How to connect wires with caps - Metals and their processing

Connecting wires with PPE caps

When assembling electrical circuits, it is necessary to connect wires 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 of 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 wire, twisting increases the chance of oxidation and does not provide a guarantee reliable connection.

Today there is another solution to such problems - these are connecting caps for twisting wires .

PPE caps for twisting wires

PPE caps 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 moves apart 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, which have 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.

Connection caps are produced in 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 are 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 a more complex design and are 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, cable twist caps with a simple device are better suited. 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 be guided by the overall dimensions for connecting the wires, and not by 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.

When twisted with a cap, the 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 the insulating layer from the conductor to ensure maximum contact area between the 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, different methods are used. 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.

When using insulating caps, apply force when twisting. It will ensure tight contact between the metals of the conductors and the spring.

To evaluate 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.

Such electrical tests help professionals recognize the weak points of the electrical circuits they create, improve their skills, and perform quality work.

Similar materials on the site:

How to measure with a multimeter

Source: https://electricvdome.ru/instrument-electrica/kolpachki-siz-dlya-skrutki-provodov.html

Legalization of twisting using PPE caps

Reliable, uninterrupted operation of any electrical network depends on the quality of contacts. A well-made connection of wires allows you to use the wiring for a long time without having to look into the junction boxes. There are many ways to ensure a reliable joint.

Among them, the least labor-intensive is twisting. The PUE does not directly prohibit it, but the paragraph of the rules describing the methods of making connections and branches does not mention this method among the permitted ones.

Lack of fixation of the turns can cause the spiral to weaken. This will someday lead to loss of contact density and heating of the joint.

A burnt contact will interrupt the current in the circuit and may cause a short circuit and fire.

Modern technologies have made it possible to increase the reliability and quality of twists by using Connecting Insulating Clamps. The article will introduce you to the design and tell you how PPE caps are used for joining wire strands.

Design, marking

The connection is made by putting on a suitable brand of personal protective equipment by twisting the stripped conductors with strong twisting until it stops. Caps for twisting wires are a simple design:

The plastic sleeve, in the shape of a truncated cone with a ribbed surface, is made of durable, non-flammable plastic. Being a good dielectric, it provides high-quality electrical insulation. Protrusions can be made on the outside of the housing. This makes it easier to grip when screwing the clamp onto the conductors;
A conical steel spring or a threaded metal insert is located in the housing hole. Spring steel with an anodized coating that ensures good electrical conductivity. When screwed onto a joint, the turns strongly compress the stripped ends of the cores together. This ensures tight contact of the surfaces of the conductors, duplicated by the contact of the metal with the coils of the spring.

There is no single standardized system for coding PPE parameters. The marking of products manufactured by one of the domestic manufacturers indicates the standard size of the connector. Each clamp size is designed to accommodate different total sections of cores and differ in dimensions and body color. Technical documentation decodes the standard size, showing the minimum and maximum sum of cross-sections of the wires being connected, overall dimensions, and the maximum operating voltage of the network.

Clamps from another manufacturer may be marked differently. Therefore, when purchasing, you need to check with the seller the parameters of the product based on the factory documentation. It should be noted that with different brands, the geometric dimensions of the clamps intended for connecting identical sections are the same.

8 types of caps from an imported manufacturer

This type of connector is very popular in the West, from where it came to us. A wide selection of models allows you to make most lighting and power wiring contacts using this method.

Types of imported PPE:

Improved design with wings makes twisting easier and more comfortable.
The clamps are of a low profile design, shorter than standard length. Convenient for installation in small junction boxes and work in cramped conditions.
A modification of the previous model, equipped with wings that facilitate and enhance twisting.
PPE for twisting aluminum conductors with copper ones. The inside of the cap is filled with a special paste that prevents oxidation.
Connectors that protect the contact from moisture. They are filled with silicone sealing paste, which prevents moisture from entering and prevents corrosion. At the entrance of the cap there is a split elastic cuff that holds the sealant. There is no need for additional sealing of the joint when making a connection outdoors or in wet areas.
A clip with a small hole at the top. The seemingly ridiculous design is needed for a twisted terminal connection. First, the end of the longer, cleaned strand is released into the hole. After screwing on the clamp, the protruding wire brought out in a loop is looped under the terminal. It is very convenient to connect the connected ground wires to the housing or terminal.

A connector where the wires are clamped not by a spring, but by a countersunk screw. It resembles the joint with our terminal block, which is placed in the PPE cap.

For sealing, you can use a special connector. It is a small plastic cup into which the completed PPE is placed. Silicone filling guarantees complete waterproofness and protection from moisture. In practice, the wire can be placed in water.

Correct twisting

It is easy to screw the PPE caps onto the pre-prepared ends of the wires. No special tools or equipment required. Two ways:

No pre-twisting.
1. the stripped conductors are folded and aligned along the edge of the insulation;
2. Simultaneously or alternately cutting the ends of the cores equalizes their length. It should be equal to the depth of the housing hole (10-12 mm);
3. holding the wires with one hand, screw the cap clockwise with the other hand until the spring is activated;
4. The twisting is completed by twisting the body until it stops with your hands or using a tool.
Fixing pre-twisted conductors:
1. the stripped and aligned cores are tightly twisted and shortened to the required length by trimming, the direction of twisting must coincide with the direction of rotation of the clamp;
2. the body is screwed on.

The choice of method depends on the cross-section of the conductors. It is better to pre-twist thin wires. There is an opinion that it is better to strip the cores during preliminary twisting a little longer than required by PPE. Increasing the number of turns will increase the contact density by increasing the contact area of the cores. The exposed area is insulated with electrical tape or heat shrink tubing.

Twisting of PPE should be careful, but as strong as possible. It should be firmly held on the twist. It cannot be torn off by hand when pulling along the axis of the wires. It is convenient to use PPE caps for connections, but you need to know and follow some rules:

Use clamps that match the cross-section of the wires being connected. The diameter of the hole is too small to allow the entire bundle of cores to be inserted into it. Too large will not create a tight contact and will not fix the wires in the clamp. The twist will heat up if it makes contact at all;
Ensure that the wires are twisted tightly. It is impossible to allow the load current to flow through the metal of the spring, heating it. Loss of springiness will turn the PPE into a simple twist;
It is prohibited to use PPE to connect copper and aluminum wires. This is done in a different way.

Do not strip the insulation with pliers or wire cutters. If there is no special tool, carefully remove the insulation with a knife, avoiding damage to the surface of the core.

Pros and cons of the method

PPE caps provide many benefits to the electrician:

No additional equipment or tools required. Simplicity and cost-effectiveness of installation, no need for separate insulation;
The housing, made of non-flammable, heat-resistant plastic, simultaneously provides three types of contact protection:
- Mechanical;
- Electrically insulating:
- Fire safety.
Compared to other connection methods, it is possible to:
- Detachable joint;
- Reusable connector over and over again.
Legalization of twists of old wiring before or after inspection by a fire inspector. The boxes are opened, the old electrical tape is removed, and new PPE is screwed onto the roll. If the direction of twist does not coincide with the direction of rotation of the cap, it will have to be redone.

There are also disadvantages:

The main one is the impossibility of connecting a stranded soft wire;
Requires careful selection of standard size;
Not a sealed joint. It is unacceptable to perform for street wiring. Wrapping the joint together with the cap with electrical tape, to some extent prevents the accumulation of moisture inside the case;
Relatively large dimensions. PPE caps take up a lot of space inside the distribution box.

Scope of application

PPE caps are used to create connections when installing electrical networks inside public and residential buildings and structures. Application in industrial, damp or chemically active environments is possible when the strands are placed in protected distribution boxes.

Legalization of twisting using PPE caps Link to main publication

Source: https://VseOToke.ru/montazh/kolpachki-siz

Caps for twisting wires - electrician's advice - Electro Genius

24.03.2017

Among the existing methods of connecting wires, PPE caps have recently become increasingly popular.

