Installation of sis. Methods of connecting wires. Purpose and design

For reliable electrical contact of wires connected by twisting, it is necessary that the surfaces of the conductors are in close contact, pressed against each other with a certain force.

Since this twisting force is provided by the tension and elasticity forces of the twisted conductors, over time due to thermal expansion and contraction, as well as due to metal fatigue and deformation in the metal structure this type connections lose their strength and reliability.

The surfaces in periodically formed gaps are covered with an oxide film and corrosive compounds, which impairs the conductivity of the connection, so twisting in a “pure” form is not allowed by the PUE.

Twist Clamps

In the above rule, attention should be paid to clamps, which include connecting insulating clamps, abbreviated as PPE caps, due to their appearance.

This cap is screwed onto the twist, thus strengthening it.

There is a lot of controversy due to the understatement of the PUE regarding PPE, but here you can appeal to GOST 50043.1-92, the requirements of which this electrical product meets. Also, some argue that this type of connection is not reliable, but, as practice shows, problems that occur in electrical wiring when using PPE, in most cases have the following reasons:

• Incompetence and amateurishness of the electricians themselves who carry out electrical installations;
• Using a low-quality fake to make a connection;
• Incorrect calculation of electrical wiring and its protection.

If you follow the instructions, selecting high-quality caps of appropriate sizes, correctly screwing them onto the twisted wires, with properly calculated cross section, That this connection, if the electrical wiring is protected by automatic devices, it will serve for as long as possible without requiring maintenance.

Design of PPE caps and their markings

The connecting insulating clamp consists of two structural parts - a cap made of non-flammable, thermally resistant plastic and a connecting spiral cone-shaped spring hidden inside the product.

The spring is made of steel with an anodized electrochemical protective coating.

spring contact in PPE

These electrical products are marked as follows:

after the abbreviation PPE, a modifier follows through a dash, which indicates the type of body, which has the shape of a cone without protrusions (1),

and with projections (2) designed for better grip of the clamp with your fingers.

After the identifier, the total cross-section of the wires connected in the clamp is indicated. PPE caps, depending on the standard size of a particular product, have the minimum and maximum possible total sections, which are in the ranges indicated in the tables.

The wires themselves, which can be connected using the entire range of PPE, have a cross-section of 0.5 - 10mm². As a rule, each standard size of the product has its own body color according to the marking, for ease of identification.

Connecting wires using PPE

According to the description from the manufacturers, the PPE cap is manually screwed clockwise with force onto the wires connected together, stripped of insulation (10-12mm), to securely fix the bundle.

There is a lot of disagreement about the method of pre-installing wires into the PPE spring. The stumbling block was the phrase “connected together.” The physical processes that occur when twisting PPE also cause a lot of controversy.

Some experts argue that it is necessary to screw the cap onto a pre-twisted clockwise twist, arguing that the conductors should be connected together in this simplest way.

But opponents argue that in this case the spring will not twist onto the existing spiral, the turns of which will direct the cap into reverse side. In their opinion, the phrase “connected together” means straight conductors placed next to each other, and the very semblance of twisting occurs during the process of screwing on the clamp.

Creating a Reliable Connection

An argument in support of the first opinion is the fact that the length of the contacting metal surfaces in a spiral twist of a certain length is greater than in straight conductors exposed to the same distance.

Considering this, as well as the fact that there are many complaints about PPE caps, many electricians have found a way out of the situation by making the twists longer than they can be insulated with a clamp, thereby ensuring reliable mechanical and electrical contact of the conductors.

A heat-shrinkable tube is placed on this twist, which also compresses the wires, leaving the part of them exposed that is intended for twisting the PPE. Some electricians, not having a heat pipe on hand, use electrical tape.

twisted wires with insulation wrap PPE over a previously exposed conductor

In any case, you need to remember that the main electrical contact must be between conductor surfaces, and not through the cap spring, otherwise it will overheat, it will release, that is, it will cease to be elastic.

Poor contact may be between oxidized wires, while when the spring is twisted, it will erase the oxide layer, as a result of which the main current will flow through it.

