wires are inserted. For crimping, it is recommended to use STK-03 pliers. While working, make sure that the tool does not snap into place. To do this, hold the ratchet lever while crimping.

Ferrule crimping

To find out which tool is best to use for crimping various types of tips, watch this video:

As you can see, you don’t need any special intelligence or experience to use the tips; everything is done easily and quickly. The only thing you will need are special devices - a stripper and press pliers, but they are affordable and can be purchased. When connecting multi-core conductors, be sure to use lugs and make the power supply as reliable and safe as possible.

Types of tips

For equipment to operate efficiently, simply connecting to an electrical outlet is not enough. Another important condition is to ensure a reliable contract between the equipment and the wire. A bad connection can cause:

• overloads;
• power surges.

These situations in most cases lead to devices breaking down and requiring expensive repairs or replacement. The use of special connectors will help to avoid such problems.

The material used for their production may vary. The most common:

• Aluminum. Suitable for wires with aluminum conductors with a cross section of 16−240 mm2. For their manufacture, an AD1M aluminum pipe is used.
• Aluminum-copper. Used to connect aluminum cables to copper terminals of electrical devices. The cylindrical part of such products is made from AD1M aluminum rod, the contact part, on which the mounting hole is located, is made from M1 copper rod. Both parts are connected by frictional diffusion.
• Copper. Used for wires with copper conductors with a diameter of 2.5−240 mm2. The starting material for them is solid drawn copper pipes of grade M2 ​​and sheets of copper grades M1 and M2.

NShVI pin lugs

NSHVI are pin sleeve lugs for wires for crimping. They are made of electrolytic copper, on the back of which insulation is installed. The material is processed by galvanic tinning. For domestic and industrial purposes, such lugs are used for cables with a cross-section of 0.25 sq. mm. NSHVI has many advantages and one of them is saving time when connecting to electrical devices.

Characteristics of pin lugs

Products come in single and double versions. When used, it only takes a few seconds to install the cable. The pin tip does not require special skills to use. There are NSHVI tips with different sleeve sizes. In this case, color marking is used.

Popular crimping tool

To install KVT tips, use the following tool:

• WS-04A is the optimal pliers for beginners. With their help, it is possible to solve the main set of problems in the process of installing various electrical circuits and assembling panels. Its functions include the ability to bite off and strip wires (cables) with a cross-section of up to 10-16 square meters. mm. In addition, it provides recesses for NShVI tips up to 6 sq. mm. (if desired, a cable up to 10 “square” is included) or up to 10 sq. mm. (includes up to 16 “square”). On sale you can find WS-04A pliers, which are equipped with dies for crimping NShVI. Their disadvantage is that the matrices can only cope with products of standard sizes up to 6 square. If you use wires with a reduced cross-section (fake), the quality of the connection will be poor.
• PKVk-10 is a universal tool that is used for crimping conductors of 0.5-10 sq. mm. But this is in theory, because in practice the situation is different. For example, to crimp a cable from 6 "square" and above, a lot of force will be required, and if you reduce the crimping force, the quality of contact when crimping connectors with a small cross-section deteriorates. The advantage of PKVk-10 is its compactness and the ability to get into even hard-to-reach places for installation (if necessary). The tool is best used for crimping conductors up to 4 square.
• STK-03 - powerful pliers that are suitable for large sections (from 10 to 25 “square”).
• PC-16. These pliers are useful for crimping TML from 6 to 10 sq. mm. The manufacturer sets the upper limit at 16 sq. mm., but in practice, crimping such a cable requires a strong hand and a lot of effort. Overall, the tool is not very good, but it has an affordable price. The PK-16u version is available for sale - a reinforced version that is more durable. The tool is suitable for cases where crimping is rarely carried out.
• PGRs-70 is a hydraulic press that is used for TML and sleeves. Many consider the tool as an alternative to PC-16. A special feature of the press is the availability of interchangeable dies with different cross-sections in the range of 4-70 sq. mm. With the help of such equipment it is convenient to crimp classic cables - six, ten or sixteen square millimeters. It does not require a lot of load or excessive effort.
• PKVsh-6 - used for crimping NShVI and NShV from 0.25 to 6 sq. mm., as well as a double tip NSHVI-2 with a cross-section from 0.5 to 4.0 sq. mm.

As for Wiedmuller or Knipex pliers, their disadvantage is the large divergence of the handles. As a result, it is difficult to crimp the NShVI with one hand (the fingers are not long enough).

To avoid discomfort when performing work, you should select a tool based on ease of use, and not focus on the brand.

What to do if you don’t have a crimper on your hands?

The situation is more complicated when there is no special tool for crimping the NShVI. Here you have to look for alternative crimping methods so as not to disrupt the work process. One option is tinning using a soldering iron, rosin and tin.

This option is good, but not suitable in all cases. In addition, the work takes time, and with large volumes of work, running with a soldering iron from one place to another is inconvenient.

Some “masters” use ordinary pliers for crimping. The essence of the technique is to press on the tip in several places for reliable fixation. The convenience of the method is undeniable, but when using it there is a risk of damaging the wires. If earlier this method of installation was acceptable, today it is better to forget about it.

If you don’t have enough money for an expensive crimper, you can buy a more affordable tool. There are many mites on sale that have decent performance in terms of price-quality ratio. In addition, it is better to take universal tools that can perform several functions at once.

Marking of wire lugs

Explanation of tip markings

Product markings differ depending on the manufacturer who specializes in the production of tips. Some of them prefer full alphanumeric markings, while others use only numeric values.

Markings and design features depend on the standard to which it was manufactured. The most popular and widespread are domestic and European standards such as GOST 23981-80, TU and din.

Letter designations:

• Types of tips: sleeve - G, ring - K, tubular - T, pin - W.
• Design: split - R, male - P, female - M.
• Additional equipment with vinyl insulation: combination VI or V.

Types

Despite the common area of ​​application for all cable lugs, they are all divided into several types. The most common gradation is based on material, end shape and installation method. Let's take a closer look at each of them.

According to the material of manufacture

Various metals can be used as a material for the manufacture of an entire electrical device or only part of its structure.

Rice. 1: types by material

Therefore, depending on the material from which the cable lugs are made, there are:

• aluminum - their design is completely made of aluminum and allows it to be connected only to aluminum conductors and the same conductor;
• copper - tips made of copper and intended for terminating copper wires and their further connection with the same conducting surfaces, can be additionally coated with a layer of tin;
• combined - consist of two materials (copper and aluminum) which are made of connected plates in various combinations; aluminum-copper lugs are used to connect copper and aluminum conductors and surfaces;
• brass - made from an alloy of zinc, tin and copper, used to connect copper and aluminum cables or an open connector type connection.

It should be noted that putting copper lugs on aluminum conductors, as well as aluminum lugs on copper ones, is strictly prohibited. This is due to the fact that at the point of such contact, diffusion of particles at the interface of two metals will occur, followed by the destruction of one of them. Over time, this will cause the connection to weaken, increasing contact resistance and causing heat. This can be avoided by using combined or brass models for terminating wires.

By installation method

Another criterion for dividing cable terminations by type is the method of their installation. In practice, types are distinguished for:

• crimping with an aluminum or copper tube is the fastest way to install a cable lug by crimping part of the cable sleeve with a special tool or at least with pliers. But, using a non-specialized tool, you can get a bad connection using the crimping method.
• tightening with screw clamps - divided into classic bolts or breakaway bolts. Conventional bolts are a classic version of a bolted connection implemented in a cable sleeve, where the conductor is clamped by one or more bolts. Breakaways are a disposable version of a bolt clamp - when a certain tightening torque is reached, the heads on the bolts come off and the core remains fixed in the cable lug.
• soldering or welding - soldering of the conductor threaded into the tip is carried out using tin solder. Welding is performed with the same metal as the current-carrying conductor using spot welding.