For an electrician, they make the work process easier to some extent, because the use of such caps does not require skills and knowledge, additional tools and materials; they are installed simply and quickly. But these clamps also have their drawbacks; they cannot always be used.

Let's talk about them in more detail and figure out when you can use such connecting clamps, and in what cases their use will not guarantee reliability and quality.

Purpose and design

PPE connecting insulating clips, otherwise called caps, are of the spring type. The main purpose of these elements is to connect two conductors (or more) and provide this contact with reliable insulation.

PPE has several standard sizes, and each has its own range of the total cross-section of switched conductors.

The manufacturer, as a rule, indicates the maximum and minimum values of this section in the passport or on the packaging.

This type of connector can be used multiple times.

The design is very simple, the cap consists of a body and a metal core:

The body is made of plastic; materials are used that do not support the combustion process - polypropylene, polyvinyl chloride, nylon. To make it easier to screw on PPE caps during installation, their bodies have protrusions or special ribs.
A metal compression spring, which has a cone-shaped shape, is used as the core. When the clamp is screwed onto the twist, the spring compresses it, thereby ensuring good contact.

Such caps are used for twisting wires during installation of electrical wiring in residential and public buildings. Their use in industrial structures and buildings is allowed, but if there is a chemically active, explosive or humid environment, then the electrical connecting unit must be located in a branch box with the appropriate degree of protection.

For information on the design and purpose of connecting caps, watch this video:

Advantages and disadvantages

The most important advantage of a PPE cap for an electrician is the simplicity and speed of installation work. This does not require any additional tools or devices.

The cap not only performs insulating functions, but also protects the connection from mechanical damage.

No other insulating materials are needed. If the installation is performed correctly and the exposed section of the wire does not extend beyond the cap body, then the insulating function of the connecting node is performed by the clamp itself.

The connection is compact and easy to use. In addition, it is considered detachable, that is, if necessary, you can unscrew the cap back, pull the wires out of it and re-seal the connection.

Like any other type of wire connection, along with the advantages, PPE caps also have a number of disadvantages:

If the cap size is chosen incorrectly, then after installation work, during operation, it may simply fly off.
PPE cannot be used for street electrical wiring.
Using PPE caps you can only connect copper wire or cable. Special clamps for aluminum conductors are very rare; their main difference is that the inside of the housing is filled with anti-oxide paste.

Choice of caps

The standard size of PPE depends on the total cross-section and the number of connected conductors. There are special factory tables from the manufacturer, according to which you can select the standard size of the clamps. They indicate two numbers - the minimum and maximum total cross-section of the cores connected together:

SIZ-1 – from 1 to 3 mm2;
SIZ-2 – from 1 to 4.5 mm2;
SIZ-3 – from 1.5 to 6 mm2;
SIZ-4 – from 1.5 to 9.5 mm2;
SIZ-5 – from 4 to 13.5 mm2.

The standard size of the cap is indicated in the product passport. How to choose the right clamp? It is necessary to calculate the total cross-section of all cores that will be connected using a PPE cap.

The resulting figure should be in the middle of the specified range.

For example, if you connect two conductors with a cross-section of 2.5 mm2, and the total figure of the total cross-section is 5 mm2, then you will need a clamp with standard size SIZ-4, but not SIZ-3.

Preparing the veins

Before connecting wires using PPE, it is necessary to strip the conductors from the insulating layer.

To do this, you will need a mechanic's knife, but you need to be extremely careful and careful not to damage the surface of the conductive core.

Try not to place the knife at an angle of 90 degrees to the conductor, in this case you can cut the core and it will subsequently break. Point the knife blade at an angle to the cut and remove the insulating layer.

Among electricians, such a device as a stripper is very popular. This tool performs many functions, one of which is stripping insulation from conductors. The stripper has calibrated holes with a cutting edge for each section of the core.

In the wires that are to be connected, it is necessary to remove the insulation layer to the same length. It is very important that after the electrical connecting unit is already insulated with a cap, no bare wires protrude from under the housing.

Therefore, it is necessary to clearly measure the length to which the wires need to be stripped. To do this, put the clamp on the wire and mark the place of the cut; it should be slightly less than the length of the clamp body.

There are manufacturers who immediately indicate the required cut length on the product itself or in its passport (from 10 to 12 mm).

Installation

There are two ways to connect wires using PPE caps: when twisting is done first and without it.

Let's first consider the twist option. Place the stripped wires tightly against each other. In the place where the insulating layer begins, squeeze the wires with your left hand or pliers. With your right hand, grab the ends of the wires and begin to twist them clockwise.

When the wire cross-section is small, you can make a strong twist by hand. If you are connecting more than two wires or they have a large cross-section, then use another pair of pliers for twisting (that is, hold the wires with one, and twist them with the other).

If you are not using twists, simply place the wires to be connected parallel to each other so that they form an acute angle at the end. Why should the tip of the wires not be straight, but slightly angled? Because the cap spring has a cone shape.

Now place the PPE cap on top of the wires and with a little force, twist it clockwise until it locks. When you screw on the cap and apply force, the spring expands and compresses the wires tightly.

It may turn out that you miscalculated a little and stripped the insulating layer of conductors longer than the cap body, and now the bare wires protrude. This can be fixed; add additional winding on top. For insulation, you can use tape, electrical tape, or a thin strip of varnished cloth.

The process of connecting wires using PPE caps is shown in this video:

Some useful tips

If the PPE caps are selected correctly according to the area of the twist, this will ensure that it does not fall off.
Experienced electricians advise that after a cap is installed on the electrical connecting unit, immediately check its insulation. The maximum load is applied to the circuit for at least 30 minutes, after which the temperature of the insulating element is checked. If the cap does not heat up, it means that everything is installed correctly and is working normally. In the case when heating is detected, it is necessary to understand and look for the reasons.
Contacts made of copper and aluminum wires cannot be isolated with PPE clamps. For this purpose, there are other devices - self-clamping terminal blocks, terminal blocks, special adapters with metal plates.
When you screw the PPE cap onto the twist, apply a little force. Apply a little pressure to create tight contact. But do not overdo it, so as not to break the compression spring.
The color design of the caps is not specified or classified anywhere, therefore multi-colored PPE is used solely for the convenience of the electrician in servicing the connection points. For example, a brown cap indicates twisting of phase conductors, blue – neutral, and green or yellow grounding conductors.
Do not cut long insulating sheaths from conductor cores. Be sure to match it with the internal length of the cap.

The advantages and disadvantages of PPE from various manufacturers are described in detail in this video:

We told you everything related to PPE clips. Next, it’s up to you to use them or choose other methods of connecting conductors. There are many situations where their use is convenient and beneficial. In addition, such clamps are inexpensive.

The only thing I would like to advise is to choose a trusted manufacturer.

On the electrical goods market, there are many cheap Chinese-made options whose body material does not have the required properties, which can lead to a fire.

Source: https://orenburgelectro.ru/montazh/kolpachki-dlya-skrutki-provodov-sovety-elektrika.html

All types of insulated PPE caps. Selection, characteristics, sizes

From the point of view of the current rules, wire twists can be roughly divided into two types:

Correct twists include those that are fixed in some way. The following can act as a retainer:

PPE caps
welding in the form of a point at the end of the twist
soldering
pressed sleeves
screw terminals

Wires that are simply twisted without fixation are considered an incorrect connection element. It doesn’t matter how many turns you made, how beautifully you connected the wires - all this is outside the rules and prohibited. More details

Soldered and welded wires are considered the best connection, but for most they are simply not suitable due to the simple lack of necessary tools or skills.

If you decide to repair the wiring yourself, assemble the junction box and at the same time save on installation, without violating the current rules, then PPE caps are an ideal option.

Firstly, you don't need to buy any special tools. For example, expensive welding machines or press pliers.