Unfortunately, there is no single international standard for marking PPE caps, therefore, when choosing this product in a store, you should study the user manual from the manufacturer, which should indicate the dimensions of the product.

Characteristics of PPE by color

If there is such an opportunity, when purchasing a batch of caps for a large volume of installation, you should test this product by screwing the clamp onto the wires to be used.

The PPE must fit so tightly on the twist that it cannot be torn off by a direct tug when grasping it with your fingers. At the same time, this connection, by definition, is removable, that is, when some unscrewing force is applied, the clamp should be removed intact and suitable for further use.

If the product does not pass any of the simple tests described above, then you should refuse to purchase this product.

• Designed for connection and fixation in twisting copper wires
• Each size has a different body color for easy identification
• Contact part: galvanized steel spring
• Housing material: polypropylene, halogen-free
• Insulation temperature resistance: 105 °C
• The housing is made of durable thermoplastic and is resistant to aggressive environmental influences.
• Conical spring ensures reliable grip and retention of twisted wires throughout the entire service life
• The housing completely insulates twisted wires
• Guaranteed quality and reliability of electrical connections
• Does not require the use of special tools. The clamp is screwed onto the previously stripped and twisted ends of the wires. Twisting of wires and subsequent screwing is done clockwise until it stops
• Reusable
• Fast, easy and safe installation

➔Operational characteristics (years)