Rice. 2: cable lugs according to installation method

According to the shape of the cable lug

Depending on the shape of the edge of the cable lug, they can be used in various devices and perform certain functions. Based on this criterion, this type of product is divided into:

• Ring tips - are a product, one part of which is made of a tube or an open sleeve, and the second is a ring. The ring is designed to be clamped under a bolt and ensures good contact over the entire area.
• Horn, fork or hook - are a plate open on one side. Allows you to quickly disconnect and connect pins; they are widely used in laboratories when conducting tests.
• Connector - represent elements of the classic mother-father connection as a cable lug.
• Plate - used to connect power cables to electrical installation elements; they are distinguished by a sufficiently thick plate that can withstand the load of the connected cable.
• Plug or sleeve lugs are a design that is placed in a connector.
• Pin - made in the form of a flat strip or bent in the shape of a needle
• Tubular - are an element for splicing two or more cores according to the principle of a cable coupling.

Rice.
3: according to the shape of the cable lug Each of the above types should be selected in accordance with the tasks that you need to solve with a specific connection. But these criteria are not the only ones that should be followed when choosing a specific cable lug model.

Decoding and purpose of NSHVI

NSHVI is a type of tip, which is deciphered as follows:

• "N" - tip.
• "Ш" - pin.
• "B" - bushing.
• "I" - isolated.

This type of tip is used when crimping copper wires with a large number of cores for subsequent connection to devices and assembly of electrical circuits.

Crimping is carried out using a special tool - NSHVI crimping pliers. In other words, the task of the product is to ensure high-quality contact and integrity of the cores when connected using a screw clamp.

Sleeve NShVI are used for copper wires with a cross-section in the range of 0.5-35 sq. mm. After installation of the product, solid pins are formed at the ends of multi-core cables, simplifying connection to the terminal or equipment.

Double insulated tips (NSHVI-2)

To compress two stranded conductors, a special connector is used - NShVI-2. Its advantage lies in the ability to connect two wires at once into one socket of an electrical device.

In addition, if you need to install several conductors of the same cross-section (for example, 4 x 1.5 sq. mm), it is also better to use NShVI-2.

It is useful in cases where it is necessary to route lines in the panel to different terminals or, for example, to connect the neutral wire from an RCD or AV to several terminals at once. Using a jumper in this case will not work.

How to crimp NShVI bushings?

Before crimping, the wire is stripped using an insulation stripper, a special knife or a stripper. The first option is the most convenient and allows you to quickly get rid of the top insulation without damaging the cores. Stripping is carried out precisely along the length of the sleeve into which the conductor is installed.

As soon as the preparatory work is completed, a sleeve is put on the insulated part. Pre-select the pin sleeve tip (NSHVI) of the required length.

When crimping, special pliers are used, which were mentioned above.

While doing the job, it is important to know how to use press jaws. If you violate the technology, the quality of fixation leaves much to be desired

To avoid errors, the sequence should be like this:

Inserting the stripped edge into the sleeve; Installing the tip into the tool groove

It is important to ensure that the insulated part is pressed tightly against the body of the pliers; Clamping the handle with sufficient force to ensure reliable fixation of the connector.

If you do everything correctly, you get a reliable connection, and the structure itself is monolithic and strong. The principle of crimping using NSHVI-2 is similar. The main thing is to accurately select the cable cross-section. This is not difficult to do. The first numbers show the cross-section, and the subsequent ones (indicated by a hyphen) show the length of the working part.

The optimal tool for crimping in terms of price-quality ratio is considered to be the WS-04A, which was mentioned earlier. Its peculiarity is the presence of lower teeth, which ensure reliable crimping of the product. Thanks to the groove, the connector is tightly compressed and cannot be removed.

When installing the NShVI, keep one nuance in mind - use the section one step lower. What does it mean?

For example, if for a cross-module the permissible cross-section of a stranded wire is specified as 16 sq. mm., after crimping a 16mm analog using NShVI, the structure will not fit into the connector. Here you should use a 10 kV cable. mm.

The PKVK-10 tool is considered no less convenient, but it is used for smaller sections. After crimping, the connector has a rectangular, rather than trapezoidal (as in the previous case) shape.

The advantages of the tool are reliability and ease of use, but even with it there are “punctures” in the form of poor-quality crimping (this nuance should be monitored when performing work).

Where are they used and what will happen if you don’t use sleeve tips?

Connecting multi-core copper wires without the use of NShVI leads to damage to the wires, deterioration of the contact connection and subsequent burnout. In addition, damaged conductors are susceptible to oxidative processes and rust faster.

NShVI (KVT) tips have a wide range of applications. They are actively used when connecting sockets and switches, installing machines in an electrical panel, connecting RCDs and other equipment.

The popularity of a multi-core cable is easy to explain, because it has a number of advantages - flexibility and the ability to pass more current through itself (when compared with a single-core wire of the same cross-section). But it is not suitable for screw connections. It is precisely these clamps that are used today in the same circuit breakers, switches and sockets.

If you operate without clamping, the wires are displaced under the pressure of the screw and are damaged. As a result, the reliability of the connection deteriorates and the quality of contact decreases.

Previously, to solve the problem, soldering of stranded wires was used, thanks to which a large number of wires became one whole.

The disadvantage of this method is that it takes a lot of time. If you need to install a dozen sockets and switches, the work will take more than one day. The use of NShVI allows you to avoid such problems and speed up the completion of work.

During the installation process, it is worth remembering that the cross-section of the wire and sleeve must clearly correspond to each other and be selected taking into account the manufacturer. This is the only way to avoid installation difficulties and prevent cable damage. You can be sure that the connection will last for the entire period of operation.

The nuances of working with NSHVI

If a multi-core cable is used, it is recommended to buy an NShVI tip. This type is not used for terminating wires with one core.

Crimping of a multi-core cable is performed as follows:

• you need to select the wire cross-section and tip brand. The veins should enter freely from the skirt side;
• The type of tip should be selected with some margin. A wire with a cross-section of 1.25 mm is crimped with a tip of 1.5 sq. mm, and the section of the skirt is up to 2.5 square meters. mm.

Required Tools

Crimping is carried out with a special tool that allows you to create the necessary force. The following tools are popular:

• Press pliers for crimping PK2 and PK2M lugs are used for terminating cores with a cross-section of up to 10 sq. mm;
• PK1 and PK1M brand tools are a more powerful version of hand pliers;
• hydraulic pliers allow you to crimp wires up to 10 sq. mm;
• In industrial production, a hand press is used. It is suitable for wires up to 240 sq. mm;
• hydraulic press with electric drive is used for cables up to 300 sq. mm.

Press pliers with hinges increase the pressure of the tool, which makes the manual crimping process easier. Devices with a ratcheting mechanism are especially convenient. They prevent the instrument from unclenching until the procedure is completed.

You can watch how to crimp a wire without tools in this video:

Sleeves for wires for crimping

Not all devices or instruments use cable lugs - there is also a sleeve termination. For cables with copper conductors, sleeves marked GML are used, which means tinned copper sleeve. The GAO brand is suitable for aluminum wires. This is a closed type sleeve made of aluminum. If it is necessary to make a connection with the connection of copper and aluminum elements, then an alloy is used.

Sleeves for crimping

Preparation for crimping

Before putting the tip on the core, it is necessary to perform certain preparations:

• Clean the required length of the wire from the insulation. You can use a special tool for this;
• Twist the wires by hand and place them in the tip from the skirt side.

It is important to choose the correct cross-section of the core to ensure easy entry into the tip sleeve

How to crimp a wire

After selecting suitable tips and wires, you will need a special tool. Press pliers resemble pliers, at the end of which there is a special matrix into which lugs and an uninsulated section of the cable are installed. This device ensures that the tip pressure is applied evenly on all sides.

Particular attention should be paid to the type of cable, which can be stranded or with a monolithic core

Crimping of stranded wires

Single terminal crimp

To make a high-quality crimp, it is recommended to follow the following recommendations:

• to prevent the cores from falling out of the socket, the conductor should be fixed when placed in the tool matrix;
• crimping is carried out using pliers until the snoring mechanism is activated, which allows you to block the tool from opening;
• if fixation is carried out manually, then control is carried out by pulling the hand. If the crimp is of high quality, then the installation will be tight without movement;
• You can use a double-circuit crimping tool. Termination is performed by compressing the insulator and bushing in sockets with different diameters;
• Finally, you need to check the strength of the contact by slightly pulling the elements.

Single wire crimping

Double terminal crimp

The connection of two phase conductors is carried out on one contact. When installing modular machines, they are connected using special jumpers. There are a pair of cables per contact.