View Secondly, you do not need to acquire any additional skills, as is the case with soldering or welding wires.

PPE stands for connecting insulating clamp. This type of caps came to us from the West. In America, this connection and method of insulating wires is considered the most common.

Moreover, foreign consumers have a much richer choice than we have.

Our manufacturers actually produce only two types of PPE:

regular smooth PPE
PPE caps with wings

In the West, as they say, you can choose one for all occasions. It is not clear why the Chinese have not yet jumped in and started producing the same thing for our market.

THIS IS INTERESTING: Why heat treatment of steel is needed

Here are the main 8 types of PPE caps that can be found there (taken from here).

This is a classic and reinforced (with wings) PPE that we are all familiar with:

PPE with an improved cap shape, providing more comfortable operation when screwing on:

PPE cap with low profile design for work in confined spaces or small junction boxes:

Low profile wing design for enhanced torque:

The next cap is a very controversial decision in my opinion, but it is also being released. PPE for connecting aluminum conductors to copper. The cap is filled with a special antioxidant that prevents oxidation:

Moisture-proof clamps that can be installed on wires in electrical cabinets on the facade of the house, or in wet rooms, and even directly in the ground in the garden:

They contain 100% silicone sealant that protects against moisture and corrosion.

https://www.youtube.com/watch?v=ZH1ZLOYL_xo

There is no need for heat shrinkage or hermetically sealed insulation of joints.

PPE with a hole in the top of the cap.

This is not a defect at all, as it might seem at first glance, but a clamp specially designed for twisting grounding conductors. One of them is brought out through a hole and connected to the body of the panel or equipment.

There are also similar clamps where the wire is pressed not by a spring, but by a screw connection.

There is also a device - a connector filled with silicone. Any PPE cap with wires can be placed inside it.

After this, this twist can easily be considered waterproof and placed underground - in the garden, near watering cans, when entering the house, etc.

Domestic and Chinese manufacturers produce PPE caps in 5 sizes from PPE-1 to PPE-5. The largest of them is designed for a total wire cross-section of up to 32mm2.

By the way, be more careful when choosing caps based on cross-sections. Some Chinese PPE may confuse you. On the cap itself it may be written that it is designed for up to 20mm2.

And on the packaging it is only up to 15mm2. It’s not clear what to believe.

Quality can be checked even by touch. Low-quality PPE is characterized by poor plastic that can burst during operation. You can distinguish it by simply squeezing it with your fingers.

More expensive and normal clamps, with difficulty, but are compressed under the force of two fingers. Low-quality options are rougher and much more difficult to compress.

Some people use pliers to help themselves when tightening the PPE. Again, with cheap Chinese caps, when doing this, a break may occur, or the spring may simply fall out.

A good PPE clamp can easily withstand the operating temperature range from -40 to +105 degrees.

Here are the markings and types of PPE caps with all the characteristics produced by the domestic manufacturer KVT:

The company also produces a reinforced version of the cap with ears or wings:

Caps with ears are of course much more convenient than simple ones, but here you need to proceed from the free space in the junction box. Since such ears can take up up to 20% of the space of the total area of the cap.

PPE, as well as sleeve and fork tips, can be distinguished by color. Each color corresponds to a specific wire section.

Using PPE, you can connect 4,5,6 wires, the main thing is that the total cross-section of the twist corresponds to the calculated purpose of the PPE.

In this case, you can safely twist wires of different sections. When crimping wires with sleeves, this causes real problems and difficulties.

You can select and order sets of PPE caps here.

Let's consider the twisting process itself when using PPE. First of all, you need to accurately select the desired clamp according to the cross-section of the wires. The quality of the connection will depend on this.

To do this, add up the total cross-section of the conductors that will be twisted inside the cap.
Let's say these are 3 wires of 1.5 mm2 each. This means the total twist cross-section is 4.5 mm2. Use the table to find the required cap.

In this case, you do not need to focus on extreme values so that there is no twisting, which is called end-to-end. In this case, the clamp simply will not work, or will work poorly, and the wires will get hot.

For our version of 4.5 mm2, it is better to choose SIZ-3, designed for twisting from 1.5 to 6 mm2. SIZ-2 in this case will not be the best choice.

Next, the whole process can be performed in two ways.

1 way to twist PPE

First, combine the wires. There is no need to pre-twist them or stack them on top of each other. Place them in a PPE cap.

Then you begin to press it inside the PPE and turn the cap itself clockwise until the spring releases. As soon as the spring has captured the wires, you can begin the process of twisting the wires.

If there is not enough manual effort, and the cap does not have “ears,” you can use pliers or even a screwdriver. The process will speed up significantly.

There is even a specially designed screwdriver attachment for quickly twisting wires using PPE. With this method, the cap remains completely undamaged.

You can, of course, adapt an ordinary “Shurik” for twisting without any adapters, but the outer insulating layer of the cap will be scratched.

2nd method of twisting PPE

The second method involves preliminary twisting of the stripped cores with pliers or again with a screwdriver.

Then you trim the ends for evenness, and only then screw the clamp onto the twisted wires.

Which method to choose depends on the cross-section of the conductors being connected.

Just try twisting together 4 GOST wires with a cross-section of at least 2.5 mm2 with your hands and a cap. The load on the cap and the spiral will be such that if you move it incorrectly, you can break it.

But twisting two 0.5mm2 wires into PPE is not very difficult.

What should the twist length be? According to the manufacturers' recommendations, the twist should be equal to or slightly less than the length of the cap itself (10-12mm).

IEK technical passport for PPE caps - download
Navigator technical passport for PPE caps - download

If you make it 3-4cm long, at first glance this should not affect the quality of the connection and its resistance. However, there is one caveat here. Namely, the dependence on the number of twisted wires.

The more there are, the more desirable it is to increase the twist length.

If you twist five wires at the same time, to a depth of the PPE cap of only 1.5 cm, then you will never be able to create the same area of contact of these wires, which is obtained with a twist length twice as long.

So be thoughtful about your approach. The main thing after this is to reliably insulate the remaining exposed part of the wire.

True, in this case it is no longer correct to call the connection PPE, since the cap itself no longer insulates the entire exposed core.

In any case and at any length, this twist is quite reliable and, thanks to the fixation with an insulated cap, the wires will not come loose during operation.

The main advantage of insulated PPE is that the plastic shell of the cap, unlike other types of insulation, provides three types of protection at once:

electrical insulating
fire protection
mechanical

The undoubted advantage of insulated caps, compared to sleeves and tips, is their ability to be reused. For example, after temporarily connecting the wires, when connecting some portable equipment, the PPE cap can easily be twisted counterclockwise.

After which it can again be safely used on other equipment or object.

Another common use of PPE is the legalization of twists in old electrical boxes following regulations from fire inspectors.

The caps themselves are made from PVC plastic, which does not propagate combustion.
And this is one of the conditions for fire safety requirements for electrical equipment. Open the box, remove the electrical tape from the old twist and screw a new cap over the cores. True, you may come across twists made counterclockwise, so be careful.

The disadvantages of insulated PPE caps include the fact that they are not suitable for multi-core wires and are only applicable for mono-core wires.

Manufacturers also do not recommend twisting aluminum wires with them, indicating that this is primarily a clamp for copper.
Some companies, as mentioned above, produce universal PPE clamps designed for aluminum too. However, for the most part, their use for this particular metal is prohibited.

And sometimes it can lead to the following consequences:

Domestic PPE also does not provide a hermetically sealed connection. In a damp room, moisture can accumulate inside the cap, which gradually leads to rust and disruption of the compressive force of the spring.

To avoid this, you can insulate both the wires and the PPE cap itself with electrical tape.

Another inconvenience of such clamps is their dimensions. If there are a lot of wires in the junction box, then the PPE will take up a lot of free space inside. Sometimes this may even force you to replace the box with another, larger one.