• Guaranteed shelf life: 15
• Warranty period: 15
• Service life: 40

Additional information

Questions and answers

• • No. Installation with twisted PPE involves connecting only copper wires. Connection of copper and aluminum wires in one twist is also prohibited. To be fair, it should be noted that two well-known global manufacturers each have one size in their line, specifically designed for mounting aluminum wires. However, the design of such clamps is fundamentally different and, among other things, involves filling the body with anti-oxidant paste. On Russian market PPE is presented only for the installation of copper wires.
• • The number of wires cannot exceed the maximum possible total cross-section specified in the characteristics for each standard size of PPE. In practice, the total cross-section of the connected wires is, as a rule, less than the maximum possible total cross-section. In general, if installation occurs without preliminary twisting of the wires using pliers, and twisting occurs directly during rotation and tightening of the PPE, then the optimal number of copper wires to be connected is 2–3. The maximum is 4. It all depends on the cross-section of the wires connected by twisting. The larger the cross-section of the wires, the more labor-intensive the installation is and the fewer wires can be connected in a twist.
• • For most sizes of PPE there is no such need. First of all, this applies to the entire range of PPE-K (KVT), which have a powerful lever in the form of special ledges (“wings”) that facilitate tightening and large sizes of PPE (N3, 4, 5). For installation without preliminary twisting, it is necessary to strip the wires and place their ends close to each other, so that they form acute angle"pyramids". After this, you should put the PPE cap on them so that the ends of the strands go inside the spring cone and, slowly rotating, screw it clockwise until it stops. In this case, the wires will twist themselves due to the force of the clamp applied to the housing during rotation. Pre-twisting wires using pliers for solid wires is a violation the right technology. In addition to the fact that the jaws of the pliers disfigure the vein, a twist made using pliers will never have the shape of a regular, tightly curled and uniform “braid”. Next, you will probably need to trim the ends of the reins. And in general, if the twisting has already been done “by hand”, why do we need PPE? You can wrap the connection with electrical tape and consider the installation process complete.
• • Often, installation of connecting insulating clamps requires certain physical training. The greater the cross-section of the mounted wires, the greater the force required when tightening PPE. If when working with wires with a cross-section of 1 or 1.5 mm², the installation progresses quickly, then when installing a power socket group with single-core wires with a cross-section of only 2.5 mm², twisting 3 wires will seem much more labor-intensive. And if wiring needs to be done in a dozen junction boxes at once, this can become a real test. And here SIZ-K comes to the rescue with its excellent ergonomics and increased leverage. There is no need to pre-twist the wires with pliers and installation time is reduced. Thanks to the special square profile of the clamping spring and the increased torque of the SIZ-K, the quality and reliability of such a connection is beyond doubt. Indeed, often further tightening of PPE is impossible not because there is not enough strength, but because the clamp body slips in the hand! In addition, PPE-K has a wider range than budget PPE. This means that just one standard size of PPE-K covers several ranges of budget PPE and can replace them. In general, take the yellow and red SIZ and SIZ-K once in your hands (their min/max ranges are almost identical) and try to connect 3x2.5 single-core copper wires. All questions will disappear automatically, and the price difference will seem unworthy of attention!
• • Can. Installation flexible wires is somewhat different from installing single-core wires and requires certain skills. When connecting flexible thin-wire cores, they should first be twisted “by hand” to give the connection a cone shape. Twisting must be done in the same direction in which the PPE will be screwed on - clockwise. If individual wires or wires protrude beyond the pyramidal contour of the twist, you can trim the tip of the twist using wire cutters or cable scissors. After this, the connection can be inserted inside the PPE body and begin twisting clockwise.
• • If the wire connection is stationary and vibration is not expected, there is no particular need for such a winding. A properly tightened twist will hold the connection even without electrical tape. If the stripping length was incorrectly calculated and the exposed part of the wires comes out from under the cap, then it makes sense to use electrical tape. In general, wrapping with electrical tape is more of an additional insurance for fixing the twist and makes the connection splash- and moisture-proof.
• • Unfortunately, there is still no single generally accepted Russian standard for PPE. It also did not exist during the Soviet Union, despite the fact that even then attempts were made to produce caps with a built-in spring according to their own specifications. The current situation in the Russian electrical market in relation to connecting insulating clamps (PPE) can be described in one word: “chaos”. The only progress that has been achieved is integration international system differences in sizes based on body colors (as opposed to clips of the same color in the early post-Soviet era). Now there are different manufacturers and importers on the market with a standard range of colors: grey, blue, orange, yellow, red. However, this is where the similarities end. Because the dimensions, installation dimensions, and quality are completely different for everyone. Those. purchasing PPE orange color with another supplier, the buyer cannot be sure that he will be able to connect wires that he had previously successfully installed with a similar orange clip. Connecting insulating clamps (PPE) trademark"KVT" are produced according to factory specifications and are distinguished by dimensional stability, high quality performance and manufacturer's warranty.
• • Both standard PPE and PPE-K produced by KVT are made of materials that suppress combustion and can be used when installing wiring indoors.
• • Connecting insulating clamps (PIC) are intended for indoor installation (in distribution boxes And electrical panels). The minimum degree of protection IP20 does not allow the use of PPE for open outdoor installation.
• • Perhaps the main reason for the popularity of connecting insulating clamps (PIC) is that they replicate the traditional technology of twisting copper wires that has existed for a century and make installation faster and more civilized. The main purpose of PPE is to simplify as much as possible the process of connecting two or more wires. If we talk about the advantages, then it makes sense to compare the installation of PPE with conventional twisting or crimping of wires. There are several advantages of installation using PPE: – Reduced installation time. In the time spent twisting, soldering and then wrapping wires with electrical tape or crimping one connection with a special tool, an installer can install up to ten connections using PPE. – Connection isolation. After twisting, soldering or crimping the wires, the resulting connections must be insulated somehow. Traditionally this was done using duct tape. When installing PPE, a durable and reliable insulating body is already present in the design. Thus, there is no need for additional operations. – Safety and health. When installing using PPE, unlike soldering, you do not have to worry about lead fumes and possible injuries from working with a soldering iron. – No need for special tools. Instead of a set of additional tools and accessories, you can limit yourself to just a good stripper for stripping insulation and PPE. - The price of the issue. Minimalism in the configuration of the installation kit cannot but have a positive effect on the price.
• • Properly selected and installed PPE, when used in normal mode, will last as long as the cable is used. In this case, the service life depends on the following main factors: – The quality of the PPE itself. If you want the connection to have proper mechanical strength, and when dismantling the spring does not fall out of the body along with the twist, choose your supplier carefully. – Correctly selected PPE is half the success. When choosing the size and type (with or without wings), pay attention to what sections it is designed for and take it “with a reserve”. You should not reinvent the wheel and try to insert large cross-section wires into a housing designed for small cross-sections. The result will be nothing but an unreliable connection or damaged personal protective equipment. – Competent installation and dismantling. If the installation is carried out according to the “rules”: without forming a preliminary twist with pliers and with a slow rotation of the body clockwise until it stops, and dismantling is done counterclockwise, then the PPE will respond to you with the same care and will last a long time. When installing flexible stranded wires, you should also calculate the forces in such a way as not to overdo it and not “bend the thread.”
• • Properly selected and installed PPE, when used in normal mode, will last as long as the cable is used. However, the service life depends on the following main factors: – Purchase connecting insulating clamps only from a trusted supplier. – Make sure that you are only going to connect copper wires. – Determine how many wires you are going to connect, and what the total cross-section of the wire bundle will be. – Depending on the total cross-section of the wires being mounted, select the desired type of connectors: SIZ or SIZ-K. In this case, choose a size “with a margin”.