In this case, it is recommended to use NShVI for two wires. Here are some installation features:

• two wires are installed inside the cuff at once;
• It is better to perform crimping using press pliers. When crimping a double tip, it is better to use a matrix with a cross section of 6 square meters. mm.

Crimping power cable lugs

To crimp the power cable, it is recommended to use a tinned copper tip, which is protected from oxidation. When cutting the cable, the edge may fluff up and become larger than the rest of the core. In this case, the edge can be removed using a sharpener. The cable should be unfolded so that the circle removes excess along the veins, but does not bend them.

You should not use the soldering method for crimping, since contacts made only with pure tin cannot be used on wires.

Power cable crimping

Working methods

When using NShVI tips, it is worth considering the following:

"SKIRT" COLOR. The product shows the cross-section of the connector. As a rule, we use the KVT standard, which is characterized by the following:

• Black - 1.5 sq. mm;
• Blue - 2.5 sq. mm;
• Gray - 4 sq. mm;
• Yellow - 6 sq. mm;
• Red - 10 sq. mm.

It is worth noting that goods from stores deviate from the standard. At the same time, the size of the product and color do not correspond to KVT in any way. The downside is low quality and rapid destruction. That is why, when choosing, you should pay attention to the color of the “skirt” and its correspondence to the cross-section.

PACKAGE. As a rule, NShVIs for crimping come in packs of one hundred products, which are packed in groups of five in a larger package. It is not possible to purchase such a product individually.

If you need to connect two cables, there is no need to “reinvent the wheel.” NShVI-2 connectors of the same type of installation are available for sale. For example, if you buy a product for four square meters. mm, it easily accepts two wires per 4 sq. mm.

Popular products in Russia

There are many factories in Russia that produce NShVI tips. The leading position in this market segment is occupied by the KVT plant, which produces electrical installation tools and cable fittings of high quality and affordable prices.

Today, the plant’s product range includes more than four thousand items, which allows you to select the appropriate tools and components.

The plant produces the following products:

• Cable lugs and sleeves designed for crimping wires and cables.
• Bolted lugs and connectors - for convenient installation of cable cores. The peculiarity lies in the versatility and reliability of contact, which allows the product to be used as components for heat-shrinkable cable sleeves.
• Insulated tips, sleeves and connectors.
• Insulated clamps and terminals.
• Cable couplings KVT.
• Elements of cable couplings and other elements of equipment designed to work with wiring.

How to crimp wire lugs: list of suitable tools

To install metal connectors on wires, do not use tools that are not designed for this purpose. There are special ferrule crimpers for wires. Each of them has unique capabilities and can therefore be used in certain conditions. Scope of use of various types of tools for crimping wires with lugs:

Most often, hydraulic or press pliers are used for crimping tips.

1. Press pliers PK2M and PK2 are designed for crimping wires whose cross-sectional size does not exceed 10 mm².
2. Press pliers PK1M and PK1 are manual pliers that are much more powerful than the previous version.
3. Hydraulic pliers – designed for crimping cables with a cross-sectional size of up to 10 mm².
4. Manual press – used in industrial production on wires up to 240 mm² in size.
5. Electrically driven hydraulic press – designed for crimping wires with a cross-section of up to 300 mm².

A tool equipped with hinges has increased pressing force. In this case, a person does not have to make a lot of effort to install the tip. The most convenient to use devices are those with a ratchet mechanism.

Important! Before starting work, you need to make sure that the diameter of the hole (matrix) on the tool is set correctly. Otherwise, the tip may be damaged during the crimping process.

What are wire lugs for crimping used for and areas of application?

The use of cable lugs significantly increases the quality of the electrician’s work and also facilitates the procedure for connecting cables. Cables are terminated with the help of lugs and sleeves for their strong fixation. Using aluminum, copper and combined lugs, it is possible to combine power sources and different installations.

Tip and stripped wire

Tips are a universal tool. On the modern market there is a huge assortment of them, from which you can choose the necessary option for a certain type of installation work.

Different types of tips

In order to be able to select a tip for a specific cross-section, it is marked at production. If the dimensions are chosen correctly, the crimping of the cable lugs will be as reliable as possible.

Correct selection of tips for crimping

Before you begin work on crimping, you need to choose the right tip. These products may have different sleeve thicknesses or different inlet diameters. To achieve a quality connection, it is important that the cable, stripped of insulation, matches the diameter of the tail part of the tip.

Connector sizes

If the tip is aluminum, then the product must be selected with the same cross-section as the wire. If the material is copper, then you may encounter certain difficulties.

The following solutions are possible here:

• the desired option can be selected using tables from GOST. In this case, knowledge about the flexibility classes of cores will be needed;
• You can measure the diameter with a caliper. Then compare it with a cross-section of the inside using a caliper.

Parameters of Tubular Copper Lugs

The material of the tips and sleeves must match the material of the core or wire. Otherwise, corrosion processes will occur.

For your information! The diameter of the core should be slightly smaller, but not larger than the diameter of the shank.

Rules for crimping: how to do it efficiently?

To get the maximum effect from using lugs, you need to crimp them correctly and thoroughly prepare the wire.

First you need to expose the veins. Ideally, this is done with a special tool - a stripper. If it is not there, then you can use improvised tools, but try to make the line as even as possible, because the quality of the insulation depends on this. The protective coating is removed 5 mm longer than the length of the shank, since during the crimping process the latter will increase in size.

Stripped copper cable

To protect against corrosion and improve contact, the exposed wire is degreased with special contact pastes.

All wires on the cut must have the same length; if this rule is neglected, the connection will not be of high quality. Some wires can break and become damaged. For the same reason, you cannot twist the wires for termination with lugs, since during the crimping process they will be crushed and will not be able to perform their functions.

Pressure testing is performed in stages. Depending on the length of the tip, 1÷2 crimps with a press may be required. For sleeves – 2÷4 pcs. They are made at a distance of 1÷2 mm. The first crimp should be at the blade, then closer to the edge of the shank.

It is necessary to select a suitable press matrix. If it is less than necessary, then large “ears” of metal will form along the edge of the crimp. After cutting them off, through holes are obtained that violate the insulation.

The tip is installed in the device so that the marking is imprinted on the front side of the element, and not on the side.

Only a small flash is allowed; here, after removing the “ears”, the insulation will be compromised

Typical frequently asked questions from readers

Which ferrule is suitable for heat resistant steel flexible wire? Aluminum or copper?

For a steel core, I would recommend using a copper or tinned tip.
Aluminum itself has a lower melting point than copper; it is easily oxidized by external factors, so damage to such a tip will appear faster. If you know the brand of this wire, then you should select the tip based on the passport data and recommendations of the manufacturer. It all depends on the range of operating temperatures that both the wire itself and the lugs connected to it will experience.

But, in your case, I am tormented by certain doubts, I apologize in advance for my skepticism, but is this really a steel wire? The thing is that wires with steel conductors are not flexible; this parameter, as a rule, is inherent in cable and wire products with copper conductors. Perhaps it is a bimetallic wire, then a completely different conversation; the tip is selected according to the material of the top layer.

I also note that heat-resistant cables and wires, for the most part, are made with copper cores or copper with the addition of an alloying material, for example, nickel. If you were guided only by color, then perhaps you should check the product passport, or at least use a magnet.

Video: crimping/crimping wires with various lugs and electrical installation tools

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Choosing the right tip allows you to save money!

Choosing the right tip allows you to save money! The table below will help you choose the size of the tip based on the cross-section of the wire. For example, when terminating a copper wire PV-1 at 95 mm 2, you need to install a T 70-10-13 tip.

Conductor classes: 1 - single-core conductor (PV1 wire, AVVG, VVG cable) for stationary installation. 2 - multi-core conductor (wire PV2, cable AVVG, VVG) for stationary installation. 3 - stranded conductor (wire PV3, cable KGL). 4 - flexible stranded conductor (wire PV4, cable KG). 5 - flexible thin-wire conductor (PVS wire, KG cable). 6 - especially flexible thin-wire conductor (KOG cable).

Purpose

Cable lugs are designed to create reliable contact between multiple conductors, a wire and a busbar, or a wire and a terminal. Electrical contact in this case can be ensured by tightly fitting the walls of the cable lug along the diameter of the core, using solder or clamping with a screw device. They are also designed to simplify installation processes in electrical installations, perform any technological operations, etc.