In general, the choice in favor of insulated PPE caps is made primarily because of their cost-effectiveness and ease of installation. If you need a more reliable and durable connection, then invite professional electricians with all the necessary equipment.

Here is an interesting test of a PPE cap for mechanical load. The guy collected the wires in PPE and hung a punching bag from it, thereby checking how mechanically reliable this contact can be:

Source: https://domikelectrica.ru/vse-vidy-izolirovannyx-kolpachkov-siz/

Twisting of PPE: insulation of electrical wires using caps, design features of twists

During operation, any wires are subject to stress and heat. Therefore, for a high-quality supply of current to an enterprise or private home, close contact between the wires is necessary. This can be achieved by twisting PPE or connecting insulating clips. They are called caps for short because of their appearance.

To assemble an electrical circuit, you need to ensure reliable contact between the cable cores. There are several options for this:

Simple or isolated twist.
Use of welding or soldering iron.
Use of screws and nuts.
Through terminal blocks or blocks.
Self-clamping elements of the Wago type.
Insulating caps.

Regular twisting and soldering are the most popular ones. However, these methods are not without drawbacks. The first of them does not involve rigid fixation of the wires, as a result of which the contact may weaken, and there is a possibility of oxidation and destruction of the bond. To make a connection using the second method, it is necessary to use special equipment, which may not be available at the installation site or its use will be inconvenient.

In addition, according to the Electrical Installation Rules (ELR), it is prohibited to connect wires using twists. In emergency situations, there may not be enough time to prepare welding or soldering equipment. Therefore, it is necessary to provide alternative options that meet the rules and regulations.

Using caps

This method does not require the employee to have special skills or use additional equipment. In addition, the speed of creating a core connection using this method is quite high in order to carry out prompt installation work. The PUE allows the use of electrical PPE in various installations.

Purpose of the device

Such clamps are of the spring type and are designed to connect two or more conductors to ensure the necessary contact and reliable insulation. Despite the fact that the Rules do not clearly regulate the operation of such devices, GOST 50043 .1−92 establishes their compliance with safety requirements.

Some electricians talk about cases from practice where PPE caps did not perform well. However, there are explanations for this:

Insufficient qualifications of the installer himself.
Use of low-quality products of dubious origin.
Incorrect calculation of the wire cross-section relative to the load on the electrical network.

If all work is carried out according to the instructions using high-quality materials of appropriate sizes, then when protecting the line using circuit breakers, such connections will last a long time without additional service.

The use of such clamps is possible not only in residential premises, but also in production. However, in places with a chemically active environment and high humidity, it is necessary to place the structure in junction boxes of the appropriate degree of protection.

Electrical PPE cannot be used when connecting conductors of dissimilar metals. Particular attention should be paid to copper and aluminum conductors. During heating, galvanic processes occur between them , destroying the contact density. In this case, it is advisable to use steel adapter terminals treated with a conductive compound.

Design

These connectors are designed for reusable use. They are made very simply. Any PPE insulating cap for twisting wires consists of a body and a spring. The first is made of plastic that does not support combustion. It can be nylon, PVC, polypropylene. For ease of handling the clamp, its surface is ribbed or with special notches. The shell performs a protective and insulating function.

The core is a metal compression spring. It has a cone shape. When screwing the cap onto the twist, it tightens, ensuring reliable contact.

The dimensions of the spiral deserve special attention. In order to select the correct cap, you need to know the cross-section of the cores being connected and the smallest base of the cone in which their contact will be created. If the wire is thinner, then it will not be possible to crimp it, and a thick one simply will not fit into the cap.

To put the crimp on the twist, you need to press harder on it to push the coils of the spring apart. The body must be rotated clockwise. By performing these simple manipulations, you can create a tight cable connection.

Product classification

Many caps for soldering conductors from various manufacturers are sold on the Russian market. Domestic standards provide for the following standard sizes of such electrical products:

Gray color, intended for two-core twisting. The cross-section of each core is 1.5 square meters. mm. Marked as SIZ-1.
SIZ-2 connects three wires of the same size and is colored blue.
For 2.5 mm conductors in the amount of 2 pieces there is orange SPE-3.
Four similar wires will fit into the yellow SIZ-4.
Eight cores with a size of 2.mm square in diameter will be placed in red PPE number five.

It should be noted that such names correspond to products of domestic manufacturers. Imported caps, despite the similarity of designations, are slightly smaller in size. Therefore, when purchasing, you should carefully read the labels on the packaging.

Methodology for working with PPE

The main requirement for manipulating caps and wires is that their sizes match. The quality of contact depends primarily on this. In order to make the right choice, you need to add up the sections of the conductors planned for twisting and select the required device from the table. It is necessary to focus not on extreme values of indicators, but on average ones. In this case, the tightest contact is ensured.

Further, all the work can be done in two ways:

Align the wires and place them in the cap without preliminary twisting. Then forcefully press it inside the housing and turn it clockwise until the spring is released. If there is not enough hand strength, you can use pliers or a screwdriver, for which a special attachment is sold that does not damage the clamp shell.
The wires can first be stripped and twisted together, the tip can be trimmed and PPE screwed onto them.

The choice of method depends on the thickness of the wire. Thin ones, for example, half a square, are not difficult to connect, but thicker ones, 2.5 square millimeters, put a high load on the spring and often break it.

Twist length

Manufacturers recommend stripping equal to the depth of the cap or slightly less. This will be approximately 10-12 millimeters. Longer tips do not seem to affect the quality of the pairing, but this must be done with a large number of connected wires. If the size of the exposed part is small, then it will not be possible to create the desired contact area for all participants in the twist.

If a bare part of the wires peeks out from under the clamp body, then it should be wrapped with electrical tape. And although the very name of the PPE in this case will not be entirely correct, the reliability of the pairing is ensured by the cap; the wires will not weaken when heated under load.

Analogues for clamps

The main competitors of such devices are terminal blocks. In this case, two wires are tightened using a screw. However, this method has several disadvantages, including weakening of the contact, which requires constant monitoring and periodic tightening. If the device is located in an inconvenient place or their number is large, then it is very costly both in terms of effort and time.

Another weak point of such connectors is the material of the block. There are many Chinese products made from cheap polyethylene sold on the market. It cannot withstand even slight heat and melts or ignites, which can lead to a fire. Therefore, the use of PPE caps is completely justified both at home and in the factory.

Source: https://220v.guru/elementy-elektriki/kolpachki-siz-soedinenie-elektricheskih-provodov-skrutkami.html

PPE for electricians: insulating caps for twisting wires
Source: `https://ProFazu.ru/provodka/montazh/siz-dlya-elektrika.html`

Connecting wires with PPE caps

If the wiring connection in the junction box is made by twisting, then it is necessary to make reliable and strong contact of the surfaces of the conductors for better electrical contact.

This can be achieved through the force applied during twisting, but this type of connection loses its strength over time due to metal fatigue, as well as as a result of thermal expansion and contraction. But according to chapter 2.1. PUE clause 2.1.21, the use of twisting is prohibited.

This method is only possible in conjunction with special connecting insulating clamps (PPE). In this article we will look at how to use PPE caps, what sizes the products come in and what are the advantages of these connectors.

Cap design

PPE caps. Types and device. Application and how to choose

To ensure more reliable contact of the wires being connected by twisting, it is necessary that they are pressed tightly against each other with force. Since this force is created by the elasticity of the twisted wires, subsequently, due to compression and thermal expansion, as well as deformation and fatigue of the metal, the twist reduces its reliability and strength. The surface of the wires in the gaps oxidizes, the conductivity of the connection decreases, therefore, according to the rules, twisting without additional devices is prohibited.

If an electrician, when connecting electrical conductors, uses the twisting method and wraps the twisted area with electrical tape, then it is better to call another specialist. This method has not been used for a long time, as it is recognized as dangerous. Certified clamps are currently used for these tasks. If we consider a household power supply network, the best way to connect conductors is PPE caps.