During assembly electrical diagrams wires need to be connected to each other. An electrical contact is created at the connection point, which has a certain electrical resistance.

The task of any installer comes down to ensuring a strong connection of the wiring with minimal transient resistance and reliable electrical insulation.

For these purposes the following are used:

• twists;
• twists with welding;
• rations;
• screw connections;
• assemblies on terminal blocks and screw blocks;
• self-clamping express terminals from WAGO or REXANT;
• insulating caps for twisting.

In this article we will talk about how to connect wires using caps.

Typically, two main methods are used to properly connect two wires: twisting followed by soldering and regular twisting (without soldering).

But it is worth noting that despite the advantages traditional methods they are also endowed with some disadvantages: soldering, being a high-quality connection, during disassembly requires complete removal (“biting off” the soldered part of the wires), which is not always possible due to the supply of wires, twisting increases the chance of oxidation and does not guarantee a reliable connection.

Today there is another solution to such problems - these are connecting ones.

PPE caps for twisting wires

PPE caps- these are connecting insulating clips that are made of non-flammable plastic. Inside these caps there is a conical metal spring.

When they are twisted with a little effort, the spring expands and compresses the wires, and the plastic sheath provides reliable electrical insulation, as well as mechanical and fire protection.

PPE caps are conical parts with metal bushings with threads inside. By inserting two wires into this part and turning it a couple of times, the wires will be securely connected. If necessary, this connection can be disassembled without the slightest problem.

Connecting caps are produced different sizes for wires from 0.5 to 1.6 millimeters in diameter.

As a rule, the color of the cap corresponds to the specific diameter and size of the connected wires for which it is intended. Thanks to the use of connecting caps, a reliable connection of wires is achieved without the use of additional tools.

PPE caps characterized by the cross-section of the total twisted wires. This cross-section is expressed by the PPE number from 1 to 5. This figure characterizes the cross-section and number of twisted cores.

Brand	Number and cross-section of cores, mm²	Color
SIZ-1	2×1.5	grey
SIZ-2	3×1.5	blue
SIZ-3	2×2.5	orange
SIZ-4	4×2.5	yellow
SIZ-5	8×2.5	red

Accordingly, the larger the number of the PPE cap, the larger the cross-section and number of wires it is intended for.

All wire connections assembled on self-clamping terminals or insulating caps are highly efficient and are gaining popularity.

Express terminals allow you to quickly create a reliable connection, but have more complex design, somewhat more expensive. They are more often used to connect conductors to new measuring, automation and protection devices operating on microprocessor circuits.

For everyday frequent use, they are best suited with simple device. The connection of the conductors is achieved by screwing their metal ends into a strong spring made in the shape of a cone-shaped spiral.

There is no need to insulate the connection point; the spiral is placed in an insulated cap. The material of its body does not support combustion, is resistant to aggressive environments, and provides good electrical insulating properties.

Twisting of PPE wires

Installing the cap on prepared wires is quick and does not require special tools. The created connection is compact. The caps are convenient to use. However, you need to know the rules for their use and develop the necessary skills. Inept handling can lead to dire consequences.