Cable lugs are designed to replace all kinds of twists and other types of homemade connections common among would-be electricians. This device ensures optimal fixation of the wire inside the sleeve and reliable contact.

Design nuances and characteristics

The NShVI tip, as a rule, has the following features:

• During the manufacturing process, M1 type copper is used;
• The upper voltage threshold is 690 V;
• The surface of the connector is subjected to electrolytic tinning;
• The dimensions of the connectors are designed to connect one cable (installation is carried out taking into account the cross-section);
• Insulation is performed using polypropylene, which does not contain halogens;
• The insulating element is characterized by high thermal resistance - it can withstand temperatures up to 105 degrees Celsius;
• KBT bushing connectors are manufactured in one color and have a common DIN standard. This is done in order to eliminate difficulties during the installation process. In addition, the color is selected taking into account the marking DIN 462228, part 4.
• The conductor is crimped on top of the copper bushing;
• The NShVI cuff has a conical shape, which eliminates problems in the process of inserting a stranded wire into the inner part of the sleeve.

Product characteristics are presented below.

Why do you need an ending?

The danger lies in excessive overheating of the connection point. Without termination, the contact will be unreliable. Such a compound will begin to heat up and become covered with a layer of oxide. The resulting oxide will further increase the contact resistance. At the connection point, an increasing amount of heat will begin to be released. The process is like growing a snowball. But the result is the same - the connection will burn out.

And it’s good if the conductor simply falls off from its proper place and that’s all over. In some cases, the cable insulation may ignite due to overheating and cause a fire. And a fallen wire can touch the grounded body of the installation or electrical panel and cause a short circuit.

Main types of lugs for crimping

There are different types of lugs for use with wires of different modifications and cross-sections. Let's look at the most popular of them:

copper tips. Used to work with copper wires. They are made from seamless tubes. On one side there is a clamping part, and on the other side there is a tubular hole for the wire. Tips of this type are used for installing electrical appliances, connecting input distribution devices and for grounding;

Copper products

aluminum. For aluminum cores, tips made of the same material are used. At one end there is a contact blade with a hole, and at the other there is a tubular hole. The cores are connected to the tip by crimping with a special tool. The product is first lubricated with quartz vaseline lubricant, which protects against oxidation;

aluminum-copper. Switchgears can use copper busbars, for which aluminum-copper lugs are suitable. In them, the landing tube is made of aluminum, and the contact blade is made of copper. Products are made using the friction diffusion method or gas-dynamic spraying method. In this case, copper sputtering covers the product on top, which allows for stable contact;

bolted These lugs are secured using a clamping bolt. In this case, crimping is not necessary, since the bolt is part of the tip. Tightening is done with a wrench.

Basic rules for crimping

To perform high-quality crimping of wires with sleeves or lugs, you must follow the following rules:

• choose the right tip;
• properly and thoroughly strip the core;
• use specialized tools for work;
• select a suitable matrix;
• Follow the crimping sequence.

It is important to correctly set the hole diameter on the tool so as not to damage the connected elements.

In the table you can see some tips for crimping

You can watch the features of crimping in this video:

Installation methods

Cable lugs are attached to wires in different ways. Most often, their installation is carried out by welding, soldering or crimping. Special installation bolts can also be used for this purpose.

The pressing method requires a special tool (press), which can be operated manually, mechanically or hydraulically, or using a pump. For installation of household contacts, a manual mechanism—a stripper—or crimping pliers is suitable. It is easy to manually attach the tip to a copper or aluminum cable used to create grounding or wiring when connecting household electrical appliances.

Crimping a power cable requires a more powerful press and can be done in three ways. The metal core is inserted into the tubular tail of the tip and compressed into the die using a punch. In certain places where the teeth of the punch are pressed in the most, the best connection between the tip and the core is ensured.

With continuous compression, the same pressure is guaranteed along the entire length of the tip. In this case, complete electrical contact between the elements is achieved. To improve the connection of the tubular part with the cable, combined crimping is used, which, under continuous crimping conditions, provides additional compression at the point where the teeth enter.

Equipment for crimping tips can vary in type of adjustable wrench or hole diameter. The standard size is considered to be a hole ranging from 0.25 to 1 millimeter.

Creating a reliable contact using a soldering iron occurs in several stages. First, the cable, stripped to a shine and treated with neutral solder, is inserted into the connector all the way, then solder is poured through a special hole.

During the installation of cable lugs using set screws, the size of their heads is controlled automatically inside the crimping apparatus. The bolts are screwed into the connector hole all the way, then their head is torn off. This ensures reliable and irreversible contact.

The advantage of bolted connections is that they can also be made without the use of a press using a wrench. The size of the connected cable may be several times smaller than the maximum diameter provided by the manufacturer for the tubular part of the tip.

A little about transition resistance

In the world of electrical engineering, sometimes there are not very pleasant pictures - melted plastic on the switchboard; burnt or even charred conductors; wires sticking out in all directions of a multi-core cable or wire, which careless electricians place under a common bolt without using washers. All this suggests that the “specialists” neglected the termination procedure. After all, it is not enough to simply connect the cable to the device and connect it. This must be done in such a way as to minimize the amount of contact resistance and ensure a reliable contact connection.

What is contact resistance? In essence, it is like a resistor through which a certain amount of heat is released. This value is directly proportional to the current load of the conductor. The more heat generated, the more likely melting and fire are.

Therefore, the first priority for any electrical connection is to achieve a minimum value of transient resistance. However, this is not always possible for several reasons:

• small contact area;
• metals are covered with an oxide film;
• The crimp is not strong enough.

To minimize these reasons and accordingly reduce the contact resistance, it was invented to crimp the wires using lugs.

Design and types

The product consists of 2 elements:

• CURRENT CONDUCTING TUBE. In the process of its manufacture, electrolytic copper with mandatory tinning is used.
• POLYAMIDE FLANGE, INSULATED.

In simple terms, NSHVI cable lugs are copper tubes processed by galvanization and having one flared end (for inserting a stranded conductor). The second part of the product is a polyamide cuff, which provides reliable insulation and protection against voltage.

During the manufacturing process, a special type of copper is used, which ensures a reliable connection at the contact point and avoids damage to the conductor due to screw pressure. Today you can buy an NShVI tip with a cross section of 0.25-150 mm.

According to the design of the device, there are two types:

• Single.
• Double.

The first are intended for crimping one, and the second - two stranded wires at the same time. This is their main advantage. For example, when power is supplied to the AB (circuit breaker), it is possible to eliminate an additional wire jumper from the circuit. Based on the characteristics of each type, the size of the plastic flange varies.

In addition to the type of product already discussed, there are other types:

• TML TIPS - used for crimping copper and aluminum cables by crimping for subsequent connection to a bus or equipment. There are two types of TMLs - copper and aluminum. The former are used to connect cables made of copper, and the latter - made of aluminum. Tinned TML products are used simultaneously with copper and aluminum conductors for crimping and soldering.
• TIPS NVI AND NKI - suitable for terminating flexible (stranded) copper conductors. Used when assembling electrical circuits when screw fixation is used during the connection process. Ring lugs are typically used to provide permanent connections to electrical equipment. If in the future it is necessary to disassemble the circuit and re-cross the clamps, it is worth using NShVI. Thanks to its use, there is no need to dismantle the fastening - just loosen the clamping screw.

Execution options

According to their design features, tips can be single or double. The product is a copper tube processed by galvanic method. The tip may be flared at one end. This is necessary when working with stranded wire. The insulating component is a polyamide cuff.

Aluminum products

For your information! Useful elements protect homes from fire or heating of wiring due to poor fixation of wires.

Labeling: how is it useful?

Each tip is marked with an alphanumeric code - this is a marking. It can provide basic information for selecting the correct electrical installation component. It looks like this: TML 70-10-11.5. Each symbol carries information:

• T is a pipe, a semi-finished product for making a part;
• M – material, in this case copper;
• L – processing method, means that this element is made of tinned copper;
• 70 (first digit of the code) – section in mm;
• 10 (second digit of the marking) – diameter of the mounting hole for the bolt in mm;
• 11.5 (third digit) is the internal diameter of the shank in mm into which the wire is inserted.