They play the role of connecting and insulating elements, which have become popular in the category of insulating materials. Such caps are screwed directly onto the twist, thereby strengthening it.

There is an opinion that this connection method is unreliable, but practice shows that all electrical wiring faults using insulating caps most often have completely different reasons:

Connecting wires with PPE caps

When assembling electrical circuits, it is necessary to connect wires 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).

Today there is another solution to such problems - these are connecting caps for twisting wires .

PPE caps for twisting wires

PPE caps 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 moves apart and compresses the wires, and the plastic sheath provides reliable electrical insulation, as well as mechanical and fire protection.

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

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.

For everyday frequent use, cable twist caps with a simple device are better suited. 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.

Twisting of PPE wires

Using PPE caps - practical application

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

When removing insulation, different methods are used. 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.

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.

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.

When using insulating caps, apply force when twisting. It will ensure tight contact between the metals of the conductors and the spring.

To evaluate 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.

Such electrical tests help professionals recognize the weak points of the electrical circuits they create, improve their skills, and perform quality work.

Similar materials on the site:

How to measure with a multimeter

Source: https://electricvdome.ru/instrument-electrica/kolpachki-siz-dlya-skrutki-provodov.html

Legalization of twisting using PPE caps

Lack of fixation of the turns can cause the spiral to weaken. This will someday lead to loss of contact density and heating of the joint.

A burnt contact will interrupt the current in the circuit and may cause a short circuit and fire.

Design, marking

The plastic sleeve, in the shape of a truncated cone with a ribbed surface, is made of durable, non-flammable plastic. Being a good dielectric, it provides high-quality electrical insulation. Protrusions can be made on the outside of the housing. This makes it easier to grip when screwing the clamp onto the conductors;
A conical steel spring or a threaded metal insert is located in the housing hole. Spring steel with an anodized coating that ensures good electrical conductivity. When screwed onto a joint, the turns strongly compress the stripped ends of the cores together. This ensures tight contact of the surfaces of the conductors, duplicated by the contact of the metal with the coils of the spring.

8 types of caps from an imported manufacturer

This type of connector is very popular in the West, from where it came to us. A wide selection of models allows you to make most lighting and power wiring contacts using this method.

Types of imported PPE:

Improved design with wings makes twisting easier and more comfortable.
The clamps are of a low profile design, shorter than standard length. Convenient for installation in small junction boxes and work in cramped conditions.
A modification of the previous model, equipped with wings that facilitate and enhance twisting.
PPE for twisting aluminum conductors with copper ones. The inside of the cap is filled with a special paste that prevents oxidation.
Connectors that protect the contact from moisture. They are filled with silicone sealing paste, which prevents moisture from entering and prevents corrosion. At the entrance of the cap there is a split elastic cuff that holds the sealant. There is no need for additional sealing of the joint when making a connection outdoors or in wet areas.
A clip with a small hole at the top. The seemingly ridiculous design is needed for a twisted terminal connection. First, the end of the longer, cleaned strand is released into the hole. After screwing on the clamp, the protruding wire brought out in a loop is looped under the terminal. It is very convenient to connect the connected ground wires to the housing or terminal.

A connector where the wires are clamped not by a spring, but by a countersunk screw. It resembles the joint with our terminal block, which is placed in the PPE cap.

For sealing, you can use a special connector. It is a small plastic cup into which the completed PPE is placed. Silicone filling guarantees complete waterproofness and protection from moisture. In practice, the wire can be placed in water.

Correct twisting

It is easy to screw the PPE caps onto the pre-prepared ends of the wires. No special tools or equipment required. Two ways:

No pre-twisting.
1. the stripped conductors are folded and aligned along the edge of the insulation;
2. Simultaneously or alternately cutting the ends of the cores equalizes their length. It should be equal to the depth of the housing hole (10-12 mm);
3. holding the wires with one hand, screw the cap clockwise with the other hand until the spring is activated;
4. The twisting is completed by twisting the body until it stops with your hands or using a tool.
Fixing pre-twisted conductors:
1. the stripped and aligned cores are tightly twisted and shortened to the required length by trimming, the direction of twisting must coincide with the direction of rotation of the clamp;
2. the body is screwed on.

Use clamps that match the cross-section of the wires being connected. The diameter of the hole is too small to allow the entire bundle of cores to be inserted into it. Too large will not create a tight contact and will not fix the wires in the clamp. The twist will heat up if it makes contact at all;
Ensure that the wires are twisted tightly. It is impossible to allow the load current to flow through the metal of the spring, heating it. Loss of springiness will turn the PPE into a simple twist;
It is prohibited to use PPE to connect copper and aluminum wires. This is done in a different way.

Do not strip the insulation with pliers or wire cutters. If there is no special tool, carefully remove the insulation with a knife, avoiding damage to the surface of the core.

Pros and cons of the method

PPE caps provide many benefits to the electrician:

No additional equipment or tools required. Simplicity and cost-effectiveness of installation, no need for separate insulation;
The housing, made of non-flammable, heat-resistant plastic, simultaneously provides three types of contact protection:
- Mechanical;
- Electrically insulating:
- Fire safety.
Compared to other connection methods, it is possible to:
- Detachable joint;
- Reusable connector over and over again.
Legalization of twists of old wiring before or after inspection by a fire inspector. The boxes are opened, the old electrical tape is removed, and new PPE is screwed onto the roll. If the direction of twist does not coincide with the direction of rotation of the cap, it will have to be redone.

There are also disadvantages:

The main one is the impossibility of connecting a stranded soft wire;
Requires careful selection of standard size;
Not a sealed joint. It is unacceptable to perform for street wiring. Wrapping the joint together with the cap with electrical tape, to some extent prevents the accumulation of moisture inside the case;
Relatively large dimensions. PPE caps take up a lot of space inside the distribution box.

Scope of application

Legalization of twisting using PPE caps Link to main publication

Source: https://VseOToke.ru/montazh/kolpachki-siz

Caps for twisting wires - electrician's advice - Electro Genius

24.03.2017

Among the existing methods of connecting wires, PPE caps have recently become increasingly popular.

Let's talk about them in more detail and figure out when you can use such connecting clamps, and in what cases their use will not guarantee reliability and quality.

Purpose and design

PPE has several standard sizes, and each has its own range of the total cross-section of switched conductors.

The manufacturer, as a rule, indicates the maximum and minimum values of this section in the passport or on the packaging.

This type of connector can be used multiple times.

The design is very simple, the cap consists of a body and a metal core:

The body is made of plastic; materials are used that do not support the combustion process - polypropylene, polyvinyl chloride, nylon. To make it easier to screw on PPE caps during installation, their bodies have protrusions or special ribs.
A metal compression spring, which has a cone-shaped shape, is used as the core. When the clamp is screwed onto the twist, the spring compresses it, thereby ensuring good contact.

For information on the design and purpose of connecting caps, watch this video:

Advantages and disadvantages

The most important advantage of a PPE cap for an electrician is the simplicity and speed of installation work. This does not require any additional tools or devices.

The cap not only performs insulating functions, but also protects the connection from mechanical damage.

The connection is compact and easy to use. In addition, it is considered detachable, that is, if necessary, you can unscrew the cap back, pull the wires out of it and re-seal the connection.

Like any other type of wire connection, along with the advantages, PPE caps also have a number of disadvantages:

If the cap size is chosen incorrectly, then after installation work, during operation, it may simply fly off.
PPE cannot be used for street electrical wiring.
Using PPE caps you can only connect copper wire or cable. Special clamps for aluminum conductors are very rare; their main difference is that the inside of the housing is filled with anti-oxide paste.

Choice of caps

SIZ-1 – from 1 to 3 mm2;
SIZ-2 – from 1 to 4.5 mm2;
SIZ-3 – from 1.5 to 6 mm2;
SIZ-4 – from 1.5 to 9.5 mm2;
SIZ-5 – from 4 to 13.5 mm2.