Insulating caps are suitable for connecting several wires of a certain diameter, which is indicated in the documentation. Manufacturers from different countries use their own designations. Therefore, it is better to navigate overall dimensions for connecting wires, and not with the manufacturer's markings.

Using PPE caps - practical application

Particular care is required when handling aluminum conductors. Soft metal is easily deformed and quickly loses strength.

At twisted cap aluminum is reliably compressed by a conical spring and works well for a long time. Due to the occurrence of electrochemical processes, aluminum wires cannot be twisted together with copper wires.

It is important to remove the optimal length of insulating layer from the conductor to ensure maximum area contact metal parts. It's easy to define. It is enough to insert one wire inside the cap and visually mark the place where the insulation is cut. Remove the insulation and repeat the test installation of the wire. Exposed metal should not extend beyond the insulating portion of the cap.

When removing insulation, use in different ways. Many older installers work with a lineman's knife, which has an insulated handle and a short, sharp blade made of durable steel. Wedge or razor sharpening is often used, which removes insulation well, but can cause harm in inexperienced hands.

A knife, especially when directed perpendicular to the conductor, can damage the outer surface of the metal. Any scratch, even a barely noticeable one, will increase in size when twisted, reduce the cross-section of the conductor, and reduce its electrical characteristics. The metal will begin to heat up and burn out, especially under heavy loads. A deep cut in the conductor will cause the wire to break when twisted.

You need to remove the insulation with a knife when its blade is positioned at an obtuse angle to the conductor relative to the direction of the cut, using light movements without damaging the metal.

A certain part of electricians use pliers or wire cutters to remove insulation; they deform the metal at the point where the conductor is crimped, which is not acceptable. Insulation can be removed efficiently using special pliers produced for such work.

The method of twisting wires with pliers and then putting on the cap does not ensure reliable contact and its insulation. The caps just fall out over time. But some installers don't understand this.

Taking advantage insulating caps, force must be applied when twisting. It will ensure tight contact between the metals of the conductors and the spring.

To assess the effectiveness of using caps before their mass use, it is necessary to connect wires with them and pass a rated current through it with a load device for about half an hour. Analyze the heating of the connection. Then exceed the current and identify problem areas.

These electrical tests help professionals find out weak points created by them electrical circuits, improve your skills, perform quality work.

Spring-type connecting insulating clamps (PPE caps) are used for safe connection of wires. The main advantage is high-quality insulation. It also takes less time to complete the work and does not require special skills or tools. Clamps are divided into several types depending on the permissible cross-section of the wires.

Many professional electricians most often use PPE caps as temporary insulation repairs. As a repair option, clamps are actively used in the repair of entrances, MOS, in junction boxes, and voltage panels.

To ensure reliable twisting

To ensure maximum contact between the conductors, it is necessary to ensure that they are in close and strong contact with each other. The spring that is built into the clamp enhances this effect. However, it should be taken into account that the metal spring has its own fatigue threshold, and over time the pressure will weaken and contact will gradually begin to be lost. Also, the bare surfaces of conductors are constantly in contact with air, due to which an oxide film and rust inevitably form on them. These factors will decrease conductivity with increasing intensity. Therefore, for greater reliability and durability of the connection, the use of PPE should be combined with other insulation methods; the reverse is prohibited by the PUE.

Advantages

• easy to install, saves a lot of time;
• do not require additional tools and skills;
• The durable cap simultaneously insulates and protects the connected wires;
• does not require large quantity additional materials;
• the result is a practical and convenient connection; if necessary, the cap can be twisted and the wires disconnected, or the connection can be remade;
• high-quality PPE can withstand temperatures from –40 to +105 degrees Celsius.

Flaws

• you need to ensure that the size of the clamp matches the cross-section of the cable;
• It is not recommended to use for installing a street line;
• It is allowed to connect only copper electrical wires, caps for aluminum cables must be with anti-oxide paste;
• It is not recommended to use the PPE compound in its pure form.