Common markings and their interpretation are presented in the table.

The production of parts for electrical installation is regulated by GOST, but you can find products manufactured according to specifications or European standards; their markings will have a different appearance.

Marking

The industry produces a large number of all kinds of tips, which differ in design and materials.

Color coding option

There is a special marking system that allows you to distinguish the material and use it for its intended purpose. Here are some notations in this system:

• A – the sleeve is made of aluminum;
• L – brass is used;
• M – the base of the product is copper;
• T – the element is made of tubular metal;
• U – the connector is made in the shape of an angle.

There is also a designation in the form of the letter O, which indicates the presence of an inspection window through which you can make sure that the cables are correctly located in the sleeve inside.

Sleeve end markings

If the marking is TML (O), then it means tinned tubular copper with an inspection window. NSHVI - means a pin sleeve tip, and NKI - a ring one. In this case, the numbers indicate the cross-sectional area or diameters of the rod. To make it easier to find suitable connectors, for example, NShVI or KVT, you can use a special catalog or tables.

Common types of tips

In electrical installation practice there are dozens of types of connectors. This diversity is due to the wide list of wires used. Each type of cable has its own tip. It must match the material and cross-section of the current-carrying conductor.

Important. To terminate aluminum wires, adapters made of the same material should be used. This rule also applies to copper conductors. Direct connection of copper with aluminum is unacceptable.

Copper tips TM

Manufactured from seamless tube. This is indicated by the letter - T. The tube is made of copper - M. The full marking looks like this: TM 35-10-9. Here:

• T - tube;
• M - copper;
• 35 - cross-section of the cable for which this tip is intended, sq. mm;
• 10 — diameter (grade) of the fastening screw, mm;
• 9 is the diameter of the shank, that is, the hole into which the cable core is inserted.

If dimensions allow, the tip model is indicated on its surface. If it is too small, then the nominal cross-section of the connected cable is stamped on the product body. For example, the number “4” next to the mounting hole means that a conductor with a cross-section of 4 square meters should be inserted into the tip. mm.

Copper with tinning TML

Copper is a good conductor of electric current. However, a greenish coating is often found on TM tips. This is a layer of copper oxide, which is no good for reliable current transmission. To combat this phenomenon, the tips are additionally coated with a protective anti-corrosion tin coating. The resulting product here means tinning. Otherwise, the TM and TML markings are similar.

Tinned wire lugs

The protective layer prevents oxidation of the copper tip. Therefore, it can be used in more humid areas. Due to increased reliability, TML is suitable for connecting critical electricity consumers.

Tinned copper with control window TML (o)

Before installing the current-carrying conductor into the tip, the protective insulation layer is removed from it. There are a couple of subtleties:

1. The stripped core should completely enter the tube and rest against its end. There should be no void left in the tip cavity.
2. The cable must be stripped to a minimum length. So that there is no exposed section of wire without insulation left at the tip shank.

To control the above conditions, TML (o) connectors are used. The small letter “o” at the end of the marking means that there is an inspection hole on the surface. The window allows you to visually assess whether the cable has reached the proper depth.

Aluminum TA tips

This type of connector is made of aluminum tube. This is indicated by the letter "A". TA lugs are designed for branching aluminum wires from busbars of similar material.

TAs have a long service life. Aluminum has increased resistance to moisture from the air and is practically not destroyed by it. This material is several times cheaper than copper, so sometimes people choose aluminum fasteners.

Aluminum cable lugs

TA are produced for wires with a cross-section of 16 square meters. mm and above. They also require the use of quartz-vaseline lubricant for additional surface protection.

Copper-aluminum TAM

The structure of these connectors uses two metals: copper and aluminum. They are connected to each other through frictional diffusion. One metal penetrates another at the molecular level. Therefore, high contact resistance is avoided.

TAMs have a unique property. They are used to connect aluminum cores to copper busbars of switchgears. Otherwise, they are no different from other tubular modifications. A screw is used to connect them, and compression is done using a press.

Other types of tips

The types of fasteners listed are not sufficient to perform all electrical tasks. Therefore, in practice, other types of tips are often found:

1. PM - cable lugs for soldering. They are made from sheet copper grade M1. In addition to soldering, this type of tip is also suitable for crimping. Available for cables with cross-sections from 2.5 to 240 sq. mm.
2. NShP - pin flat. Used to connect copper cables. Made of copper. The main purpose is to connect wiring to circuit breakers. Inside it has ring notches to improve contact with the current-carrying conductor.
3. NShV - pin bushing. Common in modern equipment. Made of electrical copper with a protective coating. Used to connect multi-core copper wires with a cross-section from 0.25 to 150 square meters. mm.
4. NSHVI - insulated pin bushing. Equipped with an additional insulating plastic skirt.

CS-CS.Net: Laboratory of the Electroshaman

Tips NSHVI, TML and tools for crimping them

...one reader once wrote to me: why don’t you make a post about NShVI tips and how to handle them. At first I thought that he had become insolent, because NShVI tips are the simplest nonsense, which is not even worth writing about. And then I remembered that even with these simple tips I had developed my own technologies and techniques that I can share. So consider this post another master class.

However, please forgive me for the quality of the photos: the idea for the post came to me this evening, and I took some of the photos in the light of a table lamp, so their white balance and focusing are off. But since I don’t teach specifics and don’t repeat stupid things, but general principles and deep ideas, I can convey information to you with the help of these photos.

Please go to cat. The entire post is divided into several parts to make it easier to read. I also discovered the band Uriah Heep, to which the post at 02:32 in the morning somehow went well. Hm. Sometimes I wonder if I should add a note indicating which music or film was used to write which post. So, the post was written to the looped “Uriah Heep - Come Back to Me (Acoustically Driven 2001)”, performed acoustically.

General. Why is this necessary?

The time when shields were assembled with “hard” wire is gradually becoming a thing of the past. Together with those who are still screaming with foam at the mouth that somewhere in the PUE it is written that boards should be mounted only with single-core (for example, electricians from housing offices and management companies periodically try to prove this to me). This is crap and nonsense, because some shields simply cannot be assembled with a single core due to its rigidity and other problems.

Any installer who starts collecting panels in large quantities and loves his work, his hands, his tools, gradually reaches flexible (stranded) wire and after that never returns to monocore. And in my posts I teach you to love yourself and your work. Well, your instrument and the world around you. In the end, sooner or later you come to the understanding that you are not working for money, but to improve the world and help other people. In this case, money somehow appears by itself.

So. It is more convenient to work with a soft wire, because it is easier to bend, it can be laid beautifully in bundles, and shorter connections can be made on larger sections: it will be easy to lead the wire where it is needed, because its flexibility is much higher than that of a monocore.

But there is the most important problem. Not all things are designed for stranded (soft) core. For example, according to the rules, fixed wiring must be done with cables. And the cables are made monocore for a bunch of different reasons, and all sorts of sockets and switches are designed for monocore. For example, spring contacts of switches, WAGO terminals, spring zero bars and other things. There are also a number of things in which the wire is clamped with the end of a screw. These are Chinese terminals, and some connectors and clamps of all kinds of equipment.

If you clamp a stranded core directly into such contacts, the screw will cut the wires of the core, and little of the useful cross-section will remain. This is bad. Some of the Kulibins are trying to tin the vein the old fashioned way. This is even worse because the solder flows under pressure and melts at a low temperature. Did you know, for example, that during some short circuits, copper busbars and all their fasteners are designed to heat up to +300 degrees? What will happen to the soldered or tinned wire in such cases? The solder will melt, the contact pressure will weaken, the contact will weaken even more and begin to heat up even more. Until it burns off.

Here I probably need to say why I think that all soldering and twisting should be prohibited in power engineering. The fact is that some wire connections are low-tech. The quality of execution depends on the specific person who makes them. Well, for example, one will make a twist 3 cm long and solder, and the other will make a twist 5 cm long. Who is right? How to evaluate this? Testing in the laboratory. But what next? A person will get tired, think, miss a couple of turns of his twist... and the technology is broken.

Other connections (crimping, spring terminals), if you use them not thoughtlessly, but considering which is better, are technologically advanced: contact is made either due to the technology of the terminal itself, or due to a certain tool, which is standard for everyone and does the same thing in different hands.