The resulting figure should be in the middle of the specified range.

Preparing the veins

Before connecting wires using PPE, it is necessary to strip the conductors from the insulating layer.

To do this, you will need a mechanic's knife, but you need to be extremely careful and careful not to damage the surface of the conductive core.

Among electricians, such a device as a stripper is very popular. This tool performs many functions, one of which is stripping insulation from conductors. The stripper has calibrated holes with a cutting edge for each section of the core.

There are manufacturers who immediately indicate the required cut length on the product itself or in its passport (from 10 to 12 mm).

Installation

There are two ways to connect wires using PPE caps: when twisting is done first and without it.

If you are not using twists, simply place the wires to be connected parallel to each other so that they form an acute angle at the end. Why should the tip of the wires not be straight, but slightly angled? Because the cap spring has a cone shape.

Now place the PPE cap on top of the wires and with a little force, twist it clockwise until it locks. When you screw on the cap and apply force, the spring expands and compresses the wires tightly.

The process of connecting wires using PPE caps is shown in this video:

Some useful tips

If the PPE caps are selected correctly according to the area of the twist, this will ensure that it does not fall off.
Experienced electricians advise that after a cap is installed on the electrical connecting unit, immediately check its insulation. The maximum load is applied to the circuit for at least 30 minutes, after which the temperature of the insulating element is checked. If the cap does not heat up, it means that everything is installed correctly and is working normally. In the case when heating is detected, it is necessary to understand and look for the reasons.
Contacts made of copper and aluminum wires cannot be isolated with PPE clamps. For this purpose, there are other devices - self-clamping terminal blocks, terminal blocks, special adapters with metal plates.
When you screw the PPE cap onto the twist, apply a little force. Apply a little pressure to create tight contact. But do not overdo it, so as not to break the compression spring.
The color design of the caps is not specified or classified anywhere, therefore multi-colored PPE is used solely for the convenience of the electrician in servicing the connection points. For example, a brown cap indicates twisting of phase conductors, blue – neutral, and green or yellow grounding conductors.
Do not cut long insulating sheaths from conductor cores. Be sure to match it with the internal length of the cap.

The advantages and disadvantages of PPE from various manufacturers are described in detail in this video:

The only thing I would like to advise is to choose a trusted manufacturer.

On the electrical goods market, there are many cheap Chinese-made options whose body material does not have the required properties, which can lead to a fire.

Source: https://orenburgelectro.ru/montazh/kolpachki-dlya-skrutki-provodov-sovety-elektrika.html

All types of insulated PPE caps. Selection, characteristics, sizes

From the point of view of the current rules, wire twists can be roughly divided into two types:

Correct twists include those that are fixed in some way. The following can act as a retainer:

PPE caps
welding in the form of a point at the end of the twist
soldering
pressed sleeves
screw terminals

Soldered and welded wires are considered the best connection, but for most they are simply not suitable due to the simple lack of necessary tools or skills.

If you decide to repair the wiring yourself, assemble the junction box and at the same time save on installation, without violating the current rules, then PPE caps are an ideal option.

Firstly, you don't need to buy any special tools. For example, expensive welding machines or press pliers.

View Secondly, you do not need to acquire any additional skills, as is the case with soldering or welding wires.

PPE stands for connecting insulating clamp. This type of caps came to us from the West. In America, this connection and method of insulating wires is considered the most common.

Moreover, foreign consumers have a much richer choice than we have.

Our manufacturers actually produce only two types of PPE:

regular smooth PPE
PPE caps with wings

In the West, as they say, you can choose one for all occasions. It is not clear why the Chinese have not yet jumped in and started producing the same thing for our market.

Here are the main 8 types of PPE caps that can be found there (taken from here).

This is a classic and reinforced (with wings) PPE that we are all familiar with:

PPE with an improved cap shape, providing more comfortable operation when screwing on:

PPE cap with low profile design for work in confined spaces or small junction boxes:

Low profile wing design for enhanced torque:

The next cap is a very controversial decision in my opinion, but it is also being released. PPE for connecting aluminum conductors to copper. The cap is filled with a special antioxidant that prevents oxidation:

Moisture-proof clamps that can be installed on wires in electrical cabinets on the facade of the house, or in wet rooms, and even directly in the ground in the garden:

They contain 100% silicone sealant that protects against moisture and corrosion.

https://www.youtube.com/watch?v=ZH1ZLOYL_xo

There is no need for heat shrinkage or hermetically sealed insulation of joints.

PPE with a hole in the top of the cap.

There are also similar clamps where the wire is pressed not by a spring, but by a screw connection.

There is also a device - a connector filled with silicone. Any PPE cap with wires can be placed inside it.

After this, this twist can easily be considered waterproof and placed underground - in the garden, near watering cans, when entering the house, etc.

Domestic and Chinese manufacturers produce PPE caps in 5 sizes from PPE-1 to PPE-5. The largest of them is designed for a total wire cross-section of up to 32mm2.

By the way, be more careful when choosing caps based on cross-sections. Some Chinese PPE may confuse you. On the cap itself it may be written that it is designed for up to 20mm2.

And on the packaging it is only up to 15mm2. It’s not clear what to believe.

Quality can be checked even by touch. Low-quality PPE is characterized by poor plastic that can burst during operation. You can distinguish it by simply squeezing it with your fingers.

More expensive and normal clamps, with difficulty, but are compressed under the force of two fingers. Low-quality options are rougher and much more difficult to compress.

Some people use pliers to help themselves when tightening the PPE. Again, with cheap Chinese caps, when doing this, a break may occur, or the spring may simply fall out.

A good PPE clamp can easily withstand the operating temperature range from -40 to +105 degrees.

Here are the markings and types of PPE caps with all the characteristics produced by the domestic manufacturer KVT:

The company also produces a reinforced version of the cap with ears or wings:

PPE, as well as sleeve and fork tips, can be distinguished by color. Each color corresponds to a specific wire section.

Using PPE, you can connect 4,5,6 wires, the main thing is that the total cross-section of the twist corresponds to the calculated purpose of the PPE.

In this case, you can safely twist wires of different sections. When crimping wires with sleeves, this causes real problems and difficulties.

You can select and order sets of PPE caps here.

For our version of 4.5 mm2, it is better to choose SIZ-3, designed for twisting from 1.5 to 6 mm2. SIZ-2 in this case will not be the best choice.

Next, the whole process can be performed in two ways.

1 way to twist PPE

First, combine the wires. There is no need to pre-twist them or stack them on top of each other. Place them in a PPE cap.

Then you begin to press it inside the PPE and turn the cap itself clockwise until the spring releases. As soon as the spring has captured the wires, you can begin the process of twisting the wires.

If there is not enough manual effort, and the cap does not have “ears,” you can use pliers or even a screwdriver. The process will speed up significantly.

There is even a specially designed screwdriver attachment for quickly twisting wires using PPE. With this method, the cap remains completely undamaged.

You can, of course, adapt an ordinary “Shurik” for twisting without any adapters, but the outer insulating layer of the cap will be scratched.

2nd method of twisting PPE

The second method involves preliminary twisting of the stripped cores with pliers or again with a screwdriver.

Then you trim the ends for evenness, and only then screw the clamp onto the twisted wires.

Which method to choose depends on the cross-section of the conductors being connected.

But twisting two 0.5mm2 wires into PPE is not very difficult.

What should the twist length be? According to the manufacturers' recommendations, the twist should be equal to or slightly less than the length of the cap itself (10-12mm).

IEK technical passport for PPE caps - download
Navigator technical passport for PPE caps - download

The more there are, the more desirable it is to increase the twist length.

So be thoughtful about your approach. The main thing after this is to reliably insulate the remaining exposed part of the wire.

True, in this case it is no longer correct to call the connection PPE, since the cap itself no longer insulates the entire exposed core.