Design

The PPE cap consists of two main parts: the cap (body) and the internal spring.

The body is made of plastic. Moreover, it must be a heat-resistant and non-flammable material. PVC or nylon are most often used. For convenient and quick connection of wires using these devices, the outer surface of the cap is equipped with ribs or grooves that increase the rotation force when screwing.

The inner spring has a cone shape, its main role is to ensure tight contact between the conductors. Typically the spring is made of steel with an anodized coating.

How to choose PPE

PPE caps should be selected according to the cross-section of the wires. To do this, you need to sum up the cross-sections of each wire and compare the resulting result with the table below or with the size table that comes with the clamps. The voltage of the electrical wiring should also be taken into account.

Types of PPE

Installation

In practice, two methods are used for twisting wires using PPE caps. First method: without preliminary twisting. Second method: with preliminary twisting.

Pre-twisted installation

Often in practice, electricians install PPE on a pre-prepared twist of bare wires. To do this, you need to take the stripped wires and press them tightly against each other. The bundle should be fixed using pliers, stepping back a couple of millimeters from the exposed veins. In this case, you need to start twisting the bare ends of the electrical wires pressed against each other clockwise. For twisting, it is best to use another pliers. A small section can be twisted by hand, but if the wires are thick or there are many of them, then use a tool. Once you've finished rolling, bite off the rest. bare wire at an acute angle.

Please take note!

Before using connecting clamps, you need to prepare the wires. To do this, they are cleaned using a stipper. If there is no stripper, then you can use a lineman's knife, but in this case, cuts perpendicular to the cable should be avoided.

Installation without twisting

PPE is installed on electrical wires and without twisting (more popular practice). To do this, you need to place the bare wires parallel so that the ends point in the same direction, insert the ends into the PPE and start screwing the cap manually (clockwise). Manual screwing must be done until the spring clicks. A click from the spring will indicate that the twist within the cap has been completed. Further, if the length of the bare wire does not extend beyond the clamp, then the work is finished.

Some electricians recommend exposing a longer section of cable to make the twist longer and more secure. In this case, it will extend beyond the cap, and after a spring click, you will need to tighten the connection using pliers or a screwdriver until the entire bundle of wires is twisted all the way to the insulating coating. After this, the exposed area must be insulated. The best way to do this is with heat shrink tubing and electrical tape.

Please pay attention!

Make sure that the wires do not stick out from under the cap. The documentation for some clamps indicates the required cut length (usually 10–12 millimeters); if there is no information, then preliminary measurements need to be taken. If you made a mistake in calculating the length of the exposed wires and they stick out from under the clamp, then you should additionally insulate them using insulating tape or varnished cloth.

It is also important that the conductors transmit current through the connection and not through the clamp spring. Since the spring is not predisposed to such loads, it will very quickly overheat and fail.

Important!

Immediately after installing PPE, you need to check the quality of the insulation. To do this, apply the maximum possible load to the line and hold it for thirty minutes. Then you need to check the temperature of the clamp. Functional PPE should not heat up; if your test shows otherwise, you should replace it and test it again.

Do not connect cables made of different metals

You also need to know that you cannot twist a combination of copper and aluminum cables together. Since in such cases, special devices (pads) with built-in metal adapters are used.

Choose the appropriate PPE size

If you choose correct size caps that will suit the total cross-section of the wires, the twisting will last a long time and the risk of overheating will be minimized.

How to choose quality PPE

There is no uniform quality standard for these devices yet. An important factor when choosing is the total cross-sectional area of ​​the wires. When choosing, you should try screwing the cap onto your bundle of conductors or a similar one with the appropriate dimensions.

In this case, the clamp must ensure the quality of twisting. It should not fly off with a strong jerk, pull, or the like. But when unscrewing it in the opposite direction, after all these manipulations, it should come off normally and be suitable for rewinding. Also check the spring; it should not fail, become severely deformed, or fall off after the first screw onto the connection.

Check the plastic, it should be pleasant to the touch and should also be resistant to squeezing with your fingers. Bad plastic will not shrink, but may break and crack. Good plastic When pressed hard, it will bend a little and then return to its original position. If you buy clamps made of low-quality plastic, they may not withstand high temperature loads.