So, in order to turn a soft wire into a “hard” one, special tips are made. We use tips of the NShVI and NShVI(2) types in shield assemblies. This is a thin metal tube with an insulating skirt. Don't confuse them with cartridge cases! The purpose of the NSHVI tip is only to hold the wire wires together. And the job of the sleeve is to create hellish clamping force and electrical contact. Therefore, the sleeve is much thicker, and those Kulibins who use NShVI as an analogue of sleeves are very wrong with the word “completely”.

In no case should a monocore (rigid, solid) wire be crimped with NShVI lugs. This, by the way, is what happens when assembling the shield. Inside the shield we assemble everything with PuGV wire and NShVI lugs, and “outside” the external lines are connected with monocore.

But what if we need to tighten the wire under a bolt or screw? And for this they came up with TML tips. You can press a wire (solid or flexible, multi-wire) into this tip, like into a sleeve, and screw the tip itself where necessary. This solution is used to supply power to buses, to connect PE or powerful power lines and cables.

And since the NSHVI is a thin-walled tube, in principle, in some cases we can stuff several wires of a smaller cross-section, or one large and one small wire, into this tip. This is something that does not work with monocore when assembling shields. For example, we need to power a frail LED light bulb from a 16 square input (post about such light bulbs from ABB). What to do? In the case of a monocore, we would have to make some kind of “loop” and seamlessly insert the monocore into this light bulb. The light bulb would have burst.

And in the case of NShVI, we will slip a thin 1.5 square wire under the 16 square NShVI and connect it to the light bulb. At the same time I give a remark. In this case, the LED light bulb does not need to be protected. There's not much to breathe there. And if it were a voltmeter or other device, then it would be good to plug a fuse into this 1.5 square piece of wire (I use terminals with .SF fuses). In large shields I began to do this.

Tool. Hand size. Why haven't I been able to get hooked on Knipex?

Here they also asked me to tell you about my instrument. OK, I’ll tell you why I can’t get rid of the KVT and why I chose just such a tool that was not intended by the manufacturer for the tasks that I assigned to it.

What types of tools are there for crimping tips? There are special pliers with fixed dies (for KVT these are STK-type pliers). The matrices of these pliers sometimes go wrong if the wire has a low cross-section. Well, you also have to keep a bunch of pliers: for single, for double tips. And another pliers for large sections.

Pliers with a set of dies. This is what I didn’t like right away, because I often need to change the crimping section. Take the same example about the input of 16 squares and 1.5 for a light bulb. I press my NShVI by 16 squares, and then I need to compress my NShVI by 1.5 squares. What, rearrange the matrix? This is a labor-intensive process, you can’t do much. Therefore, I immediately brushed aside such ticks.

To assemble all my shields I now need the following tool:

• KVT WS-04A (on the KVT website). This is my most basic and very favorite tool. I recommend it to those who are starting to get into panelboards or repairs. This tool, due to the undocumented feature of crimping NSHVI, covers most of the tasks of assembling panels. The tool can bite and strip cables up to approximately 10..16 squares. It also has grooves into which NShVI tips fit up to 1x10 (with difficulty up to 1x16) or 2x6 (with difficulty up to 2x10) squares. I’ll tell you more about this feature when I get to the NSHVI itself. Important! There is the same tool WS-04 B (on the KVT website) with dies for crimping NShVI. But I don’t like it: the matrices there are made without taking into account counterfeit wires and wires of undersized cross-sections and they press NShVI only up to 6 squares. And with matrix grooves from WS-04 A you can press more sections. Using WS-04 A I press the tips into 6 squares. I also chose WS-04A because it’s not good to clutter up the workplace with a bunch of tools. It’s good when part of the tool is universal (of course, if this versatility does not interfere with the work and quality of the tool).
• KVT PKVk-10 (on the KVT website). This tool is positioned as a universal crimp for NShVI with sections from 0.5 to 10 squares. But in reality this is not entirely true. To press the NSHVI even 6 squares, you need to have a strong hand and press with all your strength. And if you adjust the pressing force downward, it will not press small NShVIs well. But this thing is cool and very compact when you need to crawl into a difficult place on the shield and press something there. I use it for crimping very small sections - up to 2.5..4 squares.
• KVT STK-03 (on the KVT website). These are tough pliers for crimping NShVI for 10, 16, 25 squares. With them I press the NSHVI into 10, 16 squares. And in the position for 16 squares you can press NShVI (2) into 10 squares. I will also tell you about this technique. Since I assemble the shields in parts - first the thick input, then the small lines - it turns out that first I work with these pliers, and then I put them aside and do not clutter up the table.
• KVT PK-16 (on the KVT website). These press pliers are suitable for crimping TML sleeves and tips up to 6..10 squares, although they are stated to be up to 16 squares. If your hands are sensitive and you love them, then you won’t force yourself trying to squeeze your hands as hard as you can. The press jaws are not very good, but they are cheap. Now there is a reinforced version of the PK-16u, which is more durable. In general, if you need to crimp TMLs once every couple of months or press the cartridges once during repairs, then the PK-16u is your choice (take the reinforced version right away).
• KVT PGRs-70 (on the KVT website). This is my new acquisition - a hydraulic press for TML and cartridges as a replacement for the PK-16. The press has replaceable dies from 4 to 70 squares, which is enough for my eyes for my new tasks (it’s easy to press TMLs for 50 square). It’s a great pleasure to press the TMLs of my common sections (6, 10, 16 squares) - your hands don’t get tired, no effort is required.

So why not Knipex or Weidmuller? Damn, because HANDS. My hands are designed in such a way that the longer my fingers are extended, the less force I can create with them. I like my hands and I don't want to be some kind of super macho. I love my sensitive fingers, so I wanted a tool that had handles that diverged at a slight angle.

I took a lot of photos for the article. Look how the WS-04 lies in my hands. The main working fingers (index, middle, ring) fit perfectly on the handle of the instrument and I can control its pressing or squeeze it with force.

Convenience of the tool handles for the hand (WS-04A)

Like this:

Convenience of the tool handles for the hand (WS-04A)

Tools like Knippex (I wanted to buy their crimp from Valentinich, but I felt it and got confused because of the handles) have handles that diverge like on STK pliers. You see, my fingers are barely enough anymore. What saves me in STK is that the handles first squeeze the jaws idle and when the jaws of the matrix reach the very tip, the squeezed handles allow me to grab the pliers more conveniently and apply force.

Inconvenient tool handles: open too wide

Also note that I'm holding them backwards. As far as I understand, the red pen should move, and the black one should lie in the corner between the thumb and forefinger. But at the same time, the matrix with grooves moves in my hands, and I have to hold the tip and wire - they move along with the matrix. And if I hold the pliers as in the photo, then the wire and tip do not move.

Well, PKVk-10 also has widely diverging handles. Don’t think that my fingers are short and my palm is not like a child’s. I just don't like forcing my fingers to do things they're not meant to do. Let the instrument suffer, not my hands.

Inconvenient tool handles: open too wide

In another position of the tool the same garbage:

Inconvenient tool handles: open too wide

Actually, that’s why pretentious brands didn’t work for me, although I tried them. But they did not pass the test for force and opening of the handles.

Tips NShVI, NShVI (2) and methods of working with them.

Well, now let’s move on to the NShVI tips themselves (here is their description on the KVT website). I have already written about why these tips are created. Two of their features should be mentioned:

• Skirt color. This color encodes the cross section of the tip. We usually adopt the KVT standard, where the tip of 1.5 squares corresponds to black; 2.5 squares - blue; 4 squares - gray; 6 squares - yellow; 10 squares - red. There is also either a branded or Chinese standard, in which six or ten can be brown, green or whatever. Typically, such tips are of poor quality and the skirts themselves crack. So don’t try to look for “10 square lugs for phase and zero.” The color should code the wire cross-section - that's all.
• Package. Most often, the tips come in packs of 100 pieces, which are packed in packages of five, that is, 500 pieces each. Not everyone sells individual tips. For example, in Moscow this is Elektromontazh or the store where Igor Valentinich used to work - ElektroMaster.
• Double tips. There is no need to try to invent something to connect two wires in one place. For this purpose there are tips NSHVI(2) . These lugs are immediately designed to connect two wires of the specified cross-section. That is, NSHVI(2) for 6 squares will accept two wires of 6 squares each.