In any case and at any length, this twist is quite reliable and, thanks to the fixation with an insulated cap, the wires will not come loose during operation.

The main advantage of insulated PPE is that the plastic shell of the cap, unlike other types of insulation, provides three types of protection at once:

electrical insulating
fire protection
mechanical

After which it can again be safely used on other equipment or object.

Another common use of PPE is the legalization of twists in old electrical boxes following regulations from fire inspectors.

The disadvantages of insulated PPE caps include the fact that they are not suitable for multi-core wires and are only applicable for mono-core wires.

Manufacturers also do not recommend twisting aluminum wires with them, indicating that this is primarily a clamp for copper.
Some companies, as mentioned above, produce universal PPE clamps designed for aluminum too. However, for the most part, their use for this particular metal is prohibited.

And sometimes it can lead to the following consequences:

To avoid this, you can insulate both the wires and the PPE cap itself with electrical tape.

In general, the choice in favor of insulated PPE caps is made primarily because of their cost-effectiveness and ease of installation. If you need a more reliable and durable connection, then invite professional electricians with all the necessary equipment.

Here is an interesting test of a PPE cap for mechanical load. The guy collected the wires in PPE and hung a punching bag from it, thereby checking how mechanically reliable this contact can be:

Source: https://domikelectrica.ru/vse-vidy-izolirovannyx-kolpachkov-siz/

Twisting of PPE: insulation of electrical wires using caps, design features of twists

To assemble an electrical circuit, you need to ensure reliable contact between the cable cores. There are several options for this:

Simple or isolated twist.
Use of welding or soldering iron.
Use of screws and nuts.
Through terminal blocks or blocks.
Self-clamping elements of the Wago type.
Insulating caps.

Using caps

Purpose of the device

Some electricians talk about cases from practice where PPE caps did not perform well. However, there are explanations for this:

Insufficient qualifications of the installer himself.
Use of low-quality products of dubious origin.
Incorrect calculation of the wire cross-section relative to the load on the electrical network.

Design

The core is a metal compression spring. It has a cone shape. When screwing the cap onto the twist, it tightens, ensuring reliable contact.

The dimensions of the spiral deserve special attention. In order to select the correct cap, you need to know the cross-section of the cores being connected and the smallest base of the cone in which their contact will be created. If the wire is thinner, then it will not be possible to crimp it, and a thick one simply will not fit into the cap.

Product classification

Many caps for soldering conductors from various manufacturers are sold on the Russian market. Domestic standards provide for the following standard sizes of such electrical products:

Gray color, intended for two-core twisting. The cross-section of each core is 1.5 square meters. mm. Marked as SIZ-1.
SIZ-2 connects three wires of the same size and is colored blue.
For 2.5 mm conductors in the amount of 2 pieces there is orange SPE-3.
Four similar wires will fit into the yellow SIZ-4.
Eight cores with a size of 2.mm square in diameter will be placed in red PPE number five.

Methodology for working with PPE

Further, all the work can be done in two ways:

Align the wires and place them in the cap without preliminary twisting. Then forcefully press it inside the housing and turn it clockwise until the spring is released. If there is not enough hand strength, you can use pliers or a screwdriver, for which a special attachment is sold that does not damage the clamp shell.
The wires can first be stripped and twisted together, the tip can be trimmed and PPE screwed onto them.

Twist length

Analogues for clamps

Source: https://220v.guru/elementy-elektriki/kolpachki-siz-soedinenie-elektricheskih-provodov-skrutkami.html

PPE for electricians: insulating caps for twisting wires
Source: `https://ProFazu.ru/provodka/montazh/siz-dlya-elektrika.html`

Connecting wires with PPE caps

If the wiring connection in the junction box is made by twisting, then it is necessary to make reliable and strong contact of the surfaces of the conductors for better electrical contact.

Cap design

The design of the device includes the following components: a cap and a steel spring. The PPE cap is made of plastic, which has electrical insulating properties. This plastic is non-flammable and resistant to high temperatures, and can also withstand a voltage of 600 Volts. These indicators are usually written on the packaging.

As for the spring, it is made of steel in the form of a cone and, with the help of coils, compresses the wire more strongly. The steel spring is additionally treated with an electrochemical protective layer. The dimensions of the spring should be equal to the area of the smallest part of the body where the wire will have maximum contact with another conductor. Therefore, it is extremely important to choose the exact dimensions so that the connection is as correct and reliable as possible.

It is worth noting that PPE caps come in two types - with ears and without ears. There are no special differences, but caps with ears are easier to screw onto the wire, and without ears they take up less space in the junction box.

Rules of application

There are two methods of twisting using PPE caps: without preliminary twisting of the cores and with it.

If it is necessary to connect two conductors, they can be conveniently inserted into the spring, applying a certain force, and twisting is carried out using rotational movements (clockwise).

If there are three or more conductors, then you must first twist them together using pliers. After this, bite off the uneven ends and, using force and rotating movements, install them into the PPE, as shown in the photo:

It is important to remember that for full contact contact, winding should be done clockwise, not vice versa. And do not forget about using force so that the coils of the spring move apart easily and then squeeze the wire well.

The plastic housing insulates the place where the connection was made and thereby mechanically protects the conductors. The insulation from the conductor should be removed taking into account that the exposed part does not extend beyond the cap, but at the same time extends as far as possible under the spring. If everything is done correctly, then additional insulation is not needed.

When the PPE is twisted, the spring expands and compresses the wire. This connection will work correctly if the correct cap is selected that matches its rating. If you choose the wrong device or install it ineptly, this can lead to bad consequences. Therefore, it is extremely important to choose the right category.

Source: https://samelectrik.ru/soedinenie-provodov-kolpachkami-siz.html

PPE caps. Types and device. Application and how to choose

They play the role of connecting and insulating elements, which have become popular in the category of insulating materials. Such caps are screwed directly onto the twist, thereby strengthening it.

There is an opinion that this connection method is unreliable, but practice shows that all electrical wiring faults using insulating caps most often have completely different reasons:

Unqualified calculation of wire cross-section and protection devices.
Use of counterfeit insulating caps.
Insufficient qualifications of the electrician performing electrical installation.

If you do everything correctly, use high-quality caps of the required sizes, install them correctly, use electrical wiring of sufficient cross-section, and also use protective devices of the required rating, then such an electrical network will work properly for a long time, without needing maintenance.

Design features

Insulating PPE caps contain a main element - a spring, as well as a plastic body with dielectric properties. The plastic of the insulating cap is resistant to elevated temperatures, does not support combustion, and can withstand voltages up to 600 V.

To make it easier to screw the cap on, the body may have special ribs or protrusions. The spring has the shape of a cone and with its coils is capable of compressing twisted wires. The spring is made of steel, its surface is covered with a special protective layer.

When choosing caps, the dimensions of the spring must correspond to the cross-section of the wires being connected in the twist.

PPE caps are manufactured in different sizes, each of which corresponds to a certain interval of the total cross-section of the connected wires. The manufacturer usually indicates on the packaging the smallest and largest values of permissible sections.

Kinds

This type of insulation of wire connections came to our country from other countries. In many countries, this type of connection and insulation of conductors is considered the most popular, and the choice of caps is much richer than ours. Domestic manufacturers produce two types of PPE caps:

Foreign manufacturers produce the following types of insulating caps:

With improved shape for comfortable twisting.
Low profile for small distribution boxes.

Low profile with wings.

PPE insulating caps for connecting copper wires to aluminum.
They are filled with an antioxidant that prevents oxidation of wires made of different metals (not recommended for use due to their unreliability; they are mainly used abroad).

Waterproof. They are installed in distribution cabinets located on the facade of the building, or in wet rooms. The silicone sealant contained in such caps provides good protection against corrosion and moisture.

There is no need for hermetically sealed insulation or heat shrinkage.
With a hole in the body . Some people may think this is a defect, but this is a special clamp for connecting ground wires. One wire exits through the hole and connects to the equipment body or panel.
With screw connection.
Silicone connector.