Why is it necessary to use PPE and not do simple “Soviet” twists?

Many amateur electricians use regular twists, without installing PPE (when the wires are arranged in parallel and twisted together using pliers). And they believe that such technology has the right to life. Many give examples that simple twists from 30 years ago still do not fail. In fact, the use of twists without connecting insulating clamps is only permissible when installing a temporary connection. Such twists gradually become loose due to the constant heating and cooling of the cable, and contact is lost. 30 years ago, such technology had a right to exist, since the power of technology was much lower and people used fewer devices in everyday life.

The PPE prevents the connection from loosening due to the fixing spring, which expands slightly due to the heating of the wire and presses the conductors together more tightly. However, such a connection does not last forever, although it can last for many years.

Is it legal to use PPE?

The use of PPE is not regulated by the PUE. The document doesn't say anything about connection clamps at all. However, insulating caps comply with the requirements of GOST 50043.1–92. Hence the conclusion is that the use of PPE is completely legal. For the greatest safety and durability, it is recommended to use permanent connections. These include: welding, soldering, pressed sleeves.

Regular twists (without insulating caps) are prohibited by the PUE. Therefore, in some cases, it is possible to screw insulating clamps onto old strands to make connections safer and compliant with the law.

Video on the topic

We have already reviewed the article: how to twist wires, but only old methods were considered there, which cannot be called safe and simple. For efficient and high-quality connection of wires, it is necessary to use PPE caps. In this article we will look at how to use PPE clamps, look at types, sizes and key benefits of use.

Design of PPE clamps

The design of the caps for connecting wires is considered very simple; it includes two components:

• The cap, it is made of plastic and shows electrical insulating properties. Plastic is not afraid of temperature changes and can even withstand a voltage of 600 V.
• Spring. As a rule, the spring has a conical shape, due to which the wires are clamped. The spring is made of steel, but other materials may be used in some situations. Additionally, the spring is treated with an electrochemical solution.

This is what the PPE cap looks like in the photo.

How to use

We will look at two methods of twisting wires using PPE:

• Without preliminary twisting of the cores.
• With pre-twisting.

If necessary, connect two wires, they can be inserted into the spring with little effort. Then you need to twist them using clockwise rotational movements.

If you need to connect several wires, then initially they must be twisted together using old methods; for this you can use ordinary pliers. After twisting, the wires must be inserted into the PPE, see photo.

Remember! The wires must be twisted until they are fully connected to ensure reliability. We perform twisting only clockwise; during this process, use force, this is what will ensure a reliable connection for a long time.

Also remember that if connected correctly, you will not need to additionally insulate the wires, since the caps do an excellent job of this task. However, here it is extremely important to choose the correct size cap so that the wire fits perfectly into it.

You can see how to use PPE clearly in the next video.

Connector classification

Our subscribers often ask the question: how to choose a cap? In fact, you should be careful here, but there is nothing complicated about it.

It’s worth highlighting right away that all PPE connectors are divided into two types:

1. Domestic.
2. European.

Their markings are the same, the only difference is the quality of execution.

The marking of PPE caps is as follows:

If we talk about such a parameter as color, then there is no particular point in paying attention to it. Only professional electricians are guided by color, who can determine the cross-section of wires at a glance. And remember that some manufacturers do not adhere to color coding.

Is it worth using: pros and cons

Initially, we will highlight several reasons why it is worth using modern connectors:

1. Quite low price.
2. Twisting wires with them is a pleasure.
3. On their body you can leave designations, for example: where is the phase or zero.
4. Safety is created and the likelihood of spontaneous combustion is minimal. Since the plastic of the connectors does not support combustion.

However, there are several disadvantages:

• In many situations, it is not possible to firmly secure the wires.
• Copper and aluminum wires cannot be connected to each other in the caps.

So we looked at what PPE connecting clips are. Finally, we recommend watching a few more videos on this topic.

One more thing, but notice there are a few errors here.