Here are different samples of tips and the same crimping tool that I talked about above when I talked about hands and handles. The bold blue tip is 50 squares =). By the way, double NShVIs are not produced for large sections. The maximum double NSHVI seems to be 16 squares.

Tips NShVI, NShVI(2) and tools for crimping them

Let's take a look at my favorite stripper KVT WS-04A in action. I will try it on maximum sections - 10 sq. mm.

Cleaner KVT WS-04A

First, she bites the wire. Anyone who can fit into the teeth. I sometimes managed to bite NYM or VVG 3x1.5 or even 3x2.5 squares the second time. In the case of assembling shields, this means that it can cut off large cross-section wires. I bite off the six with nippers with carbide jaws, but I bite off the ten and 16 with a scraper.

Stripper KVT WS-04A: Wire cutting

Well, she also strips the wire. Standardly, it has a stripping length adjuster, which didn’t work for me and just gets in the way. So I unscrew it the hell out, and determine the stripping length by the right rivet. For the six, the wire should not reach the rivet a little, and for the ten, it should go a little over it:

Stripper KVT WS-04A: Wire stripper

Usually it is enough to squeeze a dozen tips so that the eye and hands remember the position of the wire - and then stripping proceeds on an intuitive level, without consuming the brain.

So we have stripped our wire. It is noteworthy that this cleaner cleans everything it comes across. It can even remove the insulation from a flat VVG or ShVVP in order to connect temporary structures at sites. One movement - they pulled off the top insulation, the second - they stripped two or three conductors at once. Just keep in mind that the thicker the wire or cable, the greater the load on the jaws, which are actually intended for one wire. Therefore, if you constantly clean VVG with such a cleaner, it will quickly die.

Stripper KVT WS-04A: Wire stripper

Well, what I really like is that the remainder of the insulation is held by the stripping sponge if you continue to squeeze the handles. I usually take it to a trash box (a box from OT63F3 switches is great). As a result, I don’t have anything lying around in my workspace and it’s clean.

Stripper KVT WS-04A: Remaining insulation is retained

And of course, I found a screw zero bar to screw the bare ten into. Do you see how she was crushed there? Do you see that some of the wires have simply moved to the sides and are not even pressed?

PuGV wire clamp into screw busbar

But what happens to the wire strands after such pressure and a screw:

Clamping the PuGV wire into a screw busbar - trace of deformation

We are not happy with this. By the way, this is also bad because if you move the wire, then all these wires will break one by one, the pressing force will weaken, and as a result we will get poor contact.

Look at the matrices (grooves, teeth) of the WS0-04A . It is precisely thanks to the lower teeth that the undocumented freebie and crimping of the NShVI is obtained. If you want to order a Chinese analogue of such a scraper, then order it with exactly these teeth!

Teeth for crimping tips in the KVT WS-04A stripper

Our NShVI tip can be placed in this tooth like this:

Using the KVT WS-04A stripper for crimping NShVI

And then press it with a stripper. There is a pressed place on the tip:

Using the KVT WS-04A stripper for crimping NShVI

The groove itself compresses the tip in this way - quite tightly. The tip crimped in this way is difficult to remove from the wire, I tried it.

Using the KVT WS-04A stripper for crimping NShVI

Well, if we repeat such crimps, moving the tip, then in the end we will get a picture like the one in the photo below. In fact, if you immediately twist your tip into the shield, you don’t need to pervert it so beautifully. It is enough to make two or three crimping points, and then the tip will be flattened with a contact screw.

NShVI tip, crimped with stripper KVT WS-04A

Now let's screw our tip into the shredder and tighten it properly. Here, perhaps, we should mention another ficus for those who don’t just look at photos in a row, but also read the text around them. In general, if you clamp a wire with an NShVI tip somewhere, then you can safely reduce the maximum cross-section of the terminal by one step. Let's say, if on some cross-module it is indicated that it accepts a monocore of 16 squares, then most likely the NSHVI for 16 squares will not fit there, but will only fit into 10 squares.

Twisting the PuGV wire in the NShVI lug into a screw busbar

After using the tip, the following is obtained. The pressure of the screw is now distributed over all the cores, because the tip prevents them from moving apart. And due to the thickness of the tip wall, the screw does not damage individual wires. In this case, such a screwed wire can be bent as much as you want - the individual wires are “tied into a bundle” and will not break.

Deformation of the NShVI tip by a screw tire

Let's play around with PKVk-10. As I said, I use it for small sections. It is a pleasure to press them with it. Sticked the tip in, squeezed - and got it!

Crimping of small tips using KVT PKVk-10

This crimper has a different design: the jaws have four edges and converge on all sides. The result is not a trapezoidal, but a rectangular crimp profile. Sometimes this helps to win precious microns of tip width that does not want to fit into some particularly small automation terminal.

Crimping of small tips using KVT PKVk-10

Sometimes the crimper becomes malfunctioning (from frequent use it becomes a little loose) and it jams part of the tip. It's not scary if you're not a perfectionist.

NShVI tip 1.5 sq.mm after crimping KVT PKVk-10

Well, here is a double tip NSHVI (2) for 6 squares. When I first bought them, I was terribly confused with their sections and tried to look for NShVI (2) for 12 squares. In fact, everything has been calculated for you and me. These lugs have a wider wire skirt and are specially designed for two wires. Sometimes I see shields where people use a 10 tip for 2x6 squares. This is bad. I did this myself, but as soon as I started collecting more than one shield every three months, I bought NSHVI(2). Don't waste your money, do it right!

NShVI(2) tip for two PuGV wires

Such NShVIs can also be safely used with the same WS-04A . This is why I say that if you want to do your own electrical repairs and assemble a small panel, then start with WS-04A.

Crimping of the tip NShVI(2) 6 using KVT WS-04A

The result is a digestible contraption. It should be taken into account that NShVI(2) is 6 squares slightly longer than a regular NShVI and in order for it to fit correctly into the machine or RCD, it will need to be bitten off a little (by ~2 mm).

Crimping of the tip NShVI(2) 6 using KVT WS-04A

Well, I press the big tips with STK-03 :

Pressing the tip to 25 sq. mm. using KVT STK-03

It turns out like this. The matrix is ​​cool and presses the tip very well!

Pressing the tip to 25 sq. mm. using KVT STK-03

Clamping of wires of different sections into one NShVI lug

Now let's talk about the undocumented features of installing shields with soft wire using NShVI tips. The first task is to remove the small wire from the large cross-section wire. It is implemented due to the fact that not all wires have thick insulation, and the tip skirt is made with a reserve in diameter.

Therefore, we can simply slip a small-section wire next to the larger one. Here I have a wire for 6 squares and 1.5 squares.

Trick: you can press wires of different sections into the NSHVI tip

I strip the small wire longer than the main one and move it forward so that it goes into the tip first:

Trick: you can press wires of different sections into the NSHVI tip

In this way. I need the wire insulation to fit into the skirt of the lug.

Trick: you can press wires of different sections into the NSHVI tip

After this, all I have to do is push the main wire all the way in and crimp the tip.

Trick: you can press wires of different sections into the NSHVI tip

The same thing can be done with double tips. I’ll take ten and the same one and a half rubles as an example.

Pressing in the tip NSHVI(2) 10 and small wire

We start again with one and a half rubles. We bring it inward to the beginning of the metal tip, and then push in the main wires.

Pressing in the tip NSHVI(2) 10 and small wire

I press NShVI (2) tips for 10 squares on the matrix “16” of STK-03 pliers. To prevent the pliers from snapping, I hold the ratchet lever.

Pressing the NShVI(2) 10 tip and small wire using KVT STK-03

It turns out that this is the crimping, also durable and high quality.

Pressing the NShVI(2) 10 tip and small wire using KVT STK-03

I also developed this same technique to the point where you can simply take several small-section wires (for example, 4 pieces of 1.5 squares each) and push them all together into a suitable NShVI (it is better to use a double tip NShVI (2)). This is necessary if we divide the lines in the panel into terminals and we need, for example, to take a zero from one machine or RCD to several different terminals at once (where a jumper is not suitable).