A connection of wires is placed inside. This twist is placed in the ground, since it is considered airtight.

How to choose PPE caps by marking

The standard size of the caps depends on the total cross-section of the wires being connected. This total cross-sectional area is determined by the cap number from 1 to 5. The higher the number, the more conductors can be connected. There are special tables from the manufacturer, which are used to select the standard size of these products. The table shows two values - the smallest and largest total cross-section of the connected wires in a twist.

PPE caps are selected as follows. First, it is necessary to determine the total cross-section of all cores connected by the cap. Next, according to the table, the standard size of the cap is selected so that the total cross-section is in the middle of the interval indicated in the table. For example, if it is necessary to connect two wires with a cross-section of 4 mm2, the total value is 8 mm2. Using the table, we see for which cap size this value will be in the center of the range. For our case, we choose PPE-5.

There are some features of marking domestic and imported connectors. The designation of their products is the same, but foreign products have denominations lower than Russian ones, so when purchasing connectors, experts recommend looking not at the cap number, but at the total cross-section, which is indicated on the packaging.

You also need to know that using such connectors you can connect wire cores made of the same materials. If you need to connect copper and aluminum wires, it is not recommended to do this with such connectors. In such cases, it is better to use a metal clamp or terminal block.

The marking is designated: SIZ-1 2x1.5, where SIZ-1 is the brand of the cap, 2x1.5 is the number and cross-section of wires. Depending on the type and size, the product body has a certain color for ease of use. The table shows colors depending on the standard size for ease of connector selection.

It is recommended to purchase PPE caps from trusted manufacturers, since cheap Chinese products are not able to provide sufficient reliability of the connection, which often leads to a fire hazard.

Advantages

Easy and fast installation.
There is no risk of spontaneous combustion of electrical wiring, since the PPE material does not support combustion, and the twisting of the wires is securely fixed.
Large selection of models in the retail chain.
Affordable price.

Flaws

Insufficiently reliable insulation and fastening of wire twists.
You cannot connect cores made of different metals (with the exception of some rarely used foreign products).

Installing Isolation Connectors

To properly install protective connectors, you need to know how to properly prepare wires and know existing installation methods.

Preparing the wires

Before connecting electrical conductors with insulating caps, it is necessary to remove the outer insulation of the conductors. This can be done with a knife, being careful and careful not to damage the wire core, otherwise it may break off when twisting. When stripping insulation, the knife should be placed at an acute angle to the wire.

The most convenient way to remove insulation is to use a stripper, which has calibrated holes with a sharp edge for different cross-sections of wires. The insulation from all connected wires is removed to the same length, which is determined in such a way that after installing the cap, bare wires do not protrude from under its body.

To do this, you need to put the connector on the wire and mark the place where the insulation is removed; it is marked slightly less than the height of the body of the insulating product. Some manufacturers indicate on the connector packaging the cut length of the insulation of the wires being connected. Usually it is 10-12 mm.

Installation

There are two methods for connecting electrical conductors using insulating connectors:

With preliminary twisting of current-carrying cores.
No pre-twisting.

Twisting method:

Place the wires stripped of insulation next to each other.
At the point where the insulation begins, squeeze the wires with pliers (with your left hand).
With your right hand, grab the ends of the wires and twist them clockwise. If the wires are thin enough, the twist will be strong.
If there are more than two wires, or they are thick, then it is necessary to use second pliers for stronger twisting.

Bite off the end of the twist at a sharp angle.
Place the connector on the twist and firmly screw it clockwise until it is securely fastened.

When wound, the spring tightly compresses the current-carrying conductors.

Method without pre-twisting:

Place the conductors parallel to each other, with one wire protruding slightly above the other so that an acute angle is formed at the end for easier winding of the conical spring.
Rotate the cap clockwise, twisting the conductors.

If the wires are thick, then it is difficult to twist with a cap, and for this they use the first method with preliminary twisting of the wires.

If, after installing the connector, bare wires still protrude from its body, then it is necessary to insulate this place with insulating tape, varnished cloth or other insulating material.

Features of application

If the PPE caps are correctly selected (in accordance with the cross-section of the wires), then their reliable connection is ensured.
It is not recommended to use the connection of current-carrying conductors from different metals, due to their rapid oxidation and reduced contact reliability. There are special devices for such purposes.
Experienced specialists recommend checking their insulation immediately after installing the caps. To do this, the most powerful consumers are connected to the circuit for 30 minutes, then the temperature of the connector is measured. If there is no strong heating, then the installation was done correctly.
If noticeable heating is observed, then the installation was performed incorrectly, or other faults have arisen in the circuit.
When twisting the connector, do not apply too much force so as not to break the spring.
It is undesirable to cut off the wire insulation to a large length, since subsequent wrapping of the exposed areas with electrical tape does not provide sufficient insulation reliability. It is better to carefully measure this length according to the depth of the cap before stripping.

Connecting wires with PPE caps

PPE caps for twisting wires

Twisting of PPE wires

Using PPE caps - practical application

Legalization of twisting using PPE caps

Design, marking

8 types of caps from an imported manufacturer

Correct twisting

Pros and cons of the method

Scope of application

Caps for twisting wires - electrician's advice - Electro Genius

Purpose and design

Advantages and disadvantages

Choice of caps

Preparing the veins

Installation

Some useful tips

All types of insulated PPE caps. Selection, characteristics, sizes

1 way to twist PPE

2nd method of twisting PPE

Twisting of PPE: insulation of electrical wires using caps, design features of twists

Using caps

Purpose of the device

Design

Product classification

Methodology for working with PPE

Twist length

Analogues for clamps

PPE for electricians: insulating caps for twisting wires Source: https://ProFazu.ru/provodka/montazh/siz-dlya-elektrika.html

Connecting wires with PPE caps

Connecting wires with PPE caps

Connecting wires with PPE caps

Connecting wires with PPE caps

Cap design

PPE caps. Types and device. Application and how to choose

PPE caps. Types and device. Application and how to choose

PPE caps. Types and device. Application and how to choose

There is an opinion that this connection method is unreliable, but practice shows that all electrical wiring faults using insulating caps most often have completely different reasons:

Connecting wires with PPE caps

PPE caps for twisting wires

Twisting of PPE wires

Using PPE caps - practical application

Legalization of twisting using PPE caps

Design, marking

8 types of caps from an imported manufacturer

Correct twisting

Pros and cons of the method

Scope of application

Caps for twisting wires - electrician's advice - Electro Genius

Purpose and design

Advantages and disadvantages

Choice of caps

Preparing the veins

Installation

Some useful tips

All types of insulated PPE caps. Selection, characteristics, sizes

1 way to twist PPE

2nd method of twisting PPE

Twisting of PPE: insulation of electrical wires using caps, design features of twists

Using caps

Purpose of the device

Design

Product classification

Methodology for working with PPE

Twist length

Analogues for clamps

PPE for electricians: insulating caps for twisting wires Source: https://ProFazu.ru/provodka/montazh/siz-dlya-elektrika.html

Connecting wires with PPE caps

Connecting wires with PPE caps

Cap design

Cap design

Rules of application

Rules of application

PPE caps. Types and device. Application and how to choose

PPE caps. Types and device. Application and how to choose

There is an opinion that this connection method is unreliable, but practice shows that all electrical wiring faults using insulating caps most often have completely different reasons:

There is an opinion that this connection method is unreliable, but practice shows that all electrical wiring faults using insulating caps most often have completely different reasons:

Design features

Design features

Kinds

PPE for electricians: insulating caps for twisting wires
Source: `https://ProFazu.ru/provodka/montazh/siz-dlya-elektrika.html`

PPE for electricians: insulating caps for twisting wires
Source: `https://ProFazu.ru/provodka/montazh/siz-dlya-elektrika.html`