Crimping several wires of small cross-section into an NShVI tip of a larger cross-section

Then we can make something like this. In NSHVI(2), three wires of 2.5 or four wires of 1.5 fit into 4 squares.

Crimping several wires of small cross-section into an NShVI tip of a larger cross-section

Manufacturing of long NShVI (for meters)

I’ll make a separate point about long tips. They are most often needed to connect meters, because a regular NShVI tip is enough for exactly half of the terminal. If you constantly work with meters (or those that require such long NShVI), then you can clearly order them. But for example, I connect one meter every six months.

So I just press the two tips one after the other. There are two ways to do this. One is to press two NShVIs against each other and bite off the skirt of the second one. But there it is difficult for the veins to get into the tip tube - after all, it does not have a skirt on the opposite side.

Therefore, I do the opposite - I bite off the skirt at the tip (my side cutters with carbide jaws are just visible here). To do this, it is enough to bite it sharply almost to the very edge. Then it cracks and is easily removed.

Manufacturing of an extended tip NSHVI (for meters)

Well, then all we have to do is add another tip tube and press it all in.

Manufacturing of an extended tip NSHVI (for meters)

As a result, with careful execution, we get this design:

Manufacturing of an extended tip NSHVI (for meters)

That's all with NSHVI. Let's move on to more evil things. And then I'll go get some sleep

TML tips and tools for crimping them. Shells.

Well, now let's dive into the world of thicker copper. TML-type terminals accept both a monocore and a stranded core, because they are actually made from GML sleeves, which are used for crimp connections. One of the edges of the sleeve is simply flattened and a hole is stamped in it. Therefore, everything that I will describe below will be applicable to cartridge cases.

These lugs are useful when you need to screw PE onto the panel body, make a transition from a steel grounding strip to copper near the facade of the house, how to transfer the connection of the old floor panel body to the riser zero... and much more. Here's what you need to know about TML tips:

• They differ not only in cross-section, but also in the diameter of the hole for the screw/bolt. For example, you can find TMLs for 10 squares for an 8 mm or 10 mm bolt.
• The shape of their plane, which is screwed on, does not fit in all places. For example, not all tips fit into machines with a molded case (TMax and others). My TMax XT1 barely fit TMLs of 25 square meters. Therefore, for such cases, you need to either buy special tips (at KVT they are called TML DIN, I think), which have a narrow contact pad specially designed for such machines, or order special extended terminals for the machine (this is useful if no one knows who will connect the cables after the machines and it will not have special tips).

Well, it’s clear that these tips have a thick wall and you can’t press them in with any WS-04 or pliers. And this is where press pliers are needed. If you need to press TMLs once or twice or press about 100 cartridges once during a repair for repairs in your apartment, then you can take the KVT PK-16 or PK-16u (reinforced version, I haven’t bought it and won’t - because it’s hydraulic bought a press).

ATTENTION! I periodically see attempts here to wriggle out. For some reason, some people try to press the tips of NShVI with such press pliers. This is not at all correct! Such pliers develop a lot of pressure and press pointwise, and because of this they can break the thin tube of the NSHVI tip! Don't do this! Buy the same WS-04A!

TML tips and press tongs KVT PK-16

Over time, the PC-16 develops the following glitch: if you often press sections into 10 or 16 squares (which, however, they are designed for), then their jaws break out like this:

Press jaws KVT PK-16 - jaw divergence

My PC-16s served me faithfully for about four years, because I pressed or mostly TMLs into 6 squares (a 10-square PuGV fit into them with force). But as soon as I started pressing dozens of them, the jaws began to bend.

I will show you how to pressurize a TML with such pliers. We clean our ten to the length of the crimp:

Tip TML-10 and its crimping using KVT PK-16

Well, we continue to press. The effort that must be applied to the PK-16 is hellish. My hands don't like it. As I already said, choose the right tool, feel yourself, your strength and hands. It’s one thing if you press something once a month. And if every... at least a week, then take care of your hands! Love yourself!

This is how the lips warp:

Tip TML-10 and its crimping using KVT PK-16

For crimping TMLki, two points are enough. I did one in the front and one in the back. Do you see how the tip was cut off during crimping due to the skew of the jaws?

Tip TML-10 and its crimping using KVT PK-16

It looks the same from the back. This is not fatal and will work, so PK-16 (I say it again) have the right to life. By the way, if you selected everything correctly, then the conventional matrix number will be printed on the tip. This means that the pressure for crimping was sufficient.

Tip TML-10 and its crimping using KVT PK-16

Well, what should you do when you need to press something into sections larger than 10 or 16 squares? For example, I needed to press TMLs for 25 and 50 squares:

TML tips of large sections (16, 25, 50)

I'm sorry, what? Buy a hydraulic press! When I was afraid to buy it, I thought it would cost about 20-40 thousand. But it turned out that it costs 6-8 rubles, depending on the model! This means it is available quickly if you start needing to press a lot. Let's say, you can even buy it for some object with an advance payment. And this is good!

Hydraulic press KVT PGRs-70 for crimping TML and GML

I bought a PGRs-70 press. He presses everything he can (TML, GML), from 4 to 70 squares. The kit includes the entire set of matrices for these sections. Such a press is already a serious contraption that makes the work much easier.

Hydraulic press KVT PGRs-70 for crimping TML and GML

The press develops pressure up to 5 tons. So he will crush his fingers in a moment. Also in press models with the letter “c” (PGR s ) an automatic pressure release is provided when the crimping is completed. I note that this pressure release rarely works for me. I noticed that this has to do with the speed of pressure applied to the press handle. If you press sharply and strongly, then the automatic pressure release works. But if it’s gentle and smooth, like me, then it doesn’t work.

Hydraulic press KVT PGRs-70 for crimping TML and GML

These are the matrices that come with the press:

Dies for crimping tips

The matrices snap into the holes at the bottom and top of the press:

Installation of dies in the press

This press has a small bug. Sometimes the matrices can be slightly skewed. But unlike PK-16, here this will not affect the quality of crimping, because the matrices are wide and they should (as it seems to me, according to the designers’ intention) automatically align.

Distortion of matrices in the press

To pressurize something with it, you need to close the tap. The tap is a small twist on the press cylinder. It closes by hand very easily. If it is closed, then the press pumps up pressure and does not release it. And if you open the tap, the pressure is released, and the press cylinder smoothly moves down.

I press the tips like this. First, I adjust the dies closer to the crimping site, so as not to do three things at once (hold the press, the tip and pump the lever):

Crimping of a TML tip using KVT PGRs-70

After this, I move the jaws with light pressure to grab the tip with them:

Crimping of a TML tip using KVT PGRs-70

Well, then I press it all the way.

Crimping of a TML tip using KVT PGRs-70

After that, I step back and repeat the crimping process just once for beauty.

Crimping of a TML tip using KVT PGRs-70

Let's have some fun?

TML tips of large sections and dies for crimping

This is what it looks like (25 and 50 squares)::

Pressed TML tips of large sections

I thought that it would be difficult to press on large sections. No matter how it is! As I pressed lightly on the handles, I pressed. The press doesn’t care what you have clamped there: 6 squares or 50. I liked it so much that now I press everything only with this press and on the PC-16 I didn’t give a damn. Well, then you just need to put heat-shrink on the tips and you’ll get something like this (machines without covers):

An example of connecting a TMax XT1 machine using TML lugs

Actually, I bought this press to crimp these wires.

Working knife.

Well, as a bonus, I want to tell you about my favorite knife, which I once found in Leroy (now they are not sold there) and at Rozhdestvenka on Mitki. This knife fits perfectly in the hand, doesn’t slip anywhere, and I use it everywhere - to trim, trim, cut.

Working knife for all tasks with replaceable blades and locking mechanism

This knife has a magazine inside with replaceable blades (you can charge 3-4 pieces). And these blades can be quickly changed automatically.

Working knife for all tasks with replaceable blades and locking mechanism

To change the blade, you need to move it all the way forward. Then the piece of iron that secures the blade will rise and release the blade. And then we move the handle all the way back, and it picks up a new blade from the magazine.

Pushing out the knife blade to replace it

Well, there is also a screw to secure this blade.

Fixing the knife blade

I won’t part with this knife either, because it covers all my tasks. When the blade is twisted, it can cut plastic without any problems! I finished this post at 04:31. Go to sleep!